Association between herpes zoster and Parkinson’s disease and dementia: a systematic review and meta-analysis

Abstract

Objectives This meta-analysis investigated the relationship between herpes zoster and the risk of dementia or Parkinson’s disease by analyzing published clinical studies. Methods We systematically searched PubMed, Cochrane, Embase, and Web of Science Core Collection databases on April 25, 2024. Hazard ratios (HR) were used for statistical analyses. Random-effects models were applied, and heterogeneity was assessed using the I 2 statistic. Results Herpes zoster was associated with a non-significant trend toward increased dementia risk (HR = 1.11, 95% CI 0.99–1.24, p = 0.07) but significantly increased Parkinson’s disease risk (HR = 1.15, 95% CI 1.03–1.30, p = 0.02). Subgroup analyses revealed that herpes zoster significantly elevated the risk of the prospective study subgroup (HR = 1.08, 95% CI 1.02–1.13, p = 0.004) and vascular dementia subgroup (HR = 1.17, 95% CI 1.00–1.37, p = 0.05). Significant heterogeneity was observed for both outcomes (dementia: I 2 = 98%, p < 0.00001; Parkinson’s disease: I 2 = 94%, p < 0.00001). Conclusion Herpes zoster raises the risk of Parkinson’s disease and vascular dementia, with a potential causal link to dementia. Early vaccination against herpes zoster is recommended over post-infection antiviral treatment to mitigate risks. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/ and our registration number is CRD42024555620.