Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic features (SUNA) are described, although SUNA is rarely reported. The phenotype of SUNCT and SUNA was characterized from a large series of patients (43 SUNCT, 9 SUNA). Three attack types were identified: stabs, groups of stabs and saw-tooth attacks. The mean duration of stabs was 58 s (1-600 s); stab groups, 396 s (10-1200 s); and saw-tooth, 1160 s (5-12 000s). The attack frequency was a mean of 59 attacks/day (2-600), and this depended largely on the type of attack. The pain was orbital, supraorbital or temporal in 38 (88%) SUNCT and 7 (78%) SUNA, and also occurred in the retro-orbital region, side, top, back of head, second and third trigeminal divisions, teeth, neck and ear. All SUNCT patients had conjunctival injection and tearing. Two SUNA patients had conjunctival injection, four had tearing, but none had both. Other cranial autonomic symptoms included nasal blockage, rhinorrhoea, eyelid oedema, facial sweating/flushing and ear flushing. Cutaneous stimuli triggered attacks in 74% of SUNCT but only in 22% of SUNA patients. The majority (95% SUNCT and 89% SUNA) had no refractory period between attacks. For SUNCT 58% and for SUNA 56% of patients were agitated with the attacks. We propose a new set of diagnostic criteria for these syndromes to better encompass the clinical presentations and which include a wider range of attack length, wider trigeminal pain distribution, cutaneous triggering and lack of refractory period.

LUSTER HEADACHE IS A STEREOtypical primary headache syndrome characterized by attacks of unilateral excruciating pain usually in the eye, periorbital region, and temple with associated cranial autonomic symptoms such as conjunctival injection, lacrimation, nasal blockage, rhinorrhea, ptosis, and eyelid edema. During attacks patients are often restless, agitated, or both. Attacks typically last for 15 to 180 minutes untreated and have a frequency of 1 every other day for up to 8 attacks a day. 1 Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years. Episodic cluster headache is defined as bouts of attacks lasting 7 days up to a year with breaks of 1 month or more between bouts. Bouts are usually circannual, occurring once a year, with a mean bout duration of 8 weeks. 2 Chronic cluster headache is defined as occurring for more than a year without remission or with remissions lasting less than a month. Cluster headache attacks may also occur with clocklike regularity during the day and may be precipitated by sleep, 3 usually occurring 90 minutes after the onset of sleep. Cluster headache affects more men than women (male-female ratio of 2.5:1) and has an estimated prevalence of 0.3% in the general population. 4 Cluster headache is probably the most severe pain known to humans. Most female patients describe each attack as worse than childbirth.See also Patient Page.

This study demonstrated activations of various subcortical structures, in particular the posterior hypothalamus and the dorsal rostral pons. If posterior hypothalamic and brainstem activation are considered as markers of trigeminal autonomic headaches and migrainous syndromes, respectively, then the activation pattern demonstrated in hemicrania continua mirrors the clinical phenotype, with its overlap with trigeminal autonomic headaches and migraine.

SUNCT (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing) and SUNA (Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic symptoms) are rare primary headache syndromes, classified as Trigeminal Autonomic Cephalalgias (TACs). Hypothalamic involvement in the TACs has been suggested by functional imaging data and clinically with deep brain stimulation. Fifty-two patients (43 SUNCT, 9 SUNA) were studied to determine the clinical phenotype of these conditions and response to medications. A functional imaging study explored activation of the posterior hypothalamus in attacks of SUNCT/SUNA. The clinical study characterised SUNCT and SUNA in terms of epidemiology, phenotype and clinical characteristics. Indomethacin is ineffective on single-blind testing. Intravenous lidocaine was effective in all cases. Open-label trails showed the effectiveness of lamotrigine, topiramate and gabapentin. On functional imaging there was hypothalamic activation bilaterally in 5/9 SUNCT patients, and contralaterally in two patients. Two SUNCT patients had ipsilateral negative activation. In SUNA the activation was bilaterally negative. There was no hypothalamic activation in a patient with SUNCT secondary to a brainstem lesion. The data suggests that there should be revised classification for SUNCT and SUNA, with an increased range of attack duration and frequency, cutaneous triggering of attacks, and a lack of refractory period. The concept of 'attack load' is introduced. The lack of response to indomethacin and the response to intravenous lidocaine, are useful in diagnostic and therapeutic terms, respectively. Preventive treatments include lamotrigine, gabapentin and topiramate. The role of hypothalamic involvement in SUNCT and SUNA as TACs is considered.

These activated subcortical structures may play a pivotal role in the pathophysiology of this syndrome.