Anti-Voltage-gated Potassium Channel Limbic Encephalitis with Psychiatric Features: a Case Report.

We report a case of anti-voltage-gated potassium channel (VGKC) limbic encephalitis in a 47-year-old man presenting with a 2-year history of psychiatric features. The patient had cognitive impairment, slurred speech, and a mildly unsteady gait but no other neurological deficits or seizures. Results of blood, urine, and cerebrospinal fluid tests and magnetic resonance imaging of the brain were normal. However, electroencephalography showed an epileptogenic focus in the bilateral temporal regions with mild to moderate diffuse encephalopathy. Autoimmune panel results confirmed the diagnosis of anti-VGKC limbic encephalitis, with a serum VGKC concentration of 6730 pmol/L. The patient was treated with Keppra and pulsed intravenous methylprednisolone for 3 days, and his behaviour improved.