Restless legs syndrome in patients with behcet's disease and multiple sclerosis: prevalence, associated conditions, clinical features

The restless legs syndrome is a sensorimotor disorder characterized by irresistible urge to move one's legs, which further deteriorates at night and the evening hours during rest. There is no testing method to diagnose this condition, and the diagnosis is based on assessment of the clinician and use of diagnostic criteria. The present study investigated the prevalence and characteristics of RLS in patients with Behcet's Disease (BD), Neuro-Behcet's Disease, and Multiple Sclerosis (MS). A total of 96 consecutive patients with BD (mean age 39.9±11.8; 51 males) and 97 patients with MS (mean age 34.97±4.1; 24 males) followed in the outpatient clinic were included in the study after an informed consent was obtained from the patients. Age- and gender-matched 100 subjects without a known peripheral or central nervous system disorder were included in the control group (the mean age was 36.18±11.10; 46 males). Demographic features, past medical history of family history were questioned, and all patients underwent neurological examination. The patients were evaluated for the presence of diagnostic criteria for RLS. The characteristics and the severity of RLS were evaluated in patients with RLS. The clinical and radiological findings of patients with BD and MS were retrieved from the medical charts. RLS was most prevalent in MS (22.8%) and Neuro-Behcet (22%) groups compared to the control group (10%) (p = 0.004 and 0.029, respectively). The prevalence of RLS in patients with BD without Neuro-Behcet's disease was close to the prevalence in the control group (10.9%). The prevalence of RLS was higher in patients with MS, which is associated with less disability. Although iron deficiency anemia was the most prevalent in the MS group (p=0.008), there was no correlation with RLS in this group. In patients with Behcet's disease, there was a significant correlation between iron deficiency anemia and RLS (p=0.004). The most severe RLS symptoms were observed in the MS group. The rate of sleep disorders was higher and the sleep onset latency was longer in the MS group. Although stress appeared to be a factor worsening RLS in all groups, the prevalence was higher in the MS group (p=0.011). There was no correlation between the distribution of MR lesions and RLS in both MS and Neuro-Behcet groups. It is well established that RLS can accompany disorders affecting peripheral and central nervous system such as all types of neuropathy, myelinopathy, and Parkinson's disease. The present study showed that MS and Neuro-Behcet's disease are a risk factors for RLS, and these conditions are associated with more severe symptoms.