Parkinson's: Sleep Disturbances Affect Clinical Motor Subtypes, Disability
Sleep-related symptoms may be associated with degree of disability and motor phenotype.
There is a significant association between sleep disturbances and clinical motor subtypes, as well as disease-related disability, among patients with Parkinson's disease (PD), according to findings from a multicenter study published in the Journal of Neurology, Neurosurgery, and Psychiatry.
Investigators examined the effect of sleep-related symptoms and clinical motor subtypes, including tremor dominant, intermediate, and postural instability and gait disturbances, in 436 patients with PD and 410 age-matched control patients. The researchers used the PD sleep scale (PDSS ) 2, Epworth Sleepiness Scale (ESS), and REM sleep behavior disorder screening questionnaire-Japanese version (RBDSQ-J) to assess various sleep-related variables.
The researchers found that patients with PD were more likely to experience PD-related sleep problems (PD-SP), excessive daytime sleepiness (EDS), and probable RBD (pRBD) compared with control patients (PDSS-2 ≥18, 35.1% vs 7.0% [P <.0001]; ESS ≥10, 37.8% vs 15.5% [P <.0001]; RBDSQ-J ≥5, 35.1% vs 7.7% [P <.0001]). Compared with patients with tremor dominant, patients with postural instability and gait disturbance had higher PDSS-2 and ESS adjusted scores.
The Movement Disorder Society-Unified PD Rating Scale part II score, which assessed disease-related disability, was significantly associated with disease duration (P <.0001), disease severity (P <.0001 ), EDS (P <.0001), and PD-SP (P <.0001).
According to the investigators, 1 limitation of this study was the lack of polysomnography use for evaluation of the patients' sleep status. In addition, the cross-sectional design and the lack of assessment of mild cognitive impairment or impulse control disorder may have presented additional limitations related to the final analysis.
The researchers concluded that the findings of this study "demonstrate the importance of the clinical assessment and management of sleep-related symptoms (PD-SP, EDS and pRBD), which have a significant impact on disease-related disability compared with motor symptoms in patients with PD."
Suzuki K, Okuma Y, Uchiyama T, et al. Impact of sleep-related symptoms on clinical motor subtypes and disability in Parkinson's disease: a multicentre cross-sectional study [published online August 28, 2017]. J Neurol Neurosurg Psychiatry. doi:10.1136/jnnp-2017-316136