A Baby with Acute Encephalopathy, Refractory Hyponatremia, and Hypertension: A Case Report

Autoimmune encephalitis (AE) is an expanding group of clinical syndromes that can occur at all ages (from <1 year to adult), but more commonly affects young adults and children.It is a rare cause of encephalopathy that has been increasingly recognized over the last decade.Most of these disorders are severe and potentially fatal; however, if recognized in a timely manner and treated with immunotherapy, patients often respond well with good outcomes.Here, we present a 7-month-old baby girl with seronegative AE, presenting with encephalopathy, hypertension, and refractory persistent hyponatremia.Prompt treatment with aggressive immunotherapy improved her neurological symptoms.This case highlights the association of hyponatremia, hypertension, and the importance of timely immunotherapy in AE.