Stereotaxic thalamotomy--experiences from the levodopa era.

After the introduction of levodopa drugs in the late 1960s, the number of thalamotomies fell dramatically world wide. However, as the Parkinsonian tremor proved rather resistant to levodopa treatment, the interest in this operation has been reviewed. During 1978-86, 51 stereotaxic thalamotomies were performed in 48 patient in our department. Thirty three of these patients had Parkinsonism, nine multiple sclerosis (MS) and the remaining six had various other involuntary movement disorders. The operation was most useful in the Parkinsonian group. Nearly 80% of these patients gained a substantial benefit in their daily lives. Patients with MS were all in advanced stages of the disease, and the operation was tried as a last resort. They had less benefit and more complications from operation than the other patients.