Pediatric anti-CaVα2δ Autoimmune Encephalitis: a case report and literature review

Abstract

Background：Anti voltage-gated calcium channel alpha-2/delta subunit (anti-CaVα2δ) encephalitis is a rare autoimmune encephalitis which was first reported in 2021. Up to now, only 2 cases of anti-CaVα2δ AE have been reported in the previous literature. The clinical characteristics, treatment and prognosis of this rare AE need broadened. Case presentation: This is a detailed report of a 9-year-old female, who initially presented with fever and lymphadenitis, which progressed to headaches, drowsiness, frequent seizures, cognitive impairment, memory loss, psychosis, and involuntary movements. Brain magnetic resonance imaging revealed lesions in the bilateral external capsule. Positive anti-CaVα2δ antibodies (1:30) using transfected cell-based assays were also revealed 3 weeks and 5 weeks after symptom onset. Video electroencephalography further showed severely diffused, slow background activity with multifocal epileptiform discharges. Although the patient was started on combined immunotherapy consisting intravenous immunoglobulin, intravenous methylprednisolone, and rituximab, neurological sequelae, including seizures, cognitive dysfunction, and dyskinesia, were recorded on her latest follow-up (Modified Rankin Scale score of 4). For further discussion of this condition, summaries of two other anti-CaVα2δ AE cases were also provided. Conclusions：Herein, we reported a paediatric case of anti-CaVα2δ AE, with comparisons to two previously reported cases. These reports broaden the clinical phenotype and prognosis of this rare condition, providing further information and clinical experience for the management of future cases.