THE EFFECTS OF LOCAL FREEZING OF THE CENTRAL NERVOUS SYSTEM OF THE CAT

In connection with his work on experimental convulsions, Speransky,1 in 1926, reported a method of producing epileptiform fits in dogs by freezing portions of the cerebral cortex. We here report our observations when this work was repeated.His method, briefly, was as follows:A small area of the cortex, excluding the motor area, was frozen through the dura to a depth of from 2 to 4 mm. by means of carbon dioxide gas for about one minute. This procedure was invariably followed in from two to five hours by severe epileptiform convulsions which, in from twelve to fifty hours, resulted in death. Speransky did not state whether an anesthetic was used. He described the convulsions as consisting first of a tonic contraction of the flexors of the hind legs and occasionally clonic convulsions of single muscles or groups of muscles. Following this there were rhythmic tonic and clonic convulsions