Comparison of subthalamic nucleus vs. globus pallidus interna deep brain stimulation in terms of gait and balance; a two year follow-up study

AIM: To compare the effects of subthalamic nucleus (STN) and globus pallidus interna (GPi) deep brain stimulation (DBS) on the motor outcome, gait and balance function, fall risk (FR), and non-motor symptoms in patients with advanced Parkinson's disease (PD). MATERIAL AND METHODS: We randomized patients with advanced PD with the indication of DBS to undergo either STN or GPi DBS and followed them for 2 years. We collected data at baseline and postoperative 6, 12, and 24 months. We compared changes in the Unified Parkinson's Disease Rating Scale (UPDRS) score, timed gait tests, posturography, non-motor symptom questionnaire (NMSQuest), hospital anxiety and depression (HAD) scale, and levodopa equivalent dose (LED). RESULTS: We enrolled and randomized 12 patients to receive either STN (n = 6) or GPi (n = 6) DBS. Postoperative motor outcomes were significantly improved in both groups (p < 0.05). In both groups, timed gait tests exhibited better performance in mobility; however, patients receiving GPi DBS performed better than those receiving STN DBS in the timed gait tests (p < 0.05). Furthermore, the posturographic evaluation demonstrated a significant elevation in the FR in the STN group (p < 0.05). CONCLUSION: Both STN and GPi DBS are equally effective in alleviating disabling motor complications. However, seemingly, STN DBS could cause more gait and balance problems; hence, a tailored approach seems to be more appropriate in the target selection.