Cerebral and extracerebral blood volume in generalized seizures in the baboon Papio papio

Relative variations of the cerebral and extracerebral blood volume (CBV) were measured continuously by a novel atraumatic method in baboons to explore the relationship between changes in the systemic circulation and in the cerebral (and extracerebral) vascular responses, before, during and after generalized seizures induced by photic stimulation. Major bursts of generalized spikes and waves are accompanied by an increase of the mean arterial pressure and of the cerebral blood volume and a decrease of the nasal blood volume. During the seizure discharge a substantial increase in CBV occurs, associated with a dramatic increase in arterial pressure. However, the greatest increase in CBV occurs after the peak mean arterial pressure. The results show that the CBV does not passively follow the blood pressure and demonstrate the dramatic responsiveness of the nasal region to seizure discharge.