Inborn metabolic brain disorders

Q.All are true regarding inborn metabolic brain disorders except

a. Alexander's disease shows  extensive white matter abnormality beginning in the frontal and periventricular white matter

b. l-2 hydroxyglutaricaciduria  involve   the periventricular white matter and corpus callosum

c. bilateral symmetrical involvement of the globus pallidus with sparing of the thalami is seen in methylmalonic acidaemia

d. Bilateral pallidal involvement is  seen as T2 hyperintensity  in Kearns–Sayer syndrome

e. Lorenzo's oil may delay disease progression of ALD

ANS .---b

The MRI findings of  l-2 hydroxyglutaricaciduria show white matter involvement with peripheral involvement, particularly of the subcortical U fibres, internal, external and extreme capsules, sparing of the periventricular white matter and corpus callosum, and with a slight frontal predominance. There is macrocephaly

Bilateral pallidal involvement is  seen as T2 hyperintensity in methylmalonic acidaemia ,GAMT (guanidinoacetate methyltransferase deficiency), Kearns–Sayer syndrome ,kernicterus and carbon monoxide poisoning

Rasmussen encephalitis

Q.All are true regarding Rasmussen encephalitis except

a. an abrupt onset of severe and intractable epilepsy

b. usually begins in childhood(6 and 8 years )

c. tends to affect hemisphere bilaterally

d. Serial scans show focal or hemispheric atrophy

e. cortical swelling with hyperintensity on T2W--earliest change on MRI--

ANS.----c

The disease tends to affect one hemisphere. Classification and staging criteria have been proposed based on MR imaging findings on T2-weighted and FLAIR images: normal volume and signal (stage 0), swelling and hyperintense signal (stage 1), normal volume and hyperintense signal (stage 2), atrophy and hyperintense signal (stage 3), and progressive atrophy and normal signal (stage 4).

Brain malformations

Q.All are true regarding  brain malformations except

a. The posterior fossa is of normal size in cerebellar hypoplasia

b. Torcular–lambdoid inversion on MRI is seen in Dandy –Walker

syndrome

c.  ‘batwing appearance’ of the fourth ventricle  is seen in Joubert's

 syndrome

d.The ‘Molar   tooth’ appearance is noted  in

rhombencephalosynapsis

 

e. a nonenhancing mass with diffusely enlarged cerebellar folia is 

feature of  L'Hermitte-Duclos
ANS.---d

Joubert's syndrome  is  considered  as generalized developmental disorder of the midbrain and hindbrain. The imaging findings reflect a failure of formation of the decussation of the superior cerebellar peduncles, lack of the pyramidal decussations and other anomalies of the midbrain crossing tracts and their nuclei. On cross-sectional imaging the fourth ventricle is enlarged with a ‘batwing appearance’ and there is a cleft in the vermis. The midbrain is small. The ‘molar tooth’ appearance seen on axial images arises from the lack of the superior cerebellar decussation and the superior peduncles also appear enlarged.