Hashimoto’s encephalopathy: a review of cases

Hashimoto’s encephalopathy (HE) is a rare autoimmune encephalitis characterised by anti-thyroglobulin and/or anti-thyroperoxidase antibodies in combination with a heterogenous array of neuropsychiatric symptoms. Often, clinical diagnosis is challenging and reliant upon diagnostic suspicion, as it is an uncommon disease with highly variable clinical presentations. This paper reviewed case reports published on PubMed, Embase, and Web of Science over the last six years, totalling 182 cases. The mean age of presentation was 43.2 years with a female predominance. The most common clinical presentations were psychiatric pathology, neurological deficit, and altered mental status; 62% of patients experienced multiple distinct symptoms. Most patients presented with raised anti-thyroperoxidase autoantibodies, with fewer exhibiting anti-thyroglobulin antibodies. Laboratory and imaging investigation findings were as disparate as patient presentations. The most common treatment was IV methylprednisolone followed by secondary immunotherapies if unresponsive. In total, 149 patients demonstrated clinical improvement, 92 made a full recovery, and 29 relapsed. Thus, the compiled data supports HE as a highly heterogenous disease, with no specific clinical presentation or diagnostic clues, so it should be suspected when neuropsychiatric symptoms fail to respond to standard treatments.