Effect of hyperbaric oxygen therapy for non-motor symptoms among patients with Parkinson's disease: A systematic review and meta-analysis.

Objective: To systematically evaluate the efficacy of hyperbaric oxygen therapy for non-motor symptoms in patients with Parkinson's disease.

Data Sources: A systematic search was performed across several databases, including the Chinese Science and Technology Periodical Database, Web of Science, SinoMed, PubMed, Cochrane Library, Embase and Wanfang databases up to 1 December 2025. Studies considered for inclusion comprised randomised controlled trials and pre-post control studies.

Review Methods: The authors conducted the data extraction and literature screening procedures independently. The selected studies' quality was evaluated using the Cochrane risk of bias technique. Review Manager 5.3 was used to conduct meta-analyses, while Stata 15.0 was utilised for sensitivity analysis and to assess publication bias.

Results: Sixteen studies with a total of 1324 individuals satisfied the inclusion criteria. The results of the meta-analysis showed that hyperbaric oxygen therapy significantly improved scores on the Hamilton Anxiety Scale and Hamilton Depression Scale compared with baseline (both < 0.05). Additionally, improvements were observed in the Montreal Cognitive Assessment, Mini-Mental State Examination, Parkinson's Disease Sleep Scale, Pittsburgh Sleep Quality Index, Kubota's Drinking Water Test and Unified Parkinson's Disease Rating Scale III. Improvements in sleep efficiency and extension of total sleep time were also noted compared with controls (all < 0.05).

Conclusion: The findings indicate that hyperbaric oxygen therapy effectively alleviates non-motor symptoms such as anxiety, depression, cognitive impairments, sleep disturbances, and swallowing dysfunction, as well as improving motor function in Parkinson's disease patients. Since the hyperbaric oxygen therapy protocol had significant differences between studies, further prospective randomised controlled trials with rigorous methodology are needed.