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  • Sixth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1995
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Esotropia; Abduction Weakness; Sixth Nerve PalsyPowerPoint Presentation: Clivus Chordoma: http://library.med.utah.edu/NOVEL/Wray/PPT/Clivus_Chordoma.ppt Shirley H. Wray, M.D., Ph.D., FRCP Harvard Medical SchoolDifficulty focusingThis 46 year old patient had at age 6, a tendency for the left eye to wander out. Her face photograph at that age shows an exotropia and at age 7, a year later, the exotropia was not quite as prominent. It was assumed that the exotropia was due to a non-paralytic strabismus. Past History: At age 1 fracture of the skull Since childhood the left eye wandered out She was never told she had a strabismus and never wore prism glasses. In Sept 1994 at age 46, she experienced intermittent double vision, seeing the image split apart horizontally, and persisting for approximately 2 minutes. By blinking her eyes she was able to refocus a single image. In December 1994 she had transient "kaleidoscopic" vision, by which she meant horizontal and oblique diplopia when she woke up. She noted this looking at the television set, the window frame or her bedside clock. By mid-December she had persistent horizontal double vision in primary gaze worse on looking to the left and was no longer able to refocus a single image but saw only one image if she closed one eye. She was referred to the Neurovisual Clinic at the Massachusetts General Hospital and admitted. Symptomatic Inquiry: No headaches, vertigo, ptosis, or unsteadiness Family History: Positive for diabetes and hypertension No history of neurological disease. Neuro-ophthalmological examination: Visual acuity 20/20 OD, 20/30 reads J2 OS Visual fields, pupils and fundus examination normal. Ocular Motility OS: Esotropia Weakness of full abduction Cranial nerves 3 and 4 normal Convergence normal Alternating exophoria at distance Vertical gaze normal Lower cranial nerves normal Neurological examination: Normal Diagnosis: Left sixth nerve palsy superimposed on a childhood non-paralytic esotropia Brain CT showed: 1. A lytic destructive lesion in the clivus with bony particles within the lesion. 2. The mass extended from the sella to the foramen magnum with extension laterally to the petrous apices and carotid canals. 3. There was a suggestion of erosion of the petrous apex on the left. 4. Partial erosion of the posterior wall of the sella 5. The mass abutted the posterior part of the left and right cavernous sinus Brain MRI showed: 1. A clival mass with extension into Meckel's cave and cavernous sinus on the left and circumferential encasement of the proximal left cavernous internal carotid artery (ICA). 2. Partial encasement of the right proximal cavernous ICA. Diagnosis: Clivus Chordoma Differential Diagnosis: Chondrosarcoma Neurosurgery Consult: The important features that established the tumor as inoperable, were the imaging studies showing infiltration and destruction of bone along the midline of the clivus stretching from the pituitary down to the lower clivus in addition to extension of the tumor into the left cavernous sinus encasing the left ICA. The patient was advised that the tumor was inoperable and biopsy was recommended. A transsphenoidal biopsy was performed. Pathology: Chordoma Treatment: Proton beam radiation to the mass and skull base.This 46 year old patient with an inoperable clivus chordoma has in her childhood photographs At age 6 exotropia of the left eye (OS) At age 7 exotropia appears less prominent The assumption was an exotropia due to a non-paralytic strabismus. At age 46 she became symptomatic with horizontal diplopia on looking left and OS deviated in. She had: • Esotropia OS • Paresis of full abduction • Paresis of abduction with OS fixing alone confirmed a paralytic sixth nerve palsy • An alternating exophoria at distanceNo neuroimaging studies are available in this patient.The abducens nucleus of the sixth nerve lies in the floor of the fourth ventricle, at the level of the lower pons, and contains three groups of neurons: 1. Abducens motoneurons which innervate the ipsilateral lateral rectus muscle. 2. Abducens internuclear neurons, which project to the contralateral medial rectus subnucleus of the oculomotor nucleus via the medial longitudinal fasciculus 3. Neurons that project to the cerebellar flocculus The genu of the facial nerve curves over the dorsal and lateral surfaces of the nucleus, while the medial longitudinal fasciculus lies medial to each nucleus. The abducens nerve fascicle join its passage in the pons, lies adjacent to the motor nucleus and fascicle of the facial nerve, the motor nucleus of the trigeminal nerve, the spinal tract of the trigeminal nerve, the superior olivary nucleus, the central tegmental tract, and the corticospinal tract. The sixth nerve emerges from the brainstem between the pons and medulla, lateral to the pyramidal prominence. It then runs upwards along the ventral surface of the pons, lateral to the basilar artery, and passes between the pons and the anterior inferior cerebellar artery to ascend through the subarachnoid space along the clivus. It then pierces the dura mata, crosses around and through the inferior petrosal sinus, and passes under the petroclinoid (Gruber's ligament) in Dorello's canal to enter the cavernous sinus. In the cavernous sinus, the nerve bends laterally around the intracavernous segment of the internal carotid artery (ICA) and runs medial and parallel to the ophthalmic division (V1) of the trigeminal nerve. The ocular sympathetic fibers leave the ICA and join briefly with the abducens nerve before joining the ophthalmic division (V1) of the trigeminal nerve. Unlike the oculomotor (third nerve) and trochlear (fourth nerve) nerves, the abducens nerve does not lie within the lateral wall of the sinus, but rather it runs within the body of the sinus. The sixth nerve enters the orbit through the superior orbital fissure, passes through the Annulus of Zinn, and innervates the lateral rectus muscle. See Ref (8) and (12) for full discussion.Review ref (8)Proton beam therapy to the mass and skull base.1. Chen KS, Hung IJ, Lin KL. Isolated abducens nerve palsy: an unusual presentation of leukemia. J Child Neurol 2002;17:850-851. http://www.ncbi.nlm.nih.gov/pubmed/12585727 2. Currie JN, Lubin JH, Lessell S. Chronic isolated abducens paresis from tumors at the base of the brain. Arch Neurol 1983;40:226-229. http://www.ncbi.nlm.nih.gov/pubmed/6830471 3. Harada T, Ohashi T, Ohki K et al. Clival chordoma presenting as acute esotropia due to bilateral abducens palsy. Ophthalmologica 1997;21:109-111. http://www.ncbi.nlm.nih.gov/pubmed/9097318 4. Harbison JW, Lessell S, Selhorst JB. Neuro-ophthalmology of sphenoid sinus carcinoma. Brain 1984;108:855-870. http://www.ncbi.nlm.nih.gov/pubmed/6478180 5. Ikezaki K, Toda K, Abe M, Tabuchi K. Intracavernous epidermoid tumor presenting with abducens nerve paresis - case report. Neurologia Medico-Chirurgica 1992;32:360-364. http://www.ncbi.nlm.nih.gov/pubmed/1381064 6. Ilhan O, Sener EC, Ozyar E. Outcome of abducens nerve paralysis in patients with nasopharyngeal carcinoma. Eur J Ophthalmol 2002;12:55-59. http://www.ncbi.nlm.nih.gov/pubmed/11936446 7. Keane JR. Bilateral sixth nerve palsy. Analysis of 125 cases. Arch Neurol 1976;33:681-683. http://www.ncbi.nlm.nih.gov/pubmed/184766 8. Leigh RJ, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Ch 9:385-474. In: The Neurology of Eye Movements, Fourth Edition. Oxford University Press, NY 2006. 9. Lopez R, David NJ, Gargano F, Post JD. Bilateral sixth nerve palsies in a patient with massive pituitary adenoma. Neurology 1981;31:1137-1138. http://www.ncbi.nlm.nih.gov/pubmed/7196535 10. Morioka T, Matsushima T, Yokoyama N. Muratami H, Fujii K, Fukui M. Isolated bilateral abducens nerve palsies caused by rupture of a vertebral artery aneurysm. J Clin Neuroopthalmol 1992;12:263-267. http://www.ncbi.nlm.nih.gov/pubmed/1287052 11. Volpe NJ, Liebach NJ, Munzenrider JE, Lessell S. Neuro-ophthalmological findings in chordoma and chondrosarcoma of the skull base. Am J Ophthalmol 1993;115:97-104. http://www.ncbi.nlm.nih.gov/pubmed/8420385 12. Wong AM. Nuclear and Infranuclear Ocular Motor Disorders Chp 12:191-242. In: Eye Movement Disorders. Oxford University Press, 2008.curriculum_fellow; VBchordoma; MTemspsixthabducen

