The early phase of cryogenic lesions: an experimental model of seizures updated.

Following cryogenic lesions in 64 rabbits, epileptic activity and gray matter edema were correlatively investigated during the initial phase (23 h). Indexes were developed to allow a quantitative assessment of epileptic activity. The indexes demonstrated that the early phase of cryogenic epilepsy is a very rapid phenomenon during the first 4 h postlesion. Epileptic activity precedes brain edema, and in individual animals, there is a significant positive correlation between the total amount of epileptic activity and the total amount of edema. The relationship between epileptic activity and brain edema are most likely interrelated at the level of pathophysiological mechanisms and several mechanisms can be postulated.