Encephalopathy Associated With Autoimmune Thyroid Disease

Autoimmune thyroid diseases (ATDs) are immune-endocrine disorders affecting the thyroid gland and, eventually, also a number of other systemic targets, including the brain and the nervous system. Encephalopathy associated with autoimmune thyroid disease (EAATD) is a rare, heterogeneous condition arising from the background of an ATD. It is characterised by neurological and/or psychiatric symptoms with acute or sub-acute onset, and virtually any neurological or psychiatric symptom can appear. However, EAATD often presents with confusion, altered consciousness, seizures, or myoclonus. The majority of cases are associated with Hashimoto’s thyroiditis, but a number of patients with Graves’ disease have also been described. EAATD is likely an immune-mediated disorder. Its exact prevalence has not been precisely elucidated, with an increasing number of cases reported in the last few years. Most EAATD patients respond in a dramatic manner to corticosteroids. However, the immunosuppressive treatment may require a long course (up to 12 months). The increasing number of EAATD cases reported in the literature demonstrates a growing interest of the scientific community about this condition, which still requires a better definition of its pathophysiology, the diagnostic criteria, and the most appropriate management, including the long-term follow-up of patients. The current clinical evidence about EAATD is mostly based on the report of single cases or small cohort studies. In this review, we present the current knowledge about EAATD, with a dedicated focus to the clinical management of the patients from a diagnostic and therapeutic perspective.