Spinal cord stimulation effects on restless legs syndrome: A single center experience

Restless legs syndrome (RLS) is a lifelong disorder characterized by recurrent, uncomfortable sensations and irresistible urges to move the legs that peak in the evening. Spinal cord stimulation (SCS) is a longstanding neuromodulation treatment for chronic neuropathic pain with emerging evidence of potential effectiveness towards RLS through a potential shared pathophysiology of central sensitization.

To evaluate whether SCS may improve RLS symptoms and/or sleep disturbances in chronic pain patients with co-morbid RLS who received SCS for chronic pain.

A retrospective review of our institution's electronic health record system was performed to identify patients who received SCS for chronic pain with a concomitant RLS diagnosis. Patients who had a diagnosis of RLS in their chart were secondarily confirmed to have RLS using the Cambridge-Hopkins RLS Questionnaire via telephone. The International Restless Leg Syndrome Study Group Rating Scale (IRLSS) and multiple Patient-Recorded Outcomes Measurements (NIH PROMIS) of sleep data were obtained via telephone with patients recalling their symptoms pre- and post-SCS implantation.

A group of 11 patients with an existing SCS system implanted for chronic pain and co-morbid RLS confirmed on the Cambridge-Hopkins questionnaire were identified. The IRLS summed score showed a statistically significant (p=0.0343) improvement with a large effect size (r=0.64) indicating that overall symptom severity measured by the IRLS scale decreased significantly with SCS. There was also a significant (p=0.0223) reduction with a large effect size (r=0.69) in the summed NIH PROMIS sleep-related impairment scores, suggesting that SCS had a substantial positive impact on sleep-related impairments. Contrary to this, insignificant (p=0.778) changes were observed in the summed NIH PROMIS sleep disturbance scores with a small effect size (r=0.09).

SCS has been shown to be an effective, novel treatment for chronic pain but also has positive effects on medication refractory RLS. While this small, retrospective study is limited by recall bias, it provides further evidence of SCS serendipitously improving RLS symptoms. Future prospective research evaluating the effects of SCS on RLS symptoms, pathophysiology, and sleep are needed to further evaluate this phenomenon.