Limbic encephalitis typically presents with subacute development of memory impairment, confusion, and alteration of consciousness, often accompanied by seizures and temporal lobe signal change on MRI. There is however no clear consensus as to the definition; even traditional distinctions between “encephalitis” and “encephalopathy”, and between “delirium” and “dementia” may be blurred in such patients. The term limbic encephalitis was initially coined to describe patients presenting with amnesia, psychiatric disturbances, and often seizures, and who had post-mortem evidence both of occult neoplastic and fairly selective inflammation within the temporal lobes.1 More recently, however, it has also been used to describe patients with a similar phenotype but in whom an infectious or non-par neoplastic autoimmune cause has been proven or suspected.