Circadian rhythm in restless legs syndrome

Abstract

Restless legs syndrome (RLS) is a sensorimotor disorder with a obvious circadian rhythm, as its symptoms often occur or worsen only in the evening or at night. The mechanisms behind the rhythms of RLS have not yet been fully elucidated. This review explores possible causes for the circadian fluctuations of the symptomatology, including the levels of iron, dopamine, melatonin, melanocortin, and thyroid-stimulating hormone in the brain, as well as conditions such as peripheral hypoxia and microvascular function disorders. The metabolic disturbances of the substances above can create a pathological imbalance, which is further aggravated by physiological fluctuations of circadian rhythms, and results in the worsening of RLS symptoms at night. The review concludes with the suggestions for RLS treatment and research directions in the future.

Registry and survey of circadian rhythm sleep-wake disorder patients

“…51 % of respondents with a CRSWD had also been diagnosed with another sleep disorder, most commonly bruxism, sleep apnea, or restless leg syndrome. Restless leg syndrome is reported to have circadian aspects, which may contribute to its comorbidity with CRSWDs [ 25 ]. The presence of other sleep disorders could complicate diagnosis and may contribute to the diagnostic delay previously noted.…”

Cerebral blood flow changes in maintenance hemodialysis patients with restless legs syndrome and their clinical significance:a cross-sectional case-control study

“…Moreover, the brain is the body's highest oxygen-consuming organ, and it has its regulatory mechanisms. Under normal conditions, decreasing oxygen levels promote vasodilation, which increases CBF and oxygen delivery to the brain, nevertheless, through the results of Salminen et al, the manifestation of peripheral hypoxia in RLS patients was observed to be highly related to the severity of RLS, and the hypothesis of microvascular abnormality in RLS was also supported [ 13 ], Thus, RLS causes a persistent chronic hypoxic state, which contributes to cerebral vascular damage and the loss of self-regulatory mechanisms, as well as ultimately results in a decrease in CBF [ 14 ]. Moreover, the frontal, precuneus, and precentral gyrus belong to the sensory-motor network (SMN), and the hippocampus is part of the limbic system, patients with MHD-RLS have reduced CBF in the sensorimotor network, indicating sensory-motor symptoms with abnormal regulation and a strong desire to move both lower extremities as a result of abnormal limbic system regulation [ 15 ].…”

Thyroid disease-related sleep disorders and its diagnostic and therapeutic recommendations: A literature review

“…A growing number of studies have confirmed that the dopaminergic system is related to the HPT axis [34,[109][110][111][112]. DA decreases thyroid hormone and thyroid-stimulating hormone (TSH) and increases TRH release over time [35].…”