Key Characteristics for Stratifying REM Sleep Behavior Disorder Risk in PD

A recent study has identified key patient characteristics that may predict the risk of probable and confirmed rapid eye movement sleep behavior disorder (RBD) in patients with Parkinson disease (PD). This study was reported in Clinical Neurology and Neurosurgery.

The investigators of this study performed a systematic review of studies that compared characteristics of patients with PD with RBD vs those with nonRBD. They performed a meta-analysis on a total of 47 studies that met the inclusion criteria. These studies included a pooled cohort of 8019 patients with PD and probable RBD, confirmed RBD, or nonRBD.

Compared with patients without RBD, those with PD and probable RBD had significantly higher duration of PD (weighted mean difference [WMD], 0.72; 95% CI, 0.37-1.07; P <.001), daily levodopa dosage (WMD, 76.61; 95% CI, 45.80-107.42; P <.001), Hoehn-Yahr stage (WMD, 0.14; 95% CI, 0.05-0.23; P =.003), Unified Parkinson’s Disease Rating Scale-III (UPDRS-III; WMD, 1.28; 95% CI, 0.31-2.24; P =.009), UPDRS motor score (WMD, 3.29; 95% CI, 0.63-5.95; P =.015), UPDRS activities of daily living (WMD, 1.92; 95% CI, 1.12-2.71; P <.001), and Epworth Sleepiness Scale (ESS; WMD, 1.57; 95% CI, 0.99-2.15; P <.001).

Probable RBD more often occurred in men (odds ratio [OR], 1.21; 95% CI, 1.03-1.40; P =.017), and in patients with dyskinesia (OR, 2.79; 95% CI, 1.49-5.21; P =.001), orthostatic hypotension (OR, 3.27; 95% CI, 1.38-7.74; P =.007), constipation (OR, 1.77; 95% CI, 1.27-2.48; P =.001), or fluctuations (OR, 2.07; 95% CI, 1.35-3.18; P =.001).

Patient characteristics that were significantly associated with confirmed RBD included older age (WMD, 2.16; 95% CI, 1.28-3.04; P <.001), longer duration of PD (WMD, 0.97; 95% CI, 0.42-1.51; P =.001), higher daily levodopa dosage (WMD, 70.33; 95% CI, 21.23-119.43; P =.005), higher Hoehn-Yahr stage (WMD, 0.23; 95% CI, 0.12-0.34; P <.001), higher UPDRS motor score (WMD, 2.85; 95% CI, 0.26-5.44; P =.031), higher ESS (WMD, 1.18; 95% CI, 0.38-1.99; P =.004), and lower MMSE (WMD, -0.92; 95% CI, -1.43 to -0.41; P <.001).

Study findings indicated that patients had an increased risk of confirmed RBD if they were men (OR, 1.49; 95% CI, 1.10-2.01; P =.009) or if they had dyskinesia (OR, 2.01; 95% CI, 1.35-3.00; P =.001), hallucinations (OR, 3.19; 95% CI, 2.24-4.55; P <.001), insomnia (OR, 5.75; 95% CI, 2.26-14.64; P <.001), dementia (OR, 2.50; 95% CI, 1.10-5.68; P =.028), orthostatic hypotension (OR, 4.87; 95% CI, 1.66-14.28; P =.004), falls (OR, 1.85; 95% CI, 1.32-2.60; P <.001), or fluctuations (OR 1.71; 95% CI, 1.18-2.47; P =.005).

A limitation of this meta-analysis was the inclusion of studies that featured various diagnostic criteria and tools to assess PD and RBD, which may have introduced possible confounders into the analysis.

Ultimately, the study investigators concluded that “further large-scale prospective cohort studies evaluating the risk factors on RBD in PD patients without RBD should be conducted.”

Reference

Xie C, Zhu M, Hu Y. Risk stratification for REM sleep behavior disorder in patients with Parkinson’s disease: a PRISMA-compliant meta-analysis and systematic review. Clin Neurol Neurosurg. 2021;202:106484. doi:10.1016/j.clineuro.2021.106484