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Eugen Boltshauser - One of the best experts on this subject based on the ideXlab platform.
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CLINICAL REPORT Interpeduncular Heterotopia in Joubert Syndrome: A Previously Undescribed MR Finding
2016Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesen-cephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration. ABBREVIATIONS: CNS central nervous system; GE gradient-echo; JSRD Joubert syndrome and related disorders; T1WI, T1-weighted imaging; T2WI T2-weighted imaging Joubert syndrome is a rare disorder (estimated prevalence1/100,000) with a characteristic complex malformation of themidbrain-hindbrain, seen as the so-calledmolar tooth sign on axial imaging. This results from vermis hypoplasia, a deep Interpeduncular Fossa and thickened, elongated, abnormally horizontal superior cerebellar peduncles.1 Joubert syndrom
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Pre- and Postnatal Neuroimaging of Congenital Cerebellar Abnormalities
The Cerebellum, 2016Co-Authors: Andrea Poretti, Eugen Boltshauser, Thierry A. G. M. HuismanAbstract:The human cerebellum has a protracted development that makes it vulnerable to a broad spectrum of developmental disorders including malformations and disruptions. Starting from 19 to 20 weeks of gestation, prenatal magnetic resonance imaging (MRI) can reliably study the developing cerebellum. Pre- and postnatal neuroimaging plays a key role in the diagnostic work-up of congenital cerebellar abnormalities. Diagnostic criteria for cerebellar malformations and disruptions are based mostly on neuroimaging findings. The diagnosis of a Dandy-Walker malformation is based on the presence of hypoplasia, elevation, and counterclockwise upward rotation of the cerebellar vermis and cystic dilatation of the fourth ventricle, which extends posteriorly filling out the posterior Fossa. For the diagnosis of Joubert syndrome, the presence of the molar tooth sign (thickened, elongated, and horizontally orientated superior cerebellar peduncles and an abnormally deep Interpeduncular Fossa) is needed. The diagnostic criteria of rhombencephalosynapsis include a complete or partial absence of the cerebellar vermis and continuity of the cerebellar hemispheres across the midline. Unilateral cerebellar hypoplasia is defined by the complete aplasia or hypoplasia of one cerebellar hemisphere. Familiarity with these diagnostic criteria as well as the broad spectrum of additional neuroimaging findings is important for a correct pre- and postnatal diagnosis. A correct diagnosis is essential for management, prognosis, and counseling of the affected children and their family.
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tecto cerebellar dysraphism with occipital encephalocele not a distinct disorder but part of the joubert syndrome spectrum
Neuropediatrics, 2011Co-Authors: Andrea Poretti, Eugen Boltshauser, Thierry A. G. M. Huisman, S Singhi, Avner Meoded, George I Jallo, Arzu Ozturk, Aylin TekesAbstract:Magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) findings in a 4-year-old child with occipital encephalocele, cerebellar vermis hypogenesis, and tectal malformation are presented. The neuroimaging findings are reminiscent of tectocerebellar dysraphism with an occipital encephalocele (TCD-OE). Additionally, elongated, thickened, and horizontally orientated superior cerebellar peduncles, an abnormally deepened Interpeduncular Fossa, subependymal heterotopia, and focal cortical dysplasia were noted. Color-coded fractional anisotropy (FA) maps revealed an absence of the decussation of the superior cerebellar peduncles. These findings are highly suggestive of Joubert syndrome and related disorders (JSRD). Our report and the review of the published cases suggest that TCD-OE is not a nosological entity, but may represent the structural manifestation of heterogeneous disorders such as the JSRD spectrum. DTI may be very helpful to differentiate between similar midbrain-hindbrain malformations.
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Interpeduncular heterotopia in Joubert syndrome: A previously undescribed MR finding
AJNR. American journal of neuroradiology, 2011Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesencephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration.
