A CONVULSION is the most serious symptom which can occur in childhood. It demands an immediate investigation as to its cause or origin. A complete and detailed description of the convulsion from the beginning to the end is the most useful aid in the attempt at localization and cause. The classification of convulsions introduced in 19341 and subsequently revised, in 1946,2 has been a very useful working chart to indicate the most probable cause of the convulsion. An accurate family history, particularly of convulsive seizures, is invaluable in this study. While an electroencephalogram3 is not essential in most cases when the history is adequate, it is the greatest diagnostic aid in medicine.4 With this sensitive apparatus it is possible to discover a potential convulsive state before a seizure has occurred.5 It is also possible to evaluate the results of treatment and to determine the need