Summary

Our patient was a previously normal boy who presented to his local hospital with an explosive onset of prolonged seizures and encephalopathy. He was treated for a presumed central nervous system infection and initial neuroimaging was normal. Despite treatment with antibiotics and antiepileptic drugs (AEDs), he remained encephalopathic and became ataxic over the next 48 hours, not related to medication. The seizures also proved resistant to treatment despite polytherapy with AEDs, and he required immune-modulatory treatment, intravenous methylprednisolone and intravenous immunoglobulin, in addition to the AEDs to achieve seizure control. The ataxia also improved following treatment. The initial EEG was normal but subsequent EEGs, separated by a week each, were abnormal and revealed subtle atypical ‘delta-brush-like waves’. The patient's serum and cerebrospinal fluid were tested for autoantibodies, and he was found to be positive for glycine receptor antibodies that are neuronal antibodies.