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rhombencephalosynapsis associated with dandy walker malformation is a molar tooth malformation
Journal of Neuroimaging, 2009Co-Authors: Andrea Poretti, Eugen BoltshauserAbstract:We have previously reported the largest pediatric series (n = 9) of rhombencephalosynapsis (RS),1 and we are currently reviewing and updating our patients with RS and the syndromic form Gomez-Lopez-Hernandez syndrome. Therefore, we read with interest the case report by R.N. Sener entitled “Rhombencephalosynapsis associated with Dandy-Walker malformation.”2 We do not agree with Sener’s neuroimaging interpretation of RS: there is no fusion of the cerebellar hemispheres, in contrast, these are clearly separated, particularly evident on coronal cuts. The superior cerebellar peduncles are not fused, as required within the definition of RS, but they are even widely separated. We consider the following alternative neuroimaging interpretation: there is clear evidence of a molar tooth sign (MTS) on axial view, with deep Interpeduncular Fossa, narrow pontomesencephalic isthmus, and elongated superior cerebellar peduncles.3 We have seen this identical MRI constellation in 3 infants (2 of them siblings of consanguineous parents). Remarkably, all infants had an occipital encephalocele, as had Sener’s patient. Parental consanguinity of his patient and the presence of bilateral optic nerve coloboma are additional arguments in favor of a disorder within the spectrum of Joubert syndrome and related disorders (JSRD).4 The interpretation of neuroimaging findings may be relevant for genetic counseling: so far all patients with RS were sporadic, while JSRD are inherited as autosomal recessive. In Sener’s and our patients the superior cerebellar peduncles are thinner than in typical MTS. However, some variability in the MTS morphology within JSRD is well known (see figures in ref. 3), in particular patients with NPHP1 (nephronophthisis 1) gene deletion tend to have thinner superior cerebellar peduncles.4-6
Andrea Poretti - One of the best experts on this subject based on the ideXlab platform.
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CLINICAL REPORT Interpeduncular Heterotopia in Joubert Syndrome: A Previously Undescribed MR Finding
2016Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesen-cephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration. ABBREVIATIONS: CNS central nervous system; GE gradient-echo; JSRD Joubert syndrome and related disorders; T1WI, T1-weighted imaging; T2WI T2-weighted imaging Joubert syndrome is a rare disorder (estimated prevalence1/100,000) with a characteristic complex malformation of themidbrain-hindbrain, seen as the so-calledmolar tooth sign on axial imaging. This results from vermis hypoplasia, a deep Interpeduncular Fossa and thickened, elongated, abnormally horizontal superior cerebellar peduncles.1 Joubert syndrom
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Pre- and Postnatal Neuroimaging of Congenital Cerebellar Abnormalities
The Cerebellum, 2016Co-Authors: Andrea Poretti, Eugen Boltshauser, Thierry A. G. M. HuismanAbstract:The human cerebellum has a protracted development that makes it vulnerable to a broad spectrum of developmental disorders including malformations and disruptions. Starting from 19 to 20 weeks of gestation, prenatal magnetic resonance imaging (MRI) can reliably study the developing cerebellum. Pre- and postnatal neuroimaging plays a key role in the diagnostic work-up of congenital cerebellar abnormalities. Diagnostic criteria for cerebellar malformations and disruptions are based mostly on neuroimaging findings. The diagnosis of a Dandy-Walker malformation is based on the presence of hypoplasia, elevation, and counterclockwise upward rotation of the cerebellar vermis and cystic dilatation of the fourth ventricle, which extends posteriorly filling out the posterior Fossa. For the diagnosis of Joubert syndrome, the presence of the molar tooth sign (thickened, elongated, and horizontally orientated superior cerebellar peduncles and an abnormally deep Interpeduncular Fossa) is needed. The diagnostic criteria of rhombencephalosynapsis include a complete or partial absence of the cerebellar vermis and continuity of the cerebellar hemispheres across the midline. Unilateral cerebellar hypoplasia is defined by the complete aplasia or hypoplasia of one cerebellar hemisphere. Familiarity with these diagnostic criteria as well as the broad spectrum of additional neuroimaging findings is important for a correct pre- and postnatal diagnosis. A correct diagnosis is essential for management, prognosis, and counseling of the affected children and their family.
