Upper limb function is normal in patients with restless legs syndrome (Willis-Ekbom Disease)

Association between restless legs syndrome and other movement disorders

OBJECTIVE

This review focuses on the possible association between restless legs syndrome (RLS) and movement disorders, including Parkinson disease (PD), other parkinsonian syndromes, essential tremor, choreic and dystonic syndromes, Tourette syndrome, and heredodegenerative ataxias.

METHODS

Review of PubMed from 1966 to September 2018 and identification of references of interest for the topic. A meta-analysis of eligible studies on the frequency of RLS in patients with PD and controls using Meta-DiSc1.1.1 software and using the PRISMA guidelines was performed.

RESULTS AND CONCLUSIONS

Although there are substantial clinical, neuroimaging, neuropathologic, and genetic differences between RLS and PD, many reports describe a higher than expected prevalence of RLS in patients with PD, when compared with the general population or with matched control groups; several studies have also suggested that RLS could be an early clinical feature of PD. RLS symptoms are frequent in multiple system atrophy, essential tremor, Tourette syndrome, Friedreich ataxia, and spinocerebellar ataxia type 3 as well. Finally, possible genetic links between PD and RLS (the presence of allele 2 of the complex microsatellite repeat Rep1 within the α-synuclein gene promoter) and between Tourette syndrome and RLS (several variants in the BTBD9 gene) have been reported in 2 case-control association studies, although these data, based on preliminary data with small sample sizes, need to be replicated in further studies.

The Association Between Sleep Duration and Hand Grip Strength in Community-Dwelling Older Adults: The Yilan Study, Taiwan

Study objectives

Different pathomechanisms may underlie the age-related decline in muscle mass and muscle power in older adults. This study aimed to examine the independent relationship between sleep duration and muscle power.

Methods

Older adults, aged 65 years and older, were randomly selected to participate in a community-based survey in Yilan city, Taiwan. Data on self-reported sleep duration, sociodemographic information, lifestyle, chronic medical and mental health conditions, sleep-related parameters, and anthropometric measurements were collected. Participants who slept ≤4 hr, 5 hr, 6-7 hr, 8 hr, and ≥9 hr were defined as shortest, short, mid-range, long, and longest sleepers, respectively. Muscle power was estimated using hand grip strength.

Results

A total of 1081 individuals participated. Their average age was 76.3 ± 6.1 years, and 59.4% were female. After controlling for covariates, including muscle mass of the upper extremities, both long (estimated mean [95% confidence interval, CI]: 19.2 [18.2-20.2], p = .03) and longest sleepers (estimated mean [95% CI]: 17.8 [16.4-19.2], p = .001) had weaker hand grip strength than mid-range sleepers (estimated mean [95% CI]: 20.9 [20.3-21.4]). When stratified by sex, the association between longest sleep duration and weaker hand grip strength was noted among men only.

Conclusions

Older adults with long sleep duration had weaker hand grip strength irrespective of muscle mass. This finding suggests that decreased muscle power may mediate or confound the relationship between long sleep duration and adverse health outcomes.