Autoimmune encephalitis and Morvan’s syndrome

Since its first recognition in 2001, hundreds of patients have been identified with autoimmune limbic encephalitis (LE) associated with antibodies that immunoprecipitate voltage-gated potassium channel (VGKC)-complex proteins. Preliminary epidemiology suggests that it is more common in men (2:1) and that the median age at onset is 65 years. The phenotype has been recognized mainly in patients over the age of 18 years at onset. The classic presentation is with subacute onset of short-term memory loss, seizures, disorientation, with psychological disturbance or hallucinations. Additional features that may occur are sleep disturbance, autonomic dysfunction, and neuromyotonia, but these would be more typical of Morvan’s syndrome.