[A case of myogenic intractable pain due to thalamic hemorrhage relieved by Vim-Vo thalamotomy].

A 58-year-old female patient with myogenic intractable pain due to thalamic hemorrhage which was relieved by stereotactic Vim-Vo thalamotomy was reported. She had an intractable pain, involuntary movement and deep sensory disturbance in her right arm. We performed stereotactic Vim-Vo thalamotomy using electrophysiological technique to relieve her involuntary movement and myogenic intractable pain. The electrophysiological recordings suggested the followings: (1) The destructive lesion by thalamic hemorrhage was located on from posterior border of Vim nucleus to the upper half of Vc nucleus. (2) Most of Vim neurons remained as intact state. (3) Thalamic electrical activities were relatively enhanced in the Vim nucleus. From these data, we can deduce that the deep sensory inputs reach the border area of Vim nucleus and Vc nucleus in the human thalamus. IMP-SPECT scans were performed before and after the operation. IMP-SPECT scan before operation showed us the contra-lateral cerebellar low perfusional state (crossed cerebellar diaschisis). This crossed cerebellar diaschisis disappeared after the operation. This result suggested that the interaction of cerebellum and Vim nucleus was very close. The above mentioned speculation was more compatible to Jones & Hirai's new parcellation of the human thalamus than to Hassler's.