Hashimoto Encephalopathy as Diagnosis by Exclusion Review of the Literature from a Case Report

Abstract

Hashimoto encephalopathy is a rare entity, with wide range of neurological manifestations including focal deficits, cognitive alterations, seizures, movement disorders, and even coma, with a subacute to fluctuating disease course. It affects more women than men, it has age of presentation around 44 years, although cases have been reported in the pediatric age. Its etiology is unclear, it develops in the presence of antithyroid antibodies, regardless of thyroid function. The presence of these antibodies, added to the exclusion of other etiologies and the response to steroid management are key to the diagnosis. We report a clinical case of a 57-year-old woman who evolved with psychosis, language impairment, cognitive impairment, myoclonus, and seizures of 5 month-duration. Other causes of rapidly progressive dementia with the presence of normal antithyroglobulin antibodies of 83.6 IU/mL (RV <100 IU/mL) and elevated antithyroperoxidase 217 IU/mL (RV < 100 IU/mL) were excluded. She was evaluated in the Endocrinology Department that detected hypothyroidism and indicated management with levothyroxine with no improvement in the neurological condition. Steroid management with methylprednisone pulses at 500 mg/day for 5 days was indicated. Clinical improvement was observed and was concluded to be a Hashimoto encephalopathy by exclusion criteria.