The impact of ergotamine induced headache and ergotamine withdrawal on information processing

Ergotamine abuse and subsequent ergotamine-induced headache is a common pro blem in the pharmacological treatment of migraine and other headache types; often, withdrawal therapy is necessary. This study investigated whether er gotamine abuse affects information processing and whether withdrawal therap y call lead to an improvement of information processing. We designed a stan dardized neurophysiological retrospective (ergotamine abuse) and prospectiv e (ergotamine withdrawal) study in a supraregional headache outpatient clin ic. Seventy-one patients abusing ergotamine derivatives with subsequent dai ly headache were enrolled and compared to 36 migraine patients without ergo tamine intake and 36 healthy subjects. Information processing was evaluated by latencies and amplitudes of visually evoked event-related potentials (E RP) before and after ergotamine withdrawal therapy. P3 latency of the ERP w as significantly increased in ergotamine abuse (442 +/- 45 ms) versus migra ine (415 +/- 40 ms) and healthy subjects (410 +/- 33 ms), there was no diff erence between ergotamine tartrate and dihydroergotamine abuse. The migrain e specific loss of habituation in information processing as measured by P3 latency could not be observed in migraine patients with ergotamine abuse. A fter successful withdrawal therapy in 36 patients, the abnormally prolonged P3 latency was significantly shortened (452 +/- 47 ms versus 433 +/- 30 ms ; P < 0.004). Our findings imply that information processing is impaired by ergotamine abuse and call be improved but not normalized after withdrawal therapy. Furthermore, our data provide strong evidence that ergotamine, bes ides its peripheral effects, has a central mode of action.