[A patient with restless legs syndrome/periodic limb movement successfully treated by wearing a lumbar corset]

We report a 77-year-old woman with restless legs syndrome(RLS) and periodic limb movement(PLM). From 62 years of age, she was awakened by tingling and involuntary movement in her legs during sleep. There symptoms disappeared when she stood up and walked. She was treated with clonazepam (2.5 mg/day) and valproate (400 mg/day) at 77 years of age, and the symptoms clearly ameliorated. However, she developed mild truncal ataxia and was referred to our hospital. On admission, neurological examination revealed Babinski and Chaddock signs bilaterally with depressed tendon reflexes in the lower limbs, mild truncal ataxia and horizontal gaze nystagmus. She did not present with involuntary movement of the legs while taking the anti-epileptic drugs. Cessation of these drugs alleviated the truncal ataxia and nystagmus, but reexacerbated abnormal sensation with involuntary movement in her legs during sleep. The involuntary movements in her legs were slower than myoclonus and resembled a Babinski reflex (duration about 1 second), and they appeared periodically (around every 30 seconds) in I-II sleep stages. Neither brain MRI nor EEG detected any abnormality. Cervical MRI revealed focal compression of the spinal cord by osteophytes at C5-C6 (more severe on the left side). Motor evoked potentials with transcranial magnetic stimulation revealed a mild delay in the central conduction time (CCT), which was more prolonged on the left side. She was thus diagnosed as having RLS/PLM with involvement of the bilateral pyramidal tracts. Although nerve conduction studies did not detect any abnormality in the peripheral nerves, RLS/PLM of the left leg was induced by electric stimulation of the left tibial nerve. Because she did not want medication any more, we treated her with a lumbar corset, hoping that wearing a lumbar corset might induce contraction of the truncal muscles that would mimic standing and walking or might produce additional sensory input that would induce a 'sensory trick'. Consequently, her abnormal sensation and involuntary movement during sleep as well as the stimulation of the tibial nerve disappeared. Wearing a lumbar corset may inhibit the excitability of the spinal cord that generates RLS/PLM, though the level of sensory input by the corset was higher than the input level of abnormal sensation in her legs. A lumbar corset may be a useful alternative choice for patients with RLS/PLM, who cannot tolerate either anti-epileptic or dopaminergic drugs.