N-type calcium channel antibody-mediated autoimmune encephalitis: An unlikely cause of a common presentation ★

We report, to our knowledge, the only known pediatric case with encephalopathy and significantly elevated titers of N-type voltage-gated calcium channel antibody (N-type VGCC). The patient, an 8th grader, was previously healthy and presented with a one-week history of confusion, aphasia, transient fever, headaches, and dizziness. An underlying autoimmune process was suspected because of inflammatory changes in the brain MRI and multiple focal electrographic seizures captured in the EEG in the absence of CSF pleocytosis. Within 24 h of presentation, the patient was empirically started on immune-modulatory therapy, and a full recovery was achieved within 3 months of the initial presentation. Immune therapy included high-dose intravenous (IV) methylprednisolone followed by a 2-week course of dexamethasone and 2 monthly courses of IV immunoglobulin (IVIG). He was also treated with anticonvulsants for one month. No tumor has been found to date. There is a paucity of reports on autoimmune epilepsy or encephalopathy associated with N-type VGCC. Complete resolution of brain lesion, seizure freedom, and full recovery of function following early and aggressive immunotherapy demonstrate that a high index of suspicion is crucial for early recognition and treatment of autoimmune encephalitis.