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Agnes M F Wong - One of the best experts on this subject based on the ideXlab platform.
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New understanding on the contribution of the central otolithic system to eye movement and Skew Deviation
Eye (London England), 2014Co-Authors: Agnes M F WongAbstract:New understanding on the contribution of the central otolithic system to eye movement and Skew Deviation
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ability of an upright supine test to differentiate Skew Deviation from other vertical strabismus causes
Archives of Ophthalmology, 2011Co-Authors: Agnes M F Wong, Linda Colpa, Manokaraananthan ChandrakumarAbstract:Objective To determine the sensitivity and specificity of a new upright-supine test to differentiate Skew Deviation from trochlear nerve palsy and other causes of vertical strabismus in a large number of patients. Methods The study consisted of 125 consecutive patients who sought treatment from January 1, 2008, through December 31, 2010, for vertical strabismus of various causes: Skew Deviation (25 patients), trochlear nerve palsy (58 patients), restrictive causes (14 patients), and other causes (eg, myasthenia gravis and childhood strabismus) (28 patients). Twenty healthy participants served as controls. The Deviation was measured by the prism and alternate cover test using a near target at ⅓ m in both the upright and supine positions. A vertical strabismus that decreased by 50% or more from the upright to supine position constituted a positive test result. Results The upright-supine test result was positive in 20 of 25 patients with Skew Deviation (sensitivity, 80%) but negative in all patients with trochlear nerve palsy, restrictive, or other causes (specificity, 100%). Conclusions The upright-supine test is highly specific for differentiating Skew Deviation from other causes of vertical strabismus. This test could be added as a fourth step after the 3-step test, and if the result is positive, neuroimaging should be considered if indicated clinically.
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Static ocular counterroll reflex in Skew Deviation
Neurology, 2011Co-Authors: M. Chandrakumar, James A. Sharpe, Alan Blakeman, H. Goltz, Agnes M F WongAbstract:Objective: The static ocular counterroll (OCR) reflex generates partially compensatory torsional eye movements during head roll. It is mediated by the utricle in the inner ear. Skew Deviation is a vertical strabismus thought to be caused by imbalance in the utriculo-ocular pathway. We hypothesized that if Skew Deviation is indeed caused by damage to this reflex pathway, patients with Skew Deviation would show abnormal OCR. Methods: Eighteen patients with Skew Deviation caused by brainstem or cerebellar lesions and 18 normal participants viewed a target at 1 m. Ocular responses to static passive head roll-tilts of approximately 20° were recorded using search coils. Static OCR gain was calculated as the change in torsional eye position divided by the change in head position during sustained head roll. Perception of the subjective visual vertical (SVV) was also measured. Results: Group mean OCR gain was reduced by 45% in patients. At an individual level, OCR gains were asymmetric between eyes and between torsional directions in 90% of patients. In addition, the hypotropic eye incyclotorting gain was lower than the hypertropic eye excyclotorting gain during head roll toward the hypotropic eye in 94% of patients. No consistent pattern of gain asymmetry was found during head roll toward the hypertropic eye. The SVV was tilted toward the hypotropic eye. Conclusion: Static OCR gain is significantly reduced in Skew Deviation. Interocular and directional gain asymmetries are also prevalent. The asymmetries provide further evidence that disruption of the utriculo-ocular pathway is a mechanism for Skew Deviation.
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Understanding Skew Deviation and a new clinical test to differentiate it from trochlear nerve palsy.
Journal of Aapos, 2010Co-Authors: Agnes M F WongAbstract:Summary Skew Deviation is a vertical strabismus caused by a supranuclear lesion in the posterior fossa. Because Skew Deviation may clinically mimic trochlear nerve palsy, it is sometimes difficult to differentiate the 2 conditions. In this review we compare the clinical presentations of Skew Deviation and trochlear nerve palsy and examine the pathophysiology that underlies Skew Deviation. We then describe a novel clinical test—the upright–supine test—to differentiate Skew Deviation from trochlear nerve palsy: a vertical Deviation that decreases by ≥50% from the upright to supine position suggests Skew Deviation and warrants investigation for a lesion in the posterior fossa as the cause of vertical diplopia.
