Untersuchung der Effekte von transkutanem spinalem Gleichstrom (tsDCS) bei Patienten mit idiopathischem Restless-Legs-Syndrom

Background: Several studies indicate an increased spinal excitability in patients with idiopathic restless legs syndrome (RLS). Transcutaneous spinal direct current stimulation (tsDCS) is a non-invasive tool which can reduce spinal cord activity. We therefore aimed to assess whether the application of tsDCS led to an alleviation of RLS symtoms. Methods: We used a double-blind placebo-controlled study design with 20 primary RLS patients and 14 healthy participants. They received one session of each anodal, cathodal and sham tsDCS of the thoracic spinal cord (2,5 mA, 15 min) . A visual analogue scale (VAS) was used to assess RLS symptom severity. The H2/H1-ratio of the spinal H-reflex was used  as a measure of spinal cord activity. VAS and H-reflex measurements were performed before and after application of tsDCS. Results:  H2/H1-ratios in RLS patients were increased in comparison to helathy controls. Application of anodal and cathodal tsDCS led to a short-lasting improvement of RLS symptoms, whereas only anodal tsDCS led to a reduction of increased H2/H1-ratios in RLS patients. Conclusion: For the first time tsDCS was applied in primary RLS with a short-lasting alleviation of symptoms.Therefore the application of tsDCS could become a new non-pharmocolgical treatment for RLS patients. Furthermore the results confirm that increased spinal cord excitability plays an important role in the pathophysiology of primary RLS.