Sick sinus syndrome: A harbinger of anti‐ LGI1 encephalitis

Abstract

Autoimmune encephalitis usually presents with short‐duration neuropsychiatric syndromes, mainly behavioral with cognitive dysfunction, recurrent seizures, and movement disorders. Among them, anti‐LGI1 encephalitis has faciobrachial dystonic seizure as a pathognomic feature. The two cases reported here exemplify another peculiar feature of anti‐LGI1 encephalitis, which has rarely been reported and is therefore not typically emphasized. Both cases were initially treated for cardiac symptoms until the full‐blown features of encephalitis became evident. The key to preventing adverse outcomes is early detection, as anti‐LGI1 encephalitis is largely reversible when treated early with immunotherapy, whereas a delay in diagnosis can lead to permanent damage or fatal outcomes.