SUNCT, SUNA and trigeminal neuralgia: different disorders or variants of the same disorder?

Abstract

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) and trigeminal neuralgia are considered different disorders, thus grouped in separate sections of the International Classification of Headache Disorders 3 beta. However, the clinical, radiological and therapeutic overlap between SUNCT, SUNA, and trigeminal neuralgia has challenged this traditional view. This review summarizes the available clinical and pathophysiological evidence on whether SUNCT, SUNA and trigeminal neuralgia should be considered separate entities or variants of the same disorder. Data on the clinical phenotype and effective management strategies in SUNCT and SUNA syndromes have shown striking similarities with trigeminal neuralgia. Moreover, studies exploring radiological findings supported the hypothesis of common aetiological and pathophysiological basis between SUNCT/SUNA and trigeminal neuralgia. However, a limitation of most studies is that they have included small samples of patients and therefore any conclusions need to be drawn cautiously. Despite being considered distinct conditions, emerging clinical and radiological evidence supports a broader nosological concept of SUNCT, SUNA, and trigeminal neuralgia. These conditions may constitute a continuum of the same disorder, rather than separate clinical entities. Further evidence is required to shed light on this nosological issue, given its potential impact on clinical practice and further research studies in this area.