Unilateral cerebellar hypoplasia.

In a 48-year-old man, marked unilateral cerebellar hypoplasia was diagnosed by CT scans and angiographic examinations, later confirmed on autopsy. Clinical findings in cerebellar hypoplasia/aplasia are discussed here, along with the pathogenesis of cerebellar hypoplasia. In this case, several grand mal seizures and persistent headache were the only neurological symptoms. Repeated neurologic explorations did not reveal any abnormality. The clear demonstration of cerebellar hypoplasia associated with ipsilateral hypoplasia of the vertebral artery favors the concept of a vascular genesis of cerebellar hypoplasia/aplasia.