  • Fourth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1993
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Hypertropia; Superior Oblique Paresis; Inferior Oblique Overaction; Fourth Nerve Palsy; Trochlear Nerve; Bielchowsky Test; Head TiltDouble visionThe patient is a 32 year old, left handed chemistry teacher who presented with intermittent vertical double vision. In August 1992 she noted, particularly late in the evening when reading in bed, vertical double vision. The images were one on top of the other and on occasions one image was slightly oblique. In September 1992 she consulted an ophthalmologist who documented a 2 diopter esotropia and hypotropia. She was prescribed prism reading glasses which helped. At the same time, she consulted a neurologist because her vision went out of focus after turning her head from side to side quickly. She denied headache and vertigo. Neurological examination by the consultant was normal apart from a "lag of abduction of the right eye". Brain MRI with and without gadolinium: Normal. Blood studies: Anti-acetylcholine receptor antibodies negative. Thyroid tests: Normal. In December 1992 she went to Nevada to see her mother. She consulted a neuro-ophthalmologist, Dr. Francis Grenn, a former post-graduate fellow of mine. Dr. Grenn obtained the history that when she changed the position of her head she could correct her diplopia. In bed at night if she tilted her head to the left, she had no double vision. She also had a single image with either eye covered. Diagnosis: Right fourth nerve palsy On return to Boston she came to the Neurovisual Clinic at the Massachusetts Genera Hospital. Symptomatic Inquiry: Negative for ptosis, bulbar muscle weakness or generalized weakness to suggest myasthenia gravis. Past History: Head trauma in 1978 when she was hit by a lacrosse ball and sustained a black eye and swelling of the right side of her face. She was stunned by the blow but not knocked out. It took several days for her to recover. During that time, she can not recall having double vision. No strabismus as a child and never wore prism glasses Family History: Father died of a myocardial infarct Mother had thyroid surgery for hyperthyroidism. Social History: Negative for alcohol abuse Non-smoker Neuro-ophthalmological examination: Visual acuity 20/25 OD 20/20 OS Visual fields, pupils and fundus examination normal. No ptosis No exophthalmos No ocular bruit Tests for diplopia: Slight right (ipsilateral) head tilt Absent stereopsis in the reading, downgaze position 1/3 animals in primary gaze Good stereopsis 4/6 circles with prism glasses Cover/uncover test: Hypertropia OD primary gaze Hypertropia most marked with right head tilt Hypertropia diminished, almost absent, left head tilt Hypertropia almost fully corrected with prism glasses at distance. Ocular Motility OD: Hypertropia and excyclotorsion Superior oblique (SO) paretic Inferior oblique (IO) overaction with elevation of the globe looking left. Cranial nerves 3 and 6 normal Ocular Motility OS: Full eye movements Hypotropia on cover/uncover test CT of the Orbit: Normal. Bone windows, no evidence of fracture Review of her old photographs The patient's old soccer photograph showed her with a slight head tilt to the right. This observation helped to establish a diagnosis of a longstanding post-traumatic fourth nerve palsy. Treatment: Strabismus surgery was discussed with the patient but she elected to wear prism glasses. In January 1997 she returned to consult the strabismus surgeon again but still elected to wear prism glasses.This tape records the "diplopia" history. The patient answers a list of specific questions with regard to her vertical double vision from a right fourth (trochlear) nerve palsy. She had no diplopia with one eye covered confirming binocular diplopia. With a history of vertical diplopia, attention is paid to the ocular muscles controlling vertical gaze. • SO: Paresis SO resulted in impaired downgaze in the adducted position with absent incyclotorsion of the eye • IO: Overaction of IO with elevation of the eyeball on gaze left, in the adducted position Alternate cover test: OD moved down to take up fixation (hypertropia) OS moved up to take up fixation (hypotropia) Two simple techniques which aid in the analysis of vertical diplopia are shown on this tape. 1. Viewing a horizontal bar The patient is seated in front of a black screen to view a horizontal bar (opaque line of tape). She confirms that she is seeing two images slanted with respect to each other, with the apparent intersection of the lines pointing toward the side of the affected, excyclodeviated eye. In this patient with a right fourth nerve palsy, the point of intersection is to the right. 2. The Lancaster red/green test requires the patient to wear a pair of red/green goggles, red lens OD, green lens OS. The patient holds a projector that places a red line on the screen. The examiner holds a projector that places a green line on the screen. The patient is directed to place the red line on top of the green line with her head in primary gaze, with head tilted to the right and with head tilted to the left - Bielchowsky head tilt test. The test was positive - there was no separation of the images on head tilt to the contralateral (left) side. An old soccer picture of the patient attached shows a very subtle right head tilt indicating the chronicity of the fourth nerve palsy. Two photographs of another patient, with a left fourth nerve palsy, first when quite young with his golf partners and then years later at a cocktail party, show a right contralateral head tilt. The clinical diagnosis in this case utilized the Three-Step Test. Step 1 - Identify which eye is hypertropic e.g. hypertropia OD. Step 2 - Determine whether the hypertropia increases on right or left gaze Step 3 - Bielchowsky's head tilt test: Tilt the head to the right and to the left. Hypertropia is maximized as the head is tilted toward the side of the lesion and minimized on contralateral head tilt, as in this case. The most reliable clinical test to diagnose fourth nerve palsy is the Bielchowsky's head tilt test. During right head tilt, the right eye incyclotorts (SO and SR), and the left eye excyclotorts (IO and IR) During left head tilt, the right eye excyclotorts (IO and IR) and the left eye incyclotorts (SO and SR). The question always asked is why does the hypertropia increase on right head tilt in right fourth nerve palsy. The explanation is as follows: During right head tilt, the otolith-ocular reflex (ocular counter roll) is activated, such that the right eye incyclotorts (SO and SR) and the left eye excyclotorts (IO and IR). The primary action of SO is incyclotorsion, and its secondary action depression, whereas the primary action of SR is elevation and its secondary action is incyclotorsion. Thus, normally, during the right head tilt, the net movement of the right eye is incyclotorsion with minimal vertical movement because the vertical action of the SO and SR cancels each other out. In a right fourth nerve palsy, the elevating action of SR is unopposed by the palsied SO; thus, the hypertropia increases during right head tilt. Differential Diagnosis: 1. Skew deviation 2. Thyroid-related ophthalmopathy 3. Brown's Syndrome 4. Primary inferior oblique overactionNo imaging studies are available in this patient. In patients who lack a history of head trauma, Brain MRI may show relevant brainstem lesions and gadolinium enhancement usually demonstrates infiltrative or inflammatory processes involving the long course of the fourth nerve. often the cause of the fourth nerve cannot be ascertained. These patients require long term follow-up.The nucleus of the fourth (trochlear) nerve lies at the ventral border of the periaqueductal gray matter at the level of the inferior colliculus in the brainstem. It lies at the dorsal margin of the medial longitudinal fasciculus. The fascicle of the fourth nerve crosses the midline at the anterior medullary vellum (anterior floor of the fourth ventricle, before exiting the brainstem) thus, the right fourth nerve fascicle becomes the left fourth nerve which innervates the left superior oblique muscle. The fourth nerve is the only cranial nerve that exits the brainstem on the dorsal surface and it has the longest intracranial course (approximately 75mm). In the subarachnoid space the nerve curves around the lateral surface of the upper pons, passing between the superior cerebellar and posterior cerebral arteries to reach the prepontine cistern. It then runs forward on the free edge of the tentorium for 1 to 2 cm before penetrating the dura of the tentorial attachment and entering the cavernous sinus. Within the lateral wall of the cavernous sinus, the nerve lies below the third cranial nerve and above the ophthalmic division (V1) of the fifth (trigeminal) nerve. It then crosses over the third nerve and receives filaments from the carotid sympathetic plexus. To reach the orbit the nerve enters through the superior orbital fissure above the Annulus of Zinn. In company with the frontal and lacrimal branches of the ophthalmic division of the trigeminal nerve. It divides into several small fascicles that innervate the superior oblique muscle.TraumaTrauma is the commonest cause of a fourth nerve palsy. Head trauma can result in a contusion or hemorrhage of the tegmentum at the junction of the midbrain and pons. Because of the short course of the fourth nerve fascicle in the brainstem, distinguishing a nuclear from a fascicular fourth nerve palsy is virtually impossible. Damage to the descending sympathetic fibers from the hyperthalamus in the dorsal brainstem, causes a Horner's syndrome, and lesions of the trochlear nucleus or fascicle may be accompanied by a Horner's syndrome. For example, a right sided midbrain lesion causes damage to the right trochlear nucleus (resulting in a left fourth nerve palsy) and damage to descending sympathetic fibers results in a right Horner's syndrome. If the lesion affects the fascicle of the fourth nerve as it crosses the midline, then the Horner's syndrome is on the same side as the fourth nerve palsy.1. Occlusion 2. Prism glasses 3. Strabismus surgery only after the palsy has been stable for at least six months using one or a combination of the following procedures: a) Weakening of the ipsilateral inferior oblique (the antagonist of the affected superior oblique) b) Weakening of the contralateral inferior rectus (the yoke muscle of the affected superior oblique) c) Strengthening the affected superior oblique1. Arruga J, DeRivas P, Espinet HL, Conesa G. Chronic isolated trochlear nerve palsy produced by intracavernous internal carotid artery aneurysm. J Clin Neuro-Ophthalmol 1991;11:104-108. http://www.ncbi.nlm.nih.gov/pubmed/1832682 2. Brazis PW, Lee AG. Binocular vertical diplopia. Mayo Clin Proc 1998;73:55-66. http://www.ncbi.nlm.nih.gov/pubmed/9443680 3. Cackett P, Fleck B, Mulhivill A. Bilateral fourth nerve palsy occurring after shaking injury in infancy. J AAPOS 2004;8:280-281. http://www.ncbi.nlm.nih.gov/pubmed/15226732 4. Gentry LR, Mehta RC, Appen RE, Weinstein JM. MR imaging of primary trochlear nerve neoplasms. Am J Neuroradiol 1991;12:707-713. http://www.ncbi.nlm.nih.gov/pubmed/1882749 5. Jacobson DM, Warner JJ, Choucair AK, Ptacek LJ. Trochlear nerve palsy following minor head trauma. A sign of structural disorder. J Clin Neuro-ophthalmol 1988;8:263-268. http://www.ncbi.nlm.nih.gov/pubmed/2977142 6. Keane JR. Fourth nerve palsy: historical review and study of 215 inpatients. Neurology 1993; 43:2439-2443. http://www.ncbi.nlm.nih.gov/pubmed/8255437 7. Leigh JR, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Chp 9;385-474. In: The Neurology of Eye Movements, 4th Edition. Oxford University Press 2006. 8. Lepore FE. Disorders of ocular motility following head trauma. Arch Neurol 1995;52:924-926. http://www.ncbi.nlm.nih.gov/pubmed/7661732 9. Richards BW, Jones FR, Younge BR. Causes and prognosis in 4,278 cases of paralysis of the oculomotor trochlear and abducens nerves. Am J Ophthalmol 1992;113:489-496. http://www.ncbi.nlm.nih.gov/pubmed/1575221 10. Schievink WI, Mokri B, Garrity JA, Nichols DA, Piepgras DG. Ocular motor nerve palsies in spontaneous dissection of the cervical internal carotid artery. Neurology 1993;43:1938-1941. http://www.ncbi.nlm.nih.gov/pubmed/8413949curriculum_fellow; MTemspfourthtrochlear; MTneurodisfourthtrochlear, VBbraininjury; VBstrabismu

