Ergotamine abuse and subsequent
ergotamine-induced
headache is a common problem in the pharmacological treatment of
migraine and other
headache types; often, withdrawal
therapy is necessary. This study investigated whether
ergotamine abuse affects information processing and whether withdrawal
therapy can lead to an improvement of information processing. We designed a standardized neurophysiological retrospective (
ergotamine abuse) and prospective (
ergotamine withdrawal) study in a supraregional
headache outpatient clinic. Seventy-one patients abusing
ergotamine derivatives with subsequent daily
headache were enrolled and compared to 36
migraine patients without
ergotamine intake and 36 healthy subjects. Information processing was evaluated by latencies and amplitudes of visually evoked event-related potentials (ERP) before and after
ergotamine withdrawal
therapy. P3 latency of the ERP was significantly increased in
ergotamine abuse (442 +/- 45 ms) versus
migraine (415 +/- 40 ms) and healthy subjects (410 +/- 33 ms), there was no difference between
ergotamine tartrate and
dihydroergotamine abuse. The
migraine specific loss of habituation in information processing as measured by P3 latency could not be observed in
migraine patients with
ergotamine abuse. After 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 can be improved but not normalized after withdrawal
therapy. Furthermore, our data provide strong evidence that
ergotamine, besides its peripheral effects, has a central mode of action.