Sunct Syndrome

SUNCT syndrome (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing) is a primary headache disorder characterized by unilateral trigeminal pain that occurs in association with ipsilateral cranial autonomic symptoms (conjunctival injection and tearing).

Epidemiology

The prevalence is estimated at approximately 1 in 15,000. It is slightly more predominant in males (male-to-female ratio of 1.5:1), with a mean age of onset of around 50 years. A few cases of SUNCT syndrome have been reported in children.

Clinical description

The disease manifests with strictly unilateral pain attacks of moderate-to-severe intensity. The pain is described as throbbing, sharp or stabbing. It usually involves the ophthalmic division of the trigeminal nerve but, rarely, it may involve any part of the head. In the majority of cases, the pain attacks are triggered by cutaneous stimuli (but not by alcohol or nitroglycerin). Spontaneous attacks have also been described. The typical SUNCT patients may have 50 to 100 short attacks a day, lasting for 1 to 5 minutes. The attacks predominate during the daytime. Prominent, ipsilateral conjunctival injection and lacrimation regularly accompany the attacks. Nasal stuffiness and rhinorrhea are frequent.

Etiology

Etiopathology remains unclear. Trauma, arteriovenous malformations and pituitary adenomas may have a causative role.

Diagnostic methods

Diagnosis is clinical.

Differential diagnosis

Trigeminal neuralgia is the major differential diagnosis. It is very important to differentiate SUNCT syndrome from other trigeminal autonomic cephalgias such as cluster headache and paroxysmal hemicrania (see these terms), as each of these syndromes has a highly selective response to treatment.

Management and treatment

There is no cure for SUNCT syndrome. SUNCT patients may benefit from administration of carbamazepine, lamotrigine, gabapentin or topiramate. Oxygen, anaesthetic blockades, and sumatriptan or indomethacin therapies, known to be effective in other trigeminal autonomic cephalgias, have little or no effect in SUNCT syndrome. In severe cases, several surgical techniques may be considered (microvascular trigeminal nerve root decompression, trigeminal ganglion balloon compression, or superior cervical ganglion opioid blockade).