Shaun T O'Keeffe1. 1. Department of Geriatric Medicine, Unit 4, Merlin Park Regional Hospital, Galway, Ireland. s.okeeffe@whb.ie
Abstract
BACKGROUND: Secondary causes of restless legs syndrome (RLS) have been reported to be more common in those with late-onset RLS. However, 'late-onset' in previous studies was defined as onset after 45 years. OBJECTIVE: To determine the prevalence of secondary causes of RLS and the relationship between aetiological factors and age of symptom onset in an older population. DESIGN: Prospective study conducted over a 5-year period. PARTICIPANTS: 80 consecutive non-related patients diagnosed with RLS. MEASUREMENTS: Patients were assessed according to a standard protocol. Age at symptom onset, severity of symptoms, neurological findings and laboratory tests were examined. RESULTS: Iron deficiency (serum ferritin <50 ng/ml) was present in 22% of patients with onset before 50 years, 39% of those with onset at 50 to 64 years and 58% in those with onset after 64 years (P = 0.009). Clinical neuropathy was also more common in older-onset patients (P = 0.08). Family history was positive in 39%, 23% and 8% of these groups, respectively (P = 0.008). CONCLUSION: Secondary causes of RLS become more common and a positive family history less common with increased age of symptom onset.
BACKGROUND: Secondary causes of restless legs syndrome (RLS) have been reported to be more common in those with late-onset RLS. However, 'late-onset' in previous studies was defined as onset after 45 years. OBJECTIVE: To determine the prevalence of secondary causes of RLS and the relationship between aetiological factors and age of symptom onset in an older population. DESIGN: Prospective study conducted over a 5-year period. PARTICIPANTS: 80 consecutive non-related patients diagnosed with RLS. MEASUREMENTS: Patients were assessed according to a standard protocol. Age at symptom onset, severity of symptoms, neurological findings and laboratory tests were examined. RESULTS:Iron deficiency (serum ferritin <50 ng/ml) was present in 22% of patients with onset before 50 years, 39% of those with onset at 50 to 64 years and 58% in those with onset after 64 years (P = 0.009). Clinical neuropathy was also more common in older-onset patients (P = 0.08). Family history was positive in 39%, 23% and 8% of these groups, respectively (P = 0.008). CONCLUSION: Secondary causes of RLS become more common and a positive family history less common with increased age of symptom onset.