Hashimoto’s encephalopathy presented with myoclonus: a case report

Myoclonus is a clinical manifestation characterized by brief, involuntary, jerky movements of a muscle or muscle group, commonly associated with cerebral disorders, epileptic conditions, and certain pharmacological agents. Hashimoto’s encephalopathy is an infrequent neurological disorder presenting with diverse clinical symptoms and elevated levels of antithyroid antibodies. A 68-year-old female exhibited subacute development of myoclonus in the lower extremities and trunk. Routine laboratory assessments, neuroimaging studies, and electroencephalography revealed no abnormalities. Thyroid function tests exhibited no irregularities, yet there was an elevation in antithyroid antibodies, including thyroglobulin antibody and anti-microsomal antibody levels. The myoclonus symptoms significantly ameliorated following treatment with prednisolone. This case highlights an instance of Hashimoto’s encephalopathy where myoclonus was the sole presenting symptom, and we elucidate distinctive diagnostic features distinguishing it from other disorders.