An unusual case of short-lasting unilateral neuralgiform headache attacks

Abstract

Background

Short-lasting unilateral neuralgiform headaches include those with conjunctival injection and tearing and with cranial autonomic symptoms. Most frequently reported as idiopathic, there is a growing number of symptomatic cases described.

Case report

A 57-year old man presented a 16-year history of right hemifacial short-lasting pain attacks accompanied by ipsilateral autonomic symptoms and simultaneous malar contractions. Brain MRI disclosed a right acoustic neuroma compressing the right facial nerve and a venous developmental anomaly perpendicular to the right facial nerve root entry zone, without lesions affecting the trigeminal nerve. He was started on lamotrigine, resulting in complete remission of pain attacks, autonomic signs and facial contractions.

Conclusions

This patient presents a typical short-lasting unilateral neuralgiform headache with response to lamotrigine. The uniqueness of the case is the co-occurring malar contractions, evocative of facial nerve involvement. We speculate whether facial nerve compression renders this nerve more susceptible to triggering during a short-lasting unilateral neuralgiform headache attack.

Background

Short-lasting unilateral neuralgiform headaches (SUNHA) include SUNCT (with conjunctival injection and tearing) and SUNA (with cranial autonomic symptoms), according to the International Classification of Headache Disorders, 3rd edition (ICHD-3) (1). Classified as trigeminal autonomic cephalalgias (TACs), these are relatively rare syndromes, with a 6 in 100,000 prevalence reported for SUNCT (2).

Most of the described cases are idiopathic, but a growing number of symptomatic patients have been identified (3). These include patients with pituitary adenomas, retro-orbital and posterior fossa lesions of diverse etiologies: tumors, vascular loops, stroke, trauma, infections and radiotherapy sequelae (4,5). Neurovascular compression has been considered a distinguishing feature from trigeminal neuralgia, due to a reduced prevalence in SUNCT (5). Notwithstanding, there are some reports of trigeminal compression by vascular loops in SUNCT patients who went into remission after microvascular decompression surgery (6,7).

We present a patient with unique clinical features that illustrate many of the issues currently under debate in this group of headache disorders.

Case report

A 57-year-old man with no relevant medical history complained of right hemifacial pain attacks since the age of 41. The pain was stabbing in nature, radiating from the bridge of the nose to the right eye, lasted for a minute and occurred at an average frequency of 50 episodes per day. It was accompanied by ipsilateral conjunctival injection, tearing, ptosis, flushing of the nasolabial fold and malar contractions. The patient reported neither triggers nor refractory period between the episodes. He experienced bouts of attacks, lasting for a few weeks at a time in a seasonal distribution, usually arising during spring and autumn.

When the patient first sought medical attention, he was diagnosed with trigeminal neuralgia. Brain MRI revealed a right cerebellopontine angle lesion, adjacent to the internal acoustic opening, suggestive of an acoustic neuroma. It caused distortion of the right facial nerve but had no discernible contact with the trigeminal nerve or pons (Figure 1(a)–(e)). Additionally, a venous malformation draining to the lateral medullary cistern resulted in a neurovascular contact near the root entry zone for the right facial nerve. This lesion also had no evidence of contact with the trigeminal nerve. Therapy with carbamazepine up to 1200 mg/day and pregabalin up to 400 mg/day proved ineffective and the patient eventually discontinued all medication. When offered, he refused surgical intervention. The episodes persisted, occurring in an episodic pattern, with remission periods that could last for a few months.

Figure 1.

T2-FLAIR (a) and T2-FIESTA (b) MRI axial sections: Right facial nerve thinned and displaced anteriorly (short arrows) by a cerebellopontine lesion, probably an acoustic neuroma. (c) T2-FIESTA axial section: Neurovascular contact (circle) of right facial nerve root entry zone with a venous structure, part of a venous developmental anomaly that was detected through contrast-enhanced T1 imaging ((d), long arrow). (e) T1 gadolinium-enhanced coronal section: No observable contact between right trigeminal nerve (thin arrow), presenting normal thickness and signal, and the acoustic neuroma (short arrow). (f) Blink reflex: The supra-orbicular nerve was stimulated, and the orbicular muscle response recorded, with normal R1, R2 and R2c waves bilaterally.

