Long-Term Outcomes and Sequelae in Patients with Anti-NMDA Receptor Encephalitis in India: A Systematic Review

Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a potentially reversible autoimmune encephalitis, but cognitive, behavioural, neurological, and functional sequelae may persist despite apparent clinical recovery. Evidence regarding long-term outcomes in Indian patients remains limited. The objective is to systematically review and narratively synthesize the available evidence on long-term outcomes and sequelae of anti-NMDAR encephalitis in India. Material and Methods: A systematic review was conducted in accordance with PRISMA 2020. MEDLINE/PubMed, Embase, Scopus, and Web of Science were searched, with supplementary reference and citation searching, through 1 August 2026. Studies conducted in India reporting outcomes at least six months after disease onset, diagnosis, treatment initiation, or hospital discharge were eligible. Data on functional, neurological, cognitive, psychiatric, behavioural, educational, occupational, and social outcomes, as well as relapse, mortality, and prognostic factors, were narratively synthesized because of clinical and methodological heterogeneity. Results: Of 388 records identified, 46 full-text reports were assessed and three studies comprising 40 reported patients met the inclusion criteria. The evidence was predominantly paediatric and derived from tertiary-care centres. Substantial neurological and functional improvement was reported; however, persistent sequelae included cognitive and behavioural impairment, speech-language dysfunction, motor deficits, and educational difficulties. Relapse was reported in two studies. Abnormal baseline magnetic resonance imaging was associated with poorer one-year functional outcome and more frequent relapse in one cohort. Interpretation was limited by small samples, heterogeneous follow-up, selected populations, and inconsistent use of standardized multidomain outcome measures. Conclusion: Indian evidence suggests that favourable functional recovery after anti-NMDAR encephalitis may coexist with persistent neuropsychiatric and participation-related sequelae. Long-term follow-up should extend beyond global disability measures, and larger prospective multicentre Indian studies using standardized multidomain assessments are needed.

Keywords: anti-NMDA receptor encephalitis; autoimmune encephalitis; long-term outcomes; cognitive sequelae; neuropsychiatric outcomes; relapse; India; systematic review.