Hemimegalencephaly is a rare brain malformation characterized by cerebral asymmetry and cortical dysplasia. Infants with the condition present with early seizures and severe encephalopathy. Five patients were studied with computed tomography and magnetic resonance (MR) imaging. MR imaging was the most efficient diagnostic method for this rare entity. It demonstrated brain hemispheric hypertrophy with lateral ventricle dilatation, abnormal gyral pattern, and a thick cortex on the enlarged side. The images correlate well with the known pathologic data.
This is a report of seven cases of aneurysm of the vein of Galen (AVG) with a review of the clinical and radiological aspects of 48 cases in the literature. The natural evolution and pathophysiology of this vascular malformation are discussed. The clinical signs of this condition are often misleading. The appearance of AVG on CT is pathognomic. Surveillance of the vascular malformation and associated cerebral lesions can be maintained with subsequent CT. Spontaneous thrombosis of the aneurysm was observed in three cases. The diagnosis of thrombosis of the AVG was always made at operation or by histological examination. The radiological appearance of a thrombosed aneurysm is typical.
We report five patients with pontoneocerebellar hypoplasia. Because the issue of cerebellar malformations is a difficult subject, we tried to define criteria for diagnosis on MRI: a thin flat pons with disappearance of the anterior curve, a small cerebellum with predominant flattening of the hemispheres and shortened cerebellar fissures, in contrast to atrophy. The posterior fossa is not enlarged. We emphasize the probable late onset of the disease in fetal life because of the demonstration of the abnormalities at US during the last trimester of the pregnancy in one patient. Prenatal diagnosis is important because of possible autosomal recessive transmission.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.