He was first observed at our clinic in May 2013 (aged 57). We observed and recorded six episodes during this visit. The attacks were similar to what the patient had described, except we did not observe tearing. Slight contractions of the malar region could be seen at the beginning of each episode, involving the right levator labii superioris and levator labii superioris alaeque nasi muscles (see Supplemental video). On neurological examination, he presented right hemifacial hypoesthesia and discrete right peripheral-type facial palsy. Repeated MRI revealed no signal or size changes of the right acoustic neuroma and vascular loop. Blink reflex electrophysiological parameters were all within normal ranges (Figure 1(f)).

He was started on gradually increasing doses of lamotrigine up to 200 mg/day and was rendered attack-free. By that time there was no longer right hemifacial hypoesthesia or facial palsy. In May 2016, an attempt to lower the dose resulted in recurrence of the attacks. The previously effective dose was reinstituted, and the patient reported no further episodes on follow-up.

Discussion

The patient's description of events fulfills the ICHD-3 criteria for episodic SUNCT (1), with severe periorbital pain attacks, lasting for 60 seconds, occurring in a series of stabs, up to 50 a day, accompanied by ipsilateral cranial autonomic symptoms including both conjunctival injection and lacrimation. However, upon direct observation, the episodes would be best classified as SUNA, given the absence of tearing (see Supplemental video). It has been proposed that SUNCT is a subtype of SUNA, being different manifestations of the same disorder (9). Here, one of two scenarios could be present: The patient experienced different episodes fulfilling criteria for both SUNCT and SUNA, as previously acknowledged (6); or the tearing description resulted from recall bias. Either way, a diagnosis of SUNHA would probably be more accurate.

The main singularity of this case is the presence of malar contractions during SUNHA episodes. Phenomenologically, these contractions could be classified as a spasm but, unlike typical hemifacial spasm, they occurred exclusively during an attack and disappeared, together with the pain and autonomic symptoms, once lamotrigine was started. Also intriguing in this patient were the abnormal findings on neurological examination (hypoesthesia and mild peripheral type facial palsy) present only at a period of crisis. The presence of atypical features should always elicit an investigation for secondary SUNHA and, in this patient, two lesions contacting the facial nerve were identified on brain MRI.

Upon literature review, we identified one report of symptomatic SUNCT with facial nerve involvement (9). In this case, a slight chin contraction was observed during an attack and the patient was found to have a right cerebellopontine angle astrocytoma that, unlike our case, displaced both the trigeminal and facial nerves. Subtotal lesion removal resulted in partial remission of the episodes.

Another report described a similar occurrence in a patient with cluster headache, with normal brain MRI, who developed hemifacial spasm occurring in a pattern similar to the cluster (10). The spasm would occur per se or accompanied by pain and improved under oxygen inhalation therapy and subcutaneous sumatriptan. Our patient had two lesions contacting the facial nerve, without evidence of trigeminal displacement, which are probably related to the episodes' phenomenology. We have tried to further study their contribution to the pathophysiology of the attacks, but could not perform a blink reflex during a SUNHA attack. Interictal parameters were normal, in line with the normal neurological examination at the time. We hypothesize that facial nerve stretching, albeit not damaging its function permanently, could lower the depolarization threshold during trigeminal autonomic activation. This would account for the malar contractions exclusively at a crisis, with the hypoesthesia and facial palsy occurring as an exhaustion phenomenon. Nakazako and colleagues hypothesized that, in the absence of an underlying lesion, the many anatomic and functional connections between trigeminal and facial nerves could facilitate a cross activation of facial motor neurons during SUNHA paroxysms (10).

Lastly, we also find it important to note the initial diagnosis of trigeminal neuralgia, highlighting the significant overlap between these conditions. Many SUNHA patients are initially diagnosed as having a different disorder (5), resulting in many years of morbidity before adequate therapy is tried, as in this case.

Supplemental Material

sj-vid-1-cep-10.1177 0333102418815652 - Supplemental Video for An unusual case of short-lasting unilateral neuralgiform headache attacks

Supplemental Video, sj-vid-1-cep-10.1177 0333102418815652 for An unusual case of short-lasting unilateral neuralgiform headache attacks by Ana Sardoeira, Gonçalo Cação, Sofia Pina, Ana Paula Sousa and Joana Damásio in Cephalalgia