Autoimmune encephalitis: Viva

Branch 1: Making the diagnosis

A strong candidate recognises this as a probable case of anti-NMDA receptor encephalitis and applies the Graus 2016 criteria. The diagnosis turns on the tempo and the pattern rather than on a single test. She has a rapid onset over days of psychiatric symptoms together with at least four of the six major symptom groups of probable anti-NMDAR disease: abnormal behaviour, speech dysfunction, seizures, movement disorder, decreased consciousness, and autonomic dysfunction or hypoventilation. She has an inflammatory CSF with lymphocytic pleocytosis and oligoclonal bands, and her mimics, particularly infectious encephalitis, are being excluded. A normal MRI is fully compatible with the diagnosis. The candidate sends a paired CSF and serum neural antibody panel, with CSF as the more sensitive sample, but does not wait for the result to treat. ^[1]