Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attack (SUNA) are rare headache disorders characterized by extremely frequent attacks of unilateral head pain and autonomic activation.
(See also Approach to the Patient With Headache.)
SUNCT, like cluster headache, is a primary headache disorder characterized by unilateral pain in the trigeminal nerve distribution and by autonomic manifestations. As such, SUNCT and cluster headaches are sometimes grouped together as trigeminal autonomic cephalgias.
Short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) is similar to SUNCT, but the autonomic manifestations include conjunctival injection or tearing, but not both. Other manifestations of SUNCT and SUNA are similar. SUNCT and SUNA are considered short-lasting unilateral neuralgiform headaches.
In SUNCT, pain paroxysms are typically periorbital, are extremely frequent (up to 200/day), and last from 5 to 250 seconds. Conjunctival injection is often the most prominent autonomic feature; tearing may also be obvious.
Diagnosis of SUNCT
Clinical evaluation
Diagnosis of SUNCT is clinical. MRI or CT is done to rule out other possible causes such as a pituitary tumor
SUNCT should be distinguished from trigeminal neuralgia, which causes similar symptoms; SUNCT differs in that
It has no refractory period.
Pain occurs predominantly in the ophthalmic division of the trigeminal nerve.
Attacks are not triggered by cutaneous stimuli.
Treatment of SUNCT
For prevention, antiseizure medications and/or occipital nerve stimulation or blockade
Reference
1. Lambru G, Stubberud A, Rantell K, et al: Medical treatment of SUNCT and SUNA: A prospective open-label study including single-arm meta-analysis. J Neurol Neurosurg Psychiatry 92 (3):233–241, 2021 doi: 10.1136/jnnp-2020-323999 Epub 2020 Dec 24.