  • Fourth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1992
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Hypertropia; Superior Oblique Paresis; Inferior Oblique Overaction; Fourth Nerve Palsy; Trochlear Nerve; Bielchowsky Test; Head TiltDouble visionThe patient is a 64 year old engineer who noted whilst driving around Thanksgiving time double vision with one image on top of the other. Vertical double vision persisted and he was referred to the Massachusetts General Hospital for evaluation. Past History: 1991 Hyperthyroidism with Graves' Disease treated with radio active iodine. 1989-1990 Writer's cramp treated with botulinium toxin injection 1989 Cancer of the colon, status colonectomy. No previous episodes of diplopia No strabismus as a child or need to wear prism glasses No history of head or eye trauma Medications: Synthroid 600 mg Calcium daily Aspirin daily Family History: Positive for diabetes Mother died cancer of the ovary Neuro-ophthalmological examination: Visual acuity 20/20 OU corrected Visual fields, color vision, pupils and fundus examination normal. Tests for diplopia showed: Left (contralateral) head tilt Good stereopsis in primary gaze 6/9 circles. Cover/uncover test: Hypertropia OD primary gaze Hypertropia most marked with right head tilt Hypertropia diminished, almost absent, left head tilt Hypertropia almost fully corrected with prism glasses at distance. Exophthalmometry 23 OU base 97 normal orbital resilience. Ocular Motility OD: Hypertropia and excyclotorsion Superior oblique (SO) paretic Inferior oblique (IO) overaction with elevation of the globe looking left. Cranial nerves 3 and 6 normal Ocular Motility OS: Full eye movements Hypotropia on cover/uncover test CT of the Orbits 1/17/92: Study showed enlargement of the inferior rectus muscle bilaterally and the right medial rectus muscle attributed to earlier Graves' disease in the past associated with hyperthyroidism. Brain MRI showed: Calcification of the wall of the carotid siphon and changes consistent with small vessel microangiopathy. Strabismus Consultation: The patient was tested with two Maddox rods and found to have an 8 diopter right hyper with the right eye extorted approximately 5 diopters in primary position. Diagnosis fourth nerve palsy, presenting in a somewhat unusual manner, possibly modified by his early Graves' disease and persistent enlargement of the inferior recti OU and the medial rectus muscle OD. Diagnosis: Right fourth nerve palsy Mild thyroid associated orbitopathy Strabismus surgery was not recommended. He returned in June 1992 and annually until July 1996 with no change in ocular motility.This tape records the "diplopia" history. The patient answers a list of specific questions with regard to his vertical double vision from a right fourth (trochlear) nerve palsy. He had no diplopia with one eye covered confirming binocular diplopia. With a history of vertical diplopia, attention is paid to the ocular muscles controlling vertical gaze. • SO: Paresis SO resulted in impaired downgaze in the adducted position with absent incyclotorsion of the eye • IO: Overaction of IO with elevation of the eyeball on gaze left, in the adducted position Alternate cover test: OD moved down to take up fixation (hypertropia) OS moved up to take up fixation (hypotropia) Review of old photographs showed that he had a longstanding left head tilt which helped establish the chronicity of the fourth nerve palsy. The Three-Step Test aids in establishing the diagnosis. Step 1 - Identify which eye is hypertropic e.g. hypertropia OD. Step 2 - Determine whether the hypertropia increases on right or left gaze Step 3 - Bielchowsky's head tilt test: Tilt the head to the right and to the left. Hypertropia is maximized as the head is tilted toward the side of the lesion and minimized on contralateral head tilt, as in this case. The most reliable clinical test to diagnose fourth nerve palsy is the Bielchowsky's head tilt test. During right head tilt, the right eye incyclotorts (SO and SR), and the left eye excyclotorts (IO and IR) During left head tilt, the right eye excyclotorts (IO and IR) and the left eye incyclotorts (SO and SR). The question always asked is why does the hypertropia increase on right head tilt in right fourth nerve palsy. The explanation is as follows: During right head tilt, the otolith-ocular reflex (ocular counter roll) is activated, such that the right eye incyclotorts (SO and SR) and the left eye excyclotorts (IO and IR). The primary action of SO is incyclotorsion, and its secondary action depression, whereas the primary action of SR is elevation and its secondary action is incyclotorsion. Thus, normally, during the right head tilt, the net movement of the right eye is incyclotorsion with minimal vertical movement because the vertical action of the SO and SR cancels each other out. In right fourth nerve palsy, the elevating action of SR is unopposed by the palsied SO; thus, the hypertropia increases during right head tilt. Differential Diagnosis: 1. Skew deviation 2. Thyroid-related ophthalmopathy 3. Brown's Syndrome 4. Primary inferior oblique overactionNo imaging studies are available in this patient. In patients who lack a history of head trauma, Brain MRI may show relevant brainstem lesions and gadolinium enhancement usually demonstrates infiltrative or inflammatory processes involving the long course of the fourth nerve. often the cause of the fourth nerve cannot be ascertained and these patients require long term follow-up.The nucleus of the fourth (trochlear) nerve lies at the ventral border of the periaqueductal gray matter at the level of the inferior colliculus in the brainstem. It lies at the dorsal margin of the medial longitudinal fasciculus. The fascicle of the fourth nerve crosses the midline at the anterior medullary vellum (anterior floor of the fourth ventricle, before exiting the brainstem) thus, the right fourth nerve fascicle becomes the left fourth nerve which innervates the left superior oblique muscle. The fourth nerve is the only cranial nerve that exits the brainstem on the dorsal surface and it has the longest intracranial course (approximately 75mm). In the subarachnoid space the nerve curves around the lateral surface of the upper pons, passing between the superior cerebellar and posterior cerebral arteries to reach the prepontine cistern. It then runs forward on the free edge of the tentorium for 1 to 2 cm before penetrating the dura of the tentorial attachment and entering the cavernous sinus. Within the lateral wall of the cavernous sinus, the nerve lies below the third cranial nerve and above the ophthalmic division (V1) of the fifth (trigeminal) nerve. It then crosses over the third nerve and receives filaments from the carotid sympathetic plexus. To reach the orbit the nerve enters through the superior orbital fissure above the Annulus of Zinn. In company with the frontal and lacrimal branches of the ophthalmic division of the trigeminal nerve. It divides into several small fascicles that innervate the superior oblique muscle.Graves'Trauma is the commonest cause of a fourth nerve palsy. Head trauma can result in a contusion or hemorrhage of the tegmentum at the junction of the midbrain and pons. Because of the short course of the fourth nerve fascicle in the brainstem, distinguishing a nuclear from a fascicular fourth nerve palsy is virtually impossible. Damage to the descending sympathetic fibers from the hyperthalamus in the dorsal brainstem, causes a Horner's syndrome, and lesions of the trochlear nucleus or fascicle may be accompanied by a Horner's syndrome. For example, a right sided midbrain lesion causes damage to the right trochlear nucleus (resulting in a left fourth nerve palsy) and damage to descending sympathetic fibers results in a right Horner's syndrome. If the lesion affects the fascicle of the fourth nerve as it crosses the midline, then the Horner's syndrome is on the same side as the fourth nerve palsy.1. Occlusion 2. Prism glasses 3. Strabismus surgery only after the palsy has been stable for at least six months using one or a combination of the following procedures: a) Weakening of the ipsilateral inferior oblique (the antagonist of the affected superior oblique) b) Weakening of the contralateral inferior rectus (the yoke muscle of the affected superior oblique) c) Strengthening the affected superior oblique1. Arruga J, DeRivas P, Espinet HL, Conesa G. Chronic isolated trochlear nerve palsy produced by intracavernous internal carotid artery aneurysm. J Clin Neuro-Ophthalmol 1991;11:104-108. http://www.ncbi.nlm.nih.gov/pubmed/1832682 2. Brazis PW, Lee AG. Binocular vertical diplopia. Mayo Clin Proc 1998;73:55-66. http://www.ncbi.nlm.nih.gov/pubmed/9443680 3. Cackett P, Fleck B, Mulhivill A. Bilateral fourth nerve palsy occurring after shaking injury in infancy. J AAPOS 2004;8:280-281. http://www.ncbi.nlm.nih.gov/pubmed/15226732 4. Gentry LR, Mehta RC, Appen RE, Weinstein JM. MR imaging of primary trochlear nerve neoplasms. Am J Neuroradiol 1991;12:707-713. http://www.ncbi.nlm.nih.gov/pubmed/1882749 5. Jacobson DM, Warner JJ, Choucair AK, Ptacek LJ. Trochlear nerve palsy following minor head trauma. A sign of structural disorder. J Clin Neuro-ophthalmol 1988;8:263-268. http://www.ncbi.nlm.nih.gov/pubmed/2977142 6. Keane JR. Fourth nerve palsy: historical review and study of 215 inpatients. Neurology 1993; 43:2439-2443. http://www.ncbi.nlm.nih.gov/pubmed/8255437 7. Leigh JR, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Chp 9;385-474. In: The Neurology of Eye Movements, 4th Edition. Oxford University Press 2006. 8. Lepore FE. Disorders of ocular motility following head trauma. Arch Neurol 1995;52:924-926. http://www.ncbi.nlm.nih.gov/pubmed/7661732 9. Richards BW, Jones FR, Younge BR. Causes and prognosis in 4,278 cases of paralysis of the oculomotor trochlear and abducens nerves. Am J Ophthalmol 1992;113:489-496. http://www.ncbi.nlm.nih.gov/pubmed/1575221 10. Schievink WI, Mokri B, Garrity JA, Nichols DA, Piegras DG. Ocular motor nerve palsies in spontaneous dissection of the cervical internal carotid artery. Neurology 1993;43:1938-1941. http://www.ncbi.nlm.nih.gov/pubmed/841394

