Endocrine Abstracts

A 67-year-old lady with a 3-year history of Graves’ hyperthyroidism complicated by florid Graves’ ophthalmopathy attended the thyroid clinic at University Hospital Birmingham for routine follow up. Her thyrotoxicosis had been managed with long-term carbimazole treatment with good control. Her past medical history included coeliac disease and hypertension. On clinic review, she appeared acutely confused and disorientated and had evidently lost weight. Her family reported a subacute history of cognitive decline over the last month (including disorientation, dyspraxia, and falls), with dramatic deterioration during the preceding few days. She demonstrated coarse tremor of upper and lower limbs but was clinically and biochemically euthyroid. She was admitted to the Clinical Decisions Unit for further investigations and management. A neurological assessment revealed tremor and clonus with hyperreflexia bilaterally. She was started on empirical treatment for meningoencephalitis with antimicrobials and dexamethasone. After two episodes of tonic-clonic seizures, phenytoin was added. She underwent a CT of the brain which was normal, followed by a lumber puncture which excluded an infective cause and was unremarkable aside from a high protein concentration. Her immunology revealed high anti-TPO (1009) and anti-ANA (1:1600) titres. Her EEG revealed diffuse slow-wave activity, while an MRI of the brain was unremarkable. A putative diagnosis of autoimmune encephalitis (likely ‘Hashimoto’s encephalitis’) was made and she responded well to immunosuppression with glucocorticoids (dexamethasone followed by prednisolone). She was discharged on prednisolone (tapering regime) 10 days after her admission. At follow-up a month later she showed complete neurological recovery. Autoimmune encephalitis in the context of Graves’ hyperthyroidism is very rare, with only six cases described in the literature. A prompt referral for urgent work-up and appropriate management with immunosuppression is of the essence and generally ensures a favourable outcome.