Characteristics and natural disease history of persistent idiopathic facial pain, trigeminal neuralgia, and neuropathic facial pain.

OBJECTIVE: This study aimed to characterize key features, and to assess the clinical development of common nondental facial pain syndromes such as persistent idiopathic facial pain (PIFP), trigeminal neuralgia (TN), and neuropathic facial pain (NEUROP). METHODS: This is a longitudinal study in which prospective questionnaire data of patients presenting to a specialized outpatient clinic were collected from 2009 to 2019. A telephone interview was conducted with the same patients in 2020 to assess the natural disease history. RESULTS: n = 411 data sets of patients with chronic facial pain were compiled. Among these were n = 150 patients with PIFP, n = 111 patients with TN, and n = 86 patients with NEUROP. Guideline therapy had not been initiated in 38.7% (58/150; PIFP), 19.8% (22/111; TN), and 33.7% (29/86; NEUROP) patients. Of the patients with PIFP, 99.3% (149/150) had primarily consulted a dentist due to their pain syndrome. The additional telephone interview was completed by 236 out of the 411 patients (57.4%). Dental interventions in healthy teeth had been performed with the intention to treat the pain in many patients (78/94 [83.0%] PIFP; 34/62 [54.8%] TN; 19/43 [44.2%] NEUROP), including dental extractions. 11.3% (7/43) of the patients with TN had never profited from any therapy. In contrast, 29.8% (28/94) of the patients with PIFP had never profited from any therapy. Furthermore, the primary pharmaceutical therapy options suggested by national guidelines were, depending on the substance class, only considered to be effective by 13.8% (13/94; antidepressants) and 14.9% (14/94; anticonvulsants) of the patients with PIFP. CONCLUSIONS: Facial pain syndromes pose a considerable disease burden. Although treatment of TN seems to be effective in most patients, patients with PIFP and NEUROP report poor effectiveness even when following guideline therapy suggestions. In addition, unwarranted dental interventions are common in facial pain syndromes.

Idiopathic Facial Pain Syndromes­An Overview and Clinical Implications.

BACKGROUND: Idiopathic facial pain syndromes are relatively rare. A uniform classification system for facial pain became available only recently, and many physicians and dentists are still unfamiliar with these conditions. As a result, patients frequently do not receive appropriate treatment. METHODS: This article is based on pertinent publications retrieved by a selective search in PubMed, focusing on current international guidelines and the International Classification of Orofacial Pain (ICOP). RESULTS: The ICOP subdivides orofacial pain syndromes into six major groups, the first three of which consist of diseases of the teeth, the periodontium, and the temporomandibular joint. The remaining three groups (non-dental facial pain) are discussed in the present review. Attack-like facial pain syndromes most closely resemble the well-known primary headache syndromes, such as migraine, but with pain located below the orbitomeatal line. These syndromes are treated in accordance with the guidelines for the corresponding types of headache. Persistent idiopathic facial pain (PIFP) is a chronic pain disorder with persistent, undulating pain in the face and/or teeth, without any structural correlate. Since this type of pain tends to become chronified after invasive procedures, no dental procedures should be performed to treat it if the teeth are healthy; rather, the treatmentis similar to that of neuropathic pain, e.g., with antidepressant and anticonvulsive drugs. Neuropathic facial pain is also undulating and persistent. It is often described as a burning sensation, and neuralgiform attacks may additionally be present. Trigeminal neuralgia is a distinct condition involving short-lasting, lancinating pain of high intensity with a maximum duration of two minutes. The first line of treatment is with medications; invasive treatment options should be considered only if pharmacotherapy is ineffective or poorly tolerated. CONCLUSION: With the aid of this pragmatic classification system, the clinician can distinguish persistent and attack-like primary facial pain syndromes rather easily and treat each syndrome appropriately.

Altered trigeminal pain processing on brainstem level in persistent idiopathic facial pain.