  • Bilateral Sixth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 2026
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Esotropia; Bilateral Abduction Weakness; Bilateral Sixth Nerve PalsyDouble visionThe patient is a 60 year old woman who consulted her ophthalmologist with a chief complaint of double vision looking to the left. He diagnosed of a left sixth nerve palsy. No investigations were done. Two years later she complained of diplopia looking to the right. A diagnosis of bilateral sixth nerve palsy was made. She was referred to the Neurovisual Clinic at the Massachusetts General Hospital and was admitted. Brain CT showed: A large clivus vascular tumor without bone destruction consistent with a meningioma. Neuro-ophthalmological Examination: Visual acuity 20/25 OU Visual fields, pupils and fundus examination normal. Ocular Motility: Esotropia OD > OS Bilateral abduction weakness Cranial nerves 3 and 4 normal Lower cranial nerves normal Neurological examination: Motor System: Normal Sensory System: Normal Coordination: No ataxia Diagnosis: Bilateral sixth nerve palsy Clivus meningioma Neurosurgical Consult: Advised conservative management without a biopsy. She was lost to follow-up.This patient with a clivus tumor, diagnosed as an inoperable meningioma, had bilateral sixth nerve palsies. • Esotropia OD > OS • Bilateral abduction weakness • Cranial nerves 3 and 4 normal • Lower cranial nerves normal Bilateral isolated sixth nerve palsies are generally "bad news" and when present should be considered due to a posterior fossa tumor until proved otherwise. The etiology of bilateral sixth nerve palsies include: • CNS lymphoma infiltrating the cavernous sinus(ID946-2) • Demyelination • Wernicke's encephalopathy (ID163-3) • Meningitis • Increased intracranial pressure • Other clivus tumors such as chordoma (ID26-1) • Leptomeningeal carcinomatosisNo imaging studies are available in this patientThe abducens nucleus of the sixth nerve lies in the floor of the fourth ventricle, at the level of the lower pons, and contains three groups of neurons: 1. Abducens motoneurons which innervate the ipsilateral lateral rectus muscle. 2. Abducens internuclear neurons, which project to the contralateral medial rectus subnucleus of the oculomotor nucleus via the medial longitudinal fasciculus 3. Neurons that project to the cerebellar flocculus The genu of the facial nerve curves over the dorsal and lateral surfaces of the nucleus, while the medial longitudinal fasciculus lies medial to each nucleus. The abducens nerve fascicle during its passage in the pons, lies adjacent to the motor nucleus and fascicle of the facial nerve, the motor nucleus of the trigeminal nerve, the spinal tract of the trigeminal nerve, the superior olivary nucleus, the central tegmental tract, and the corticospinal tract. The sixth nerve emerges from the brainstem between the pons and medulla, lateral to the pyramidal prominence. It then runs upwards along the ventral surface of the pons, lateral to the basilar artery, and passes between the pons and the anterior inferior cerebellar artery to ascend through the subarachnoid space along the clivus. It then pierces the dura mata, crosses around and through the inferior petrosal sinus, and passes under the petroclinoid (Gruber's ligament) in Dorello's canal to enter the cavernous sinus. In the cavernous sinus, the nerve bends laterally around the intracavernous segment of the internal carotid artery (ICA) and runs medial and parallel to the ophthalmic division (V1) of the trigeminal nerve. The ocular sympathetic fibers leave the ICA and join briefly with the abducens nerve before joining the ophthalmic division (V1) of the trigeminal nerve. Unlike the oculomotor (third nerve) and trochlear (fourth nerve), the abducens nerve does not lie within the lateral wall of the sinus, but rather it runs within the body of the sinus. The sixth nerve enters the orbit through the superior orbital fissure, passes through the Annulus of Zinn, and innervates the lateral rectus muscle. See Ref (8) and (12) for full discussion.Review ref (8)Conservative1. Chen KS, Hung IJ, Lin KL. Isolated abducens nerve palsy: an unusual presentation of leukemia. J Child Neurol 2002;17:850-851. http://www.ncbi.nlm.nih.gov/pubmed/12585727 2. Currie JN, Lubin JH, Lessell S. Chronic isolated abducens paresis from tumors at the base of the brain. Arch Neurol 1983;40:226-229. http://www.ncbi.nlm.nih.gov/pubmed/6830471 3. Harada T, Ohashi T, Ohki K et al. Clival chordoma presenting as acute esotropia due to bilateral abducens palsy. Ophthalmologica 1997;21:109-111. http://www.ncbi.nlm.nih.gov/pubmed/9097318 4. Harbison JW, Lessell S, Selhorst JB. Neuro-ophthalmology of sphenoid sinus carcinoma. Brain 1984;108:855-870. http://www.ncbi.nlm.nih.gov/pubmed/6478180 5. Ikezaki K, Toda K, Abe M, Tabuchi K. Intracavernous epidermoid tumor presenting with abducens nerve paresis - case report. Neurologia Medico-Chirurgica 1992;32:360-364. http://www.ncbi.nlm.nih.gov/pubmed/1381064 6. Ilhan O, Sener EC, Ozyar E. Outcome of abducens nerve paralysis in patients with nasopharyngeal carcinoma. Eur J Ophthalmol 2002;12:55-59. http://www.ncbi.nlm.nih.gov/pubmed/11936446 7. Keane JR. Bilateral sixth nerve palsy. Analysis of 125 cases. Arch Neurol 1976;33:681-683. http://www.ncbi.nlm.nih.gov/pubmed/184766 8. Leigh RJ, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Ch 9:385-474. In: The Neurology of Eye Movements, Fourth Edition. Oxford University Press, NY 2006. 9. Lopez R, David NJ, Gargano F, Post JD. Bilateral sixth nerve palsies in a patient with massive pituitary adenoma. Neurology 1981;31:1137-1138. http://www.ncbi.nlm.nih.gov/pubmed/7196535 10. Morioka T, Matsushima T, Yokoyama N. Muratami H, Fujii K, Fukui M. Isolated bilateral abducens nerve palsies caused by rupture of a vertebral artery aneurysm. J Clin Neuroopthalmol 1992;12:263-267. http://www.ncbi.nlm.nih.gov/pubmed/1287052 11. Volpe NJ, Liebach NJ, Munzenrider JE, Lessell S. Neuro-ophthalmological findings in chordoma and chondrosarcoma of the skull base. Am J Ophthalmol 1993;115:97-104. http://www.ncbi.nlm.nih.gov/pubmed/8420385 12. Wong AM. Nuclear and infranuclear ocular motor disorders. Chp 12:919-242. In: Eye Movement Disorders. Oxford University Press, 2008.curriculum_fellow; MTemspsixthabducens; MTemspsixthabducen

Shirley H. Wray - One of the best experts on this subject based on the ideXlab platform.

  • Sixth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1995
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Esotropia; Abduction Weakness; Sixth Nerve PalsyPowerPoint Presentation: Clivus Chordoma: http://library.med.utah.edu/NOVEL/Wray/PPT/Clivus_Chordoma.ppt Shirley H. Wray, M.D., Ph.D., FRCP Harvard Medical SchoolDifficulty focusingThis 46 year old patient had at age 6, a tendency for the left eye to wander out. Her face photograph at that age shows an exotropia and at age 7, a year later, the exotropia was not quite as prominent. It was assumed that the exotropia was due to a non-paralytic strabismus. Past History: At age 1 fracture of the skull Since childhood the left eye wandered out She was never told she had a strabismus and never wore prism glasses. In Sept 1994 at age 46, she experienced intermittent double vision, seeing the image split apart horizontally, and persisting for approximately 2 minutes. By blinking her eyes she was able to refocus a single image. In December 1994 she had transient "kaleidoscopic" vision, by which she meant horizontal and oblique diplopia when she woke up. She noted this looking at the television set, the window frame or her bedside clock. By mid-December she had persistent horizontal double vision in primary gaze worse on looking to the left and was no longer able to refocus a single image but saw only one image if she closed one eye. She was referred to the Neurovisual Clinic at the Massachusetts General Hospital and admitted. Symptomatic Inquiry: No headaches, vertigo, ptosis, or unsteadiness Family History: Positive for diabetes and hypertension No history of neurological disease. Neuro-ophthalmological examination: Visual acuity 20/20 OD, 20/30 reads J2 OS Visual fields, pupils and fundus examination normal. Ocular Motility OS: Esotropia Weakness of full abduction Cranial nerves 3 and 4 normal Convergence normal Alternating exophoria at distance Vertical gaze normal Lower cranial nerves normal Neurological examination: Normal Diagnosis: Left sixth nerve palsy superimposed on a childhood non-paralytic esotropia Brain CT showed: 1. A lytic destructive lesion in the clivus with bony particles within the lesion. 2. The mass extended from the sella to the foramen magnum with extension laterally to the petrous apices and carotid canals. 3. There was a suggestion of erosion of the petrous apex on the left. 4. Partial erosion of the posterior wall of the sella 5. The mass abutted the posterior part of the left and right cavernous sinus Brain MRI showed: 1. A clival mass with extension into Meckel's cave and cavernous sinus on the left and circumferential encasement of the proximal left cavernous internal carotid artery (ICA). 2. Partial encasement of the right proximal cavernous ICA. Diagnosis: Clivus Chordoma Differential Diagnosis: Chondrosarcoma Neurosurgery Consult: The important features that established the tumor as inoperable, were the imaging studies showing infiltration and destruction of bone along the midline of the clivus stretching from the pituitary down to the lower clivus in addition to extension of the tumor into the left cavernous sinus encasing the left ICA. The patient was advised that the tumor was inoperable and biopsy was recommended. A transsphenoidal biopsy was performed. Pathology: Chordoma Treatment: Proton beam radiation to the mass and skull base.This 46 year old patient with an inoperable clivus chordoma has in her childhood photographs At age 6 exotropia of the left eye (OS) At age 7 exotropia appears less prominent The assumption was an exotropia due to a non-paralytic strabismus. At age 46 she became symptomatic with horizontal diplopia on looking left and OS deviated in. She had: • Esotropia OS • Paresis of full abduction • Paresis of abduction with OS fixing alone confirmed a paralytic sixth nerve palsy • An alternating exophoria at distanceNo neuroimaging studies are available in this patient.The abducens nucleus of the sixth nerve lies in the floor of the fourth ventricle, at the level of the lower pons, and contains three groups of neurons: 1. Abducens motoneurons which innervate the ipsilateral lateral rectus muscle. 2. Abducens internuclear neurons, which project to the contralateral medial rectus subnucleus of the oculomotor nucleus via the medial longitudinal fasciculus 3. Neurons that project to the cerebellar flocculus The genu of the facial nerve curves over the dorsal and lateral surfaces of the nucleus, while the medial longitudinal fasciculus lies medial to each nucleus. The abducens nerve fascicle join its passage in the pons, lies adjacent to the motor nucleus and fascicle of the facial nerve, the motor nucleus of the trigeminal nerve, the spinal tract of the trigeminal nerve, the superior olivary nucleus, the central tegmental tract, and the corticospinal tract. The sixth nerve emerges from the brainstem between the pons and medulla, lateral to the pyramidal prominence. It then runs upwards along the ventral surface of the pons, lateral to the basilar artery, and passes between the pons and the anterior inferior cerebellar artery to ascend through the subarachnoid space along the clivus. It then pierces the dura mata, crosses around and through the inferior petrosal sinus, and passes under the petroclinoid (Gruber's ligament) in Dorello's canal to enter the cavernous sinus. In the cavernous sinus, the nerve bends laterally around the intracavernous segment of the internal carotid artery (ICA) and runs medial and parallel to the ophthalmic division (V1) of the trigeminal nerve. The ocular sympathetic fibers leave the ICA and join briefly with the abducens nerve before joining the ophthalmic division (V1) of the trigeminal nerve. Unlike the oculomotor (third nerve) and trochlear (fourth nerve) nerves, the abducens nerve does not lie within the lateral wall of the sinus, but rather it runs within the body of the sinus. The sixth nerve enters the orbit through the superior orbital fissure, passes through the Annulus of Zinn, and innervates the lateral rectus muscle. See Ref (8) and (12) for full discussion.Review ref (8)Proton beam therapy to the mass and skull base.1. Chen KS, Hung IJ, Lin KL. Isolated abducens nerve palsy: an unusual presentation of leukemia. J Child Neurol 2002;17:850-851. http://www.ncbi.nlm.nih.gov/pubmed/12585727 2. Currie JN, Lubin JH, Lessell S. Chronic isolated abducens paresis from tumors at the base of the brain. Arch Neurol 1983;40:226-229. http://www.ncbi.nlm.nih.gov/pubmed/6830471 3. Harada T, Ohashi T, Ohki K et al. Clival chordoma presenting as acute esotropia due to bilateral abducens palsy. Ophthalmologica 1997;21:109-111. http://www.ncbi.nlm.nih.gov/pubmed/9097318 4. Harbison JW, Lessell S, Selhorst JB. Neuro-ophthalmology of sphenoid sinus carcinoma. Brain 1984;108:855-870. http://www.ncbi.nlm.nih.gov/pubmed/6478180 5. Ikezaki K, Toda K, Abe M, Tabuchi K. Intracavernous epidermoid tumor presenting with abducens nerve paresis - case report. Neurologia Medico-Chirurgica 1992;32:360-364. http://www.ncbi.nlm.nih.gov/pubmed/1381064 6. Ilhan O, Sener EC, Ozyar E. Outcome of abducens nerve paralysis in patients with nasopharyngeal carcinoma. Eur J Ophthalmol 2002;12:55-59. http://www.ncbi.nlm.nih.gov/pubmed/11936446 7. Keane JR. Bilateral sixth nerve palsy. Analysis of 125 cases. Arch Neurol 1976;33:681-683. http://www.ncbi.nlm.nih.gov/pubmed/184766 8. Leigh RJ, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Ch 9:385-474. In: The Neurology of Eye Movements, Fourth Edition. Oxford University Press, NY 2006. 9. Lopez R, David NJ, Gargano F, Post JD. Bilateral sixth nerve palsies in a patient with massive pituitary adenoma. Neurology 1981;31:1137-1138. http://www.ncbi.nlm.nih.gov/pubmed/7196535 10. Morioka T, Matsushima T, Yokoyama N. Muratami H, Fujii K, Fukui M. Isolated bilateral abducens nerve palsies caused by rupture of a vertebral artery aneurysm. J Clin Neuroopthalmol 1992;12:263-267. http://www.ncbi.nlm.nih.gov/pubmed/1287052 11. Volpe NJ, Liebach NJ, Munzenrider JE, Lessell S. Neuro-ophthalmological findings in chordoma and chondrosarcoma of the skull base. Am J Ophthalmol 1993;115:97-104. http://www.ncbi.nlm.nih.gov/pubmed/8420385 12. Wong AM. Nuclear and Infranuclear Ocular Motor Disorders Chp 12:191-242. In: Eye Movement Disorders. Oxford University Press, 2008.curriculum_fellow; VBchordoma; MTemspsixthabducen

