SUNCT syndrome and SUNA syndrome & PH

These are grouped as trigeminal autonomic cephalgias, together with cluster headache. (TACs)

SUNCT= short acting unilateral neuralgiform headache with conjunctival injection and tearing. Usually SUNCT headaches are retroorbital with stabs, groups of stabs or sawtooth pain and may occur 3-200 times per day and last 15-240 seconds. They are strictly unilateral and may resemble paroxysmal hemicrania, cluster headache or trigeminal neuralgia. They may resist treatment although in one case in Neurology a patient responded to topiramate, AAN2009 lamictal was reported as drug of choice. Men experience it more in a 2:1 ratio, whereas paroxysmal hemicrania occurs more in women and last 15 minutes v. less than a minute for SUNCT. The location of the pain is supraorbital, orbital, retroorbital, temporal, in the top or side of the head, in a V2 or V3 distribution, or in the teeth, neck or ear. All patients have conjunctival injection and tearing. GBN also has been used. Neurology(2002) patients with pituitary tumors (adenomas) after beginning therapy with bromocriptene. Other cases are triggered by exercise. In the above series, authors speculate that extension of the tumor into the cavernous sinus may be contributory.

In Cohen AS et al, Brain 2006 (129:2746-2760) a series of 43 patients were reported with SUNCT and 9 with the less known SUNA syndrome. 2 SUNA patients had tearing, 4 had conjunctival injection but none had both. Other cranial autonomic features seen include nasal blockage, rhinorrhea, eyelid edema, facial sweating, flushing or ear flushing. Most patients did not have a refractory period between attacks and were agitated with the attacks. Pain severity is greater in SUNCT than SUNA. In general analgesic overuse ought to be avoided.


SUNA stands for "Short-lasting Unilateral Neuralgiform headache Attacks with cranial autonomic symptoms." Occassionally it can present with Horner's syndrome.

Other pearls for diagnosis: ipsilateral photophobia and phonophobia differentiates TACS from migraines. Interictal pain occurs in one third, often those with personal/family history of migraine. In patients with cluster headache, more than half have OSA so do a sleep study. TAC like pain occurs at a very high rate with pituitary tumors, so MRI with pituitary thin cuts is indicated.

Paroxysmal hemicrania (PH) has a unilateral brief headache attack that occurs several times daily. It most often but not exclusively affects first division of trigeminal nerve. It lasts 2-30 minutes (longer than SUNCT/SUNA) with 1-40 attacks per day, and may be episodic in 20 percent (attacks for up to a week with a month or more remission between) or chronic in 8- percent with no remission of remission of less than a month. Distinctively, it responds to indomethacin.

(I try to AVOID basic science but) common to all 3 is activation of posterior hypothalamus on all syndromes.

Symptomatic (or secondary) TACs occur rarely, and clinical features alerting to possibility include atypical phenotype, abnormal exam, and refractory to treatment. Summarized by Cittadini et al (Neurologist 2009; 15: 305-312) include historical points such as unusual triggers such as postprandial, or sitting or standing; altered consciousness, impotence, galactorrhea, acromegaly, fever, and purulent nasal discharge. Physical signs included opthalmoplegia, optic atrophy, temporal hemianopia, Adie syndrome, swelling of the eye, persistent partial or complete Horner's syndrome, absent nasal tickle reflex, signs of acromegaly, testicular atrophy, and absent radial pulse. In PH atypical features included onset with carotid massage (gangliocytoma extending to carotid artery from pituitary lesion).

Since one in ten patients may have incidental pituitary microadenoma and one in 500 an incidental macroadenoma, the role of imaging may be less certain, with decided risk of unknown importance of discovering and treating an incidental finding.

AAN 2010 suggested SUNCT/SUNA responsive to occipital stimulator