Dorsal subthalamotomy for Parkinson's disease

We report our experience of unilateral subthalamotomy in patients with Park inson's disease (PD). Eleven patients were included in a pilot, open-labele d study to assess the effect of unilateral lesion of the subthalamic nucleu s (STN) with a minimum of 12 months of follow-up. The guidelines of CAPIT ( Core Assessment Program for Intracerebral Transplantation) were followed fo r recruitment into the study and followup assessment. Levodopa equivalents daily intake (mean 967 mg) were unchanged during the first 12 months in all but one patient who stopped medication. The sensorimotor region of the STN was defined by semimicrorecording and stimulation and a thermolytic lesion was placed accordingly. There was a significant reduction in both UPDRS pa rts II and III in the "off" state at 1-, 6-, and 12-month follow-up. This e ffect was maintained in four patients up to 24 months. The dyskinesia score did not change postoperatively. Lesion-induced dyskinesias were not a mana gement problem except in one patient who developed a large infarction sever al days postsurgery. This initial study indicates that a lesion of the STN is not generally associated with hemiballismus in PD. Subthalamotomy may in duce considerable motor benefit and could become another surgical option un der specific circumstances.