Autoantibodies Targeting Unknown Epitope Autoimmune Encephalitis and the Effect of Modified Electroconvulsive Therapy: Report of Three Cases.

ABSTRACT

Objective: Generally autoimmune encephalitis (AE) cases present with central nervous system symptoms. Many types of autoantibodies are associated with autoimmune encephalitis, with anti-N-methyl-D-aspartate receptor being the most commonly reported. However, autoimmune encephalitis cases with autoantibodies targeting unknown epitopes are increasingly recognized. This article aims to summarize the clinical experience and assess the feasibility of modified electroconvulsive therapy (MECT) as an adjunctive treatment method for autoimmune encephalitis patients with poor response to first-line immunotherapy and mainly displaying psychiatric symptoms. Methods: This work reports three cases of which two have been diagnosed as autoantibodies targeting unknown epitope autoimmune encephalitis while one has been diagnosed as anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and all were effectively treated with MECT. Results: All three cases that otherwise failed to respond to standard immunotherapy for controlling psychiatric symptoms exhibited excellent clinical outcomes following MECT. The underlying mechanism of action of MECT is unclear and whether such an effect involves a neurotransmitter rebalance in the brain remains uncertain. At present, we have observed only a small number of clinical cases, warranting further research among a larger number of clinical cases and more systematic multicenter retrospective analysis. Conclusions: It should be noted that, while our experience supports the utility of MECT in the treatment of certain cases of AE, this option should be regarded as an adjuvant therapy after standard immunosuppressive therapy. Clinicians must be aware that patients should be provided with psychiatric or neurological services for timely diagnosis along with timely and appropriate treatment.