Freezing of gait after bilateral subthalamic nucleus stimulation for Parkinson's disease

OBJECTIVE: To determine the long-term effect of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) on freezing of gait in Parkinson's disease patients. PATIENTS AND METHODS: Sixty-seven patients were followed 12 months after bilateral STN DBS and 32 patients were followed 24 months post-surgery. Patients were evaluated with the Unified Parkinson's Disease Rating Scale (UPDRS) with medications on and off at baseline and again in both conditions with stimulation on at follow-up. Specific attention was paid to the freezing item of the ADL section. RESULTS: Freezing scores in the medication off state improved significantly with stimulation at 1 and 2 years. In the medication on state there were no significant improvements in freezing. CONCLUSION: Off period freezing of gait is significantly improved with STN DBS up to 24 months; however, on period freezing is not affected by STN DBS.