Hashimoto’s Encephalopathy: A Diagnosis in Disguise, Case Report and Review of Literature

Abstract

While Hashimoto's encephalopathy (HE) is quite rare (there may only be several dozen diagnosed patients in the USA), it is also likely that there are many more undiagnosed sufferers. Because it is little known and its symptoms are primarily neurological, it is easy to misdiagnose or overlook and the symptoms frequently lead to mistaken neurological diagnoses. We report a case of an elderly female presenting with aphasia, cognitive decline, dysphagia and left hemiparesis as manifestation of this disorder. She failed to respond to high dose steroids and intravenous immunoglobulins which can be seen in rare subsets of patients. HE is a neuropsychiatric disorder of exclusion. It is important to identify this disease as most could be treated with steroids and immunosuppressants and therefore the term steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT). Diagnosis is made in the first instance by excluding other toxic, metabolic and infectious causes of encephalopathy with neuroimaging and CSF examination. Response to treatment is quite variable despite most patients being steroid responsive. There are small subsets of patients who show poor response to steroids and immunoglobulins including this one and may require prolonged treatment to see any improvement.

Hashimoto's encephalopathy in a pregnant female: A diagnosis in disguise

“…[1] It is relapsing-remitting and sometimes progressive encephalopathy occurring in association with Hashimoto's thyroiditis. [2]…”

“…Because it is little known and its symptoms are primarily neurological, it is easy to misdiagnose or overlook and the symptoms frequently lead to mistaken neurological diagnoses. [2] Therefore, for all patients with unexplained acute- or sub-acute encephalopathy, or atypical psychiatric manifestations, especially patients who have autoimmune thyroid disease, HE must be included in the differential diagnosis. [3] If treatment is delayed due to misdiagnosis, it often becomes fatal, and therefore physicians should have a high degree of suspicion and awareness for this condition.…”