New Onset Focal Seizure Clusters in Children: Expanding the Spectrum of Anti NMDAR Encephalitis

Neurol India. Nov-Dec 2020;68(6):1374-1377. doi: 10.4103/0028-3886.304087.

Abstract

Introduction: Anti-N-methyl-d-aspartate receptor (Anti-NMDAR) Encephalitis classically presents with polysymptomatic presentation of behavioral or cognitive changes, seizures, and focal deficits. Large series in adults and children have described the above features. Monosymptomatic presentation of Anti NMDAR encephalitis is rare and in literature single case reports in adults and children are available. Here we report a series of 6 children presenting with seizure alone and thus expanding the clinical spectrum of Anti NMDAR encephalitis.

Materials and methods: This is a a retrospective case series of 6 cases of anti NMDAR encephalitis treated in our institute, which is a tertiary referral center between 2010 and 2014. All the patients with NMDA encephalitis were initially included. The baseline demographics, clinical presentations, investigations (CSF, MRI and EEG), course in the hospital, details of treatment, short and long term outcomes were documented from the available medical records. Children presenting with monosymptomatic seizure clusters were only included in the final analysis.

Results: Twenty eight children were diagnosed with ant NMDA R encephalitis during the study period. 22 children had classical polysymptomatic presentations and were not included in this analysis. The remaining 6 children (5 girls and one boy), who presented with only acute seizure clusters were included in the study. All children presented with acute cluster of focal seizures. Four out of six had focal status epilepticus while 2 out of six had recurrent focal seizures. Commonest semiology was clonic seizure in 4/6 and one child had dystonic seizure and one had tonic seizure. All patients were started on steroids and antiepileptic drugs. No other immunomodulators or immunosuppressants were used. On discharge all patients where seizure free and with no focal deficits.

Conclusion: This is the first series of Anti NMDAR encephalitis presenting as new onset seizure clusters in children. Unlike the existing literature, these children did not develop any other symptoms. We propose that focal encephalitis could be the reason for this monosymptomatic presentation.

Keywords: AntiNMDAR encephalits; monosymptomatic presentation; seizure cluster.