ABSTRACT: Persistent idiopathic facial pain (PIFP) is a poorly understood chronic pain syndrome of the face, formerly known as atypical facial pain. It is characterized by a constant painful sensation without neurological abnormalities and without clinically objectifiable cause. Similarities to neuropathic pain conditions have been discussed and are currently thought to be relevant for the pathophysiology of this disease. In this study, we aim to characterize the trigeminal pain processing in PIFP using functional magnetic resonance imaging of the brainstem. Twenty-five patients suffering from PIFP and 25 healthy controls underwent a standardized and well-established paradigm of painful stimulation of the trigeminal nerve using gaseous ammonia. Functional images were acquired within a 3T magnetic resonance imaging scanner using an optimized protocol for high-resolution echo planar brainstem imaging. Patients with PIFP show exclusively a stronger activation to painful stimulation in the spinal trigeminal nucleus when contrasted against healthy controls. Our data suggest that abnormal central pain processing plays a role in the pathophysiology of PIFP. An integration of these findings into neuropathic pain models might help to gain a better general understanding of the pathophysiology of PIFP.

Predicting the outcome of the greater occipital nerve block - an observational study on migraine patients with and without musculoskeletal cervical impairment.

BACKGROUND AND OBJECTIVE: The importance of neck pain and the trigeminocervical complex in migraine is of high pathophysiological interest since a block to the greater occipital nerve is more effective for some primary headaches than others. This observational study hypothesised that the response to manual palpation of the upper cervical spine predicts the efficacy of the greater occipital nerve-block. METHODS: We divided patients, scheduled by a neurologist to receive a greater occipital nerve-block to reduce their migraine symptoms, into three groups: Patients with no pain response to manual palpation of the neck, patients with local pain, and those with referred pain to the head. Primary outcome was the percentage change in headache frequency. Additionally, items from the quantitative sensory testing protocol were included. RESULTS: Eighty-seven chronic migraine patients were recruited consecutively from a specialised outpatient clinic and 71 were included for analyses and stratified into the three groups: No pain (n = 11), local pain (n = 28), and referred pain to the head (n = 32). Overall, patients experienced a reduction of 1.9 headache days per month (SD 3.4, p < 0,0001). The groups differed significantly in the percentage change of headache frequency (p = 0.041) with the "no pain" group showing the largest reduction. The pressure-pain-threshold over C2 and headache on the day of the intervention influenced the outcome significantly (R2 0,27, p = 0,00078). No serious adverse events occurred. Sixty-five percent of the patients had headaches during the examination. The groups did not differ regarding the distribution of patients with neck-pain in absence of migraine at baseline (p = 0.618). CONCLUSION: Patients that were less sensitive to palpation in the cervical region and headache-free on the day of the intervention improved more after the greater occipital nerve-block.Registration: Registered a priori at the German Clinical Trials Register (DRKS00015995).

Central effects of erenumab in migraine patients: An event-related functional imaging study.

OBJECTIVE: To determine whether erenumab, a new monoclonal antibody to the calcitonin gene-related peptide (CGRP) receptor, exerts functional central effects in migraineurs by performing functional imaging scans on patients treated with erenumab. METHODS: We conducted an fMRI study on 27 patients with migraine using a well-established trigeminal nociceptive paradigm, examining patients before and 2 weeks after administration of the CGRP receptor antibody erenumab 70 mg. RESULTS: Comparing both visit days in all patients (n = 27) revealed that erenumab leads to a decrease in activation in the right thalamus (i.e., contralateral to the stimulated side), right middle temporal gyrus, right lingual gyrus, left operculum, and several clusters on both sides of the cerebellum. Furthermore, when responders (n = 9) and nonresponders (n = 8) of the respective same headache state were compared, we found a significant reduction of hypothalamic activation after the administration of erenumab in responders only (t = 4.78; contrast estimate 29.79 [90% confidence interval 19.53-40.05]). This finding of reduced hypothalamic activation was confirmed when absolute headache days was used as a regressor. INTERPRETATION: These findings suggest that erenumab may not be an exclusively peripheral migraine treatment but has additional central effects. Whether this is due to secondary changes after peripheral modulation of sensory input or indeed represents a direct central mode of action is discussed.

