Objective: A preliminary study of subthalamic nucleus (STN) stimulation was performed to determine its applicability for the treatment of gait and postural disturbances in Parkinson's disease.
Methods: Five Parkinson's disease patients with freezing gait and postural instability were selected for this study. Their ages ranged from 60 to 73 years (mean+/-standard deviation, 65.6+/-4.8 years). Semi-microelectrode recording was used to identify the STN and to place a chronic electrical stimulation electrode within the right STN in all patients. The Unified Parkinson's Disease Rating Scale and the modified Hoehn and Yahr Staging Scale were used to assess patients in on- and off-drug conditions before surgery and 3 months after surgery.
Results: The scores on the Hoehn and Yahr Staging Scale and the total Unified Parkinson's Disease Rating Scale for akinesia (P < 0.05), gait (P < 0.05), and gait and posture (P < 0.01) in off-drug on-stimulation conditions significantly improved over the preoperative and postoperative off-drug off-stimulation conditions (analysis of variance [ANOVA], P < 0.01). Improvement over the preoperative scores was 24% on the Hoehn and Yahr Staging Scale, 43.6% on the total Unified Parkinson's Disease Rating Scale, 33.4% for akinesia, 36.6% for gait, and 38.7% for gait and posture. However, stimulation in the on-drug phase did not show a significant difference compared with pre- and postoperative conditions (ANOVA, P > 0.05). Comparisons between preoperative on-drug and postoperative off-drug on-stimulation conditions revealed that there were no significant differences in the scores, except for gait (ANOVA, P < 0.05). The scores on subscales for falling, freezing, walking, and gait in off-drug on-stimulation conditions were significantly improved over the scores for preoperative and postoperative off-stimulation (ANOVA, P < 0.05), but the score for postural stability remained unchanged.
Conclusion: Our findings showed that STN stimulation effectively alleviates freezing gait and improves walking to its status during the preoperative on-drug phase and can be applied for treatment of Parkinson's disease patients with these symptoms.