[Experimental study on hypertensive crises in epileptic seizures--changes in pial artery diameter, intracranial pressure and regional cerebral blood flow].

It is well known that severe hypertension occurs during epileptic seizures, but little information is available concerning these hypertensive crises. We therefore investigated them by monitoring regional cerebral blood flow (rCBF), intracranial pressure (ICP) and pial artery diameter (PAD) in paralyzed mechanically-ventilated cats with penicillin-induced seizures. The animals were assigned to two groups. In one (Group H), they were maintained in an untreated state. In the other (Group C), spinal cord injury was performed in advance to prevent the rise in arterial blood pressure during the seizures. In both groups, the values of the various parameters increased during seizure activity, but the increases in group H, were greater than in group C. In both groups, PAD, rCBF and ICP increased immediately at the onset of the seizures with no hypertension. In group H, further increases in PAD, rCBF, and ICP were found concurrent with the elevation of arterial blood pressure in the latter half of the seizure, while in group C, rCBF decreased concurrent with the increase in ICP in the latter half of the seizure, although PAD was found to be maximal. These findings suggest that hypertensive crises during epileptic seizures represent a protective mechanism to maintain perfusion pressure.