[Restless legs syndrome in patients with high serum ferritin and normal iron levels]

Abstract

Aim: To document the association between restless legs syndrome (RLS) and high ferritin levels in five patients.

Patients and methods: The five patients were male, mean age: 59 years (range: 36-73 years). The patients were referred for RLS (two of them blood donors), in two cases associated with obstructive sleep apnea. Patients underwent a video-PSG recording. Serum iron and serum ferritin were determined.

Results: All patients fulfilled the clinical criteria for RLS: leg paresthesias associated with an urge to move, motor restless-ness, worsening of symptoms during the evening and night, and partial relief with activity, difficulty falling asleep, and presence of nocturnal awakenings due to RLS. Neurological examination, EEGs, EMGs and MRIs were normal. Video-PSGs recordings showed a disturbed and fragmented sleep with a reduction in total sleep time, low sleep efficiency, respiratory abnormalities with an apnea-hipopnea index > 10/h in two cases, and in all of them a periodic leg movements index > 5/h. The serum iron levels were within the normal range in all cases, whereas those in serum ferritin levels were high.

Conclusions: To our knowledge the association of normal serum iron with high serum ferritin levels in patients diagnosed clinically and polygraphically as having RLS with periodic leg movements has not been described before. The notion of an involvement of a dopaminergic mechanism in the pathophysiology of RLS is supported by the decrease in the values of serum ferritin concentration observed in one patient during follow-up while being treated with dopaminergic agents.