Hashimoto’s encephalopathy is a steroid responsive disorder characterised by high titres of anti-thyroid antibodies and manifesting as sub-acute onset of confusion, episodes of myoclonus, seizures, and stroke-like episodes. Although excellent response to steroids is characteristic, other treatments such as plasmapheresis or administration of azathioprine or cyclophosphamide have been occasionally tried. We report a case of initially steroid responsive Hashimoto’s encephalopathy which became steroid resistant and then responded well to intravenous immunoglobulins.

Case report

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.

During the next 14 years, the patient was admitted on several occasions with episodes of confusion and agitation: investigations including lumbar puncture, CT scans, EEG, thyroid function, porphyria screens, autoantibody screens (including antinuclear antibodies, ANCA, and those against …