Challenging diagnosis and treatment decision of a long-history autoantibody-negative autoimmune encephalitis: Expert commentary

The discovery of several neuronal surface antibodies in the past two decades has revolutionized the field of clinical neurology.1 Those antibodies define recognizable clinical phenotypes and some have associations with certain neoplasms.1 Although neuronal antibody-mediated syndromes typically present with acute or subacute cognitive decline and a myriad of other rapidly progressive neurological symptoms, 2an increasing number of cases have an indolent course.3,4 While subacute presentations often result in hospital admission and inpatient workup, cases with insidious onset or protracted course can present to outpatient neurologists including movement disorder specialists.