  • Fourth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1993
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Hypertropia; Superior Oblique Paresis; Inferior Oblique Overaction; Fourth Nerve Palsy; Trochlear Nerve; Bielchowsky Test; Head TiltDouble visionThe patient is a 32 year old, left handed chemistry teacher who presented with intermittent vertical double vision. In August 1992 she noted, particularly late in the evening when reading in bed, vertical double vision. The images were one on top of the other and on occasions one image was slightly oblique. In September 1992 she consulted an ophthalmologist who documented a 2 diopter esotropia and hypotropia. She was prescribed prism reading glasses which helped. At the same time, she consulted a neurologist because her vision went out of focus after turning her head from side to side quickly. She denied headache and vertigo. Neurological examination by the consultant was normal apart from a "lag of abduction of the right eye". Brain MRI with and without gadolinium: Normal. Blood studies: Anti-acetylcholine receptor antibodies negative. Thyroid tests: Normal. In December 1992 she went to Nevada to see her mother. She consulted a neuro-ophthalmologist, Dr. Francis Grenn, a former post-graduate fellow of mine. Dr. Grenn obtained the history that when she changed the position of her head she could correct her diplopia. In bed at night if she tilted her head to the left, she had no double vision. She also had a single image with either eye covered. Diagnosis: Right fourth nerve palsy On return to Boston she came to the Neurovisual Clinic at the Massachusetts Genera Hospital. Symptomatic Inquiry: Negative for ptosis, bulbar muscle weakness or generalized weakness to suggest myasthenia gravis. Past History: Head trauma in 1978 when she was hit by a lacrosse ball and sustained a black eye and swelling of the right side of her face. She was stunned by the blow but not knocked out. It took several days for her to recover. During that time, she can not recall having double vision. No strabismus as a child and never wore prism glasses Family History: Father died of a myocardial infarct Mother had thyroid surgery for hyperthyroidism. Social History: Negative for alcohol abuse Non-smoker Neuro-ophthalmological examination: Visual acuity 20/25 OD 20/20 OS Visual fields, pupils and fundus examination normal. No ptosis No exophthalmos No ocular bruit Tests for diplopia: Slight right (ipsilateral) head tilt Absent stereopsis in the reading, downgaze position 1/3 animals in primary gaze Good stereopsis 4/6 circles with prism glasses Cover/uncover test: Hypertropia OD primary gaze Hypertropia most marked with right head tilt Hypertropia diminished, almost absent, left head tilt Hypertropia almost fully corrected with prism glasses at distance. Ocular Motility OD: Hypertropia and excyclotorsion Superior oblique (SO) paretic Inferior oblique (IO) overaction with elevation of the globe looking left. Cranial nerves 3 and 6 normal Ocular Motility OS: Full eye movements Hypotropia on cover/uncover test CT of the Orbit: Normal. Bone windows, no evidence of fracture Review of her old photographs The patient's old soccer photograph showed her with a slight head tilt to the right. This observation helped to establish a diagnosis of a longstanding post-traumatic fourth nerve palsy. Treatment: Strabismus surgery was discussed with the patient but she elected to wear prism glasses. In January 1997 she returned to consult the strabismus surgeon again but still elected to wear prism glasses.This tape records the "diplopia" history. The patient answers a list of specific questions with regard to her vertical double vision from a right fourth (trochlear) nerve palsy. She had no diplopia with one eye covered confirming binocular diplopia. With a history of vertical diplopia, attention is paid to the ocular muscles controlling vertical gaze. • SO: Paresis SO resulted in impaired downgaze in the adducted position with absent incyclotorsion of the eye • IO: Overaction of IO with elevation of the eyeball on gaze left, in the adducted position Alternate cover test: OD moved down to take up fixation (hypertropia) OS moved up to take up fixation (hypotropia) Two simple techniques which aid in the analysis of vertical diplopia are shown on this tape. 1. Viewing a horizontal bar The patient is seated in front of a black screen to view a horizontal bar (opaque line of tape). She confirms that she is seeing two images slanted with respect to each other, with the apparent intersection of the lines pointing toward the side of the affected, excyclodeviated eye. In this patient with a right fourth nerve palsy, the point of intersection is to the right. 2. The Lancaster red/green test requires the patient to wear a pair of red/green goggles, red lens OD, green lens OS. The patient holds a projector that places a red line on the screen. The examiner holds a projector that places a green line on the screen. The patient is directed to place the red line on top of the green line with her head in primary gaze, with head tilted to the right and with head tilted to the left - Bielchowsky head tilt test. The test was positive - there was no separation of the images on head tilt to the contralateral (left) side. An old soccer picture of the patient attached shows a very subtle right head tilt indicating the chronicity of the fourth nerve palsy. Two photographs of another patient, with a left fourth nerve palsy, first when quite young with his golf partners and then years later at a cocktail party, show a right contralateral head tilt. The clinical diagnosis in this case utilized the Three-Step Test. Step 1 - Identify which eye is hypertropic e.g. hypertropia OD. Step 2 - Determine whether the hypertropia increases on right or left gaze Step 3 - Bielchowsky's head tilt test: Tilt the head to the right and to the left. Hypertropia is maximized as the head is tilted toward the side of the lesion and minimized on contralateral head tilt, as in this case. The most reliable clinical test to diagnose fourth nerve palsy is the Bielchowsky's head tilt test. During right head tilt, the right eye incyclotorts (SO and SR), and the left eye excyclotorts (IO and IR) During left head tilt, the right eye excyclotorts (IO and IR) and the left eye incyclotorts (SO and SR). The question always asked is why does the hypertropia increase on right head tilt in right fourth nerve palsy. The explanation is as follows: During right head tilt, the otolith-ocular reflex (ocular counter roll) is activated, such that the right eye incyclotorts (SO and SR) and the left eye excyclotorts (IO and IR). The primary action of SO is incyclotorsion, and its secondary action depression, whereas the primary action of SR is elevation and its secondary action is incyclotorsion. Thus, normally, during the right head tilt, the net movement of the right eye is incyclotorsion with minimal vertical movement because the vertical action of the SO and SR cancels each other out. In a right fourth nerve palsy, the elevating action of SR is unopposed by the palsied SO; thus, the hypertropia increases during right head tilt. Differential Diagnosis: 1. Skew deviation 2. Thyroid-related ophthalmopathy 3. Brown's Syndrome 4. Primary inferior oblique overactionNo imaging studies are available in this patient. In patients who lack a history of head trauma, Brain MRI may show relevant brainstem lesions and gadolinium enhancement usually demonstrates infiltrative or inflammatory processes involving the long course of the fourth nerve. often the cause of the fourth nerve cannot be ascertained. These patients require long term follow-up.The nucleus of the fourth (trochlear) nerve lies at the ventral border of the periaqueductal gray matter at the level of the inferior colliculus in the brainstem. It lies at the dorsal margin of the medial longitudinal fasciculus. The fascicle of the fourth nerve crosses the midline at the anterior medullary vellum (anterior floor of the fourth ventricle, before exiting the brainstem) thus, the right fourth nerve fascicle becomes the left fourth nerve which innervates the left superior oblique muscle. The fourth nerve is the only cranial nerve that exits the brainstem on the dorsal surface and it has the longest intracranial course (approximately 75mm). In the subarachnoid space the nerve curves around the lateral surface of the upper pons, passing between the superior cerebellar and posterior cerebral arteries to reach the prepontine cistern. It then runs forward on the free edge of the tentorium for 1 to 2 cm before penetrating the dura of the tentorial attachment and entering the cavernous sinus. Within the lateral wall of the cavernous sinus, the nerve lies below the third cranial nerve and above the ophthalmic division (V1) of the fifth (trigeminal) nerve. It then crosses over the third nerve and receives filaments from the carotid sympathetic plexus. To reach the orbit the nerve enters through the superior orbital fissure above the Annulus of Zinn. In company with the frontal and lacrimal branches of the ophthalmic division of the trigeminal nerve. It divides into several small fascicles that innervate the superior oblique muscle.TraumaTrauma is the commonest cause of a fourth nerve palsy. Head trauma can result in a contusion or hemorrhage of the tegmentum at the junction of the midbrain and pons. Because of the short course of the fourth nerve fascicle in the brainstem, distinguishing a nuclear from a fascicular fourth nerve palsy is virtually impossible. Damage to the descending sympathetic fibers from the hyperthalamus in the dorsal brainstem, causes a Horner's syndrome, and lesions of the trochlear nucleus or fascicle may be accompanied by a Horner's syndrome. For example, a right sided midbrain lesion causes damage to the right trochlear nucleus (resulting in a left fourth nerve palsy) and damage to descending sympathetic fibers results in a right Horner's syndrome. If the lesion affects the fascicle of the fourth nerve as it crosses the midline, then the Horner's syndrome is on the same side as the fourth nerve palsy.1. Occlusion 2. Prism glasses 3. Strabismus surgery only after the palsy has been stable for at least six months using one or a combination of the following procedures: a) Weakening of the ipsilateral inferior oblique (the antagonist of the affected superior oblique) b) Weakening of the contralateral inferior rectus (the yoke muscle of the affected superior oblique) c) Strengthening the affected superior oblique1. Arruga J, DeRivas P, Espinet HL, Conesa G. Chronic isolated trochlear nerve palsy produced by intracavernous internal carotid artery aneurysm. J Clin Neuro-Ophthalmol 1991;11:104-108. http://www.ncbi.nlm.nih.gov/pubmed/1832682 2. Brazis PW, Lee AG. Binocular vertical diplopia. Mayo Clin Proc 1998;73:55-66. http://www.ncbi.nlm.nih.gov/pubmed/9443680 3. Cackett P, Fleck B, Mulhivill A. Bilateral fourth nerve palsy occurring after shaking injury in infancy. J AAPOS 2004;8:280-281. http://www.ncbi.nlm.nih.gov/pubmed/15226732 4. Gentry LR, Mehta RC, Appen RE, Weinstein JM. MR imaging of primary trochlear nerve neoplasms. Am J Neuroradiol 1991;12:707-713. http://www.ncbi.nlm.nih.gov/pubmed/1882749 5. Jacobson DM, Warner JJ, Choucair AK, Ptacek LJ. Trochlear nerve palsy following minor head trauma. A sign of structural disorder. J Clin Neuro-ophthalmol 1988;8:263-268. http://www.ncbi.nlm.nih.gov/pubmed/2977142 6. Keane JR. Fourth nerve palsy: historical review and study of 215 inpatients. Neurology 1993; 43:2439-2443. http://www.ncbi.nlm.nih.gov/pubmed/8255437 7. Leigh JR, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Chp 9;385-474. In: The Neurology of Eye Movements, 4th Edition. Oxford University Press 2006. 8. Lepore FE. Disorders of ocular motility following head trauma. Arch Neurol 1995;52:924-926. http://www.ncbi.nlm.nih.gov/pubmed/7661732 9. Richards BW, Jones FR, Younge BR. Causes and prognosis in 4,278 cases of paralysis of the oculomotor trochlear and abducens nerves. Am J Ophthalmol 1992;113:489-496. http://www.ncbi.nlm.nih.gov/pubmed/1575221 10. Schievink WI, Mokri B, Garrity JA, Nichols DA, Piepgras DG. Ocular motor nerve palsies in spontaneous dissection of the cervical internal carotid artery. Neurology 1993;43:1938-1941. http://www.ncbi.nlm.nih.gov/pubmed/8413949curriculum_fellow; MTemspfourthtrochlear; MTneurodisfourthtrochlear, VBbraininjury; VBstrabismu

