High prevalence of Dopaminergic Premonitory Symptoms in migraine patients with Restless Legs Syndrome: a pathogenetic link?

In order to assess the prevalence of Dopaminergic Premonitory Symptoms (DPS) in migraine patients with Restless Legs Syndrome (RLS), we chose migraine patients from a large Italian clinical headache population previously investigated for an association between primary headaches and RLS. We evaluated a total sample of 164 patients with migraine, in particular 114 with migraine without aura (MO), 10 with migraine with aura (MA) and 40 with MO and MA in various combinations between them or with episodic tension-type headache (ETTH), defined as a "mixed group". About 20% of all migraine patients referred at least one of the following DPS: yawning, nausea, somnolence or food craving, confirming data already indicated in the literature. Among migraine patients with RLS (25.6%), DPS were referred from about half of the patients (47.6%) compared to those without RLS (47.6% vs. 13.1%; p<0.001). Based on migraine subtype, patients with MO referred DPS (26.3%) more frequently compared to the MA group and "mixed group" (12.0%, p<0.05), particularly in the presence of RLS (63.0% vs. 20.0%, p<0.01). No statistical differences were found between clinical and demographic data of the subgroups or related to medical conditions investigated (anxiety, depression, sleep disorders, body mass index). It is interesting that the chances of having RLS in migraine patients were more than 5 times higher in the presence of DPS. These results could support a hypothetical dopaminergic imbalance in RLS and migraine, as the dopamine is involved in the pathogenesis of both disorders and it is responsible for the migraine DPS reported above.