Abstracts

Rationale: Dr. Wilder Penfield has been celebrated for his pioneering work with epilepsy patients. In particular with electrical stimulation of the brain, thereby mapping almost the entire human cerebral cortex. _x000D_
Methods: We conducted a study analyzing the original operating room (OR) log books from the Montreal Neurological Hospital (MNI) over the course of Dr. Penfield´s career from 1934 to 1960. We examined the data in five-year intervals with a focused review on epilepsy cases._x000D_
Results: He performed 2337 procedures during his career at the MNI. 601 operations were performed for epilepsy which corresponds to 26% of his practice. Epilepsy cases were divided according to the type of anesthesia eg. local vs. general and if the procedure was a focal resection or lobectomy. _x000D_ _x000D_ In the first period from 1934 to 1940, he performed 81 epilepsy procedures. This included 69 focal resections done under local anesthesia. He also implanted 4 patients with subdural electrodes. In this early era, most of the surgeries were done under local anesthesia with extensive cortical exposure in order to map the brain, now known as the “Montreal procedure”. Also in this period, the homunculus was described in 1937 and in 1939 the EEG laboratory was created with Dr Herber Jasper. This resulted in electrocorticography (ECoG) becoming the standard of care._x000D_ _x000D_ From 1941 to 1945, he performed 86 procedures, with the majority (77) done under local anesthesia with ECoG guided focal resection. During this period the electric stimulation of the temporal lobe, especially the mesial structures allowed the first descriptions of mesial temporal lobe epilepsy and temporal lobe function.  According to the OR log, the first procedure described solely as an anterior temporal lobe resection was done in 1942. _x000D_ _x000D_ From 1946 to 1950, he performed 223 epilepsy surgeries. Here we note the gradual introduction of lobectomies with 30 procedures were described as such. Temporal lobectomy, mostly of the right-side, were done now under general anesthesia._x000D_ _x000D_ From 1951 to 1955, he performed 152 epilepsy procedures. Eighty-eight were described as focal resection and 64 were classified as lobectomies. During the final years from 1956 to 1960, he performed 59 epilepsy surgeries, and a similar number of cases were focal resection and lobectomies._x000D_
Conclusions: To our knowledge, this is the most complete and comprehensive account of the surgical career of Dr. Penfield. We have taken note of the changing practice profile over the course of his career. During the early years, patients with focal epilepsy, often from trauma, where treated through large craniotomies with ECog recording and stimulation to tailor the resection. This type of procedure lead to a better understanding of the human cortex and the division of the function that permit the evolution of the technique and the use of general anesthesia. In the period of 1945 to 1950, we see the introduction of temporal lobectomy as a standard procedure. The last two periods were marked by a more balanced number of cases of focal resection versus lobectomies. Of note, over the course of his career only 26% of operations were specifically for the treatment of epilepsy. He remained productive during his whole career. _x000D_
Funding: None