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The Linear Vestibulo-Ocular Reflex in Patients with Skew Deviation
Investigative ophthalmology & visual science, 2008Co-Authors: Matthew Schlenker, Alan Blakeman, Giuseppe Mirabella, Herbert C. Goltz, Paul Kessler, Agnes M F WongAbstract:PURPOSE. The linear vestibulo-ocular reflex (LVOR) is mediated primarily by the otolith organs in the inner ear. Skew Deviation is a vertical strabismus believed to be caused by imbalance of otolithic projections to ocular motor neurons (disynaptically through the medial longitudinal fasciculus in the brain stem or polysynaptically through the cerebellum). The authors postulated that if Skew Deviation is indeed caused by damage to these projections, patients with Skew Deviation would show abnormal LVOR responses. METHODS. Six patients with Skew Deviation caused by brain stem or cerebellar lesions and 10 healthy subjects were recruited. All subjects underwent brief, sudden, interaural translations of the head (head heaves) using a head-sled device at an average peak acceleration of 0.42g (range, 0.1-1.1g) while continuously viewing an earth-fixed target monocularly at 15 and 20 cm. LVOR sensitivity (peak rotational eye velocity to peak linear head velocity) and velocity gain (peak actual-to-ideal rotational eye velocities) were calculated for the responses within the first 100 ms after onset of head movements. RESULTS. LVOR sensitivities and velocity gains in patients were decreased by 56% to 62% in both eyes compared with healthy subjects. This binocular reduction in LVOR responses was asymmetric-the magnitude of reduction differed between eyes by 37% to 143% for sensitivities and by 36% to 94% for velocity gains. There were no differences in response between right and left heaves. CONCLUSIONS. The binocular, asymmetric reduction in LVOR sensitivity and velocity gain provides support that imbalance in the otolith-ocular pathway is a mechanism of Skew Deviation.
Eric Eggenberger - One of the best experts on this subject based on the ideXlab platform.
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differentiating acute and subacute vertical strabismus using different head positions during the upright supine test
JAMA Ophthalmology, 2018Co-Authors: Joao Lemos, Adnan Subei, Cesar Nunes, Christopher C Glisson, Eric Eggenberger, Luis Cunha, Mário SousaAbstract:Importance: Accurate clinical differentiation between Skew Deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. Objective: To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute Skew Deviation vs 4NP. Design, Setting, and Participants: This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having Skew Deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. Main Outcomes and Measures: A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright - measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Results: Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with Skew Deviation and 18 (49%) with 4NP. Eighteen patients with Skew Deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with Skew Deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the Skew Deviation and 4NP groups for head tilt to the hypotropic eye (difference, -0.33 prism diopters; 95% CI, -0.43 to -0.20; P < .001). Cyclotorsion worsened in the supine position only in patients with Skew Deviation (hypertropic eye: difference, -7.6 prism diopters; 95% CI, -13.00 to -0.75; P = .01; hypotropic eye: difference, 8.2 prism diopters; 95% CI, 0 to 15.75; P = .03). Conclusions and Relevance: The upright-supine test with the head centered is not a sensitive method to separate acute or subacute Skew Deviation from 4NP. Conversion of an incomitant vertical Deviation in the upright position to a comitant vertical strabismus in the supine position in all head positions, as well as the absence of additional ocular motor and/or neurologic signs, may constitute a more useful clue.
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Differentiating Acute and Subacute Vertical Strabismus Using Different Head Positions During the Upright-Supine Test.
JAMA Ophthalmology, 2018Co-Authors: Joao Lemos, Adnan Subei, Cesar Nunes, Christopher C Glisson, Luis Cunha, Mário Sousa, Eric EggenbergerAbstract:Importance: Accurate clinical differentiation between Skew Deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. Objective: To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute Skew Deviation vs 4NP. Design, Setting, and Participants: This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having Skew Deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. Main Outcomes and Measures: A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright - measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Results: Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with Skew Deviation and 18 (49%) with 4NP. Eighteen patients with Skew Deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with Skew Deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the Skew Deviation and 4NP groups for head tilt to the hypotropic eye (difference, -0.33 prism diopters; 95% CI, -0.43 to -0.20; P
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Skew Deviation: clinical updates for ophthalmologists.