Stabbing facial pain reminiscent of primary stabbing headache.

Primary stabbing headache (PSH) is a transient and localized headache disorder. Facial variants of this rare pain syndrome have not been previously described. Four patients (n = 2 female, 2 male) presented themselves to our headache and facial pain outpatient clinic. They suffered daily from several dozen to several hundred short-lasting stabbing pain paroxysms primarily in the second and third trigeminal branches (V2 and V3) without lateral predominance. These non-neuralgic pain paroxysms did not strictly follow dermatomes, were not accompanied by trigeminal autonomic features and could not be triggered but occurred exclusively spontaneously. They did not fulfill any existing ICHD-3 criteria but appeared clinically to have similarities to primary stabbing headache syndromes. Indomethacin showed no efficacy. Exclusive facial variants of stabbing pain paroxysms should be classified as separate entities and tentatively be called stabbing facial pain.

Shortcomings and missed potentials in the management of migraine patients - experiences from a specialized tertiary care center.

BACKGROUND: Migraine is a common and severely disabling neurological disorder affecting millions of patients in Europe. Despite the availability of evidence-based national and international guidelines, the management of migraine patients often remains poor, which is often attributed to a low availability of headache specialists. The aim of this study was to investigate the adherence to national guidelines and to assess the possible potential of optimized therapy regimens in migraine patients. METHODS: We collected data of migraine patients presenting to our out-patient clinic via standardized questionnaires regarding headache, diagnostics and experience with previous treatments. We also assessed the efficacy of treatment started by our center. RESULTS: 1,935 migraine patients were included between 2010 and 2018. In the 12 months before consulting our headache clinic 89.5% of the patients had consulted a general practitioner and 74.9% had consulted a neurologist because of their migraine. Nevertheless, 50% of the patients underwent unnecessary diagnostics and 34.2% had not been treated according to evidence-based treatment guidelines. Out of 1,031 patients who had not been prescribed a preventative treatment 627 (60.8%) had in average 3 or more migraine attacks per month and thus qualified for a preventative treatment. These patients missed in the 3 months prior to consultation on average 5 work or school days. Initiating a preventative treatment was effective in 71.2% of the patients, that provided follow-up data. CONCLUSIONS: Our data suggest, that many migraine patients to this day do not receive state-of-the-art therapy. Adherence to national and international European guidelines could improve the outcome in migraine patients. Future research should try to answer why guidelines are not followed.

Facial presentations of migraine, TACs, and other paroxysmal facial pain syndromes.

OBJECTIVE: To assess the prevalence of facial pain (V2 and/or V3) presentations among nearly 3,000 patients with headache treated in a university tertiary care center. METHODS: Between 2010 and 2018, we routinely assessed the prevalence of facial pain presentations of all patients with primary headaches. RESULTS: Of 2,912 patient datasets, 291 patients reported facial pain either as an independent or as an additional symptom. Among patients with migraine, 2.3% (44 of 1,935) reported a facial involvement, most commonly in V2. Of these, 18 patients (40.9%) experienced the pain predominantly in the face. In patients with cluster headache, 14.8% (42 of 283) reported a facial involvement, of which 31.0% perceived the pain predominantly in the face. A facial involvement was seen in 45.0% of patients with paroxysmal hemicrania (9 of 20), 21.4% of patients with hemicrania continua (9 of 42), and 20.0% of patients with short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing/short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (3 of 15). In addition, we present 6 patients who reported a constant side-locked facial pain with superseded well-defined facial pain attacks of 10- to 30-minute duration that appeared several times per day. CONCLUSION: Our data suggest that a facial involvement in primary headaches is infrequent but not uncommon. A sole facial presentation of primary headache symptomatology seems to be exceptionally rare. We describe 3 different types of facial pain involvement and, in this context, distinguish patients with paroxysmal orofacial pain syndromes that have not been previously described. These patients may represent a new entity that could tentatively be called constant unilateral facial pain with added attacks.