Hemispheric venous dysgenesis in a woman presenting with seizures, weakness and parkinsonism.

This report describes an unusual case of a woman who developed progressive hemiparesis, seizures and hemiparkinsonism associated with MRI and angiographic evidence of chronic venous hypertension in the contralateral cerebrum and cerebellum. In the absence of inflammatory or veno-occlusive disorders, the patient's clinical and neuroradiological findings point to a developmental disorder, such as a hemispheric venous dysgenesis, as the underlying lesion.