Stabbing facial pain reminiscent of primary stabbing headache

Abstract

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.

Abbreviations

ICHD-3: International classification of headache disorders, 3rd edition

NRS: Numeric Rating Scale

MGUS: Monoclonal gammopathy of undetermined significance

MRI: Magnetic resonance imaging

PIFP: Persistent idiopathic facial pain

PSH: Primary stabbing headache

SUNCT: Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing

SUNFA: short-lasting unilateral neuralgiform facial pain attacks

TN: Trigeminal neuralgia

V1: First trigeminal branch, n. ophthalmicus

V2: Second trigeminal branch, n. maxillaris

V3: Third trigeminal branch, n. mandibularis

Background

Primary stabbing headache (PSH) is a transient and localized headache disorder (1). It has previously been called “ophthalmodynia periodica”, “icepick-like pain”, “idiopathic stabbing headache” or “jabs and jolts syndrome” (2–4). Pain paroxysms are usually short lasting (“up to a few seconds”) and the current International Classification of Headache Disorders, 3rd edition (ICHD-3) notes that “stabs last three seconds or less; rarely, stabs last for 10–120 seconds” (5). The temporal pattern of the syndrome shows a great variability (4,6). Patients presenting with PSH as the main complaint for a medical consultation usually suffer from several stabs per day (6). The life-time prevalence of occasional ultrashort headache paroxysms in the general population is most likely high, however with a negligible clinical significance in most people. It was reported to be 35.2% in “an unselected rural Norwegian population” (7). Another study found the lifetime prevalence to be much lower at only 2% (8). Since only a few patients need to consult a physician because of this syndrome, it is possible that they are underreported in the second study. The current ICHD-3 mentions in the PSH criterion C that “stabs recur with irregular frequency, from one to many per day” (1), thereby putting the threshold of pathological significance at a minimum of one stab per day, which appears reasonable for a primarily scientific classification.

The 2nd edition of the ICHD specified the first trigeminal branch (V1) as the area where primary stabbing headaches are felt either exclusively or predominantly (9). The current ICHD-3 abandoned this specification because, in up to 70% of the cases, extra-trigeminal manifestations (“auricular, posterior parietal, occipital and nuchal areas”) had been reported (1,6). Trigeminal areas described in previous studies included mainly V1 (orbital, frontal, anterior temporal, anterior parietal and vertex areas) (4,6).

While orbital pain is very common, facial pain according to ICHD-3 criteria (pain below the orbitomeatal line) has previously not been mentioned as a possible area where PSH occurs and to our knowledge no case of an exclusive facial presentation (V2 and/or V3) of PSH has been described.

In the following, we present four patients suffering from pain paroxysms fitting to the ICHD-3 criteria of 4.7 Primary stabbing headache with the exception that exclusively the second and third trigeminal branches (V2 and V3) were affected and the term “headache” therefore does not suffice. The patients gave consent to the anonymous publication of their medical history.

Case 1

The 49-year-old female patient first presented herself to our facial pain outpatient clinic in March 2018. She reported having suffered for approximately 5–6 years from pain paroxysms strictly confined to the trigeminal branches V2 and V3 on both sides (not simultaneously); more accurately the cheeks, the maxilla, the mandible, and the teeth (predominantly the incisors and premolars of the maxilla, but also all other teeth) in a random manner on both sides of her face. Other areas, including the head, were never affected. Pain paroxysms always occurred as single stabs (described as “feeling exactly like a needle stab and never radiating”), lasting one second or less, of moderate to severe intensity (around 6–7/10 on the numeric rating scale [NRS]). The afflicted area was very small and subjectively described as less than one square centimeter in size. Stabs appeared between 2 and 50 times per day but not during her sleep. Usually, there were at least minutes between them, only rarely could a stab be followed by a second one immediately afterwards. Stabs could not be triggered and only occurred spontaneously. There were no accompanying symptoms such as trigeminal-autonomic symptoms or migrainoid features. The frequency was irregular over the previous 6 years, with no tangible periodicity or episodic character. There were pain-free intervals of up to 3 weeks, but usually the pain paroxysms occurred daily.

