FRCR mcq ------Cortical malformation

230.All are true regarding malformation of cortical development except

a. dysembryoplastic neuroepithelial tumor is a glial abnormalities

b. tuberous sclerosis shows abnormal neuronal proliferation

c. hemimegalencephaly has contralateral ventricular enlargement,

d. cortical thickening and radial bands extending toward the ventricle noted in tuberous sclerosis

e. balloon cell focal cortical dysplasia of Taylor appears hyperintense on T2W

230.---c

 Features of hemimegalencephaly include hemispheric enlargement (or a portion of it), white matter hyperintensity, ipsilateral ventricular enlargement, heterotopia, and thickened cortex.

Glial abnormalities consist of developmental neoplasms such as dysembryoplastic neuroepithelial tumor , ganglioglioma, and gangliocytoma. These abnormalities are usually cortical in location and appear as focal lesions on MR, often with a cystic component.

 Abnormal neuronal proliferation is typified by disorders with “balloon cell” proliferation , such as tuberous sclerosis, balloon cell focal cortical dysplasia of Taylor, and hemimegalencephaly.

Balloon cells are large progenitor cells with both neural and glial characteristics.

The imaging findings in balloon cell focal cortical dysplasia(type II focal cortical dysplasia) and tuberous sclerosis are similar . Both have hyperintense cortical lesions on T2-weighted images, often with cortical thickening and radial bands extending toward the ventricle.

However, unlike tuberous sclerosis, the balloon cell focal cortical dysplasia is not associated with multiplicity of cortical lesions, subependymal nodules, or systemic manifestations (such as the cardiac, renal, and dermatologic abnormalities found in tuberous sclerosis).

Because of focal hyperintensity on T2-weighted images, balloon cell cortical dysplasia may mimic a tumor. Other features of balloon cell dysplasia (i.e., cortical thickening, homogeneous bright signal in subcortical white matter, and radial bands) facilitate the distinction . This differentiation may be crucial for surgical management