Encefalitis autoinmune por anticuerpos antirreceptor de NMDA: a propósito de un caso

Abstract

Introduction

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis. It usually begins with psychiatric symptoms and heterogeneous manifestations that make diagnosis challenging, thereby delaying appropriate treatment. It is crucial to be aware of this condition and to consider it for exclusion in cases of atypical first psychotic episodes.

Clinical findings and diagnosis

We present the case of a 28-year-old woman who visited the emergency room five times over 12 days due to generalized tonic–clonic seizures, accompanied by psychotic symptoms. She was initially diagnosed with a conversion disorder at two general hospitals before being referred for urgent psychiatric admission. A neurology consultation revealed positive anti-NMDA antibodies (1:16) in cerebrospinal fluid (CSF), leading to the diagnosis of anti-NMDAR encephalitis. A gynecology consultation subsequently detected a left ovarian teratoma.

Conclusions

In the event of a first psychotic episode with additional neurological symptoms or poor evolution, encephalitis should be excluded. In some cases, magnetic resonance imaging (MRI) and electroencephalographic (EEG) patterns may be normal, making CSF analysis essential. Given the strong association of tumors with anti-NMDAR encephalitis, particularly ovarian teratomas in young women, good coordination between services is critical for early diagnosis and treatment.