Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing syndrome: a review

The clinical features of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome have been reviewed in 50 patients reported in the English language literature. SUNCT syndrome is a rare condition that predominates slightly in men. The mean age at onset is 50 years. It is characterized by strictly unilateral attacks centered on the orbital or periorbital regions, forehead, and temple. Generally, the pain is severe and neuralgic in character. The usual duration ranges from 5 to 250 seconds, although the reported range of duration is 2 seconds to 20 minutes. Ipsilateral conjunctival injection and lacrimation are present in most, but not all patients. Most patients are thought to have no refractory periods and this has probably been unreported in the past. Episodic and chronic forms of SUNCT exist. The attack frequency varies from less than one attack daily to more than 60 attacks per hour. The attacks are predominantly diurnal, although frequent nocturnal attacks can occur in some patients. A functional magnetic resonance imaging study in SUNCT syndrome has demonstrated ipsilateral hypothalamic activation. SUNCT was thought to be highly refractory to treatment. However, recent open-label trials of lamotrigine, gabapentin, topiramate, and intravenous lidocaine have produced beneficial therapeutic responses. These results offer the promise of better treatments for this syndrome, but require validation in controlled trials.