Commentary on Westergaard’s “Definitions of medication-overuse headache in population-based studies and their implications on prevalence estimates: A systematic review”

We read with interest the paper by Westergaard et al. (1) on a systematic review of Definitions of medication-overuse headache in population-based studies in Cephalalgia, and believe it to be a significant contribution to the field. Undoubtedly, a more universal and reliable definition of medication-overuse headache will aid clinicians and patients alike in achieving more accurate diagnosis, treatment and population-based data regarding the condition. We take issue with a small part of the introduction, which states, “Medication-overuse headache’ as a diagnosis is very new. A classification scheme for headache was first published by an ad hoc committee of the US National Institutes of Health in 1962 but there was no mention of medication overuse as a cause or associated factor. More than twenty years later, in 1986, an expert group agreed on a definition of ‘drug-related headache’.” Although accurate, this fails to give credit to the man who is responsible for defining this condition and conducting the first controlled trial in 1978.

Dr Lee Kudrow presented his results on analgesics for the treatment of chronic headache at a symposium on the Use of Analgesics held in the Bahamas in 1979 and subsequently published in the proceedings of that meeting (2). The result of his four-cell study showed that analgesics have little value in patients with chronic headache and that rebound pain might occur with its use. He was the first to show that withdrawal of the offending medication was beneficial and the addition of low-dose amitriptyline augmented the improvement. He went on to state that analgesics used for chronic headache not only did not work, but seemed to further sustain the painful condition.

He published this study in 1982 in Advanced Neurology, describing withdrawal of the overused analgesic as an effective treatment of medication overuse, the effect of which was enhanced by the use of low-dose amitriptyline (3). Since that time headache specialists have been treating medication-overuse headache patients with withdrawal of the offending agent(s), and sometimes with addition of preventive medication (4,5). Now, as Westergaard et al. have documented, there have been field trials and frequently changing diagnostic criteria of medication-overuse headache (as rebound headaches are now termed). Although no trials have been conducted requiring and using the definition of pre-existing headache disorders, we owe thanks to Dr Kudrow for discovering, documenting and popularizing the concept that patients with pre-existing chronic headache disorders will often worsen when they overuse analgesics (and other acute-care headache medications).