Restless legs syndrome: clinicoetiologic correlates.

Despite recent attempts to better characterize restless legs syndrome (RLS), this neurologic disorder remains poorly understood. The relationship between idiopathic and secondary and between familial and sporadic (nonfamilial) cases have not been previously defined. We studied 54 patients (29 women and 25 men) who satisfied the diagnostic criteria for RLS. The mean age of the patients was 62.69 +/- 13.82 years, and the mean age at onset was 34.13 +/- 20.30 years. We found that 92% of patients with idiopathic RLS (without neuropathy) had a family history of RLS, whereas only 13% of those with neuropathic RLS (associated with peripheral neuropathy) had a positive family history. The sporadic/neuropathic patients were older at symptom onset and tended to have a more rapid progression than the familial/idiopathic patients. There were no other significant differences between the subgroups. Levodopa and dopamine agonists were the most effective treatments. We conclude that there are two major etiologic subgroups of RLS but that the two share central pathophysiologic mechanisms.