Historical evolution of stereotactic amygdalotomy for the management of severe aggression

Friedrich Goltz first reported in the 1890s that temporal lobe removal had a taming effect in animals. The results of studies by Klüver and Bucy, and later Terzian and Ore, demonstrated that an amygdalectomy combined with a temporal lobectomy had a significant taming effect in both animals and humans. Based on these observations, Narabayashi and colleagues reported the first clinical series of patients with temporal lobe epilepsy and/or severe behavioral disturbances in which stereotactic amygdalotomy was performed to address aggressive disorders, using a frame-based stereotactic device designed by Narabayashi. Use of pneumoencephalography, combined with physiological localization by means of olfactory stimulation and field potential recordings, enabled these investigators to define the lateral part of the amygdala, while simultaneously using wax injections to create lesions. Chitanondh used a similar localization technique to produce medial amygdala lesions by injecting a mixture of olive oil, wax, and iodized oil. In 1966, Heimburger and coworkers reported results from a series of 25 patients with epilepsy and aggressive behavior who underwent stereotactic amygdalotomy. Their technique was slightly different and their target localization was solely anatomical, based on pneumoencephalography or contrast ventriculography, and they utilized a cryoprobe to make lesions. In 1970, Balasubramaniam and Ramamurthi reported the largest clinical series to date on this technique; pneumoencephalography or contrast ventriculography was used for anatomical localization, and depth electrode recordings were used to obtain physiological confirmation of their targets, whereas either diathermy or a Bertrand loop was used for making lesions. The development of magnetic resonance imaging technology in late 1980 allowed for a more accurate anatomical localization of the amygdala, and the improvement of radiofrequency generators also made lesioning more precise. Despite these and subsequent technological advances, the number of amygdalotomies performed has geometrically decreased during the last 20 years.