For a considerable period of time,ligation of the carotid artery has been used as a therapeutic measure for a variety of serious cranio-cerebral conditions5. Originally it was used as an emergency measure in an effort to control severe hemorrage following lacerations of the largr vessels of the neck and head. During the middle years of the nineteenth century it was attempted for the purpose of relieving cerebral disorders, which were then incurable. However,the operation was discarded because the mortality was high and the permanent symptoms of recovered patients serious5.
In the past thirty years,with the increasing safety of surgical measures,the procedure has been reintroduced. The seriousness of carotid ligation was stressed by Pilcher and Thuss,5 who concluded that in from twenty to twenty to twenty-five percent of patients who survive the operation cerebral complications develop.
On the basis of controversies on this problem and the interest manifested in the writer an interest was stimulated to re-investigate the effects of carotid ligation on brain tissue
