Stereotactic mesencephalic tractotomy for thalamic pain.

Forty years after its first reported use, stereotactic mesencephalic tractotomy remains effective in relieving thalamic pain. Twenty seven patients suffering central pain following cerebrovascular accidents were treated by this operation and twenty four were reviewed: sixteen (66.7%) reported long term relief. Fourteen underwent surgery at the original 'superior colliculus' target, nine out of twelve (75%) reporting significant relief. Thirteen had surgery at a revised 'inferior colliculus' target, seven out of twelve (58.3%) obtaining relief. Postoperative disorders of ocular movement were reduced from 83.3% to 20%, and significant problems of binocular vision from 50% to nil. The mortality rate was 7.4%.