Efficacy of Deep Brain Stimulation for Camptocormia in Parkinson's Disease: A Systematic Review and Meta-Analysis

Background: Camptocormia is one of the most common postural disorders of Parkinson’s disease (PD) which has limited treatment options. In this review, we summarize the efficacy of deep brain stimulation (DBS) for camptocormia in PD. Methods: The PubMed (https://pubmed.ncbi.nlm.nih.gov/) and EMBASE databases (https://www.embase.com/) were searched for the terms “Parkinson Disease” and “camptocormia” in combination with “deep brain stimulation”. We then explored the efficacy of DBS for camptocormia by statistical analysis of the bending angle, the Unified Parkinson’s Disease Rating Scale III (UPDRS-III) and L-dopa equivalent daily dose (LEDD), and by evaluating the prognosis after DBS. Results: Twenty articles that reported results for 152 patients were included in this review. These comprised 136 patients from 16 studies who underwent subthalamic nucleus deep brain stimulation (STN-DBS), and 13 patients from 3 studies who underwent globus pallidus internus deep brain stimulation (GPi-DBS). One study used both STN-DBS (2 patients) and GPi-DBS (one patient). After 3–21 months of follow-up, the mean bending angle during the Off-period was significantly reduced compared to pre-DBS (31.5 ± 21.4 vs. 53.6 ± 22.7, respectively; p < 0.0001). For the STN-DBS trials, the mean post-operative bending angles during both Off- and On-periods were significantly reduced compared to pre-operative (32.1 ± 22.7 vs. 55.4 ± 24.1, p = 0.0003; and 33.1 ± 21.5 vs. 43.7 ± 20.6, p = 0.0003, respectively). For GPi-DBS, the mean bending angle post-DBS during the Off-period was considerably lower than pre-DBS (28.5 ± 10.7 vs. 42.9 ± 9.9, p < 0.001). The decrease in bending angle after DBS was negatively correlated with the duration of camptocormia (R = – 0.433, p = 0.013), whereas positively associated with the pre-bending angle (R = 0.352, p = 0.03). Conclusions: DBS is an effective treatment for camptocormia in PD. Patients in the early stage of camptocormia with more significant bending angle may benefit more from DBS.