Cranial impedance plethysmography-rheoncephalography as a method of detection of cerebrovascular disease.

Rheoencephalography, the monitoring of cerebral blood flow by impedance methods, has been used successfully in clinical medicine in Europe and Russia but not in the United States. Three cases are presented to demonstrate the potential value of this method in the diagnosis of cerebrovascular pathology. These cases also demonstrate that the method appears to monitor intracranial circulation in humans. The first case of the subclavian steal syndrome second to any extravascular occlusion disease is presented.