Relation between epileptic activities and edema formation after cryogenic injury in the rabbit.

Although cryogenic lesions have been widely used as experimental models of either focal epilepsy or focal BE, the relation between these two disorders has never been discussed. In these experiments EA and gray matter edema were correlatively investigated during the early phase (1 to 23 hr) after a cryogenic lesion in the rabbit. Indexes were developed to allow a quantitative assessment of EA. The indexes demonstrated that the early phase of cryogenic epilepsy is a rapid phenomenon during the first 4-hr postlesion. Epileptic activity precedes BE, and in individual animals, there is a significant positive correlation between the total amount of EA and edema. EA and BE are most likely interrelated at the level of pathophysiological mechanisms. Excitotoxins and ions would be possible candidates mediating both phenomena.