Autoimmune encephalitis (AIE) refers to brain inflammation caused by a misdirected immune response against self-antigens in the central nervous system. The expansion of this field has been fueled by identification of several pathogenic autoantibodies causing neurological and neuropsychiatric diseases. A significant proportion of pediatric AIE cases are diagnosed as seronegative based on diagnostic criteria. Early identification and treatment improve patient outcomes of both serogroups.

Data from 15 pediatric patients with AIE were retrospectively analyzed from May 2025 to March 2026. The clinical profile and response to immunotherapy in autoimmune encephalitis were studied.

15 subjects (10 males, 5 females) were identified, with a mean age of 6.5 years. 10 children who tested antibody positive were classified as definite-AIE (Anti-NMDAR, n=8; Anti-GAD, n=2). Clinical presentation for Anti-NMDAR encephalitis included behavioral abnormalities (10/10), seizures (10/10), dyskinesia (9/10), sleep disturbance (8/10), and emotional lability (8/10). Anti-GAD syndromes presented with behavioral abnormalities and refractory epilepsy. Five seronegative patients who showed improvement with immunotherapy were categorized as probable-AIE. EEG abnormality was seen in (10/15) of cases. MRI (Brain) abnormality was observed in (3/15) of cases.  Immunotherapy was administered to all (initial co-administration of methylprednisolone, 30 mg/kg/day and IVIG, 2 g/kg/day; in non-responders, plasma-exchange and rituximab, was given). The average response rate to immunotherapy was 4-6 weeks in seropositive AIE and 3-4 weeks in seronegative. EEG correlated with recovery. Second-line immunotherapy was required in 3/15 refractory cases with Anti-NMDAR and Anti-GAD encephalitis.

Early initiation of immunotherapy was associated with favorable outcomes. EEG is often a better monitoring tool for tracking cognitive/recovery improvements. Seropositive encephalitis children more often required second-line immunotherapy, highlighting the importance of early diagnosis and timely escalation of treatment to improve neurological outcomes.