Study objective: A variety of sensory stimuli relieve restless legs syndrome symptoms. Because systematic evaluations of sensory stimulation in restless legs syndrome are largely lacking, we performed a randomized crossover study to evaluate the effect of external sensory stimulation on restless legs syndrome symptoms.
Methods: Eighteen patients underwent 3 consecutive suggestive immobilization tests with the order of the following 3 conditions randomly assigned: no electrical stimulation (condition 1), tactile and proprioceptive sensory stimulation (condition 2), and tactile sensory stimulation only (condition 3). Restless legs syndrome symptoms were quantified by visual analog scales, and periodic leg movements during wake were measured.
Results: Baseline visual analogue scale score was 4.5 (range 0-60) in condition 1, 10.5 (range 0-96) in condition 2, and 8.5 in condition 3 (p = 0.21). There was a tendency towards a higher maximum visual analogue scale score and visual analogue scale score at the end of the suggested immobilization test in the conditions with tactile sensory stimulation, though not significant (p = 0.74 and p = 0.29, respectively). Fifteen patients suffered from periodic leg movements during wake. Median indices were 18 (range 0-145) in condition 1, 26 (range 0-190) in condition 2, and 49 (range 0-228) in condition 3 (p = 0.76).
Conclusions: We found a tendency towards less leg discomfort in the conditions in which an external sensory input was applied. This potential benefit of sensory stimuli on restless legs syndrome severity merits further investigation as this could open new ways towards a better pathophysiological understanding and non-pharmacological treatments.
Keywords: periodic limb movement disorder; restless legs syndrome; suggestive immobilization test.