December 14, 2018

By Kris Schanilec

New research has found that nerve activity outside the central nervous system may play a role in restless legs syndrome (RLS) symptoms.

In a study published in the Journal of Physiology, scientists report that nerve cells supplying muscles in the legs behave differently in people who have RLS.

Until now, RLS research and treatment has focused largely on processes deep within the brain. First-line RLS treatments target the brain's dopamine and glutamate systems, and brain iron deficiency is also known to be a factor in RLS.

In the new study, the researchers applied electrical stimulus to motor and sensory axons (or nerve fibers) of the median nerve, which is one of the major nerves along the arm. Study participants who had RLS showed higher activity in the motor axons but not the sensory axons, compared to participants who did not have RLS. In their paper, the researchers stated, “Taken together, our results suggest an increase in the excitability of motor units in RLS that could enhance the likelihood of leg movements.”

While the study was small, involving 33 RLS patients and 38 healthy controls, its findings open new avenues for exploration – including medications that could be developed to potentially treat RLS by targeting the nervous system outside the brain and spinal cord.

The research was conducted by the University of Gottingen in German, in collaboration with the University of Sydney in Australia, and Vanderbilt University in the US. RLS Foundation Scientific and Medical Advisory Board member Art Walters is a co-author of the study.