A 29 year old woman was admitted in 1987 with an episode of headache, confusion, agitation, and hallucination. She had a mild fever and was thought to have neck stiffness. A CT scan was normal as were the inflammatory markers. CSF examination showed 9240 red cells and 33 white cells (45% polymorphs and 55% lymphocytes). CSF protein, glucose, and microbiology were normal. A presumed diagnosis of meningo-encephalitis was made and the patient was treated with acyclovir and antibiotics. The patient made a good recovery but was re-admitted a week later with agitation and confusion with pain and weakness down the left side. No focal neurology was found on examination and the patient was thought to be suffering from an anxiety state.