Partial hydrocephalus with chronic subdural hematoma.

Two adult patients with unilateral chronic subdural hematomas are reported because of the presence of dilatation of the lateral ventricle opposite the hematoma. In both cases, dilatation was limited to the contralateral atrium and the occipital and temporal horns. The selective dilatation, we believe, is explained on the basis of the anatomy of the skull base and the falx. This phenomenon may contribute to an increase of the supratentorial pressure, originally elevated by the hematoma. This characteristic finding on computed tomographic scans should be regarded as critical in cases of chronic subdural hematoma.