  • Fourth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 1992
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Hypertropia; Superior Oblique Paresis; Inferior Oblique Overaction; Fourth Nerve Palsy; Trochlear Nerve; Bielchowsky Test; Head TiltDouble visionThe patient is a 64 year old engineer who noted whilst driving around Thanksgiving time double vision with one image on top of the other. Vertical double vision persisted and he was referred to the Massachusetts General Hospital for evaluation. Past History: 1991 Hyperthyroidism with Graves' Disease treated with radio active iodine. 1989-1990 Writer's cramp treated with botulinium toxin injection 1989 Cancer of the colon, status colonectomy. No previous episodes of diplopia No strabismus as a child or need to wear prism glasses No history of head or eye trauma Medications: Synthroid 600 mg Calcium daily Aspirin daily Family History: Positive for diabetes Mother died cancer of the ovary Neuro-ophthalmological examination: Visual acuity 20/20 OU corrected Visual fields, color vision, pupils and fundus examination normal. Tests for diplopia showed: Left (contralateral) head tilt Good stereopsis in primary gaze 6/9 circles. Cover/uncover test: Hypertropia OD primary gaze Hypertropia most marked with right head tilt Hypertropia diminished, almost absent, left head tilt Hypertropia almost fully corrected with prism glasses at distance. Exophthalmometry 23 OU base 97 normal orbital resilience. Ocular Motility OD: Hypertropia and excyclotorsion Superior oblique (SO) paretic Inferior oblique (IO) overaction with elevation of the globe looking left. Cranial nerves 3 and 6 normal Ocular Motility OS: Full eye movements Hypotropia on cover/uncover test CT of the Orbits 1/17/92: Study showed enlargement of the inferior rectus muscle bilaterally and the right medial rectus muscle attributed to earlier Graves' disease in the past associated with hyperthyroidism. Brain MRI showed: Calcification of the wall of the carotid siphon and changes consistent with small vessel microangiopathy. Strabismus Consultation: The patient was tested with two Maddox rods and found to have an 8 diopter right hyper with the right eye extorted approximately 5 diopters in primary position. Diagnosis fourth nerve palsy, presenting in a somewhat unusual manner, possibly modified by his early Graves' disease and persistent enlargement of the inferior recti OU and the medial rectus muscle OD. Diagnosis: Right fourth nerve palsy Mild thyroid associated orbitopathy Strabismus surgery was not recommended. He returned in June 1992 and annually until July 1996 with no change in ocular motility.This tape records the "diplopia" history. The patient answers a list of specific questions with regard to his vertical double vision from a right fourth (trochlear) nerve palsy. He had no diplopia with one eye covered confirming binocular diplopia. With a history of vertical diplopia, attention is paid to the ocular muscles controlling vertical gaze. • SO: Paresis SO resulted in impaired downgaze in the adducted position with absent incyclotorsion of the eye • IO: Overaction of IO with elevation of the eyeball on gaze left, in the adducted position Alternate cover test: OD moved down to take up fixation (hypertropia) OS moved up to take up fixation (hypotropia) Review of old photographs showed that he had a longstanding left head tilt which helped establish the chronicity of the fourth nerve palsy. The Three-Step Test aids in establishing the diagnosis. Step 1 - Identify which eye is hypertropic e.g. hypertropia OD. Step 2 - Determine whether the hypertropia increases on right or left gaze Step 3 - Bielchowsky's head tilt test: Tilt the head to the right and to the left. Hypertropia is maximized as the head is tilted toward the side of the lesion and minimized on contralateral head tilt, as in this case. The most reliable clinical test to diagnose fourth nerve palsy is the Bielchowsky's head tilt test. During right head tilt, the right eye incyclotorts (SO and SR), and the left eye excyclotorts (IO and IR) During left head tilt, the right eye excyclotorts (IO and IR) and the left eye incyclotorts (SO and SR). The question always asked is why does the hypertropia increase on right head tilt in right fourth nerve palsy. The explanation is as follows: During right head tilt, the otolith-ocular reflex (ocular counter roll) is activated, such that the right eye incyclotorts (SO and SR) and the left eye excyclotorts (IO and IR). The primary action of SO is incyclotorsion, and its secondary action depression, whereas the primary action of SR is elevation and its secondary action is incyclotorsion. Thus, normally, during the right head tilt, the net movement of the right eye is incyclotorsion with minimal vertical movement because the vertical action of the SO and SR cancels each other out. In right fourth nerve palsy, the elevating action of SR is unopposed by the palsied SO; thus, the hypertropia increases during right head tilt. Differential Diagnosis: 1. Skew deviation 2. Thyroid-related ophthalmopathy 3. Brown's Syndrome 4. Primary inferior oblique overactionNo imaging studies are available in this patient. In patients who lack a history of head trauma, Brain MRI may show relevant brainstem lesions and gadolinium enhancement usually demonstrates infiltrative or inflammatory processes involving the long course of the fourth nerve. often the cause of the fourth nerve cannot be ascertained and these patients require long term follow-up.The nucleus of the fourth (trochlear) nerve lies at the ventral border of the periaqueductal gray matter at the level of the inferior colliculus in the brainstem. It lies at the dorsal margin of the medial longitudinal fasciculus. The fascicle of the fourth nerve crosses the midline at the anterior medullary vellum (anterior floor of the fourth ventricle, before exiting the brainstem) thus, the right fourth nerve fascicle becomes the left fourth nerve which innervates the left superior oblique muscle. The fourth nerve is the only cranial nerve that exits the brainstem on the dorsal surface and it has the longest intracranial course (approximately 75mm). In the subarachnoid space the nerve curves around the lateral surface of the upper pons, passing between the superior cerebellar and posterior cerebral arteries to reach the prepontine cistern. It then runs forward on the free edge of the tentorium for 1 to 2 cm before penetrating the dura of the tentorial attachment and entering the cavernous sinus. Within the lateral wall of the cavernous sinus, the nerve lies below the third cranial nerve and above the ophthalmic division (V1) of the fifth (trigeminal) nerve. It then crosses over the third nerve and receives filaments from the carotid sympathetic plexus. To reach the orbit the nerve enters through the superior orbital fissure above the Annulus of Zinn. In company with the frontal and lacrimal branches of the ophthalmic division of the trigeminal nerve. It divides into several small fascicles that innervate the superior oblique muscle.Graves'Trauma is the commonest cause of a fourth nerve palsy. Head trauma can result in a contusion or hemorrhage of the tegmentum at the junction of the midbrain and pons. Because of the short course of the fourth nerve fascicle in the brainstem, distinguishing a nuclear from a fascicular fourth nerve palsy is virtually impossible. Damage to the descending sympathetic fibers from the hyperthalamus in the dorsal brainstem, causes a Horner's syndrome, and lesions of the trochlear nucleus or fascicle may be accompanied by a Horner's syndrome. For example, a right sided midbrain lesion causes damage to the right trochlear nucleus (resulting in a left fourth nerve palsy) and damage to descending sympathetic fibers results in a right Horner's syndrome. If the lesion affects the fascicle of the fourth nerve as it crosses the midline, then the Horner's syndrome is on the same side as the fourth nerve palsy.1. Occlusion 2. Prism glasses 3. Strabismus surgery only after the palsy has been stable for at least six months using one or a combination of the following procedures: a) Weakening of the ipsilateral inferior oblique (the antagonist of the affected superior oblique) b) Weakening of the contralateral inferior rectus (the yoke muscle of the affected superior oblique) c) Strengthening the affected superior oblique1. Arruga J, DeRivas P, Espinet HL, Conesa G. Chronic isolated trochlear nerve palsy produced by intracavernous internal carotid artery aneurysm. J Clin Neuro-Ophthalmol 1991;11:104-108. http://www.ncbi.nlm.nih.gov/pubmed/1832682 2. Brazis PW, Lee AG. Binocular vertical diplopia. Mayo Clin Proc 1998;73:55-66. http://www.ncbi.nlm.nih.gov/pubmed/9443680 3. Cackett P, Fleck B, Mulhivill A. Bilateral fourth nerve palsy occurring after shaking injury in infancy. J AAPOS 2004;8:280-281. http://www.ncbi.nlm.nih.gov/pubmed/15226732 4. Gentry LR, Mehta RC, Appen RE, Weinstein JM. MR imaging of primary trochlear nerve neoplasms. Am J Neuroradiol 1991;12:707-713. http://www.ncbi.nlm.nih.gov/pubmed/1882749 5. Jacobson DM, Warner JJ, Choucair AK, Ptacek LJ. Trochlear nerve palsy following minor head trauma. A sign of structural disorder. J Clin Neuro-ophthalmol 1988;8:263-268. http://www.ncbi.nlm.nih.gov/pubmed/2977142 6. Keane JR. Fourth nerve palsy: historical review and study of 215 inpatients. Neurology 1993; 43:2439-2443. http://www.ncbi.nlm.nih.gov/pubmed/8255437 7. Leigh JR, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Chp 9;385-474. In: The Neurology of Eye Movements, 4th Edition. Oxford University Press 2006. 8. Lepore FE. Disorders of ocular motility following head trauma. Arch Neurol 1995;52:924-926. http://www.ncbi.nlm.nih.gov/pubmed/7661732 9. Richards BW, Jones FR, Younge BR. Causes and prognosis in 4,278 cases of paralysis of the oculomotor trochlear and abducens nerves. Am J Ophthalmol 1992;113:489-496. http://www.ncbi.nlm.nih.gov/pubmed/1575221 10. Schievink WI, Mokri B, Garrity JA, Nichols DA, Piegras DG. Ocular motor nerve palsies in spontaneous dissection of the cervical internal carotid artery. Neurology 1993;43:1938-1941. http://www.ncbi.nlm.nih.gov/pubmed/841394

