High-frequency, short-duration headaches include the trigeminal autonomic cephalgias (episodic and chronic cluster headache, episodic and chronic paroxysmal hemicrania), SUNCT and SUNA syndromes, hypnic headache, and exertional headaches.
The trigeminal autonomic cephalgias are characterized by unilateral pain in the trigeminal distribution, with ipsilateral autonomic features. The most common disorder in this family is cluster headache. The pain of cluster headache is described variously as sharp, boring, drilling, knife-like, piercing, or stabbing, in contrast to the pulsating pain of migraine. It usually peaks in 10 to 15 minutes but remains excruciatingly intense for an average of 1 hour within a duration range of 15 to 180 minutes. During this pain, patients find it difficult to lie still, often exhibiting marked agitation and restlessness, and autonomic features are usually obvious. After an attack, the patient remains exhausted for some time (Halker et al 2010).
Like cluster headache, the paroxysmal hemicranias are characterized by unilateral attacks of trigeminal pain and autonomic features. In contrast to cluster headache, the paroxysmal hemicranias have 3 main features: (1) greater frequency (more than 5 per day); (2) short lasting duration (2 to 30 minutes); (3) absolute response to therapeutic doses of indomethacin. They are rare (Goadsby et al 2010).
Another autonomic cephalgia, SUNCT, is a rare primary headache. The diagnostic criteria require at least 20 high-frequency attacks (3 to 200 per day) of unilateral orbital, supraorbital, or temporal stabbing or pulsating pain, lasting 5 to 240 seconds and accompanied by ipsilateral conjunctival injection and lacrimation. The attacks are characteristically dramatic, with moderately severe pain, peaking in intensity within 3 seconds, and prominent tearing (Goadsby et al 2010).
SUNA syndrome is similar to SUNCT, but it is even rarer. Attacks may last slightly longer and be less frequent. Either conjunctival injection or tearing may be present, but not both, and other autonomic features are more common (Cohen et al 2006).
Hypnic headache is a primary headache disorder of the elderly, characterized by short-lived attacks (typically 30 minutes) of nocturnal head pain that awaken the patient at a consistent time each night, in many cases on more nights than not. It does not occur outside sleep. Hypnic headache is usually bilateral (although unilaterality does not exclude the diagnosis) and usually mild to moderate, different from the unilateral orbital or periorbital, knife-like, intense pain of cluster headache. Autonomic features are absent (Obermann and Holle 2010).
Headaches triggered by cough, exertion, and sexual activity include the disorders named for these triggers. Especially in patients presenting in the emergency department, or during an attack, these headaches may only be diagnosed after an exhaustive and methodic search for secondary causes. However, in a patient previously investigated or previously diagnosed, repeating the investigation is usually not necessary, and patients should be treated (Wang and Fu 2010).