Restless legs syndrome in the older adult: diagnosis and management

Restless legs syndrome (RLS) is common in the elderly, with an estimated prevalence of 10 to 35% in individuals over 65 years of age. RLS is characterised by paraesthesias and dysaesthesias of the legs, typically occurring in the evening. The symptoms occur at rest and result in motor restlessness; movement often temporarily relieves the symptoms. Patients with poorly controlled RLS may develop related problems including insomnia (due to sleep-onset restlessness or periodic limb movements or related sleep fragmentation) and depression. RLS can be a primary disorder that develops in the young and includes familial cases. Secondary RLS occurs in association with iron-deficiency anaemia, uraemia and polyneuropathies. Typically, RLS is misdiagnosed or undiagnosed for years. In the elderly, both primary and secondary types of the disorder are common. It is thought that RLS represents lower CNS levels of, or reduced responsiveness to, dopamine. The symptoms improve with dopaminergic therapy. Ergotamine dopamine-receptor agonists such as pergolide, and the non-ergotamine dopamine-receptor agonists pramipexole and ropinirole, are becoming more commonly used to treat RLS. The dopamine precursor levodopa, in combination with carbidopa, is another effective therapeutic agent. An advantage of levodopa is lower cost than non-ergotamine and ergotamine dopamine-receptor agonists. However, the adverse effect of symptom augmentation appears to develop more frequently with levodopa than dopamine-receptor agonists; therefore, levodopa may currently be used somewhat less often as first-line therapy. Patients with painful symptoms may respond favourably to the anticonvulsants gabapentin and carbamazepine. Opioids and hypnosedatives are helpful in selected patients; however, these agents may have troubling adverse effects in the elderly. Correction of iron deficiency improves symptoms in patients with low ferritin levels. Lifestyle modification may also be helpful. Therapy is directed at symptoms, and most symptomatic patients benefit from treatment. It is important to consider RLS in the differential diagnosis of any patient with paraesthesias of the limbs.