MS patients about twice as likely to have restless legs syndrome: Study
Those with voluntary movement issues more likely to develop condition
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A person lies in bed, with their legs uncovered and more faint images showing the legs in different positions.
- Multiple sclerosis patients are twice as likely to develop restless legs syndrome.
- Family history and pyramidal symptoms increase the risk in MS patients.
- Routine RLS assessment is crucial for MS patients, especially those with sleep issues or motor impairment.
People with multiple sclerosis (MS) are about twice as likely to develop restless legs syndrome (RLS) — a constant urge to move the legs during rest or inactivity — than those without the disease, according to a study in Spain.
Among MS patients, having a family history of RLS and pyramidal symptoms — problems related to voluntary movement, such as muscle weakness and stiffness — was associated with a higher likelihood of developing the condition.
“These findings highlight the importance of routine assessment for RLS in MS patients, particularly in those presenting with sleep disturbances or motor impairment linked to pyramidal [tract] involvement,” researchers wrote.
The study, “Prevalence of restless legs syndrome in patients with multiple sclerosis, as confirmed by sleep disorders specialists,” was published in the Journal of Neurology.
Previous estimates of RLS prevalence in MS varied widely
RLS is characterized by uncomfortable sensations in the lower legs and feet that create an urge to move, especially during periods of rest. The condition often interferes with sleep and is known to occur more frequently in people with MS than in the general population.
However, previous estimates of RLS prevalence in MS varied widely, ranging from 13% to 65%. However, many of those studies either lacked a control group or relied only on questionnaires, without confirmation of the RLS diagnosis by a sleep specialist.
To address these limitations, a team of researchers in Spain evaluated the prevalence of RLS among 440 MS patients treated at their hospital and 241 individuals without the disease matched by age and sex.
Most patients were women, with a mean age of 50, and had relapsing forms of MS (83.9%). The mean disease duration was nearly 15 years. Compared with controls, MS patients were more frequently taking medications that may worsen RLS (30.7% vs. 14.1%).
RLS cases were identified through a two-step process. First, patients completed a structured questionnaire covering the four main symptoms of RLS. A sleep specialist then interviewed those with suspected RLS.
Of 86 MS patients flagged by the questionnaire, 67 received a confirmed diagnosis, corresponding to a prevalence of 15.2%. In the control group, the prevalence was about half that, at 7.9%.
Notably, 22% of possible RLS cases identified by the questionnaire were false positives, underscoring “the need for confirmation by a sleep-medicine specialist,” the researchers wrote. False positives were more common among patients with leg stiffness and discomfort related to spasticity and severe sensory symptoms.
The high prevalence of RLS in [people with MS] and the association of this syndrome with pyramidal tract involvement support the hypothesis of MS as a cause of RLS, at least in some patients.
When comparing MS patients with or without RLS, those with the syndrome were significantly older (52.5 vs. 49.6 years) and more frequently had pyramidal tract involvement (67.2% vs. 49%) and a family history of RLS (26.9% vs. 7.5%).
No significant differences were observed between the two groups in brain MRI activity, but spinal cord lesions tended to be more common among people without RLS.
Consistently, pyramidal symptoms and a family history significantly increased the likelihood of developing RLS — by 4 to 5 times — while spinal cord lesions appeared to be protective, decreasing the likelihood of RLS by more than 60%.
“The high prevalence of RLS in [people with MS] and the association of this syndrome with pyramidal tract involvement support the hypothesis of MS as a cause of RLS, at least in some patients,” the researchers wrote. “These findings highlight the importance of routine assessment for RLS in MS patients, particularly in those presenting with sleep disturbances or motor impairment linked to pyramidal [tract] involvement.”
