Orofacial Migraine

Migraine is defined by the International Headache Society (IHS) as a stabbing or throbbing headache with maximum pain intensity usually in the frontotemporal region and accompanying symptoms (ICHD-II) (1). Occasionally, patients are referred to our orofacial pain unit for evaluation and pain management because of a distinctive type of episodic dental pain, lasting hours to days. Some of these patients have dental treatment for this reason. When asked specifically, they might report some degree of associated headache episodes, and, interestingly, accompanying symptoms reminiscent of migraine.

Here we present two such patients, both of whom have been evaluated by a neurologist and a dentist.

Case reports

Patient 1

A 44-year-old, otherwise healthy female had experienced episodic pain for the past 6 years. Pain localization had always been in the left mandible. She reported pain episodes that started off as a diffuse toothache and tended to extend, within 30 min to 2 h, over the left side of her head (frontotemporal and parietal). The pain maximum remained in the lower jaw and teeth, during the entire attack. The pain was described as predominantly throbbing, most unpleasant in the teeth, usually lasting half a day. The patient had treated herself with several over-the-counter non-steroidal anti-inflammatory drugs in low dosages, without substantial relief.

The patient denied any visual or other aura symptoms. With phonophobia and photophobia as a regular accompaniment, she preferred to rest in a dark, quiet room during the attacks. She did not report any nausea. These pain attacks occurred once a week on average, with psychological distress being a trigger factor.

Neurological examination performed during a pain-free interval was normal. Radiological dental examinations as well as brain magnetic resonance imaging were unremarkable. We initiated attack therapy with zolmitriptan 2.5 mg which resulted in significant pain relief within 30 min and complete relief within 1 h. Because of a presumed migraine diagnosis, treatment with topiramate was initiated but discontinued due to intolerable fatigue.

Patient 2

A 48-year-old, otherwise healthy female reported pain episodes since early childhood. These episodes characteristically began with a unilateral throbbing pain around the temple, mostly on the right-hand side. They were occasionally preceded by lateral visual field restriction fulfilling IHS criteria of a typical visual aura. Within 1 h the pain usually spread to the right side of the face with the most intense ache persisting in the maxillary front teeth until the end of the attack. This patient's chief complaint was of a toothache.

Intensity rating reached up to 8 out of 10 on a verbal rating scale, which corresponds to approximately 8 cm out of 10 cm on a visual analogue scale. These attacks were accompanied by phono- and photophobia and severity was significantly increased by physical activity. Toothache prevented her from eating. Neurological examination at the time of presentation was unremarkable. Untreated attacks usually lasted for 1 day.

Over the course of several years, attacks became increasingly frequent and severe. At the time of examination, she suffered from one or two attacks per week. In the past, she had taken a combination drug containing ergotamine and diclofenac, with satisfactory pain relief. However, this drug had been withdrawn from the Swiss market. Since then she had treated herself with low-dose diclofenac (12.5 mg) and complained of low effectiveness. We made the diagnosis of migraine with and without aura (ICHD-II 1.1, ICHD-II 1.2.1). Triptan medication was proposed, but the patient was unwilling to try this medication at that time.

Discussion

We describe two patients with dental pain as presenting complaint. Except for pain localization, both patients described typical migraine attacks fulfilling ICHD-II criteria (ICHD-II 1.1) (1). The predominantly unilateral, episodic pain attacks of pulsating character lasted between 4 and 72 h. Both patients reported sensory hypersensitivity to light, sound and movement. In the second patient, the inability to eat could partly be explained by allodynia (2). One patient experienced additional aura symptoms, hence fulfilling the diagnostic criteria for migraine with aura (ICHD-II 1.2).

Since pathologies in dental and surrounding tissues as well as referred pain from distant areas were ruled out by careful clinical and radiological examination, the differential diagnosis according to ICHD-II criteria was limited to persistent idiopathic facial pain (ICHD-II 13.18.4), previously known as atypical facial pain (1, 3). Since our patients presented with typical symptoms for migraine but unusual pain localization, the categorization of this migraine with predominantly orofacial manifestation (‘orofacial migraine’) was difficult within the current IHS classification.

We are not the first to address the diagnostic problem related to migraine symptoms associated with orofacial pain. Lance listed lower half headache under vascular headache of migraine type, a group distinct from atypical facial pain (4). He reasoned that ‘migraine headache may be limited to a particular part of the vascular tree …’ ‘… even involving the internal maxillary and other branches of the external carotid system to produce facial pain known as “lower half headache” ’. In a more recent edition of the same textbook, facial migraine is considered ‘if usually unilateral pain involves nostril, cheek, gums and teeth, sometimes spreading to neck ear or eye …’, and separate from persistent idiopathic facial pain (5). Waespe and Isler, in a discussion on the IHCD-I criteria, also raised the question of how to best classify patients with facial pain sharing migraine features (6). A considerable number of cases with migraine symptoms and predominant pain in the orofacial area have been reported, indicating that the diagnostic issue is of clinical importance (6–10). Benoliel et al. have described 55 patients with symptoms characterized by ‘orofacial pain with vascular-type features’ (9). A subgroup of these had accompanying nausea, phonophobia and photophobia, but the authors did not conceptualize this subgroup according to the accompanying symptoms. A case of dental pain and associated migraine symptoms has been reported by Namazi (7). Six percent of 973 patients treated in a rhinological setting described migraine-associated pain isolated to the second division of the trigeminal nerve (8). Most recently, Penarrocha et al. reported 11 patients whom they classified as lower half facial migraine. In their series, four patients reported nausea, vomiting, photophobia and phonophobia associated with their facial pain (10).

Although treatment response is not a criterion in the current IHS classification, the prompt positive response of one of our patients to a triptan and the response of the second to an ergot underscore the possible therapeutic impact of recognizing the clinical presentation as a migraine subtype.

Current understanding of migraine mechanisms includes neurogenic inflammation within the trigeminovascular system. Neuropeptides such as calcitonon gene-related peptide (CGRP), substance P and neurokinin A are thought to be involved (11–13). It has been hypothesized that the activation of a feed-forward neurovascular dilator mechanism is functionally specific for the first (ophthalmic) division of the trigeminal (14). Our clinical data indicate that this mechanism might not be restricted to the dura and the frontotemporal area, and therefore the first trigeminal branch, but may also extend to the second and third division involving maxillary and mandibulary fibres. In line with the above, nociceptive nerve fibres exhibiting substance P- and CGRP-positive immunoreactivity have been demonstrated in human dental pulp tissue (15). Another putative mechanism discussed in the context of limb pain associated with primary headaches is related to nociceptive convergence of trigeminal and lower segmental inputs in the central nervous system (16).

In conclusion, our patients, as well as similar cases in the literature, suggest that migraine pain may not be restricted to the first trigeminal division but may also extend to the two orofacial (i.e. the maxillary and mandibular) divisions.

Acknowledgement

C.G. was research fellow at the University of Zürich at the time of preparation of this work.