  • Bilateral Sixth Nerve Palsy
    Spencer S. Eccles Health Sciences Library University of Utah, 2026
    Co-Authors: Shirley H. Wray, Professor Of Neurology Harvard Medical School, Unit For Neurovisual Disorders, Massachusetts General Hospital
    Abstract:

    Esotropia; Bilateral Abduction Weakness; Bilateral Sixth Nerve PalsyDouble visionThe patient is a 60 year old woman who consulted her ophthalmologist with a chief complaint of double vision looking to the left. He diagnosed of a left sixth nerve palsy. No investigations were done. Two years later she complained of diplopia looking to the right. A diagnosis of bilateral sixth nerve palsy was made. She was referred to the Neurovisual Clinic at the Massachusetts General Hospital and was admitted. Brain CT showed: A large clivus vascular tumor without bone destruction consistent with a meningioma. Neuro-ophthalmological Examination: Visual acuity 20/25 OU Visual fields, pupils and fundus examination normal. Ocular Motility: Esotropia OD > OS Bilateral abduction weakness Cranial nerves 3 and 4 normal Lower cranial nerves normal Neurological examination: Motor System: Normal Sensory System: Normal Coordination: No ataxia Diagnosis: Bilateral sixth nerve palsy Clivus meningioma Neurosurgical Consult: Advised conservative management without a biopsy. She was lost to follow-up.This patient with a clivus tumor, diagnosed as an inoperable meningioma, had bilateral sixth nerve palsies. • Esotropia OD > OS • Bilateral abduction weakness • Cranial nerves 3 and 4 normal • Lower cranial nerves normal Bilateral isolated sixth nerve palsies are generally "bad news" and when present should be considered due to a posterior fossa tumor until proved otherwise. The etiology of bilateral sixth nerve palsies include: • CNS lymphoma infiltrating the cavernous sinus(ID946-2) • Demyelination • Wernicke's encephalopathy (ID163-3) • Meningitis • Increased intracranial pressure • Other clivus tumors such as chordoma (ID26-1) • Leptomeningeal carcinomatosisNo imaging studies are available in this patientThe abducens nucleus of the sixth nerve lies in the floor of the fourth ventricle, at the level of the lower pons, and contains three groups of neurons: 1. Abducens motoneurons which innervate the ipsilateral lateral rectus muscle. 2. Abducens internuclear neurons, which project to the contralateral medial rectus subnucleus of the oculomotor nucleus via the medial longitudinal fasciculus 3. Neurons that project to the cerebellar flocculus The genu of the facial nerve curves over the dorsal and lateral surfaces of the nucleus, while the medial longitudinal fasciculus lies medial to each nucleus. The abducens nerve fascicle during its passage in the pons, lies adjacent to the motor nucleus and fascicle of the facial nerve, the motor nucleus of the trigeminal nerve, the spinal tract of the trigeminal nerve, the superior olivary nucleus, the central tegmental tract, and the corticospinal tract. The sixth nerve emerges from the brainstem between the pons and medulla, lateral to the pyramidal prominence. It then runs upwards along the ventral surface of the pons, lateral to the basilar artery, and passes between the pons and the anterior inferior cerebellar artery to ascend through the subarachnoid space along the clivus. It then pierces the dura mata, crosses around and through the inferior petrosal sinus, and passes under the petroclinoid (Gruber's ligament) in Dorello's canal to enter the cavernous sinus. In the cavernous sinus, the nerve bends laterally around the intracavernous segment of the internal carotid artery (ICA) and runs medial and parallel to the ophthalmic division (V1) of the trigeminal nerve. The ocular sympathetic fibers leave the ICA and join briefly with the abducens nerve before joining the ophthalmic division (V1) of the trigeminal nerve. Unlike the oculomotor (third nerve) and trochlear (fourth nerve), the abducens nerve does not lie within the lateral wall of the sinus, but rather it runs within the body of the sinus. The sixth nerve enters the orbit through the superior orbital fissure, passes through the Annulus of Zinn, and innervates the lateral rectus muscle. See Ref (8) and (12) for full discussion.Review ref (8)Conservative1. Chen KS, Hung IJ, Lin KL. Isolated abducens nerve palsy: an unusual presentation of leukemia. J Child Neurol 2002;17:850-851. http://www.ncbi.nlm.nih.gov/pubmed/12585727 2. Currie JN, Lubin JH, Lessell S. Chronic isolated abducens paresis from tumors at the base of the brain. Arch Neurol 1983;40:226-229. http://www.ncbi.nlm.nih.gov/pubmed/6830471 3. Harada T, Ohashi T, Ohki K et al. Clival chordoma presenting as acute esotropia due to bilateral abducens palsy. Ophthalmologica 1997;21:109-111. http://www.ncbi.nlm.nih.gov/pubmed/9097318 4. Harbison JW, Lessell S, Selhorst JB. Neuro-ophthalmology of sphenoid sinus carcinoma. Brain 1984;108:855-870. http://www.ncbi.nlm.nih.gov/pubmed/6478180 5. Ikezaki K, Toda K, Abe M, Tabuchi K. Intracavernous epidermoid tumor presenting with abducens nerve paresis - case report. Neurologia Medico-Chirurgica 1992;32:360-364. http://www.ncbi.nlm.nih.gov/pubmed/1381064 6. Ilhan O, Sener EC, Ozyar E. Outcome of abducens nerve paralysis in patients with nasopharyngeal carcinoma. Eur J Ophthalmol 2002;12:55-59. http://www.ncbi.nlm.nih.gov/pubmed/11936446 7. Keane JR. Bilateral sixth nerve palsy. Analysis of 125 cases. Arch Neurol 1976;33:681-683. http://www.ncbi.nlm.nih.gov/pubmed/184766 8. Leigh RJ, Zee DS. Diagnosis of Peripheral Ocular Motor Palsies and Strabismus. Ch 9:385-474. In: The Neurology of Eye Movements, Fourth Edition. Oxford University Press, NY 2006. 9. Lopez R, David NJ, Gargano F, Post JD. Bilateral sixth nerve palsies in a patient with massive pituitary adenoma. Neurology 1981;31:1137-1138. http://www.ncbi.nlm.nih.gov/pubmed/7196535 10. Morioka T, Matsushima T, Yokoyama N. Muratami H, Fujii K, Fukui M. Isolated bilateral abducens nerve palsies caused by rupture of a vertebral artery aneurysm. J Clin Neuroopthalmol 1992;12:263-267. http://www.ncbi.nlm.nih.gov/pubmed/1287052 11. Volpe NJ, Liebach NJ, Munzenrider JE, Lessell S. Neuro-ophthalmological findings in chordoma and chondrosarcoma of the skull base. Am J Ophthalmol 1993;115:97-104. http://www.ncbi.nlm.nih.gov/pubmed/8420385 12. Wong AM. Nuclear and infranuclear ocular motor disorders. Chp 12:919-242. In: Eye Movement Disorders. Oxford University Press, 2008.curriculum_fellow; MTemspsixthabducens; MTemspsixthabducen

Masahito Yamamoto - One of the best experts on this subject based on the ideXlab platform.

