Abstract
Unilateral head pain focused on frontal, orbital or parietal regions is a leading symptom of migraine attacks. Rarely, head pain in migraine can extend involving the maxillary or mandibular region of the face, sometimes isolated facial pain is the only and atypical presentation of migraine. The prevalence of these unusual symptoms in migraine is unknown. We aimed to estimate the true prevalence of facial pain in migraine in a population-based sample of 517 migraine patients in Germany. In 46 (8.9%) cases migraine pain involved the head and the lower half of the face. Patients with facial pain suffer more trigemino-autonomic symptoms than migraine patients (47.8% vs. 7.9%; α2 = 66.23, P < 0.001). In one case isolated facial pain without headache was the leading symptom of migraine. Our results demonstrate that facial pain is not unusual in migraine, whereas isolated facial migraine is extremely rare.
Introduction
Migraine is a very common, chronic, remitting and painful disorder characterized by headache attacks lasting 4–72 h, mostly of unilateral location, throbbing or pulsating character, moderate to severe pain intensity and somethimes accompanied by autonomic symptoms (1). Usually migraine patients locate their headache at the frontal, temporal or parietal part of the head. However, a number of patients report typical features of a migraine attack with atypical pain in the face in one or both of the lower two distributions of the trigeminal nerve (V2 and V3). Sometimes the headache in migraine spreads to the lower half of the face, but rarely isolated facial pain is the only and atypical presentation of migraine. Thus far, few single case descriptions and small case series have described migraine presenting as isolated facial pain or pain in the mouth and teeth (2,3). This condition presents as a challenge to the headache specialist, as underlying migraine symptoms often remain unrecognized (4,5). These patients are often seen first by dentists or general practitioners with little migraine experience and are misdiagnosed as ‘sinus headache’ or trigeminal neuralgia (6). Systematic studies on the prevalence of facial pain in migraine do not exist. Here, we present the prevalence of facial pain in migraine in a population-based sample of migraine patients in Germany.
Methods
Data collection
The current study was part of an epidemiological survey of the German Headache Consortium, which investigates the prevalence of primary headache syndromes in the general population in Germany. The study population comprised a random sample of 6000 inhabitants of the city of Essen, a city of North Rhine-Westphalia in the western part of Germany. Essen has 585 481 inhabitants, including 305 726 women and 279 755 men. Inclusion criteria were: age > 18 years and proper command of the German language. The study was approved by the local ethics committee of the University of Duisburg-Essen. All participants gave their written informed consent according to the Declaration of Helsinki.
Study sample
Six thousand randomly selected subjects received a questionnaire by postal mail
and, in a case of non-response, a reminder 2 weeks later. Subjects who did not
respond were called and asked for an interview over the phone, which was
performed by trained medical students based on the same questionnaire. Subjects
were considered non-responders after eight unsuccessful phone calls or refusal
of interview by postal mail or by phone. Figure 1 illustrates the
screening procedure. Algorithm of epidemiological screening procedure.
Methods
The questionnaire was constructed based on the International Headache Society criteria and validated prior to the survey. The results of the validation are reported separately (7,8). The sensitivity and specificity for migraine were 73.2 and 96.1%, respectively.
All responders with questionnaire-diagnosed migraine were asked having recurrent facial pain. All positive responders were offered a face-to-face interview with one of six neurologists experienced in headache (M-S.Y., D.M., N.H., F.P., M.S., M.O.). In case of refusal the study participants were asked for a telephone interview. Both personal and phone interviews were semistructured and aimed to describe the features of facial pain (e.g. characteristics, times of occurrence, relation to migrainous head pain and autonomic features).
Statistics
Comparison of interval scaled variables was performed using a
T-test of ordinal scaled variables and a χ2
test. Crude prevalence of facial migraine and migraine with associated facial
pain was expressed as the number of cases per 100 000 inhabitants.
Ninety-five per cent confidence intervals were calculated as suggested
previously (9). All statistics were performed with
Results
Initial sample
The study sample comprised 6000 subjects including 2971 (49.5%) men and 3029 (50.5%) women. Mean age was 44.7 ± 12.7 years. Distribution of gender and age was similar to that of the population of the region of North Rhine-Westphalia.
Responder
The overall response rate was 55.8% (3351/6000), 33.4% responded by mail, 22.4% were interviewed by telephone. We did not find any statistical differences in age between those who responded by postal mail and those who were interviewed (45.5 ± 12.7 vs. 47.5 ± 12.7 years). Our study population consisted of more women (53.7% vs. 46.4%).
Facial pain in migraine patients
Five hundred and seventeen (15.4%) individuals with migraine were identified based on the diagnoses of the screening questionnaire. Of these, 154 (29.8%) reported recurrent facial pain. One hundred and three (66.9%) responders were examined personally, 26 (16.9%) were interviewed by phone and 25 (16.2%) refused the interview.
