Hemicrania continua: a clinical study of 39 patients with diagnostic implications

Abstract

Hemicrania continua is an uncommon primary headache disorder, characterized by continuous unilateral pain, where pain exacerbations are associated with cranial autonomic features. The hallmark of this condition is the absolute response to indometacin. We describe the phenotype of this condition in a large series of patients. Thirty-six (92%) patients had side-locked pain and 3 (8%) had side-alternating pain. The majority (82%) of the patients had the chronic (unremitting) form and the severity range of background pain was 1-10 out of 10 on verbal rating scale, with a mean of 6.5. Thirty-eight (97%) of the patients rated the painful exacerbations between 6.5 and 10 with a mean of 9 and 28 (71%) described their severe pain as excruciating. Of the cohort, 97% had at least one cranial autonomic feature during exacerbations: 73% had lacrimation, 51% nasal congestion, 46% conjunctival injection and 40% ptosis and facial flushing. Other cranial autonomic features included rhinorrhoea, forehead/facial sweating, itching eye, eyelid oedema, sense of aural fullness and periaural swelling, miosis, mydriasis and swelling of the cheek and face. Thirty-one (79%) had phonophobia, which was unilateral in 14 (48%); 29 (74%) had photophobia, which was unilateral in 14 (48%); and 27 (69%) had motion sensitivity. In addition, about two-thirds were agitated or restless, or both, and about one-quarter were aggressive, mainly verbally, with severe pain. All patients had a positive placebo-controlled indometacin test (100-200 mg intramuscularly) or a positive oral indometacin trial, or both. We suggest the International Headache Society criteria be revised to remove the absence of side-shift pain as a criterion. Furthermore, revised criteria should encompass a more extensive range of cranial autonomic features and consider pain as fluctuating with moderate, severe and very severe intensity. Currently the sine qua non for hemicrania continua is a response to indometacin. Since there is no reliable clinical marker of that response, we recommend an indometacin test, either orally or by injection, for any patient with unilateral pain, with or without cranial autonomic symptoms.

Headache, Primary Headaches and Their Treatment

“…40 Primary stabbing headache: Stabbing pain confined to the head or rarely the face lasting from 1 to many seconds or minutes.…”

Headache and facial pain

“…4 There are chronic varieties of other, rarer primary headaches, such as cluster headache, paroxysmal hemicrania, and SUNCT syndrome (shortlasting neuralgiform headache attacks with conjunctival injection and tearing) 5 as well as a rare but underdiagnosed primary headache disorder called hemicrania continua. 6 In the other set of cases, patients start to have a headache one day, and it simply never goes away. This is a syndrome that goes under the name 'new daily persistent headache', and is an important pattern to recognize, because it is within this set of headaches that many of the serious causes lie (Table 3); an example is the 'thunderclap headache' typical of subarachnoid haemorrhage, which is a genuine medical emergency.…”

Tension-Type Headache Mimics

“…While this phenomenon is sometimes termed bilateral HC, Solomon and Newman suggested a better term for this condition might be indomethacin-responsive daily headache because HC by definition is a unilateral headache [36]. In addition, some patients with conventional, unilateral HC in their course may ultimately develop bilateral pain, perhaps as a consequence of medication overuse on a background of an underlying personal or family history of migraine [38]. Some authors recommend a trial of indomethacin in the more common forms of CDH that do not respond to conventional treatment [36].…”

“…Like CTTH, HC is more common in women, with a female-to-male ratio of 1.6:1 to 2.4:1 in the largest case series [32,38]. However, CTTH is usually bilateral, lacks autonomic features, and is not associated with exacerbations of severe pain [32].…”