Current opinion in ophthalmology, 2014Co-Authors: Aditya Tri Hernowo, Eric EggenbergerAbstract:PURPOSE OF REVIEW: This article discusses the current approach in diagnosing Skew Deviation, as well as recent findings in the lesion localization. RECENT FINDINGS: Skew Deviation can be defined as vertical misalignment of the eyes that does not map to any of cyclovertical muscles, in association with neurologic symptoms and signs and with posterior fossa lesion. It can be differentiated from trochlear nerve palsy by the direction of ocular torsion and the change in the degree of vertical Deviation with upright and supine head position. It is commonly caused by ischemia of the posterior paramedian pons, medial thalamus, or cerebellum. Other less common mechanism being demyelinating lesion, mass effect, infection, hemorrhage, or intracranial hypertension. When the vestibular nuclei are involved, Skew Deviation may occur with acute vestibular syndrome. Ground-in or Fresnel prism may alleviate diplopia in relatively small vertical Deviation; however, patient with larger Deviation or with the presence of ocular torsion may benefit from surgery of the cyclovertical muscles. SUMMARY: Skew Deviation can be appropriately diagnosed from the nature of the ocular torsion and the vertical Deviation, along with the presence of lesion involving posterior paramedian pons and/or medial thalamus.
Michael C. Brodsky - One of the best experts on this subject based on the ideXlab platform.
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Something to sink your teeth into.
Survey of ophthalmology, 2011Co-Authors: Steven M. Couch, Scott E. Brodie, Jacqueline A. Leavitt, Michael C. BrodskyAbstract:Abstract A 21-year-old Kuwaiti man had cerebral palsy, retinitis pigmentosa, hypertension, and renal failure. His younger brother and sister displayed similar findings. Ocular motility examination disclosed aperiodic alternating Skew Deviation in the patient and his younger brother. Magnetic resonance imaging showed hypoplasia of the superior cerebellar vermis with a "molar tooth" sign. Genetic testing confirmed an AHPI gene mutation on chromosome 6p23.3 in the patient and his siblings, confirming the diagnosis of Joubert syndrome. This case demonstrates the need to consider the diagnosis of Joubert syndrome in adults with retinitis pigmentosa or familial alternating Skew Deviation.
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head position dependent changes in ocular torsion and vertical misalignment in Skew Deviation commentary
Archives of Ophthalmology, 2008Co-Authors: Manoj V. Parulekar, Agnes M F Wong, Shuan Dai, Raymond J Buncic, Michael C. BrodskyAbstract:Objectives: To investigate whether ocular torsion and vertical misalignment differ in the upright vs supine position in Skew Deviation and to compare these findings with those in trochlear nerve palsy. Methods: Ten patients with Skew Deviation, 14 patients with unilateral peripheral trochlear nerve palsy, and 12 healthy subjects were prospectively recruited. With subjects first in the upright position and then in the supine position, ocular torsion was measured by double Maddox rods and vertical misalignment was measured by the prism and alternate cover test. Results: In patients with Skew Deviation, the abnormal torsion and vertical misalignment in the upright position decreased substantially with change to the supine position, whereas in patients with trochlear nerve palsy, it changed little between positions. Torsion was decreased by 83% in patients with Skew Deviation, 2% in patients with trochlear nerve palsy, and 6% in healthy subjects (P <.001). Similarly, vertical misalignment was decreased by 74% in patients with Skew Deviation and increased by 5% in patients with trochlear nerve palsy and 6% in healthy subjects (P<.001). Conclusions: Our findings provide the basis for additional clinical tests to support the classic 3-step test: ocular torsion and vertical misalignment that decrease from the upright position to the supine position indicate Skew Deviation, whereas torsion and vertical misalignment that do not change significantly between positions indicate trochlear nerve palsy.
