Symptomatic intracranial steal.

The phenomenon of shunting of blood in association with various intracranial lesions is well known; however, usually clinical symptoms are attributable to the lesion and not to the redistribution of regional cerebral blood flow (rCBF). We report three patients investigated by angiography and rCBF studies in whom symptoms appeared to be due to a hemodynamic steal within one cerebral hemisphere, between hemispheres, and from the brain into a tumor, respectively.