Restless Leg Syndrome May be Associated with Migraines

November 2, 2007 — Restless legs syndrome (RLS) occurs more frequently in patients with migraine than in those without, according to results of a case-control study conducted in Germany. A possible co-association of depressive symptoms with both disorders also emerged in the study.


While the underlying mechanism for the comorbidity of migraine and RLS remains undetermined, it might involve dysfunction of the dopaminergic system, the researchers note in the November issue of the journal Cephalalgia.
Dr. Stefan Evers from the University of Munster and colleagues investigated the prevalence of RLS in 411 patients with migraine and 411 sex- and age-matched controls who had no history of headache suggestive of migraine.



"In addition, patients with migraine showed a trend towards worse symptoms of RLS than patients who suffer only from RLS," Dr. Evers and colleagues note.


There was no significant association between migraine and a diagnosis of depression — 9.6% of migraineurs were diagnosed with depression compared with 4.0% of controls (p = 0.190). However, the Beck's Depression Inventory (BDI) score was significantly higher in the migraine group than in the control group (8.8 vs 6.1; p < 0.001).


Similarly, rates of depression were not significantly different in the 71 migraine patients with RLS and the 340 migraineurs without RLS (13.6% and 8.7%, respectively; p = 0.312), but migraine patients with RLS had significantly higher BDI scores than migraine patients without RLS (12.1 vs 8.0; p < 0.001).


Dr. Evers and colleagues also found evidence that older age and longer duration of migraine may raise the risk of RLS. Migraine patients with RLS in the study were significantly older than patients with migraine only.


Age and the duration of migraine "are of special importance because patients with migraine and RLS have probably taken headache medication for a longer time," the clinicians note. "These patients may more often exhibit a symptomatic RLS based on renal insufficiency due to medication overuse."


Older migraine patients are likely also to have used ergotamine derivatives for headache, they point out, which "can cause myalgia and paraesthesia as a side-effect of clinical or subclinical ergotism. In these cases, the symptoms of the vascular side-effects could mimic RLS or ergotamine use, with subsequent (e)ffects on the spinal tract, and polyneuropathy might lead to symptomatic RLS," Dr. Evers and colleagues write.


They note that future studies may uncover a common genetic background for both RLS and migraine.


Migraine has been associated with sleep disorders such as prolonged rapid eye movement sleep latency and narcolepsy, and an association with RLS has been suggested, with dopaminergic pathways as a possible mediator for both conditions. RLS is a sensorimotor condition with a prevalence of 2.5% to more than 10% in the white population, and prevalence increases to a peak at age 65 years and then decreases, with diagnosis based on criteria of the International RLS study group. A positive family history is seen in 50% of patients with idiopathic RLS, and family history is also described for patients with migraine. In addition, patients with migraine have a 3-fold increased risk for depression, and a higher prevalence of anxiety and depression has also been described among patients with RLS.


This is a prospective case-control study to examine the association between migraine and RLS, and migraine and depression in patients presenting to neurology clinics.
Reuters Health Information November 2007