Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) attack 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
History and physical 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.
Indomethacin does not relieve symptoms, as it does in some other headache disorders.Indomethacin does not relieve symptoms, as it does in some other headache disorders.
Treatment of SUNCT
For terminating a cycle of acute attacks, IV lidocaineFor terminating a cycle of acute attacks, IV lidocaine
For prevention, antiseizure medications and/or occipital nerve stimulation or blockade
Treatment of SUNCT can include IV lidocaine to terminate a cycle of acute attacks and, for prevention, antiseizure medications (eg, lamotrigine, topiramate, gabapentin) and occipital nerve blockade (eg, with a mixture of lidocaine and methylprednisolone) or stimulation.Treatment of SUNCT can include IV lidocaine to terminate a cycle of acute attacks and, for prevention, antiseizure medications (eg, lamotrigine, topiramate, gabapentin) and occipital nerve blockade (eg, with a mixture of lidocaine and methylprednisolone) or stimulation.
In one clinical trial, IV lidocaine can terminate the cycle of acute attacks in most patients when it is given for 7 to 10 days (In one clinical trial, IV lidocaine can terminate the cycle of acute attacks in most patients when it is given for 7 to 10 days (1). It is the most successful treatment, followed by lamotrigine, followed by oxcarbazepine.). It is the most successful treatment, followed by lamotrigine, followed by oxcarbazepine.
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