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Head Position-Dependent Changes in Ocular Torsion and Vertical Misalignment in Skew Deviation. Commentary
Archives of Ophthalmology, 2008Co-Authors: Manoj V. Parulekar, Agnes M F Wong, Shuan Dai, J. Raymond Buncic, Michael C. BrodskyAbstract:Objectives: To investigate whether ocular torsion and vertical misalignment differ in the upright vs supine position in Skew Deviation and to compare these findings with those in trochlear nerve palsy. Methods: Ten patients with Skew Deviation, 14 patients with unilateral peripheral trochlear nerve palsy, and 12 healthy subjects were prospectively recruited. With subjects first in the upright position and then in the supine position, ocular torsion was measured by double Maddox rods and vertical misalignment was measured by the prism and alternate cover test. Results: In patients with Skew Deviation, the abnormal torsion and vertical misalignment in the upright position decreased substantially with change to the supine position, whereas in patients with trochlear nerve palsy, it changed little between positions. Torsion was decreased by 83% in patients with Skew Deviation, 2% in patients with trochlear nerve palsy, and 6% in healthy subjects (P
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Skew Deviation revisited
Survey of ophthalmology, 2006Co-Authors: Michael C. Brodsky, Sean P. Donahue, Michael S. Vaphiades, Thomas BrandtAbstract:Skew Deviation is a vertical misalignment of the eyes caused by damage to prenuclear vestibular input to ocular motor nuclei. The resultant vertical ocular Deviation is relatively comitant in nature, and is usually seen in the context of brainstem or cerebellar injury from stroke, multiple sclerosis, or trauma. Skew Deviation is usually accompanied by binocular torsion, torticollis, and a tilt in the subjective visual vertical. This constellation of findings has been termed the ocular tilt reaction. In the past two decades, a clinical localizing value for Skew Deviation has been assigned, and a cogent vestibular mechanism for comitant and incomitant variants of Skew Deviation has been proposed. Our understanding of Skew Deviation as a manifestation of central otolithic dysfunction in different planes of three-dimensional space is evolving. The similar spectrum of vertical ocular Deviations arising in patients with congenital strabismus may further expand the nosology of Skew Deviation to include vergence abnormalities caused by the effects of early binocular visual imbalance on the developing visual system.
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Three dimensions of Skew Deviation.
The British journal of ophthalmology, 2003Co-Authors: Michael C. BrodskyAbstract:Are all Skew Deviations the clinical expressions of central vestibular dysfunction in three dimensional space? Skew means set, placed, or running obliquely; slanting.1 For a century, Skew Deviation has been the descriptive term for an acquired vertical Deviation that slants the interpupillary axis to an oblique orientation.2,3 This condition has traditionally connoted a severe and debilitating neurological injury within the posterior fossa.4, Subsequent investigation has refined our understanding of this disorder and expanded the boundaries of this diagnosis.5 Working over the past two decades, the promethean team of Brandt and Dieterich have established that Skew Deviation has a clinical localising value within the posterior fossa6,7; that it is a component of the ocular tilt reaction (a triad of Skew Deviation, binocular torsion, head tilt)7–9; and that it is associated with a tilt in the subjective visual vertical.8–11 These studies have supplanted our basic descriptive definition of Skew Deviation with a mechanistic understanding of this complex disorder. The underlying mechanism for Skew Deviation involves a unilateral lesion that inhibits (or occasionally stimulates) central otolithic pathways which run from the medulla to the mesencephalon.10,11 Since a physiological imbalance in central graviceptive tone is normally produced by a head or body tilt in the roll plane, this lesion produces the sensation of body tilt and evokes the same stimulus as is evoked by the Bielschowsky head tilt test.12 By activating prenuclear input to the superior rectus and superior oblique muscles of the ipsilateral eye, and the inferior rectus and oblique muscles of the contralateral eye, and by simultaneously inhibiting their antagonists, a cyclovertical divergence is produced, with intorsion of the higher eye, extorsion of the lower eye, and a corrective head tilt toward the side of the …
Joao Lemos - One of the best experts on this subject based on the ideXlab platform.
