Medication-overuse headache: where are we now?
OBJECTIVE
Many important studies on medication-overuse headache have been published in the last year. Some of them investigated the pathophysiology of headache chronicity, others focused on evaluation of risk factors. The International Headache Society revised the classification criteria. We provide a summary of the new findings and concepts.


RESULTS
Medication-overuse headache was previously defined by the International Headache Society as a chronic headache which occurs following overuse of headache drugs and improves after withdrawal. Hence, the improvement of headache after withdrawal was mandatory for diagnosis. The new appendix criteria appeared last year and established a broader concept of medication-overuse headache no longer requiring improvement after discontinuation of medication overuse. Several large population-based longitudinal studies clearly demonstrated that overuse of any kind of acute headache medication is the main risk factor leading to development of chronic headache. Imaging studies provided new important insights into the pathophysiology of headache chronicity. New treatment strategies have been suggested.


CONCLUSIONS
Recent data provide better insight into pathophysiology of medication-overuse headache. Epidemiological studies clearly demonstrate the necessity of establishing a predictive model for early recognition of patients at high risk to intervene early and avoid development of chronic headache.
Katsarava
Zaza
Z
Department of Neurology, University of Essen, Essen, Denmark. zaza.katsarava@uni-due.de
Jensen
Rigmor
R
D000700:Analgesics / Q000009:adverse effects*; D016021:Epidemiologic Studies; D020773:Headache Disorders / Q000139:chemically induced* / Q000145:classification* / Q000453:epidemiology; D006801:Humans; D008881:Migraine Disorders / Q000139:chemically induced / Q000453:epidemiology / Q000503:physiopathology; D018579:Patient Selection; D012307:Risk Factors; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000628:therapy; D018781:Tension-Type Headache / Q000139:chemically induced / Q000453:epidemiology / Q000503:physiopathology
D000700:Analgesics