Tic, Triggering, and Tearing: From CTN to SUNHA

Premise: Classical trigeminal neuralgia (CTN) and the short-lasting unilateral neuralgiform headache attacks (SUNHA) are clinically similar. Problem: The SUNHAs include short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). Shared clinical signs with CTN include severe, unilateral trigeminal pain that is often triggered by innocuous stimuli and accompanied by a dull persistent background pain. Recent reports on trigeminal neuralgia cases with atypical features such as autonomic signs and prolonged attack duration further blur the clinical distinction between CTN and SUNHAs. Potential solutions: Are the similarities greater than their differences? If so, this may reflect a spectrum of disease ranging from typical CTN attacks to typical SUNHAs with a mixed phenotype in the middle. In this review they will summarize the overlap between these entities and contrast the pathophysiology and treatment approach.