Hypothalamic Seizures From Stimulation of Rhinencephalon and Isocortex in Cat

Abstract

Hypo-thalamic seizure activity can be elicited by stimulation of the amygdala, hippocampus, hippocampal gyrus, septum and basal olfactory structures. The ventromedial hypothalamic nucleus shows the most prominent ictal after-discharge to all the above structures except to stimulation of the dorsal hippocampus which principally affects the mammillary body. Stimulation of the posterior portion of the lateral amygdaloid nucleus produces longer seizure activity in the hypothalamus than do anterior portions of this nucleus. Repeated constant stimulations of the same structure may result in seizures of varying character in the hypothalamus. Not all dorsolateral areas of isocortex are epileptogenic for the hypothalamus. Epileptogenic areas are located in the temporal and occipital regions, the anterior and posterior ectosylvian, posterior inferior ectosylvian, posterior suprasylvian and posterior lateral gyri specifically. Other areas can become epileptogenic with respect to the hypothalamus only when much stronger stimuli are used, and after spread to temporal and occipital areas occurs.