Neurological Insights into Sleep Disorders in Parkinson's Disease

Sleep duration in middle-aged years of life predicts the age of diagnosis of Parkinson's disease

Introduction

Chronic short sleep duration (i.e., <7 h sleep daily) could reduce the brain's ability to attenuate toxin and protein accumulation, which may contribute to Parkinson's disease (PD). The purpose of this study was to characterize the relationship between self-reported sleep duration from adolescence to adulthood and the age of diagnosis in people with PD. A secondary purpose was to characterize the interaction between sleep duration and physical activity through the lifespan on the age of PD diagnosis.

Methods

A secondary data analysis was performed using the Fox Insight data set. Multiple regression analysis was used to determine the age range that sleep duration best predicted the age of diagnosis of PD. Hierarchical linear multiple regression was performed to assess if self-reported sleep duration, physical activity, and their interaction predicted the age of diagnosis for PD, after accounting for sociodemographic factors.

Results

Both sleep (p < 0.001) and physical activity time (p = 0.013) significantly predicted the of age of onset of PD. In contrast, there was no evidence to support an interaction of sleep by physical activity on the age of diagnosis of PD. Sleep duration at 46-55 years maintained significance after controlling for education, income, race, ethnicity, and sex (p < 0.001). Weekly duration of time spent performing moderate-intensity physical activity was added as an input variable.

Conclusion

Sleep duration significantly predicts the age of diagnosis of PD, with shorter sleep duration associated with a younger age of diagnosis of PD.

Non-motor symptoms of Parkinson`s disease-insights from genetics

Parkinson's disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor symptoms (NMS). NMS including sleep disturbances, depression, anxiety, and constipation are diverse, can precede motor symptoms, and significantly impact patients` quality of life. The severity and type of NMS vary based on age, disease severity, and motor symptoms, and while some respond to dopaminergic treatments, others may be induced or exacerbated by such treatments. NMS also play a role in differentiating PD from drug-induced parkinsonism and are related to gait dysfunction in both early and advanced stages. Genetic factors play a significant role in the development of NMS in PD, with mutations in genes such as SNCA, LRRK2, PRKN, and GBA being associated with severe and early NMS. Familial studies and identification of susceptibility factors have provided insights into the genetic underpinnings of NMS in PD. Neurobehavioral changes, including cognitive decline, are common NMS in PD, and their genetic basis involves a spectrum of mutations shared with other neurodegenerative disorders. Further research is needed to elucidate the functional implications of these genetic factors and their contributions to the pathogenesis of NMS in PD.

Short-Term Therapeutic Effect of Repetitive Transcranial Magnetic Stimulations of Sleep Disorders in Parkinson's Disease: A Randomized Clinical Trial (Pilot Study)

This study aimed to evaluate the efficacy of rTMS in treating sleep disorders in PD. It included 24 patients with PD who had sleep disorders. Group allocations (active or sham with a ratio of 2:1) were placed in serially numbered closed envelopes. Each patient was evaluated with the following: MDS-UPDRS, Parkinson's Disease Sleep Scale (PDSS), Beck Depression Inventory (BDI), and polysomnography (PSG) before and 10 days after the treatment sessions. Each session consisted of 10 trains, 20 Hz, 10 sec for each, over the parietal cortex (bilaterally). Scores of UPDRS, BDI, and PDSS improved significantly in the active group but not in the sham group. The PSG data showed that sleep onset and rapid eye movement (REM) latencies (min), REM duration, and time spent awake (both as %TST) were improved after rTMS in the active group compared with the sham group. The number of awakenings, the wake-after-sleep onset index, the arousal index, and periodic leg movements (PLMs) were all significantly reduced in the active group but not in the sham group. Ten sessions of 20 Hz rTMS over parietal cortexes improved sleep quality and PLMs in patients with PD. The improvement in PSG and PDSS were correlated with improvements in UPDRS and BDI scores.

The Genetic Landscape of Sleep Disorders in Parkinson's Disease

Parknson's disease (PD) is the second most common neurodegenerative disease, affecting 1% of people aged over 60. PD is characterized by a wide range of motor symptoms, however the clinical spectrum of PD covers a wide range of non-motor symptoms, as well. Sleep disorders are among the most common non-motor symptoms of PD, can occur at any stage of the disease and significantly affect quality of life. These include rapid eye movement sleep behavior disorder (RBD), restless legs syndrome (RLS), excessive daytime sleepiness (EDS), insomnia, obstructive sleep apnea (OSA) and circadian rhythm disturbances. One of the main challenges in PD research is identifying individuals during the prodromal phase of the disease. Combining genetic and prodromal data may aid the early identification of individuals susceptible to PD. This review highlights current data regarding the genetic component of sleep disorders in PD patients, focusing on genes that have currently been associated with this PD co-morbidity.