3-year-old male with a history of cerebral palsy and left hemiplegia. There is a large right extra-axial fluid collection within the right frontotemporal region, which communicates with the ventricular system via the lateral aspect of the lateral right lateral ventricle. The communication is lined by gray matter compatible with schizencephaly. There is mass effect on the adjacent right sided brain parenchyma as well as the right lateral ventricle from the fluid collection, 3 mm of midline shift, as well subtle osseous remodeling with slight enlargement of the right middle cranial fossa and hemicranium overall. There is no associated susceptibility or diffusion-weighted abnormality. The absence of traversing vessels coursing through the fluid collection indicate that much of this fluid collection is likely within the subdural space although likely communicating with the subarachnoid space. For reference, the diameter of the fluid component in the right middle cranial fossa measures 42 mm and and the diameter in the right frontal region is 30 mm.There is also some probable remodeling along the anterior floor of the right anterior cranial fossa with the right gyrus rectus located slightly more caudally compared to the contralateral side, again likely secondary to the chronic fluid collection and resultant mass effect. The right frontal and temporal lobes and somewhat dysmorphic and hypoplastic secondary to the chronic mass effect. There are areas of gyral thickening and possible micronodular appearance along the cleft within the right inferior frontal lobe that are suggestive of polymicrogyria. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
1.Findings compatible with a right frontotemporal open lipped schizencephaly in communication with the right lateral ventricle. Suspected polymicrogyria along the cleft, which could be better evaluated with 3-D T1 imaging.2.Large chronic right lateral extra-axial frontotemporal fluid collection possibly from a ball and valve mechanism between the subarachnoid and subdural spaces which results in significant mass effect on the adjacent brain parenchyma as well as chronic remodeling of the right hemicranium.