We identified one 42-year-old man with isolated facial migraine, who suffered from attacks of isolated lower half facial pain associated with typical autonomic features of a migraine attack (phono- and photophobia, nausea, vomiting) lasting 48 h with an infrequent attack frequency. He reported a family history of headache without being able to report any further details. He had suffered from typical migraine headache for the last 20 years. During the last 5–6 years he reported having had two types of attack: (i) typical migraine with head pain localized in the frontal-parietal region of the head, and (ii) more rarely, attacks with the facial pain accompanied by migraine-like autonomic symptoms. His family practitioner advised him to try a triptan (sumatriptan 6 mg subcutaneously), which treated the facial pain successfully. We repeated this treatment to ensure the clinical effect.
Demographic and clinical characteristics of patients with facial pain and migraine
NS, not significant.
Discussion
We used a combination of postal mail and phone interviews and achieved a good response rate of 56% in this population-based design. Comparing the demography of non-responders and responders we found a slight tendency towards a selection bias, which is not unusual in population-based samples. However, the difference did not reach statistical significance. The sex and age distribution in our study population is comparable to data for the general population of the region of North-Rhine Westphalia. We are confident that with a reasonable approximation the investigated sample can be considered representative of the general population in Germany.
We identified only one individual with isolated facial migraine who reported a good response to triptans. The prevalence of additional lower half facial pain in the entire population of migraine patients was 9%. Two recent case series have reported detailed clinical descriptions of patients with isolated facial migraine (10,11). Few case reports have focused on migraine presenting as odontalgia (2,12), while most information on migraine representation in the face report concomitant pain in the mouth and face distribution of the trigeminal nerve with additional typical unilateral headache (13). Benoliel et al. reported eight patients suffering from orofacial pain with vascular-type features similar to those in migraine without aura (10). Daudia et al. identified 24 patients with facial pain in the second distribution of the trigeminal nerve and concomitant migrainous features in a cohort of 973 consecutively recruited patients in a rhinology clinic (14). Penarrocha et al. recently described 11 patients with facial pain and migrainous features, with nine patients responding to antimigraine treatment with ergotamine. They referred to this condition as ‘lower-half facial migraine’ (15). The main challenge of clinical series derived from specialized headache, pain or dental clinics is selection bias. We therefore studied a population-based sample of migraine sufferers in order to estimate the ‘true’ prevalence of facial pain in migraine.
Migraine patients with additional facial pain report enhanced pain intensity. In addition, they suffer more migraine days per month with a longer history of migraine. In our population migraine patients with facial pain also showed more trigemino-autonomic symptoms compared with migraine patients without accompanying facial pain. Apparently a longer-lasting history of migraine and extend migraine days per month lead to increased pain intensity with enhanced activation of the trigemino-autonomic system. However, it remains unclear whether this facilitation of the trigemino-autonomic system and increasing inclusion of autonomic fibres are due to the increased pain intensity, increased migraine frequency or other underlying pathology within the trigemino-autonomic system in these migraine patients.
From the clinical perspective, facial pain in migraine patients is often misleading. Unfortunately it often remains misdiagnosed and inappropriately treated as trigeminal neuralgia or ‘sinus headache’ due to rhinosinusitis (16,17). The Sinus, Allergy and Migraine Study reviewed 100 patients physician- or self-diagnosed with ‘sinus headache’ and found that up to 85% had migraine or probable migraine (6).
The clinical phenomenon of spread and referred pain has been intensively investigated in the past, but the underlying pathophysiological mechanisms are still not fully understood. This clinical referral phenomenon, where pain originates from an affected tissue but is perceived as coming from a distant receptive field, has been explained by convergence mechanisms of trigeminal (dura, skin) and cervical (muscle, joints, skin) afferents on to the same nociceptive second-order ascending projection neuron in the trigemino-cervical complex in the brainstem (18,19), which receives input from many afferent sources including facial and corneal receptive fields representing dural-sensitive neurons with high convergence potential (20–22). The direct coupling between meningeal afferents and cervical afferents in the cervical spinal dorsal horn has been shown electrophysiologically as evidence for the suspected anatomical overlap of trigeminal and cervical afferents throughout the trigemino-cervical complex (23). This convergence of a visceral nerve (dura) with a somatic spinal nerve (greater occipital nerve) may explain the atypical localization of pain in our migraine patients, where the somatic part of the trigeminal nerve (V2 and V3) may also converge with its visceral part (V1) in the trigeminal nucleus caudalis, leading to a referral of pain with otherwise typical clinical symptoms of a migraine attack. It is easily conceivable that this is often associated with additional typical migraine head pain location and only rarely seen as isolated facial pain without the accompanying head pain. Whether the latter clinical presentation can be considered as progression from typical migraine-associated facial pain variant requires further investigation.
We are aware of some limitations of this study. The screening question about having headache in the previous year probably led to the interest bias leading to the artificially high prevalence of migraine. We studied migraine sufferers with respect to additional or isolated facial pain. Therefore, those having isolated facial pain without any other migraine symptoms could be neglected.
In conclusion, the data suggest that approximately 9% of patients with migraine can experience pain in the lower half of the face in addition to headache. The syndrome of isolated facial migraine appears to be very rare.