Impact of Subthalamic Nucleus Deep Brain Stimulation on Gastrointestinal Symptoms and Gastric Emptying in Parkinson's Disease: A Systematic Review and Meta-Analysis.

Objective: This systematic review and meta-analysis evaluates the efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in improving gastric motility in patients with Parkinson's disease (PD).

Materials And Methods: A systematic search was conducted in Scopus, Web of Science, PubMed, and Cochrane CENTRAL until December 15, 2024. Observational studies and clinical trials evaluating DBS effects on gastric motility and gastric emptying in patients with PD were included. Primary outcomes were changes in the gastrointestinal (GI) domain of the Non-Motor Symptoms Scale (NMSS) and CO excretion time (T). Meta-analysis was performed using Review Manager 5.4, using a random-effects model when necessary.

Results: Eight studies (N = 379) were included. Meta-analysis showed a significant reduction in NMSS-GI domain scores after DBS (MD: -1.29, 95% CI: [-2.16, -0.42], p = 0.004). Subgroup analysis revealed sustained improvements at six months (MD: -1.46, 95% CI: [-2.34, -0.57], p = 0.001) and 12 months (mean difference [MD]: -1.12, 95% CI: [-2.23, -0.01], p = 0.05). For gastric emptying (TCO), no significant difference was found between patients on medication before DBS (with medication [WM]) and those off medication before DBS (without medication [WOM]) (MD: 2.58, 95% CI: [-3.94, 9.10], p = 0.44). However, a significant reduction in TCO was observed in DBS-ON-WOM vs DBS-OFF-WOM (MD: -11.71, 95% CI: [-17.41, -6.02], p < 0.0001) and DBS-ON-WOM vs WM before DBS (MD: -15.46, 95% CI: [-20.89, -10.03], p < 0.00001).

Conclusions: Meta-analysis suggests that STN-DBS significantly relieves GI symptoms and improves gastric motility in patients with PD, with sustained benefits over 12 months. Future studies should assess long-term effects and optimize stimulation parameters for autonomic dysfunction.