Autoimmune encephalitis and CSF anti-AMPA GluR3 antibodies in childhood: a case report and literature review

Acute autoimmune encephalitis is a severe neurological disorder presenting with altered level of consciousness, confusion, irritability, headache, vomiting, and in some cases seizures. An infective event precedes by 1–2 weeks the onset of the symptoms. Cognitive impairment is considered the cardinal symptom. The autoimmune encephalitis comprises an increasingly group of inflammatory brain disorder caused by an underlying abnormal immune response to the CNS to the infective agent. In children, several antibodies have been recorded as causative agent. Among these, GAD65, MOG, and NMDAR antibodies are more commonly reported and with less frequency, the Dopamine-2 receptor, GABA A receptor, GABA B receptor, and Glycinereceptorandm-GluR5. We report here a 10-year-old male with acute autoimmune encephalitis with altered status of consciousness and severe cerebral involvement at the brain-MRI. Serum and cerebrospinal fluid disclosed the presence of anti-AMPA-GluR3 antibodies suggesting a possible pathogenetic correlation with the disorder presented by the proband. Precocious treatment with intravenous methylprednisolone and immunoglobulin resulted in progressive but constant improvement. At 3-month follow-up, the clinical condition of the child and the neuro-radiological brain anomalies returned to the normal. At the 2-year follow-up, no recurrence or other disturbances were reported.