Clinical outcome of unilateral stereotactic pallidotomy without microelectrode recording for intractable Parkinson's disease

Objective: To study the effects of unilateral stereotactic pallidotomy performed without microelectrode recording for advanced Parkinson's disease. Methods: Stereotactic coordinates were calculated by comparing preoperative inversion recovery MRI sequences with intraoperative CT scans. Conventional stereotactic stimulation techniques were employed to confirm correct probe placement. Patients were assessed using a modified CAPIT protocol with the off-state UPDRS motor score as the primary efficacy measure. Results: A statistically significant decline in off-state UPDRS motor scores occurred at 2 months (21% improvement in 32 patients) and also at 1 year postoperatively (30% improvement in 12 patients). Levodopa-induced dyskinesias on the side contralateral to surgery were reduced 97% in the cohort with 1 year of follow-up. No deleterious effects of surgery on global neuropsychological functioning were seen. A major surgical complication (mild but persistent hemiparesis) occurred in one patient. Conclusions: We believe that stereotactic pallidotomy can be performed safely and effectively without microelectrode recording when coordinates are calculated using CT with comparison to preoperative MRI sequences.