SENSORY, MOTOR, AND REFLEX CHANGES IN TWO CASES OF INTRACTABLE PAIN AFTER STEREOTACTIC MESENCEPHALIC TRACTOTOMY

Abstract

A considerable degree of sensibility remained on the contralateral side of the body, particularly the trunk and face, following extensive lesions from stereotactic mesencephalic tractotomy in 2 terminal lung cancer patients. With the medial lemniscus and spinothalamic tracts completely severed on one side it was possible that some fine dispersed fibers avoided destruction or that transmission occurred through ipsilateral spinothalamic fibers. This is not the only possible explanation, however. It is suggested that extralemniscal components such as the crossed and uncrossed fibers of the dorsal trigeminal tracts and from the spinal cord to the reticular, tegmental and tectal regions and then on to the thalamus, being integrated through the reticular and intralaminar thalamic nuclei, are involved in sensory transmission of varying quality. Tendon, abdominal and plantar reflexes in one patient were increased on the contralateral side of the lesion without involvement of corticospinal fibers. This indicates that these reflexes may be influenced by extra-pyramidal lesions.