Abstract
Postoperative resolution of neurological symptoms was assessed in eight patients with chronic subdural hematoma by means of noninvasive skull impedance plethysmography. A control population comprising 20 normal adults was also studied. Preoperatively, in comparison with the control subjects, the patients with chronic subdural hematoma had much higher intracranial pressure, considerably reduced mean cerebral blood flow, greater cerebrovascular resistance, a longer cerebrovascular conduction time, and somewhat lower cerebrovascular compliance and cerebral perfusion pressure. The differences in the last five parameters reflect pathophysiological changes due to elevated intracranial pressure in the hematoma patients. Among those who showed neurological improvement after surgery, the most dramatic changes, as demonstrated by a 5-minute 3% CO2 inhalation test, were mean increases in mean cerebral blood flow of 106.7% and in cerebrovascular compliance of 101.5%. Among the patients who responded poorly to surgery, the corresponding mean increases were only 44.5% and 46.5%, respectively.
