Prevalence of axial postural abnormalities and their subtypes in Parkinson's disease: a systematic review and meta-analysis

Background and purpose Axial postural abnormalities, mainly involving the spinal deformities, are disabling symptoms of Parkinson's disease (PD). However, the prevalence of axial postural abnormalities in PD and their clinical correlates remain unclear. The present study aimed to conduct a systematic review and meta-analysis of the prevalence of overall and subtypes of axial postural abnormalities in PD. Methods PubMed, Embase, Web of Science and Cochrane databases were searched up to 31st March, 2022. We identified studies that reported the prevalence of axial postural abnormalities in PD. The pooled estimate of prevalence was calculated using a random effect model. Subgroup analysis and meta-regression were performed. Results There were 19 studies met the inclusion criteria. The overall prevalence of axial postural abnormalities in PD was 22.1% (95% CI 19.7-24.5%). The prevalence of each subtype of axial postural abnormalities was 19.6% for scoliosis (95% CI 10.6-28.7%), 10.2% for camptocormia (95% CI 7.7-12.7%), 8% for Pisa syndrome (95% CI 4.7-11.4%), and 7.9% for antecollis (95% CI 3.9-11.9%). Subgroup analysis showed that the measuring method of axial postural abnormalities exerted significant effects on prevalence estimates. Axial postural abnormalities in PD were associated with older age, longer disease duration, higher H-Y stage, greater levodopa equivalent daily dose, more severe motor symptoms, motor fluctuations, and akinetic-rigid subtype. Conclusions Axial postural abnormalities, which include scoliosis, camptocormia, Pisa syndrome, and antecollis, are not uncommon in patients with PD. Future research on axial postural abnormalities should be based on uniform diagnostic criteria and measuring methods.