Additionally, the patient suffered nearly daily from episodes of subtle non-painful paresthesia in the same facial regions lasting between two and 30 minutes, sometimes up to three times a day. This phenomenon was very variable but painful stabs never occurred during the paresthesia. The patient consulted dentists, an oro-maxillo-facial surgeon, an otolaryngologist and a neurologist prior to presenting to us. The patient also underwent dental extractions and an occlusal splint therapy, both of which could not alleviate the symptoms. None of the consulted specialists committed themselves to a diagnosis. Extensive diagnostics including magnetic resonance imaging of the head and dental x-ray imaging showed no abnormalities. The clinical neurological examination also revealed no relevant abnormalities.

Partially successful therapy regimens included ibuprofen 400 to 600 mg up to four times a day and metamizole 500 mg, which could reduce the frequency and intensity of pain paroxysms. Additionally, the patient relied on alternative medicine, which subjectively alleviated the symptoms. Because of the similarities to PSH, we proposed the intake of indomethacin. However, even dosages of up to three times 75 mg indomethacin per day had no effect on intensity and frequency of the stabs. On the contrary, the patient reported suffering from a dull and throbbing facial pain in the maxilla of moderate to severe intensity when taking 50 mg of indomethacin thrice daily. The fact that indomethacin can itself cause headache is known (10). This pain became more intense at 75 mg thrice daily; the patient subsequently discontinued the intake and the continuous facial pain ceased accordingly.

We also proposed the intake of gabapentin or possibly lamotrigine, which the patient however did not start. Until today, she suffers from under five stabs per day in average and does not take any pain medication. The patient very rarely suffered from unspecific headaches (i.e. when suffering from infections of the nasopharynx). Primary headaches, including episodic tension-type headache, have never been experienced by this patient.

Unrelated to the facial pain, the patient suffered from occasional gastroesophageal reflux and twice from deep vein thrombosis; first in 1999 and for the second time in December 2018. Extensive lab tests in our university coagulation outpatient clinic could, however, not objectify any disorder of her hemostasis and no other underlying disease was diagnosed.

Accordingly, at the time of the last contact (July 2019) the patient had pantoprazole 40 mg and rivaroxaban 20 mg as preventative medications, as well as ibuprofen 600 mg when required.

Case 2

In July 2019, a 63-year-old male patient presented himself to our facial pain outpatient clinic with a stabbing facial pain syndrome that had lasted for 2 years. The symptomology began with 2–3 attacks per week but worsened continuously. By the time of presentation, he suffered from 150–200 stabbing pain paroxysms in the trigeminal branches V2, V3 and very rarely V1 on both sides; however, not simultaneously (predominantly the cheeks, the maxilla, seldom the mental and rarely the frontal region). The regional distribution appeared completely random to the patient. The attacks were described as short-lasting (seconds) stabs (“like sewing needles”) and were always accompanied by an itching sensation which made it necessary to exert slight pressure to the affected area. This could stop the attacks reliably and quickly. Without touching the affected area, the itching sensation lasted for 5–7 minutes and was extremely uncomfortable for the patient, hence he usually scratched the affected areas immediately. The pain paroxysms were not accompanied by any trigeminal autonomic symptoms or migrainoid features.

They were present during the whole day; however, with fewer attacks at night and more attacks later in the day. The attacks could not be triggered in any way and occurred solely spontaneously.

The clinical neurological examination of the patient revealed no abnormalities at the time of presentation in July 2019, especially no allodynia, dysesthesia or hypesthesia in the trigeminal region. Magnetic resonance imaging of the head revealed no pathological findings.