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differentiating acute and subacute vertical strabismus using different head positions during the upright supine test
JAMA Ophthalmology, 2018Co-Authors: Joao Lemos, Adnan Subei, Cesar Nunes, Christopher C Glisson, Eric Eggenberger, Luis Cunha, Mário SousaAbstract:Importance: Accurate clinical differentiation between Skew Deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. Objective: To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute Skew Deviation vs 4NP. Design, Setting, and Participants: This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having Skew Deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. Main Outcomes and Measures: A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright - measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Results: Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with Skew Deviation and 18 (49%) with 4NP. Eighteen patients with Skew Deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with Skew Deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the Skew Deviation and 4NP groups for head tilt to the hypotropic eye (difference, -0.33 prism diopters; 95% CI, -0.43 to -0.20; P < .001). Cyclotorsion worsened in the supine position only in patients with Skew Deviation (hypertropic eye: difference, -7.6 prism diopters; 95% CI, -13.00 to -0.75; P = .01; hypotropic eye: difference, 8.2 prism diopters; 95% CI, 0 to 15.75; P = .03). Conclusions and Relevance: The upright-supine test with the head centered is not a sensitive method to separate acute or subacute Skew Deviation from 4NP. Conversion of an incomitant vertical Deviation in the upright position to a comitant vertical strabismus in the supine position in all head positions, as well as the absence of additional ocular motor and/or neurologic signs, may constitute a more useful clue.
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Differentiating Acute and Subacute Vertical Strabismus Using Different Head Positions During the Upright-Supine Test.
JAMA Ophthalmology, 2018Co-Authors: Joao Lemos, Adnan Subei, Cesar Nunes, Christopher C Glisson, Luis Cunha, Mário Sousa, Eric EggenbergerAbstract:Importance: Accurate clinical differentiation between Skew Deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. Objective: To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute Skew Deviation vs 4NP. Design, Setting, and Participants: This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having Skew Deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. Main Outcomes and Measures: A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright - measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Results: Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with Skew Deviation and 18 (49%) with 4NP. Eighteen patients with Skew Deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with Skew Deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the Skew Deviation and 4NP groups for head tilt to the hypotropic eye (difference, -0.33 prism diopters; 95% CI, -0.43 to -0.20; P
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Differentiating Acute and Subacute Vertical Strabismus Using Different Head Positions During the Upright-Supine Test.
JAMA ophthalmology, 2018Co-Authors: Joao Lemos, Adnan Subei, Cesar Nunes, Christopher C Glisson, Luis Cunha, Mário Sousa, Eric R. EggenbergerAbstract:Importance Accurate clinical differentiation between Skew Deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. Objective To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute Skew Deviation vs 4NP. Design, Setting, and Participants This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having Skew Deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. Main Outcomes and Measures A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright − measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Results Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with Skew Deviation and 18 (49%) with 4NP. Eighteen patients with Skew Deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with Skew Deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the Skew Deviation and 4NP groups for head tilt to the hypotropic eye (difference, −0.33 prism diopters; 95% CI, −0.43 to −0.20;P Conclusions and Relevance The upright-supine test with the head centered is not a sensitive method to separate acute or subacute Skew Deviation from 4NP. Conversion of an incomitant vertical Deviation in the upright position to a comitant vertical strabismus in the supine position in all head positions, as well as the absence of additional ocular motor and/or neurologic signs, may constitute a more useful clue.
Manokaraananthan Chandrakumar - One of the best experts on this subject based on the ideXlab platform.
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ability of an upright supine test to differentiate Skew Deviation from other vertical strabismus causes
Archives of Ophthalmology, 2011Co-Authors: Agnes M F Wong, Linda Colpa, Manokaraananthan ChandrakumarAbstract:Objective To determine the sensitivity and specificity of a new upright-supine test to differentiate Skew Deviation from trochlear nerve palsy and other causes of vertical strabismus in a large number of patients. Methods The study consisted of 125 consecutive patients who sought treatment from January 1, 2008, through December 31, 2010, for vertical strabismus of various causes: Skew Deviation (25 patients), trochlear nerve palsy (58 patients), restrictive causes (14 patients), and other causes (eg, myasthenia gravis and childhood strabismus) (28 patients). Twenty healthy participants served as controls. The Deviation was measured by the prism and alternate cover test using a near target at ⅓ m in both the upright and supine positions. A vertical strabismus that decreased by 50% or more from the upright to supine position constituted a positive test result. Results The upright-supine test result was positive in 20 of 25 patients with Skew Deviation (sensitivity, 80%) but negative in all patients with trochlear nerve palsy, restrictive, or other causes (specificity, 100%). Conclusions The upright-supine test is highly specific for differentiating Skew Deviation from other causes of vertical strabismus. This test could be added as a fourth step after the 3-step test, and if the result is positive, neuroimaging should be considered if indicated clinically.
