Neuropathologic and MR imaging correlation in a neonatal case of cerebellar cortical dysplasia

Abstract

Little documentation of the correlation between MR imaging findings in isolated cerebellar cortical dysplasia (CCD) and its neuropathologic characteristics exists in the recent literature. We documented a postmortem neuropathologic study of a clinically and radiologically well-documented case of CCD in a neonate with severe hypotonia and status epilepticus. MR imaging revealed a global vermian hypoplasia with marked cortical dysplasia. CCD was associated with a voluminous heterotopic mass. The postmortem neuropathologic study confirmed vermian hypoplasia and CCD, which consisted of right cerebellar cortical polymicrogyria with subcortical heterotopia. CCD is a pathologic entity that could be well diagnosed with MR imaging even in the neonatal period.

Fig 1.

MR images in CCD associated with heterotopic and vermian hypoplasia. A, Axial T2-weighted image (5000/12/2 [TR/TE/NEX]) shows vertically oriented and disorganized folia (white arrows) in the posteroinferior part of the hemisphere. B, Coronal T2-weighted image (5000/120/2) shows vertically oriented fissures (black arrow) in the cerebellar cortex, consistent with the diagnosis of CCD. Note cerebellar white matter hyperintensity (white dot) and heterotopia (white arrow).

Fig 2.

Coronal microscopic sections (posterior to anterior view) of the cerebellar lesions at vermian (top) and hemispheric (bottom) levels show vermian hypoplasia with irregularly shaped foliation. A large central multinodular conglomerate (arrows) corresponding to juxtaposed ectopic polymicrogeria nodules is seen in the right hemisphere and vermis.

Fig 3.

Histologic sections in CCD associated with heterotopic and vermian hypoplasia. A, Vermis and right cerebellar hemisphere show abnormal cerebellar lamella associated with typical polymicrogyria: deep folding of the cerebellar surface (black arrows). Note the heterotopic aspect of polymicrogyria in the white matter: cavities appear obliterated (white arrows). (Luxor blue stain, original magnification ×25.) B, Right cerebellar hemisphere shows abnormally large cerebellar folia (as in premature cerebellum) (white arrows) associated with a large nodule of compact polymicrogyria with obliterated cavities and containing mixed cells (spindle, granular cells, and large neurons) (black arrows). (Luxol blue stain, original magnification ×50.)