Effects of ultrasonic radiation in experimental focal epilepsy in the cat

Experimental focal epilepsy was induced in thirty-seven cats by subcortical injection of 0.1 ml of alumina cream. Fifteen of these were treated by surgical removal of the epileptogenic focus, twelve by irradiation with focused ultrasound and nine with medication. One died before any therapy could be instituted. Ultrasonic irradiation effectively relieved the animals of the seizures and abnormal EEG patterns by eradication of the epileptogenic focus with less untoward effects and postoperative complications than did surgery. Medical therapy was ineffective. Post-mortem examination of the brains showed grossly that ultrasonic irradiation eradicated the epileptogenic focus without destroying extensively the overlying and adjacent brain tissue and without forming corticodural adhesions. Microscopically, irradiated foci could be distinguished from the surgically treated ones by inter alia absence of trabeculated loose vascular scar tissue and paucity of fibroblasts and collagen fibers.