Case of the quarter: Autoimmune limbic encephalitis: a reversible form of rapidly progressive amnesia and seizures

Many forms of rapidly progressive cognitive impairment are irreversible and  rarely  treatable.  We  present  a  case  of  autoimmune  limbic  encephalitis associated with voltage-gated potassium channel autoantibodies that led to rapid cognitive  deterioration  and  bizarre  behaviour,  which  subsequently  improved following  immunosuppressant  therapy.  The  diagnosis  of   autoimmune   limbic encephalitis  needs  to  be  considered  in  patients  presenting  with  apparent  viral encephalitis, in more unusual clinical situations in subjects with acute psychiatric illness  and  in  cases  of  refractory  epilepsy,  particularly  if  there  is  evidence  of amnesia. The diagnosis depends on the detection of specific antibodies directed against  central  nervous  system  targets.  There  can  be  a  good  response  to immunosuppressant therapy.