Prevalence and Clinical Characteristics of Dementia and Cognitive Impairment in Multiple System Atrophy: A Systematic Review and Meta-Analysis.

BACKGROUND

Cognitive impairment is a clinical feature of multiple system atrophy (MSA). However, the prevalence and factors influencing the prevalence of cognitive impairment and dementia in MSA patients remain unclear.

OBJECTIVE

We aim to provide an estimate of the prevalence of cognitive impairment and dementia in patients with MSA and to evaluate the possible effect of demographic, clinical and methodological factors on the prevalence.

METHODS

We systematically searched the PubMed, Embase, and Web of science databases to identify studies that report the prevalence of cognitive impairment or dementia in MSA published up to February 2022. We computed the estimates of the pooled prevalence using random-effects models. Heterogeneity was investigated by subgroup analyses and meta-regression. Differences between MSA patients with and without cognitive impairment in demographic and clinical features were explored.

RESULTS

A total of 23 studies comprising 2064 MSA patients were included in meta-analysis. The pooled prevalence of cognitive impairment in MSA patients was 37% (95% CI: 29% -45%), the prevalence of dementia was 11% (95% CI: 7% -15%). The subgroup analyses showed the prevalence of dementia in pathologically-confirmed MSA was 7% (95% CI: 0% -12%), in clinically diagnosed MSA was 14% (95% CI: 10% -18%). Cognitive impairment in MSA patients was associated with older age, lower education, longer disease duration and more severe motor symptoms.

CONCLUSION

Cognitive impairment is a common non-motor symptom in MSA. Dementia can develop in a few patients with MSA as well, but usually in the late stage.