  • examination of the annular tendon Annulus of Zinn as a common origin of the extraocular rectus muscles 2 embryological basis of extraocular muscles anomalies
    Investigative Ophthalmology & Visual Science, 2020
    Co-Authors: Ji Hyun Kim, Masahito Yamamoto, Gen Murakami, Shogo Hayashi, Jorg Wilting, Jose Francisco Rodriguezvazquez
    Abstract:

    Purpose Many reports have described anomalous connections of the superior rectus (SR) with other extraocular rectus muscles, in which additional heads of the other three rectus muscles likely provided the connections. We examined how these connections are established during fetal development. Methods We analyzed paraffin-embedded horizontal sections from 25 late-stage fetuses. Horizontal sections are best suited for understanding the mediolateral relationships of muscle origins. Results We confirmed a common tendinous origin of the lateral rectus (LR), inferior rectus (IR) and medial rectus (MR) muscles that was separated from the SR origin. Notably, eight fetuses (32%) had tendinous or muscular connections between the SR and other rectus muscles that had one of four morphologies: (a) a thin tendon from the SR to the common tendon of the three rectus muscles (2 fetuses), (b) a thin tendon to the LR (one fetus), (c) a thin tendon to the inferior rectus muscle origin (two fetuses), and (d) SR muscle fibers arising from an additional head of the LR (three fetuses). Conclusions The SR seemed to issue a thin tendon that passed along the inferior or lateral side of the oculomotor nerve. Conversely, the LR and inferior rectus muscle were likely to carry a supernumerary bundle that reached the SR. The accessory head of the medial rectus muscle showed a stable morphology in that it seemed to also provide an anomalous double head. However, the presence of an accessory head in the LR was rare. In contrast with our previously published diagram of the orbital apex, the accessory head of the medial rectus muscle passed along the lateral side of the superior oblique.

  • examination of the topographical anatomy and fetal development of the tendinous Annulus of Zinn for a common origin of the extraocular recti
    Investigative Ophthalmology & Visual Science, 2019
    Co-Authors: Tetsu Naito, Kwang Ho Cho, Masahito Yamamoto, Hidetomo Hirouchi, Gen Murakami, Shogo Hayashi, Shinichi Abe
    Abstract:

    Purpose The aim was to clarify the topographical anatomy of the common tendinous ring for the four rectus muscles in both adults and fetuses. Methods We histologically examined the annular ligament for a common origin of the extraocular rectus muscles using 10 specimens from elderly individuals and 31 embryonic and fetal specimens. Results At 6 to 8 weeks, each rectus carried an independent long tendon, individually originating from the sphenoid. Notably, we found additional origins from the optic or oculomotor nerve sheath. At 12 to 15 weeks, the lateral, inferior, and medial recti muscles were united to provide a C-shaped musculofibrous mass that was separated from the superior rectus originating from the edge of the optic canal opening. Morphologic features at 31 to 38 weeks were almost the same as those at 12 to 15 weeks, but the long and thick common tendon of the three recti reached the sphenoid body in the parasellar area. In adults, a ring-like arrangement of the rectus muscles ended at a site 8.1 to 12.0 mm anterior to the optic canal opening and independent of the superior rectus origin, the lateral, inferior, and medial recti formed a C-shaped muscle mass. The united origins of the three recti changed to a fibrous band extending along the superomedial wall of the orbital fissure. Conclusions Consequently, none of the specimens we examined exhibited an annular tendon representing a common origin of the four recti, suggesting that the common tendinous ring includes only medial, lateral, and inferior rectus muscles with the superior rectus taking its origin independently.

Shogo Hayashi - One of the best experts on this subject based on the ideXlab platform.

  • examination of the annular tendon Annulus of Zinn as a common origin of the extraocular rectus muscles 2 embryological basis of extraocular muscles anomalies
    Investigative Ophthalmology & Visual Science, 2020
    Co-Authors: Ji Hyun Kim, Masahito Yamamoto, Gen Murakami, Shogo Hayashi, Jorg Wilting, Jose Francisco Rodriguezvazquez
    Abstract:

    Purpose Many reports have described anomalous connections of the superior rectus (SR) with other extraocular rectus muscles, in which additional heads of the other three rectus muscles likely provided the connections. We examined how these connections are established during fetal development. Methods We analyzed paraffin-embedded horizontal sections from 25 late-stage fetuses. Horizontal sections are best suited for understanding the mediolateral relationships of muscle origins. Results We confirmed a common tendinous origin of the lateral rectus (LR), inferior rectus (IR) and medial rectus (MR) muscles that was separated from the SR origin. Notably, eight fetuses (32%) had tendinous or muscular connections between the SR and other rectus muscles that had one of four morphologies: (a) a thin tendon from the SR to the common tendon of the three rectus muscles (2 fetuses), (b) a thin tendon to the LR (one fetus), (c) a thin tendon to the inferior rectus muscle origin (two fetuses), and (d) SR muscle fibers arising from an additional head of the LR (three fetuses). Conclusions The SR seemed to issue a thin tendon that passed along the inferior or lateral side of the oculomotor nerve. Conversely, the LR and inferior rectus muscle were likely to carry a supernumerary bundle that reached the SR. The accessory head of the medial rectus muscle showed a stable morphology in that it seemed to also provide an anomalous double head. However, the presence of an accessory head in the LR was rare. In contrast with our previously published diagram of the orbital apex, the accessory head of the medial rectus muscle passed along the lateral side of the superior oblique.

  • examination of the topographical anatomy and fetal development of the tendinous Annulus of Zinn for a common origin of the extraocular recti
    Investigative Ophthalmology & Visual Science, 2019
    Co-Authors: Tetsu Naito, Kwang Ho Cho, Masahito Yamamoto, Hidetomo Hirouchi, Gen Murakami, Shogo Hayashi, Shinichi Abe
    Abstract:

    Purpose The aim was to clarify the topographical anatomy of the common tendinous ring for the four rectus muscles in both adults and fetuses. Methods We histologically examined the annular ligament for a common origin of the extraocular rectus muscles using 10 specimens from elderly individuals and 31 embryonic and fetal specimens. Results At 6 to 8 weeks, each rectus carried an independent long tendon, individually originating from the sphenoid. Notably, we found additional origins from the optic or oculomotor nerve sheath. At 12 to 15 weeks, the lateral, inferior, and medial recti muscles were united to provide a C-shaped musculofibrous mass that was separated from the superior rectus originating from the edge of the optic canal opening. Morphologic features at 31 to 38 weeks were almost the same as those at 12 to 15 weeks, but the long and thick common tendon of the three recti reached the sphenoid body in the parasellar area. In adults, a ring-like arrangement of the rectus muscles ended at a site 8.1 to 12.0 mm anterior to the optic canal opening and independent of the superior rectus origin, the lateral, inferior, and medial recti formed a C-shaped muscle mass. The united origins of the three recti changed to a fibrous band extending along the superomedial wall of the orbital fissure. Conclusions Consequently, none of the specimens we examined exhibited an annular tendon representing a common origin of the four recti, suggesting that the common tendinous ring includes only medial, lateral, and inferior rectus muscles with the superior rectus taking its origin independently.

Gen Murakami - One of the best experts on this subject based on the ideXlab platform.

  • examination of the annular tendon Annulus of Zinn as a common origin of the extraocular rectus muscles 2 embryological basis of extraocular muscles anomalies
    Investigative Ophthalmology & Visual Science, 2020
    Co-Authors: Ji Hyun Kim, Masahito Yamamoto, Gen Murakami, Shogo Hayashi, Jorg Wilting, Jose Francisco Rodriguezvazquez
    Abstract:

    Purpose Many reports have described anomalous connections of the superior rectus (SR) with other extraocular rectus muscles, in which additional heads of the other three rectus muscles likely provided the connections. We examined how these connections are established during fetal development. Methods We analyzed paraffin-embedded horizontal sections from 25 late-stage fetuses. Horizontal sections are best suited for understanding the mediolateral relationships of muscle origins. Results We confirmed a common tendinous origin of the lateral rectus (LR), inferior rectus (IR) and medial rectus (MR) muscles that was separated from the SR origin. Notably, eight fetuses (32%) had tendinous or muscular connections between the SR and other rectus muscles that had one of four morphologies: (a) a thin tendon from the SR to the common tendon of the three rectus muscles (2 fetuses), (b) a thin tendon to the LR (one fetus), (c) a thin tendon to the inferior rectus muscle origin (two fetuses), and (d) SR muscle fibers arising from an additional head of the LR (three fetuses). Conclusions The SR seemed to issue a thin tendon that passed along the inferior or lateral side of the oculomotor nerve. Conversely, the LR and inferior rectus muscle were likely to carry a supernumerary bundle that reached the SR. The accessory head of the medial rectus muscle showed a stable morphology in that it seemed to also provide an anomalous double head. However, the presence of an accessory head in the LR was rare. In contrast with our previously published diagram of the orbital apex, the accessory head of the medial rectus muscle passed along the lateral side of the superior oblique.

  • examination of the topographical anatomy and fetal development of the tendinous Annulus of Zinn for a common origin of the extraocular recti
    Investigative Ophthalmology & Visual Science, 2019
    Co-Authors: Tetsu Naito, Kwang Ho Cho, Masahito Yamamoto, Hidetomo Hirouchi, Gen Murakami, Shogo Hayashi, Shinichi Abe
    Abstract:

    Purpose The aim was to clarify the topographical anatomy of the common tendinous ring for the four rectus muscles in both adults and fetuses. Methods We histologically examined the annular ligament for a common origin of the extraocular rectus muscles using 10 specimens from elderly individuals and 31 embryonic and fetal specimens. Results At 6 to 8 weeks, each rectus carried an independent long tendon, individually originating from the sphenoid. Notably, we found additional origins from the optic or oculomotor nerve sheath. At 12 to 15 weeks, the lateral, inferior, and medial recti muscles were united to provide a C-shaped musculofibrous mass that was separated from the superior rectus originating from the edge of the optic canal opening. Morphologic features at 31 to 38 weeks were almost the same as those at 12 to 15 weeks, but the long and thick common tendon of the three recti reached the sphenoid body in the parasellar area. In adults, a ring-like arrangement of the rectus muscles ended at a site 8.1 to 12.0 mm anterior to the optic canal opening and independent of the superior rectus origin, the lateral, inferior, and medial recti formed a C-shaped muscle mass. The united origins of the three recti changed to a fibrous band extending along the superomedial wall of the orbital fissure. Conclusions Consequently, none of the specimens we examined exhibited an annular tendon representing a common origin of the four recti, suggesting that the common tendinous ring includes only medial, lateral, and inferior rectus muscles with the superior rectus taking its origin independently.