Thalamic pain and stereotactic mesencephalotomy.

The severe pain that can be experienced by stroke patients is refractory both to drugs and to non-medical therapies. Various surgical procedures are widely advocated for its relief, stereotactic mesencephalic tractotomy in particular providing good results. Twenty seven patients with pain of central origin following stroke underwent stereotactic mesencephalic tractotomy by thermocoagulation at one of two alternative sites. Fourteen had lesions created at the original target adjacent to the superior colliculus, 75% reporting long term relief of their pain. Of this group, 83% had residual postoperative ocular dysfunction (50% symptomatic) and two died soon after surgery. Thirteen patients had surgery at the revised target at the level of the inferior colliculus: 58% had long term pain relief, 23% had ocular problems (none symptomatic) and mortality was nil.