TOPLINE:

The frequency of developing restless legs syndrome (RLS) among patients with multiple sclerosis (MS) was about twice as that among those without MS, with diagnoses confirmed by a sleep disorder specialist. Notably, a family history of RLS and pyramidal tract involvement were the strongest factors associated with its development.

METHODOLOGY:

• Researchers conducted a case-control study to assess how often RLS occurs in patients with MS, with diagnoses confirmed by a sleep disorder specialist, and factors linked to its development.
• They included 440 patients with MS from a MS unit at a Spanish hospital who met the McDonald 2017 diagnostic criteria and 241 matched control participants without MS between 2023 and 2024.
• Cases of RLS were identified in two stages, through telephone or in-person interviews, using a structured questionnaire according to the diagnostic criteria of the International Restless Legs Syndrome Study Group, followed by confirmation interviews with a sleep disorder specialist for those meeting the initial criteria.
• Clinical and radiologic features of MS were assessed to identify key factors associated with the development of RLS.

TAKEAWAY:

• According to questionnaire-based screening, the frequency of RLS was 19.6% among patients with MS in contrast to 9.6% among those in the control group, with a false positive rate of 22.1%.
• After confirmation by a sleep disorder specialist, the frequency of RLS was 15.2% among patients with MS compared with 7.9% among those in the control group (P = .006).
• In patients with MS, having a family history of RLS and symptoms of pyramidal tract involvement were associated with approximately fivefold and fourfold higher odds of developing RLS (P < .001 for both).
• Patients with spinal cord lesions had 60% lower odds of developing RLS (P = .011).

IN PRACTICE:

"[The study] 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 track [tract] involvement," the authors wrote.

SOURCE:

This study was led by Yolanda Aladro, Department of Neurology, Hospital Universitario de Getafe, Carretera Toledo, Getafe, Madrid, Spain. It was published online on January 25, 2026, in the Journal of Neurology.

LIMITATIONS:

Milder and/or episodic cases may have been underestimated as the study did not use the symptom frequency threshold for establishing the diagnosis of RLS. Data on the age at onset and severity of RLS were not systematically collected in all cases. All patients with MS, except pregnant women, were included, regardless of comorbidities that could have contributed to RLS.

DISCLOSURES:

This study received funding from the Foundation for Biomedical Research and the Research Institute of La Paz University Hospital, Madrid, and Almirall Pharmaceuticals. Two authors reported receiving grants for research projects from Almirall and fees for seminars, consulting, and travel to conferences from various pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.