Confusional migraine in the emergency department: A case report of an adult patient with altered mental status

Acute confusional migraine (ACM) is an under-recognized migraine variant that presents with abrupt, reversible altered mental status and can closely mimic high-stakes neuroemergencies routinely triaged in the ED. It is not formally indexed in the International Classification of Headache Disorders and remains a diagnosis of exclusion guided by proposed criteria from pooled case data. This case report describes an adult ED presentation of ACM, a condition predominantly described in children, to highlight its relevance to emergency practice. A 41-year-old man with history of complex migraine presented to the ED with a unilateral headache and blurred vision followed by confusion, dysarthria, and reported left-sided weakness. On arrival, he was disoriented with strained, slowed speech and effort-dependent motor function. Neurovascular imaging and laboratory workup revealed no acute pathology. He received migraine-directed therapy with steady improvement to baseline mentation. He was ultimately discharged home in stable condition with a dexamethasone taper and close outpatient follow-up. This case underscores how ACM can present in adults and warrants consideration in the ED once time-critical neurologic emergencies have been appropriately excluded. In recurrent, well-characterized presentations, considering ACM may support diagnostic consistency and help limit duplicated evaluation. Still, standardized diagnostic criteria and ED-specific guidelines are needed.