[N-methyl-d-aspartate receptor antibody encephalitis: a treatable disorder involving B-lymphocytes. A report of two patients]. / Encéphalite à anticorps anti-récepteur du NMDA : une entité traitable impliquant les lymphocytes B. Deux observations.

INTRODUCTION: N-methyl-D-aspartate receptor antibody (anti-NMDA-r AB) encephalitis has been recently identified. We report two cases illustrating the clinical features, response to immunomodulatory treatment and involvement of B-lymphocytes that characterizes this disorder. CASE REPORTS: These patients illustrated the classic clinical features of anti-NMDA-r AB encephalitis including occurrence in young female, presence of severe neurological and psychiatric manifestations with confusion, seizures, mutism, hypovigilence and involuntary movements, and inflammatory cerebrospinal fluid. Both patients improved after immunotherapy. In case 1, the encephalitis was associated with an ovarian teratoma containing neuronal elements. In case 2, there was no tumor identified. A brain biopsy showed prominent perivascular B-cells infiltrates with some T-cells distributed in the brain parenchyma. CONCLUSION: Anti-NMDA-r AB encephalitis is certainly not rare and needs to be promptly recognized and treated. An associated neoplasia is inconstant and the pathophysiology involves humoral immunity.