Background: Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) are rare and disabling primary headache disorders that are subtypes of Short-lasting unilateral neuralgiform headache attacks (SUNHA).
Aim: The aim of this narrative review was to provide a comprehensive update on headache phenotype, pathophysiology, and various treatment options available for SUNCT and SUNA.
Methods: References for this review were identified by searches of articles published in the English language in PubMed between 1978 and October 2020 using "short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)", "short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA)", "short-lasting unilateral neuralgiform headache attacks (SUNHA)", "trigeminal autonomic cephalalgias" as keywords in various combinations.
Results: Of a potential 1103 articles, seven case series describing clinical characteristics of SUNCT/SUNA patients were identified for this review. For symptomatic/secondary SUNCT/SUNA, 53 individual case reports, and one case series were reviewed. One placebo-controlled trial and 11 open-label case series that evaluated various medical and surgical treatments in SUNCT/SUNA were also reviewed. Available literature suggests that SUNCT and SUNA are subtypes of the same disorder characterized by severe side locked short duration headache with ipsilateral prominent cranial autonomic symptoms and signs. Pathophysiology may involve both peripheral and central mechanisms. Lamotrigine is the most effective preventive therapy while intravenous lidocaine is the most efficacious drug as transitional therapy for severe disabling attacks. Surgical options including microvascular decompression in those having neurovascular conflict, occipital nerve stimulation, and hypothalamic deep brain stimulation can be alternative treatment options for medically refractory patients.
Keywords: Cranial autonomic symptoms; SUNA; SUNCT; trigeminal autonomic cephalalgia.