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Molar tooth sign with ataxia and see-saw nystagmus (Joubert syndrome).

Byju N, Jose J, Saifudheen K, Musthafa M - Ann Indian Acad Neurol (2011)

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Medical College, Calicut, Kerala, India.

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Patient had two siblings, one brother and one sister... A detailed neurological examination on them did not reveal any abnormality... His magnetic resonance imaging (MRI) of brain showed vermian agenesis [Figure 1], which is thick and maloriented superior cerebellar peduncles with deep interpeduncular fossa forming the molar tooth appearance [Figure 2]... On the basis of the clinical and MRI findings, a diagnosis of Joubert syndrome was made... Classical Joubert syndrome is characterized by Molar tooth sign in MRI, hypotonia, developmental delay/mental retardation, oculomotor apraxia, and breathing abnormalities... The main oculomotor anomalies described in this syndrome include occulomotor apraxia, decreased smooth pursuit gain and vestibulo-ocular reflexes, hypometric volitional saccades, optic nerve dysplasia, severe visual loss, pendular see-saw nystagmus, gaze-holding nystagmus, and pigmentary changes in the fundus... See-saw nystagmus is an uncommon and interesting eye movement disorder found in this condition characterized by cyclic movement of the eye with conjugate torsional component and disjunctive vertical component... The pathognomonic neuroradiological finding in Joubert syndrome and related disorders is the molar tooth sign-with its three components; partial or complete absence of vermice, thickened and elongated superior cerebellar peduncles, and deepened interpeduncular fossa... Lack of normal decussation of the superior cerebellar peduncular fibres leads to enlargement of peduncles, which follow a more horizontal course extending perpendicular to the brainstem between the midbrain and cerebellum... The absence of crossing fibres is also responsible for decreased anteroposterior diameter of the brainstem and deep interpeduncular cistern... The absence of normal vermis creates a midline cleft between two normal appearing cerebellar hemispheres resulting in a characteristic ‘batwing’ appearance of the fourth ventricle on axial MR images.

No MeSH data available.


Axial T1 weighted image at the level of the upper pons showing bat-wing morphology of fourth ventricle (white arrow).
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Figure 0003: Axial T1 weighted image at the level of the upper pons showing bat-wing morphology of fourth ventricle (white arrow).

Mentions: His blood and urine routine examinations including renal function and liver function tests were normal. Ultrasonogram of abdomen was normal. His magnetic resonance imaging (MRI) of brain showed vermian agenesis [Figure 1], which is thick and maloriented superior cerebellar peduncles with deep interpeduncular fossa forming the molar tooth appearance [Figure 2]. Fourth ventricle showed a batwing appearance at the level of pons [Figure 3] and the mid sagittal images showed a high position of the ventricles with curved roof [Figure 4]. On the basis of the clinical and MRI findings, a diagnosis of Joubert syndrome was made.


Molar tooth sign with ataxia and see-saw nystagmus (Joubert syndrome).

Byju N, Jose J, Saifudheen K, Musthafa M - Ann Indian Acad Neurol (2011)

Axial T1 weighted image at the level of the upper pons showing bat-wing morphology of fourth ventricle (white arrow).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108085&req=5

Figure 0003: Axial T1 weighted image at the level of the upper pons showing bat-wing morphology of fourth ventricle (white arrow).
Mentions: His blood and urine routine examinations including renal function and liver function tests were normal. Ultrasonogram of abdomen was normal. His magnetic resonance imaging (MRI) of brain showed vermian agenesis [Figure 1], which is thick and maloriented superior cerebellar peduncles with deep interpeduncular fossa forming the molar tooth appearance [Figure 2]. Fourth ventricle showed a batwing appearance at the level of pons [Figure 3] and the mid sagittal images showed a high position of the ventricles with curved roof [Figure 4]. On the basis of the clinical and MRI findings, a diagnosis of Joubert syndrome was made.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Medical College, Calicut, Kerala, India.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Patient had two siblings, one brother and one sister... A detailed neurological examination on them did not reveal any abnormality... His magnetic resonance imaging (MRI) of brain showed vermian agenesis [Figure 1], which is thick and maloriented superior cerebellar peduncles with deep interpeduncular fossa forming the molar tooth appearance [Figure 2]... On the basis of the clinical and MRI findings, a diagnosis of Joubert syndrome was made... Classical Joubert syndrome is characterized by Molar tooth sign in MRI, hypotonia, developmental delay/mental retardation, oculomotor apraxia, and breathing abnormalities... The main oculomotor anomalies described in this syndrome include occulomotor apraxia, decreased smooth pursuit gain and vestibulo-ocular reflexes, hypometric volitional saccades, optic nerve dysplasia, severe visual loss, pendular see-saw nystagmus, gaze-holding nystagmus, and pigmentary changes in the fundus... See-saw nystagmus is an uncommon and interesting eye movement disorder found in this condition characterized by cyclic movement of the eye with conjugate torsional component and disjunctive vertical component... The pathognomonic neuroradiological finding in Joubert syndrome and related disorders is the molar tooth sign-with its three components; partial or complete absence of vermice, thickened and elongated superior cerebellar peduncles, and deepened interpeduncular fossa... Lack of normal decussation of the superior cerebellar peduncular fibres leads to enlargement of peduncles, which follow a more horizontal course extending perpendicular to the brainstem between the midbrain and cerebellum... The absence of crossing fibres is also responsible for decreased anteroposterior diameter of the brainstem and deep interpeduncular cistern... The absence of normal vermis creates a midline cleft between two normal appearing cerebellar hemispheres resulting in a characteristic ‘batwing’ appearance of the fourth ventricle on axial MR images.

No MeSH data available.