SUNCT syndrome with paroxysmal mydriasis: Clinical and pupillometric findings.

SUNCT syndrome (short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing) is a primary headache characterised by a high frequency of attacks associated with marked autonomic periocular signs and symptoms. Activation of the hypothalamus via the superior salivary nucleus is probably responsible for some of the autonomic involvement observed during SUNCT attacks. We describe a case of SUNCT with unusual autonomic features (e.g., mydriasis) and early onset. Pupillometric studies were performed both in a basal condition (without anisocoria) and after instillation of phenylephrine (a drug with direct sympathomimetic activity) and pilocarpine (a parasympathetic agonist). The findings in this patient seem to indicate involvement of the ocular sympathetic supply in SUNCT, responsible for the mydriasis, and seem to strengthen the possibility that the autonomic phenomena in this syndrome vary with different levels of pain severity.