Abstract
Introduction
SUNCT syndrome is a painful condition comprising unilateral neuralgiform attacks, of short duration, located in the orbital-periorbital areas and associated with ipsilateral autonomous phenomena, notably conjunctival hyperaemia, lacrimation and rhinorrhoea, occurring predominantly in males (1).
Pain intensity is moderate to severe, the character is a burning sensation, stabbing or electric shock-like, lasting from 5 s to 250 s. The frequency of the pain can range from one to two crises per day to 10–30 crises per hour and may follow an erratic time pattern or a cluster pattern of variable duration (2–5). Attacks may be precipitated by mechanical manoeuvres of the neck and may be associated with cutaneous trigger zones in a trigeminal and even extra-trigeminal topography (1–9).
Thus, it is evident that SUNCT shares the triggering factors of trigeminal neuralgia, the autonomic features of the cluster headache and the main location (orbital) and the cyclically recurrent crises of both. Nevertheless, due to a number of differences between the conditions (10), many authors have placed SUNCT in a distinct nosologic category.
Most of the described SUNCT cases already originated as such, but Bouhassira et al. (6) described a SUNCT case deriving from trigeminal neuralgia. The new case described here also initiated as trigeminal neuralgia and later evolved to SUNCT. Nevertheless, during this ‘SUNCT period’ severe algic crises with autonomic features were observed to alternate with minor crises accompanied by slight or no autonomic signs, suggesting that SUNCT is strongly related to trigeminal neuralgia, being probably a variation of the latter.
Case report
A 60-year-old white male patient was hospitalized with a history of severely disabling algic condition for the past 4 years, which consisted of pain in the left supraorbital region, with bouts lasting from 4 to 10 months and remission periods lasting 3–6 months. The pain was considered severe, resembling either an electric shock or a pressure sensation with no vasomotor phenomena and lasting no more than ‘few seconds’. The pain attacks occurred several times a day, but did not prevent the patient from working. The condition was worsened and triggered by light touch on the ipsilateral scalp and bridge of nose and also by talking, swallowing or chewing. The patient reported that despite the severity of the pain, he had only made use of home remedies (all of which were ineffective) due to the difficult access to medical care.
In August 1998 the patient experienced a new cycle of pain, with an initial stage similar to previous ones. However, during the second month, the clinical picture changed, acquiring characteristics of SUNCT syndrome, and then the patient was hospitalized in January 1999. During his stay in Hospital, we watched crises of unilateral pain, located deep inside the left ocular region and with no irradiation. The onset of pain was quickly progressive, and its intensity varied from moderate to excruciating, most attacks being excruciating and burning or stabbing in quality. The number of crises varied from one to eight crises per hour, lasting from 10 s to 1 min (mean of 20–30 s). Between paroxysms, the patient could be asymptomatic or present mild burning sensation in the ocular area. The more severe attacks were accompanied by extensive unilateral lacrimation and conjunctival hyperaemia increasing concomitantly to the increase in intensity and duration of the pain. Brief and moderate algic paroxysms with no autonomic signs or with only minor lacrimation were also observed. Rhinorrhoea and nasal obstruction were not present, although the patient complained of great discomfort in both nostrils (‘as if there was something strange inside’), causing him to blow his nose constantly, the effort proving useless. He also complained that after the worsening of the condition his left upper eyelid was slightly red and with persistent oedema.
During the more severe crises the patient remained still, closed the left eye (blepharospasmus?) at the onset of lacrimation and conjunctive hyperaemia, immediately interrupted the conversation and pressed the eyeball or all of the left hemiface against the hand or pillow with fascies of great suffering. Even during moderate crises he always stopped his activities. The crises appeared spontaneously but principally during talking, chewing or swallowing of solid or liquid foods, this resulting in loss of weight of almost 10 kg during this period. The crises occurred predominantly during the day but also during the night, waking the patient from sleep.
The patient denied other autonomous signs and symptoms, as well as prodromes or auras, fever and purulent nasal discharge.
The patient's clinical and neurological examinations were normal except for persistent and moderate oedema and hyperaemia of the left upper eyelid. Cranial tomographies both with and without contrast and cranial NMR were normal.