In 2015, the patient suffered from a probable neuralgic amyotrophy of his right arm. During the following hospitalization elevated IgG kappa levels were detected, and after excluding an underlying malignancy, a monoclonal gammopathy of undetermined significance (MGUS) was diagnosed. Testing of the cerebrospinal fluid revealed no abnormalities. Extensive laboratory tests revealed no pathological results for diseases of the rheumatoid or autoimmune spectrum. Lastly, a small fiber neuropathy was diagnosed after skin biopsy of the lower leg. However, the patient only reported paresthesia of his feet at the time of presentation and did not require any medication for these symptoms.

Due to the stabbing character, we proposed the intake of indomethacin up to 225 mg per day, which had no effect on either the frequency or the intensity of the stabs. Subsequently, we proposed the intake of gabapentin. Dosages of 2700 mg/day reduced the frequency from 150–200 attacks/day to approximately 20–40 attacks/week and also reduced the intensity by 80%. At the last time of presentation, in September 2019, the patient still took gabapentin 2700 mg regularly with a sustained good efficacy and good tolerability.

Case 3

The 46-year-old female patient consulted us first in February 2018 and reported about suffering for 3 years from stabbing facial pain attacks in her mandible and seldom in her maxilla, on both sides (but not simultaneously). The attacks usually lasted around one second and were felt in the depth of the tissue or possibly bone but not superficially. These attacks were moderately painful (NRS 3–5/10) and were followed by a refractory phase of approximately 30 seconds and then the next attack would occur. Overall, she suffered from dozens of these stabs per day. These attacks would occur in episodes of 4 to 7 days which was followed by attack freedom for about 3 weeks. This periodicity was not associated with the menstrual cycle. The attacks could not be triggered in any way and were not accompanied by any trigeminal autonomic symptoms or migrainoid features.

The clinical neurological examination as well as the MR imaging of the head was unremarkable. Also, a dentist and orthodontist could not objectify any abnormalities.

Unrelated to the facial pain syndrome, the patient had rarely suffered from migraine with aura in the past. By the time of presentation, the headaches had ceased nearly completely and she experienced only rarely typical visual auras without headache.

The patient could treat the pain paroxysms with ibuprofen 800 mg, which reduced the frequency and the intensity. We proposed the intake of indomethacin as well as gabapentin. Both were not tried by the patient, as her level of suffering did not require this.

By the time of the last consultation in November 2019, the symptomology had not changed significantly; however, the patient had experienced a pain-free interval of a few months.

Case 4

In May of 2019, a 35-year-old male patient consulted us with stabbing pain paroxysms that had occurred for 2 years and became more frequent over that time. The pain was strictly localized in the depth of the mandibular angle on both sides and was of high intensity (10/10 NRS). The paroxysms occurred only on one side at a time, but with randomly changing sides between attacks. Paroxysms lasted a second or less and occurred spontaneously without any rhythm or periodicity between 0 and 20 times (a mean of 10) per day. In between attacks he was completely pain free and there could be pain free intervals of 2–3 days, but usually he suffered from these pain attacks daily. There were no accompanying features. He suffered from no other diseases and the clinical neurological examination, as well as MR imaging of the head was unremarkable. The patient consulted experts for temporomandibular disorders, who referred the patient to us in the first place and could not diagnose any abnormalities, despite extensive diagnostics. Also, the patient’s phenotype did not suggest temporomandibular joint pain.

The patient had refrained from taking any medication prior to consulting us. We proposed the intake of indomethacin. Dosages of up to 75 mg thrice daily had no effect on the pain but caused somnolence. Subsequently, the patient stopped the intake. By August 2019, the time of the last consultation, the symptomology had not changed considerably; however, the patient did not want to start gabapentin, which was proposed by us.

