Objective To present a new case of anti-NMDAR positive autoimmune encephalitis treated with electroconvulsive therapy and to review the recent literature and published case reports.

Method Autoimmune encephalitis is a poorly understood condition that can present with a combination of neurological and psychiatric symptoms, either of which may predominate. There are many autoantibodies associated with a variety of clinical syndromes – anti-NMDAR is the commonest. Currently, the most widely used therapy is prompt plasmapheresis and steroid treatment (and tumour resection if indicated), followed by second line immunosuppression if this fails. Given the growing awareness of autoimmune encephalitis as an entity, it is increasingly important that we consider it as a potential diagnosis in order to provide timely, effective treatment. We discuss several previously published case reports and one new case. These reports examined the effects of ECT on patients with autoimmune encephalitis, particularly those in whom psychiatric symptoms are especially debilitating and refractory to standard treatment. We also discuss factors predicting good outcome and possible mechanisms by which ECT may be effective.

Results Numerous cases, such as those presented by Wingfield, Tsutsui, Florance, Sansing, Braakman and Matsumoto, demonstrate effective use of ECT in anti-NMDAR encephalitis patients with severe psychiatric symptoms such as catatonia, psychosis, narcolepsy and stupor who had failed to respond to standard treatments alone. We also present a new case of a 71 year old female who presented to a psychiatric unit initially with depression, which escalated to catatonia, delusions, nihilism and auditory hallucinations. After anti-NMDAR antibodies were isolated, she was treated by the neurology team with plasmapheresis and steroids, with a partial response. She received multiple sessions of ECT and her psychiatric symptoms completely resolved and she returned to her premorbid state.

Conclusions In conclusion, there is a growing body of evidence that ECT is effective in treating neuro-psychiatric symptoms of autoimmune encephalitis. Hence, it is reasonable to suggest that it should be considered as an alternative or adjunct to standard immunosuppressive therapies. There is a difficulty in differentiating between ‘functional’ causes of psychosis and the psychosis seen in anti-NMDAR encephalitis which may lead to some patients being treated inappropriately with anti-psychotics for possible schizophrenia or mood disorder rather than immunomodulatory treatments. It is, therefore, crucial for clinicians to be aware of the potential for patients to present to either psychiatry or neurology services so that timely diagnosis is made and appropriate treatment administered promptly.