Nighttime sleep disorders in patients with daytime sleepiness in Parkinson s disease

Abstract

Daytime sleepiness is one of the clinically significant non-motor manifestations of Parkinson's disease (PD). One of its insufficiently studied aspects is a relationship between daytime sleepiness and nighttime sleep disorders.Objective:to clarify the clinical characteristics of PD in patients with different types of daytime sleepiness and to estimate of the ratio of daytime sleepiness to clinical and polysomnographic characteristics of nighttime sleep in patients with advanced stages of PD.Patients and methods. The investigation included 110 patients (56 men and 54 women) (mean age, 63.78+0.6 years) with PD (Hoehn and Yahr stage 2.6+0.2; disease duration, 6.3+3.2 years) without dementia. All the patients received therapy with levodopa at a mean daily dose of 667.8 mg; 98 of them had the drug in combination with dopamine receptor agonists at a stable dose. The unified PD rating scale, the PD sleep scale (PDSS), and the Epworth sleepiness scale (ESS) were applied. Nocturnal polysomnography (PSG) and the multiple sleep latency test (MSLT) were performed.Results and discussion. There was daytime sleepiness in 44% of the patients: permanent sleepiness in 15%, sudden daytime sleep attacks (along with low daytime sleepiness (ESS) in 14%, and permanent drowsiness concurrent with sleep attacks in 15%. The PSG findings showed a decrease in sleep efficiency, an increase in the duration of the first stage of sleep, a reduction in the duration of the second and third sleep stages, an extension of rapid eye movement (REM) sleep latency, and frequent awakenings (sleep fragmentation). PSG also demonstrated REM sleep behavior disorders (RBD) in half of the examinees.Patients with sleep attacks differed from those with permanent drowsiness without sleep attacks with more severe sleep disorders (PDSS) and shorter sleep latency (MSLT). Patients with the RBD phenomenon had shorter sleep latency (MTLS) than those without this parasomnia. Patients with moderate or severe sleepiness (ESS scores of >10) differed from those with milder drowsiness (ESS scores of 410) and a lower representation of the third sleep stage.Conclusion.There is evidence for the association of daytime sleepiness in PD with reduced efficiency, changes in the nighttime sleep pattern, and RBD.