Discussion

All four patients presented with paroxysmal facial pain syndromes that mirror idiopathic stabbing headaches but for the location, which led us to tentatively diagnose them as “stabbing facial pain”. Similarities to other facial pain syndromes are obvious; however, no facial pain syndrome is congruent with the presented symptomatology. The short duration of pain paroxysms makes trigeminal neuralgia (TN) a viable differential diagnosis. However, pain paroxysms could not be triggered in any way, which is a hallmark feature of TN (11) and as per ICHD-3 and ICOP (12) also a disease-defining characteristic. Furthermore, the pain quality and character in these four patients were not neuralgic but rather stabbing (identical to needle stabs). More to the point, these stabbing pains are – just like in primary stabbing headache – not confined to a dermatome or nerve distribution, did not spread, but instead occur randomly in time and location and in principle are both-sided, the latter point being extremely rare in TN (13).

In contrast to “pre-trigeminal neuralgia” (14), a prodromal pain condition before actual TN, which is characterized by “dull, continuous, aching” before developing typical TN symptomology in the same trigeminal branch, these patients suffered from single stabs only, and this randomly on both sides throughout the 2nd and 3rd trigeminal branches. It is highly unlikely that they would eventually develop TN bilaterally and then also in multiple trigeminal branches, rendering pre-trigeminal neuralgia an unlikely differential diagnosis.

Unlike in facial SUNCT or SUNA (15), no autonomic symptoms were present and also the pain paroxysms were not confined to one trigeminal division (maxillary or mandibular) or side. Case 4 showed similarities to the so called first bite syndrome (FBS) (16) due to the pain location (mandibular angle/parotid glands). However, the pain paroxysms in FBS are usually bilateral and do not occur spontaneously but exclusively before and during food intake, rendering it an unlikely differential diagnosis.

Lastly, in case 1, the pain projected sometimes into the teeth. Acute or chronic pulpitis and also symptomatic periapical lesions were excluded by dental specialists and indeed the patient presented herself to several different specialists without any morphologic abnormality before consulting us.

The pathophysiological mechanisms of PSH are unclear, however “irritations of the peripheral branches of the trigeminal or other nerves, as well as deficits in central pain control mechanisms” have been discussed (6,17). This case series cannot answer pathophysiological questions. We note that the second patient showed signs of a small fiber neuropathy in a skin biopsy, though the facial region was not specifically evaluated. The first patient showed no objective test results for a neuropathic nerve damage but described a subtle non-painful paresthesia. Therefore, at least in these two patients, irritations of peripheral trigeminal branches could theoretically play a role, but none of the patients showed a reliable sign of trigeminal neuropathy such as hypoesthesia. We note that there was no persisting facial pain, as seen in other neuropathic facial pain syndromes, such as TN or painful post-traumatic trigeminal neuropathy (1) and there were neither negative or positive persisting signs of neuropathy in the facial region of these patients.

It is remarkable that indomethacin had no effect in the patients that tried it. This stands in contrast to PSH, which is usually considered an indomethacin-responsive headache (18). A good response to gabapentin has also been reported in PSH (19) and the remarkable response of the second patient may underline this concept.

A limitation of this study is that carbamazepine, which is very effective in TN, has not been tested in these patients. Either patients improved under other medications or decided not to take the medication proposed by us. One could argue that a good response to sodium channel blockers is suggestive for TN or related pathophysiologic mechanisms. A good response to these medications, however, would not necessarily help in deciding which pathology is truly underlying. The same medication can help in different but “related” diseases (i.e. triptans in migraine and cluster headache) but also in likely “unrelated” diseases (i.e. beta-blockers in migraine and hypertension). Diagnosis ex juvantibus inherently carries the possible bias of false negative results.

We propose that exclusive facial variants of stabbing pain syndromes should be subclassified as separate entities and tentatively be called “stabbing facial pain”, in order to allow them to be investigated prospectively and to verify the hypothesis that they are different from extreme short-lasting headache syndromes.

Clinical implications

Facial variants of short-lasting stabbing pain syndromes have not been previously described.

Stabbing facial pain should be subclassified as a separate paroxysmal facial pain syndrome.