Abstract
Introduction
SUNCT is a syndrome of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing. It was first described in 1978 and characterized more fully in 1989 (1, 2). Suggested criteria for the diagnosis of SUNCT include attacks of unilateral, moderately severe orbital or temporal, stabbing or throbbing pain lasting 15–120 s, with attack frequency of 3–100 a day and where pain is associated with at least one of the following signs and symptoms of the affected side, with conjunctival injection being most often present and prominent: lacrimation, nasal congestion, rhinorrhoea, ptosis and/or eyelid oedema (3). The disorder has a male predominance and tends to affect the elderly, although the age of onset varies from 40 to 82 years (4). Status-like SUNCT has been reported in young women in their twenties, however (5).
We describe a young female patient with right orbital cystic lesion masquerading as SUNCT, with complete resolution of her symptoms following excision surgery.
Case report
In 2001 a young 23-year-old woman of Indian extraction was admitted to our service complaining of severe pain over the right supraorbital ridge and orbit, extending to the right temple, associated with prominence of autonomic symptoms such as lacrimation and conjunctival injection. She had no nasal congestion or eyelid oedema, and had no past history of headaches. She did not recall any trauma to her head. The pain was episodic, occurring in spurts of 10–60 s, with periods of respite of up to 30 min, and lasted through the night, i.e. over a period of 8 h, preventing and interrupting sleep. The pain was triggered when she moved or rubbed her eyes, but was not exacerbated by chewing, change of temperature, facial movements or washing her face. She had an average of 20–30 attacks each day.
Clinical examination was unremarkable, except for mild lacrimation, conjunctival injection and exacerbation of orbital pain on looking ‘up and out’. There was no proptosis.
She was prescribed analgesics, which did not ameliorate her orbital pain. Our differential diagnoses at the time included trigeminal neuralgia, involving the ophthalmic division of the trigeminal nerve (V-1 trigeminal neuralgia), and an orbital cause such as a space-occupying lesion or inflammation of the globe of the eye or the surrounding intraorbital structures, cluster headaches and SUNCT. Magnetic resonance imaging of the brain and orbits was performed within a week of presentation, with administration of gadolinium contrast (Fig. 1). There was a 21 × 12 × 11 mm lobulated mass lesion in the lateral aspect of the right orbit, extraconal in location (i.e. outside the cone of muscle) and displacing the lateral rectus medially. There was increased signal intensity on spin-echo in T1 and fast spin echo T2 weighted images. The signals were nulled in the fat suppression sequences, and there was no contrast enhancement (Fig. 1). Provisional diagnosis radiologically was that of an orbital lipoma or dermoid.
Axial T1-weighted magnetic resonance image showing 21 × 12 × 11 mm extraconal lobulated mass lesion in the lateral aspect of the right orbit displacing the lateral rectus medially.
Orbitotomy was performed. The thin cyst wall ruptured, leaking yellowish fluid. No formed elements were seen within. No histological examination was performed. Operative diagnosis was that of a lacrimal gland retention cyst or a cholesterol cyst from an old haemorrhage. She recovered post-operatively with no recurrence of her headaches, which had persisted from the time of onset until the lesion was excised 1 month later.
Discussion
Unilateral headaches can be attributed to a number of causes, among which are migraines, tension headaches, trigeminal neuralgia, paroxysmal hemicrania, including SUNCT, and cluster headaches. Orbital lesions are well known to cause unilateral headaches, especially orbital pain. Trochleitis (6) and orbital myositis (7) have recently been described to cause unilateral headaches. Orbital apex syndrome from infection (8) and orbital tumours (9) have also been described to cause orbital pain, but these are usually associated with painful ophthalmoplegia. Headache from SUNCT was initially thought to be extremely refractory to treatment (4), though recent reports of successful amelioration of the pain with anti-convulsants such as lamotrigine (10), gabapentin (11) and surgical treatment with percutaneous trigeminal ganglion compression (12) offer hope for the sufferer.
Our patient's orbital tumour was extraconal (i.e. outside of the muscle cone) and cystic. Cystic lesions account for approximately 8% of orbital lesions (13, 14). This limited the number of differential diagnoses to that of a dermoid cyst, mucocoele or retention cyst. Dermoid cysts account for 80% of cystic orbital lesions (15).
Our patient's clinical presentation was rather unusual in that she had not experienced any headaches in the past, but developed sudden onset of brief episodes of lancinating pain over the orbit. The sharp, unilateral, lancinating pain associated with lacrimation and conjunctival injection made the diagnosis of SUNCT a possibility. However, her age and sex were rather unusual for SUNCT. These episodes were subsequently attributed to contraction of the right lateral rectus muscle abutting the cystic lesion, which explained the brief recurrent episodes of pain and suggested a paroxysmal hemicranial headache. The exacerbation of pain when she rubbed her eyes and the presence of unilateral pain were consistent with the diagnosis of trigeminal neuralgia. V-1 trigeminal neuralgia patients may report mild autonomic signs, usually lacrimation, that tend to occur during severe attacks and after suffering from headaches for years, whereas SUNCT attacks are characterized by conjunctival injection and lacrimation from the onset, often in a dramatic way (16). It is important to realize that diagnosis of SUNCT and trigeminal neuralgia are made after excluding other causes, and this case clearly illustrates the need to do so. The consistent history of pain exacerbated by eye movement, however, clearly argued for the need to exclude an orbital lesion. It has been maintained that SUNCT is a form of trigeminal neuralgia with lacrimation. Pareja et al. (16) have described how marked lacrimation and conjunctival injection support SUNCT over V-1 trigeminal neuralgia.
Orbital lesions are well-known causes of unilateral headache. Red flags for the diagnosis include proptosis, visual disturbances and pain on moving the globe of the eye. Our patient had neither proptosis nor visual loss, which was unusual in someone with an orbital mass. The presence of eye discomfort on eye movement provided the diagnostic clue. The complete resolution of her headaches with surgery is an indication that her headaches were caused by the orbital lesion. SUNCT has been described to be associated with intracranial lesions (17, 18), for which surgical treatments have been performed successfully (19). However, SUNCT has also been successfully treated medically, and surgical treatment of the condition can only be advocated with caution. Black and Dodick (20) described two cases of SUNCT who underwent exhaustive invasive surgical procedures which failed to provide therapeutic relief. In conclusion, it must be remembered that unilateral headache syndromes such as SUNCT may have more than one cause, and it is important to elucidate the underlying cause of headache.