A single-health system retrospective case series of electroconvulsive therapy for catatonic syndrome associated with anti-NMDAR encephalitis and new-onset psychosis of suspected immune origin

Background: Anti-NMDA receptor encephalitis frequently presents with a wide range of psychiatric and behavioral symptoms such as catatonia and psychosis. Although immunomodulatory therapy, together with the teratoma removal whenever present, is the mainstay treatment, additional treatments are often needed to mitigate the psychosis and catatonia. However, antipsychotics are often either ineffective or poorly tolerated. We present a single-health system retroactive case series of the use of electroconvulsive therapy (ECT) in catatonic syndrome of definitive, probable, or possible immune origin. Objective: To determine the efficacy and safety of ECT for the management of catatonic syndrome associated with anti-NMDAR encephalitis and new-onset psychoses of suspected immune origin using consensus criteria described by Pollak et al in 2020. Methods: A retrospective medical records review on the demographic data, clinical characteristics, relevant laboratory findings, immunomodulatory therapies administered, and clinical outcomes of all the patients treated with ECT at our health system from Jan 2017 to Dec 2022 for the catatonic syndrome associated with anti-NMDR encephalitis or new-onset psychosis of either possible or probable immune origin. Clinical assessment of catatonic symptoms using the Bush Francis Catatonia Rating Scale (BFCRS) before and after ECT treatments as well as the time interval from the estimated onset of illness to first ECT treatment were reviewed and reported. Results;: There were 12 cases of ECT used as an adjuvant therapy to manage persistent catatonic syndrome, despite treatment with various immunotherapies, associated with either anti-NMDAR encephalitis (n=4), or new-onset psychosis of possible (n=2) or probable (n=6) immune origin. Patients were often young (mean age 26 years) with slight female predominance (58%). Mean initial BFCRS score was 18.2 (range: 5-25). All patients responded well to the combination of immunotherapies and ECT, and showed some response after 3 ECT treatments. Complete resolution of catatonia was achieved in 11 patients (92%). Patients required an average of 11 ECT treatments (range: 3-21) to achieve maximum improvement. Conclusions: This is the largest single-health system retrospective case series showing ECT modality to be highly effective and safe adjuvant therapy for all forms of catatonic syndrome of confirmed or suspected immune origin, including those refractory to the standard treatment combined with immunotherapies. Our report underscores the importance of high index of clinical suspicion in early recognition of the immune-mediated catatonic syndrome, particularly among those with a prior history of psychiatric illnesses. This is important to prevent catatonia-related medical complications. It also provides additional support for early and consistent use of ECT modality in the management of immune-mediated catatonia in association with anti-NMDAR encephalitis and other suspected central nervous system autoimmunity. Large-scale randomized clinical studies might provide pivotal insights sufficient for incorporating ECT modality into the treatment algorithm for catatonic syndrome associated with autoimmunity