3.3 Short-lasting unilateral neuralgiform headache attacks

Attacks of moderate or severe, strictly unilateral head pain lasting seconds to minutes, occurring at least once a day and usually associated with prominent lacrimation and redness of the ipsilateral eye.

Diagnostic criteria
A. At least 20 attacks fulfilling criteria B–D
B. Moderate or severe unilateral head pain, with orbital, supraorbital, temporal and/or other trigeminal distribution, lasting for 1–600 sec and occurring as single stabs, series of stabs or in a saw-tooth pattern
C. At least one of the following cranial autonomic symptoms or signs, ipsilateral to the pain:

    1. conjunctival injection and/or lacrimation
    2. nasal congestion and/or rhinorrhoea
    3. eyelid oedema
    4. forehead and facial sweating
    5. forehead and facial flushing
    6. sensation of fullness in the ear
    7. miosis and/or ptosis

D. Attacks have a frequency of at least one a day for more than half of the time when the disorder is active
E. Not better accounted for by another ICHD-3 diagnosis.

Longer-duration attacks are characterized by multiple stabs or a saw-tooth pain pattern.

Two subtypes of 3.3 Short-lasting unilateral neuralgiform headache attacks are recognized in ICHD-3 (beta): 3.3.1 Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and 3.3.2 Short lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). 3.3.1 SUNCT may be a subform of 3.3.2 SUNA, although this requires further study. Meanwhile, each is classified as a separate subtype, described below.

3.3.1 SUNCT and 3.3.2 SUNA are usually triggerable without a refractory period. This is in contrast to 13.1 Trigeminal neuralgia, which usually has a refractory period after each attack.