Sympathetic skin response in migraineurs and patients with medication overuse headache

Background.-Autonomic dysfunction has been reported in patients with migraine, and it may play a role in promoting attacks. Objective.-To investigate changes in the autonomic function of migraineurs and patients with medication overuse headache via sympathetic skin response, and to determine whether psychiatric comorbidity is related to any changes recorded. Methods.-A consecutive series of patients with migraine (n = 45) and medication overuse headache (n = 53) were studied. Patients with other chronic diseases requiring medication were excluded. Sympathetic skin response latencies and amplitudes from the patients with headache (N = 98) and 40 healthy controls were compared statistically. Results.-Sympathetic skin response latencies in patients with medication overuse headache and in migraineurs were significantly longer than in controls. To analyze the effect of psychiatric comorbidity, patients with medication overuse headache and migraineurs were each divided into 2 groups: those with psychiatric comorbidity and those without comorbidity. When the sympathetic skin response results of these 4 groups were compared with controls, the only statistically significant difference was between the sympathetic skin response latencies of controls and the latencies of patients with psychiatric comorbidity. We could not find any difference between the results from patients without psychiatric comorbidity and those of controls. Conclusion.-Psychiatric disease may affect the results of autonomic function testing in migraineurs and patients with medication overuse headache. Consideration should be given to excluding patients with psychiatric comorbidity from studies investigating autonomic dysfunction in patients with headache.