Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT) syndrome

Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT) syndrome (1,2,3):

• is considered a rare condition characterized by moderate or severe neuralgiform pain typically located in the area of the first division of the trigeminal nerve –though can be felt anywhere in the head
  • attack episodes are very short (5 to 250 seconds) and can be described as single stabs, series of stabs or in a sawtooth pattern
• male-to-female ratio of 1.5:1 (2)
• a mean age of onset around 50 years
• rare with an annual incidence of 1.2 per 100,000 (2)
• proposed mechanisms involve trigeminal–autonomic reflex activation and hypothalamic dysfunction, although the exact etiology remains unclear
• secondary causes, such as posterior fossa lesions, pituitary pathology, and vascular compression, must be excluded

Clinical features:

• attacks are strictly unilateral, generally with the pain persistently confined to the ocular/periocular area
• most attacks are moderate to severe in intensity and burning, stabbing or electrical in character
• mean duration of paroxysms is 1 minute, with a usual range of 10 to 120 seconds (total range 5 to 250 seconds)
• a diagnosis of SUNCT requires at least 20 episodes, with a minimum of 1 daily attack (2)
• prominent, ipsilateral conjunctival injection and lacrimation regularly accompany the attacks
• nasal stuffiness/rhinorrhoea are frequently noted
• during attacks, there is increased intraocular pressure on the symptomatic side and swelling of the eyelids
• no changes in pupil diameter have been observed (3)

Comparison of SUNCT with cluster headaches:

Open Image in Modal

Management:

• seek expert advice
• intravenous lidocaine has demonstrated partial symptom relief in patients with SUNCT (2)
• long-term therapy
  • lamotrigine is the first-line therapy, with up to 80% of patients reporting symptomatic improvement (2)
  • alternative options include carbamazepine, oxcarbazepine and lamotrigine

Notes:

• short-lasting unilateral neuralgiform headache (SUNHA) is a rare primary headache disorder within the trigeminal autonomic cephalalgias, characterized by very frequent, brief attacks of moderate-to-severe unilateral orbital or temporal pain lasting seconds to minutes
  • two phenotypes include
    • short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and
    • short-lasting unilateral neuralgiform headache with cranial autonomic symptoms (SUNA)

Reference:

1. Gay-Escoda C et al. Sunct syndrome. Report of a case and treatment update. J Clin Exp Dent. 2015 Apr 1;7(2):e342-7.
2. Al Khalili Y, Patel J, Veerapaneni KD. Short-Lasting Unilateral Neuralgiform Headache. [Updated 2026 Mar 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-.
3. Pareja JA, Caminero AB, Sjaastad O. SUNCT Syndrome: diagnosis and treatment. CNS Drugs. 2002;16(6):373-83.