Rheumatologic serologies in secondary restless legs syndrome

Area of Science:

• Neurology
• Rheumatology
• Internal Medicine

Background:

• Diagnostic criteria for restless legs syndrome (RLS) exist, but its underlying pathophysiology is unclear.
• Secondary causes of RLS include renal failure, iron deficiency, pregnancy, and neuropathy.
• RLS is reported in about 25% of patients with rheumatoid arthritis and Sjögren's syndrome.

Purpose of the Study:

• To investigate the prevalence of rheumatologic disease in patients with RLS.
• To determine if rheumatologic conditions are a significant secondary cause of RLS.
• To compare rheumatologic disease with other potential secondary causes of RLS.

Main Methods:

• Clinical and serologic evaluations were performed on 68 patients diagnosed with RLS.
• Patients were assessed for concurrent rheumatologic disease.
• Evaluations were compared with other postulated secondary causes of RLS.

Main Results:

• No patient exhibited clinical evidence of rheumatologic disease.
• Only four patients had positive serologic evaluations (two positive SSA/SSB, two mildly elevated RF titers).
• Patients without a family history of RLS showed lower ferritin levels, more neuropathy cases, and older age at symptom onset.

Conclusions:

• Rheumatologic disease is unlikely to be a significant secondary cause of RLS.
• Serologic investigation for rheumatologic disease is not recommended for RLS unless clinical signs are present.
• Neuropathy and serum iron deficiency are suggested as significant secondary causes of RLS.