For 2 weeks, the patient received the following medications: dilacoron (480 mg), lythium (600 mg), lorazepan (2 mg), carbamazepine (600 mg) and oxygen therapy, all of which proved equally ineffective On the third week valproate (1500 mg) in association with prednisone (40 mg) and nortriptyline (25 mg) was introduced. A marked progressive improvement of the patient's condition was observed, and after 15 days of medication he was capable of eating. The oedema and hyperaemia of the upper eyelid gradually resolved. After 4 weeks of the above mentioned regime, the patient's improvement score was almost 100%. The patient was discharged from Hospital on this therapeutic regimen and was well for 40 days, after which he reported worsening of his condition, with mild ‘tolerable’ burning-type ocular discomfort with overlapping paroxysms with and without disautonomia. The condition did not prevent the patient from eating. The patient returned to his home in the rural area and was lost to follow up.
Discussion
SUNCT syndrome as described by Sjaastad et al. in 1989 is considered a rare type of headache, likely to be misdiagnosed, whose aetiology, treatment and relation with V1 trigeminal neuralgia is yet unclear (1–7). In the case reported here, the initial condition, although retrospectively assessed, is highly suggestive of V1 trigeminal neuralgia, it evolving to SUNCT only in the last algic cycle. It was evident, in this cycle, that despite slight changes in the clinical picture, the most remarkable feature was the onset of the vasomotor phenomenon (‘the hallmark of SUNCT’) associated with the increased severity of pain as seen by the higher frequency, duration, and intensity of the attacks. In addition, during the ‘SUNCT period’ we also observed a direct correlation between severity of pain and the intensity of the vasomotor phenomenon, i.e. the expression of disautonomia was so dependent on the intensity and duration of pain that it was possible to determine the severity of the painful paroxysm by observing the extent of hyperaemia and lacrimation produced by the condition; in other words, the more severe the disautonomia, the greater the severity of pain and vice versa.
Bouhassira et al. (6) described a case with a similar pattern, in which three distinctive stages of the pain were apparent: the first stage was consistent with a V1 trigeminal neuralgia and responded to the use of carbamazepine; the second was compatible with trigeminal neuralgia associated with SUNCT; this stage was marked by bouts of more severe intensity, with irradiating pain to V2 and V3, with the onset of autonomic phenomena and the failure to respond to carbamazepine; and the third stage; consistent with SUNCT alone.
The association of autonomic features in V1 trigeminal neuralgia is not well documented. However, Sjaastad et al. reviewed 19 patients with V1 trigeminal neuralgia and observed that lacrimation had occurred as the most frequently autonomic sign, although in a minor way. The triad lacrimation, conjuntival injection and rhinorrhoea occurred in just two cases. They concluded that the autonomic signs in V1 trigeminal neuralgia occurred just in the later stages of disease and during particularly severe and long-lasting attacks (10).
Thus, it is possible that in our case, after 4 years of pain, the severity of the algia (higher frequency, intensity and duration) is the decisive factor in whether the paroxysms appear with or without autonomic signs, i.e. the autonomic features occur just above a ‘certain pain threshold’. Although it is conceivable that two different disorders may be asynchronously concurrent in the same patient, we believe that in our patient, the ‘SUNCT period’ may be a modified trigeminal neuralgia, characterized by overall more painful episodes, capable of triggering concomitant autonomous phenomena, suggesting just a single pathologic condition; most likely trigeminal neuralgia with and without autonomic features.
Another factor that strongly linked our patient to trigeminal neuralgia was pain intensity, which was excruciating and severely disabling (this resulting in weight loss of 10 kg), as opposed to reports of SUNCT cases (2–5).
Regarding treatment, we believe that the patient's improvement observed with the use of valproate, prednisone and nortriptyline appears to have resulted from their use, but it is also possible that the algic crises might have been reaching their final stage with a natural trend to spontaneous alleviation of the condition.
In conclusion, it is possible that cases like ours and the one reported by Bouhassira may help to elucidate the enigmatic SUNCT syndrome, suggesting that it could be a modified trigeminal neuralgia. It is tempting to presume that many cases diagnosed as SUNCT are in reality trigeminal neuralgia with autonomic signs. Nevertheless, other reports are necessary to distinguish or to link definitively these two clinical syndromes and to develop a pathogenesis hypothesis. We suggest that every patient with diagnosed SUNCT must be carefully investigated concerning the absence of autonomic signs at the initiation of the algic condition. In case of affirmative replay we do believe that the correct diagnosis is V1 trigeminal neuralgia. This may be the tenuous but definitive link between SUNCT and trigeminal neuralgia and vice versa.