The Hemicrania Continua Diagnosis

Abstract

More than 16 years after the first description of hemicrania continua (HC), its aetiology and pathogenesis remain obscure. Clinically, HC is considered a syndrome with two pivotal characteristics: (i) strictly unilateral (moderate, fluctuating, relatively long-lasting) headache; and (ii) absolute response to indomethacin. HC is further characterized by some ancillary, but mostly "negative", features such as: (iii) relative paucity of accompaniments; and (iv) lack of precipitating factors. The female preponderance is also remarkable, although not diagnostic in the solitary case. Finally, a non-specific, but remarkable feature is the temporal pattern. HC may present as a remitting or chronic (continuous) headache. In HC, unilaterality and absolute response to indomethacin are considered crucial diagnostically. Existing controversy, such as regarding atypical features, particularly the so-called "HC resistant to indomethacin", is discussed. The nature of hemicrania with negative indomethacin response remains most unclear; it may not belong to the HC cycle at all. Accordingly, we propose that the typical clinical picture of HC, including an absolute response to indomethacin, be termed Hemicrania continua vera. More or less analogous, but indomethacin-resistant, clinical pictures can provisionally be termed Hemicrania generis incerti (of undetermined nature), provided other diagnostic possibilities have been ruled out. The differential diagnosis of HC vs. other unilateral headaches is commented on. Previous attempts at classification of HC into the group chronic daily headache (CDH) are discussed. The only acceptable "link" of HC with the other headaches classified as CDH is the temporal pattern (which is a non-specific feature). HC is probably pathophysiologically different from the others disorders classified under CDH. Conversely, HC and chronic paroxysmal hemicrania share many common features, including the absolute response to indomethacin. HC should probably be included in the IHS group 3.

Is there need to search for alternatives to indomethacin for hemicrania continua? Case reports and a review

“…It provides alternative to indomethacin. The effective dose of idomethacin in the patients of HC is highly variables (25 mg every 2 d to 300 mg daily) [2,27]. Similar type of observations was noted even with ibuprofen.…”

“…In the recent past, many cases of HC with atypical features and in association with other pathologies (symptomatic HC) have been reported. Even the diagnostic criteria of HC have been repeatedly modified and revised over the last 10 years [1,27,32]. Because of the limited number of case reports and unknown pathophysiology, it may be hard to define, classify, or make the diagnostic criteria of any disease entity.…”

Hemicrania continua: a report of ten new cases

“…Spierings defend that "hemicrania continua that is resistant to indomethacin, as suggested by Kuritzky 13 does not exist" 2 . The IHS classification does require therapeutic response criteria to make the diagnosis of some headaches, Tolosa-Hunt syndrome being one well-know example 5,14 . The response to indomethacin being so dramatic, it is reasonable to consider it as a strong indicative of HC.…”

Uncommon primary headaches

“…Hemicrania continua (HC) is an uncommon primary headache of unclear pathophysiology, first described in 1984 by Sjaastad [10] and subsequently better defined [11,12]. The literature, to date, describes just over 100 cases, characterized by continuous, moderate-to-severe unilateral pain with absolute response to indomethacin.…”