-
tecto cerebellar dysraphism with occipital encephalocele not a distinct disorder but part of the joubert syndrome spectrum
Neuropediatrics, 2011Co-Authors: Andrea Poretti, Eugen Boltshauser, Thierry A. G. M. Huisman, S Singhi, Avner Meoded, George I Jallo, Arzu Ozturk, Aylin TekesAbstract:Magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) findings in a 4-year-old child with occipital encephalocele, cerebellar vermis hypogenesis, and tectal malformation are presented. The neuroimaging findings are reminiscent of tectocerebellar dysraphism with an occipital encephalocele (TCD-OE). Additionally, elongated, thickened, and horizontally orientated superior cerebellar peduncles, an abnormally deepened Interpeduncular Fossa, subependymal heterotopia, and focal cortical dysplasia were noted. Color-coded fractional anisotropy (FA) maps revealed an absence of the decussation of the superior cerebellar peduncles. These findings are highly suggestive of Joubert syndrome and related disorders (JSRD). Our report and the review of the published cases suggest that TCD-OE is not a nosological entity, but may represent the structural manifestation of heterogeneous disorders such as the JSRD spectrum. DTI may be very helpful to differentiate between similar midbrain-hindbrain malformations.
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Interpeduncular heterotopia in Joubert syndrome: A previously undescribed MR finding
AJNR. American journal of neuroradiology, 2011Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesencephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration.
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rhombencephalosynapsis associated with dandy walker malformation is a molar tooth malformation
Journal of Neuroimaging, 2009Co-Authors: Andrea Poretti, Eugen BoltshauserAbstract:We have previously reported the largest pediatric series (n = 9) of rhombencephalosynapsis (RS),1 and we are currently reviewing and updating our patients with RS and the syndromic form Gomez-Lopez-Hernandez syndrome. Therefore, we read with interest the case report by R.N. Sener entitled “Rhombencephalosynapsis associated with Dandy-Walker malformation.”2 We do not agree with Sener’s neuroimaging interpretation of RS: there is no fusion of the cerebellar hemispheres, in contrast, these are clearly separated, particularly evident on coronal cuts. The superior cerebellar peduncles are not fused, as required within the definition of RS, but they are even widely separated. We consider the following alternative neuroimaging interpretation: there is clear evidence of a molar tooth sign (MTS) on axial view, with deep Interpeduncular Fossa, narrow pontomesencephalic isthmus, and elongated superior cerebellar peduncles.3 We have seen this identical MRI constellation in 3 infants (2 of them siblings of consanguineous parents). Remarkably, all infants had an occipital encephalocele, as had Sener’s patient. Parental consanguinity of his patient and the presence of bilateral optic nerve coloboma are additional arguments in favor of a disorder within the spectrum of Joubert syndrome and related disorders (JSRD).4 The interpretation of neuroimaging findings may be relevant for genetic counseling: so far all patients with RS were sporadic, while JSRD are inherited as autosomal recessive. In Sener’s and our patients the superior cerebellar peduncles are thinner than in typical MTS. However, some variability in the MTS morphology within JSRD is well known (see figures in ref. 3), in particular patients with NPHP1 (nephronophthisis 1) gene deletion tend to have thinner superior cerebellar peduncles.4-6
Ali F Krisht - One of the best experts on this subject based on the ideXlab platform.
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dividing the posterior communicating artery in approaches to the Interpeduncular Fossa technical aspects and safety
Neurosurgery, 2007Co-Authors: Niklaus Krayenbuhl, Ali F KrishtAbstract:OBJECTIVE: Cutting the posterior communicating artery (PComA) can improve the neurosurgeon's view and maneuverability while performing surgery within the Interpeduncular Fossa. Although mentioned in some reports, its technique and safety have not been studied in detail thus far. METHODS: Patients undergoing surgery for vascular and neoplastic lesions in the Interpeduncular Fossa in which the PComA was cut were retrospectively analyzed regarding the location where the PComA was divided, the size of the PComA in relation to the posterior cerebral artery, and the vascular risk factors. Clinical and radiological outcomes and the related complications were recorded and analyzed. RESULTS: The PComA was divided in 25 patients, and was operated on for vascular (in 23 patients) and neoplastic (in 2 patients) lesions. The PComA was divided at a perforator-free-zone. This zone was most commonly located at the junction of the PComA and the posterior cerebral artery (88% of patients). One patient had delayed postoperative bleeding from the divided PComA stump. There were no ischemic complications either in the territory of the PComA perforator or in the posterior cerebral artery. CONCLUSION: This is the largest reported experience with dividing the PComA. It shows that this surgical step is safe and that it constitutes an important option to help improve the exposure, maneuverability, and safety of surgery in the region of the Interpeduncular Fossa.
