Rating of daytime and nighttime symptoms in RLS: validation of the RLS-6 scale of restless legs syndrome/Willis-Ekbom disease

Background: The International Restless Legs Scale (IRLS) is the most widely used of the scales rating the severity of restless legs syndrome/Willis-Ekbom disease (RLS/WED). It has been well validated and is the primary end point for most of the therapeutic and nontherapeutic studies of RLS/WED. It has excellent psychometric properties, although it does not capture the severity of RLS under a wide variety of circumstances and times of day. Moreover, the IRLS has a large placebo effect. Methods: The Restless Legs Syndrome-6 Scale (RLS-6), however, takes another potentially valuable approach. Six items are rated on a 0-10 scale from no symptoms at 0 to very severe at 10. In addition to questions on satisfaction with sleep and sleepiness, the scale rates the severity of RLS for the past week under four separate circumstances: while falling asleep, during the night, during the day while sitting or lying, and during the day when moving around. The purpose of the current study is to report the validation of the RLS-6 under baseline and therapeutic conditions. Results: The RLS-6 seems to be an acceptable, reliable, precise, valid, and responsive instrument for the assessment of RLS severity in a specific and pragmatic manner. Conclusions: At present, we view the RLS-6 not as a replacement for the IRLS but as a supplement, as each scale provides information not captured by the other.S

Validation of the Kohnen Restless Legs Syndrome-Quality of Life instrument

Background: Due to the symptoms and the sleep disturbances it causes, Restless Legs Syndrome (RLS) has a negative impact on quality of life. Measurement of such impact can be performed by means of questionnaires, such as the Kohnen Restless Legs Syndrome-Quality of Life questionnaire (KRLS-QoL), a specific 12-item instrument that is self-applied by patients. The present study is aimed at performing a first formal validation study of this instrument. Methods: Eight hundred ninety-one patients were included for analysis. RLS severity was assessed by the International Restless Legs Scale (IRLS), Restless Legs Syndrome-6 scales (RLS-6), and Clinical Global Impression of Severity. In addition the Epworth Sleepiness Scale (ESS) was assessed. Acceptability, dimensionality, scaling assumptions, reliability, precision, hypotheses-related validity, and responsiveness were tested. Results: There were missing data in 3.58% patients. Floor and ceiling effects were low for the subscales, global evaluation, and summary index derived from items 1 to 11 after checking that scaling assumptions were met. Exploratory parallel factor analysis showed that the KRLS-QoL may be deemed unidimensional, ie, that all components of the scale are part of one overall general quality of life factor. Indexes of internal consistency (alpha = 0.88), item-total correlation (rS = 0.32-0.71), item homogeneity coefficient (0.41), and scale stability (ICC = 0.73) demonstrated a satisfactory reliability of the KRLS-QoL. Moderate or high correlations were obtained between KRLS-QoL scores and the IRLS, some components of the RLS-6, inter-KRLS-QoL domains, and global evaluations. Known-groups validity for severity levels grouping and responsiveness analysis results were satisfactory, the latter showing higher magnitudes of response for treated than for placebo arms. Conclusions: The KRLS-QoL was proven an acceptable, reliable, valid, and responsive measure to assess the impact of the RLS on quality of life.S

Anisotropic Polar Magneto-Optic Kerr Effect of Ultrathin Fe/GaAs (001) Layers du to Interfacial Spin-Orbit Interaction

We report the observation of the anisotropic polar magneto-optical Kerr effect in thin layers of epitaxial Fe/GaAs(001) at room temperature. A clear twofold symmetry of the Kerr rotation angle depending on the orientation of the linear polarization of the probing laser beam with respect to the crystallographic directions of the sample is detected for ultrathin magnetic films saturated out of the film plane. The amplitude of the anisotropy decreases with increasing Fe film thickness, suggesting that the interfacial region is the origin of the anisotropy. The twofold symmetry is fully reproduced by model calculations based on an interference of interfacial Bychkov-Rashba and Dresselhaus spin-orbit coupling

GBA mutations are associated with Rapid eye movement sleep behavior disorder

Rapid eye movement sleep behavior disorder and GBA mutations are both associated with Parkinson’s disease. The GBA gene was sequenced in idiopathic rapid eye movement sleep behavior disorder patients (n = 265), and compared to controls (n = 2240). Rapid eye movement sleep behavior disorder questionnaire was performed in an independent Parkinson’s disease cohort (n = 120). GBA mutations carriers had an OR of 6.24 (10.2% in patients vs. 1.8% in controls, P < 0.0001) for rapid eye movement sleep behavior disorder, and among Parkinson’s disease patients, the OR for mutation carriers to have probable rapid eye movement sleep behavior disorder was 3.13 (P = 0.039). These results demonstrate that rapid eye movement sleep behavior disorder is associated with GBA mutations, and that combining genetic and prodromal data may assist in identifying individuals susceptible to Parkinson’s disease

Progressive development of augmentation during long-term treatment with levodopa in restless legs syndrome: results of a prospective multi-center study

The European Restless Legs Syndrome (RLS) Study Group performed the first multi-center, long-term study systematically evaluating RLS augmentation under levodopa treatment. This prospective, open-label 6-month study was conducted in six European countries and included 65 patients (85% treatment naive) with idiopathic RLS. Levodopa was flexibly up-titrated to a maximum dose of 600 mg/day. Presence of augmentation was diagnosed independently by two international experts using established criteria. In addition to the augmentation severity rating scale (ASRS), changes in RLS severity (International RLS severity rating scale (IRLS), clinical global impression (CGI)) were analyzed. Sixty patients provided evaluable data, 35 completed the trial and 25 dropped out. Augmentation occurred in 60% (36/60) of patients, causing 11.7% (7/60) to drop out. Median time to occurrence of augmentation was 71 days. The mean maximum dose of levodopa was 311 mg/day (SD: 105). Patients with augmentation compared to those without were significantly more likely to be on higher doses of levodopa (≥300 mg, 83 vs. 54%, P = 0.03) and to show less improvement of symptom severity (IRLS, P = 0.039). Augmentation was common with levodopa, but could be tolerated by most patients during this 6-month trial. Patients should be followed over longer periods to determine if dropout rates increase with time