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the perforator free zone of the posterior communicating artery and its relevance in approaches to the Interpeduncular cistern especially the transcavernous approach an anatomic study
Neurosurgery, 2007Co-Authors: Debbie Beumer, Ernstjan Delwel, Gertjan Kleinrensink, Sadek Akouri, Alberto Torres, Ali F KrishtAbstract:Objective Because the microsurgical working space in the Interpeduncular Fossa is very narrow, using different surgical approaches such as the pterional approach and/or the pretemporal transcavernous approach in combination with a division of the posterior communicating artery (PComm) at the longest perforator-free zone (PFZ) can help to enlarge the microscopic field of view and the working space in this area of the brain. Methods In this microanatomic study, the variability of several parameters of the PComm, especially the location of the longest PFZ of the PComm, was examined and described in 23 cadaveric heads. Results In most cases, the mean length of the longest PFZ was found to be between 2 and 6 mm. In 80% of the cases, the longest PFZ was located closer to the posterior cerebral artery than to the internal carotid artery. A total of 82.5% of all the PComms measured were of the adult type. In 55% of all arteries, a premamillary artery was identified. When a short and adult-type PComm obscures the microscopic view of the operative field, dividing the PComm is mandatory. In other situations, dividing the PComm is facultative. Because the PComm is usually predominantly irrigated by the internal carotid artery, it is of hemodynamic advantage that the longest PFZ is typically located closest to the posterior cerebral artery. Conclusion On the basis of this descriptive anatomic study, we conclude that when it is needed, division of an adult-type PComm at the longest PFZ is usually feasible and results in a low risk of compromising the blood flow to the branching perforators of the PComm.
Ricardo L Carrau - One of the best experts on this subject based on the ideXlab platform.
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Anatomic comparison of the endonasal and transpetrosal approaches for Interpeduncular Fossa access
Neurosurgical focus, 2014Co-Authors: Kenichi Oyama, Daniel M Prevedello, Leo F. S. Ditzel Filho, Jun Muto, Ramazan Gun, Edward E. Kerr, Bradley A. Otto, Ricardo L CarrauAbstract:Object The Interpeduncular cistern, including the retrochiasmatic area, is one of the most challenging regions to approach surgically. Various conventional approaches to this region have been described; however, only the endoscopic endonasal approach via the dorsum sellae and the transpetrosal approach provide ideal exposure with a caudal-cranial view. The authors compared these 2 approaches to clarify their limitations and intrinsic advantages for access to the Interpeduncular cistern Methods Four fresh cadaver heads were studied. An endoscopic endonasal approach via the dorsum sellae with pituitary transposition was performed to expose the Interpeduncular cistern. A transpetrosal approach was performed bilaterally, combining a retrolabyrinthine presigmoid and a subtemporal transtentorium approach. Water balloons were used to simulate space-occupying lesions. “Water balloon tumors” (WBTs), inflated to 2 different volumes (0.5 and 1.0 ml), were placed in the Interpeduncular cistern to compare visualizatio...
I. Harting - One of the best experts on this subject based on the ideXlab platform.
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CLINICAL REPORT Interpeduncular Heterotopia in Joubert Syndrome: A Previously Undescribed MR Finding
2016Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesen-cephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration. ABBREVIATIONS: CNS central nervous system; GE gradient-echo; JSRD Joubert syndrome and related disorders; T1WI, T1-weighted imaging; T2WI T2-weighted imaging Joubert syndrome is a rare disorder (estimated prevalence1/100,000) with a characteristic complex malformation of themidbrain-hindbrain, seen as the so-calledmolar tooth sign on axial imaging. This results from vermis hypoplasia, a deep Interpeduncular Fossa and thickened, elongated, abnormally horizontal superior cerebellar peduncles.1 Joubert syndrom
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Interpeduncular heterotopia in Joubert syndrome: A previously undescribed MR finding
AJNR. American journal of neuroradiology, 2011Co-Authors: I. Harting, Andrea Poretti, U. Kotzaeridou, A. Seitz, J. Pietz, M. Bendszus, Eugen BoltshauserAbstract:SUMMARY: The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the Interpeduncular Fossa, which in one patient was combined with a more extensive intramesencephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the Interpeduncular heterotopia results from misdirected migration.
