Not Just Another Cause of Confusion — a Rare Case of Steroid‐Responsive Encephalopathy

1Reading Health System, West Reading, PA

Meeting: Hospital Medicine 2013, May 16-19, National Harbor, Md.

Abstract number: 459

Case Presentation:

A 76‐year‐old white man with a medical history of Hashimoto's thyroiditis, atrial fibrillation, coronary artery disease and hypertension presented to the emergency department with clouding of consciousness for 1 day. His vital signs were stable. Chest and cardiovascular examination was normal. He was admitted for further workup, which revealed CBC and electrolytes to be normal normal. Urine drug screen was negative. Septic workup was negative. His ABG was normal. Serum cortisol was normal. TSH and anti‐TPO antibodies were elevated at 11.4 UIU/mL, and 128 IU/mL, respectively. CT of the chest and MRI of the head were negative. EKG and cardiac enzymes were normal. EEG revealed continuous slow and generalized pattern. Even after 2 days he continued to be encephalopathic. Based on the history of Hashimoto's thyroiditis, raised TSH, and anti‐TPO antibodies and EEG findings, he was started on steroid for presumed Hashimoto's encephalopathy. He showed significant improvement. He was discharged on steroids. This case well demonstrates that early recognition of Hashimoto's encephalitis is crucial and significant improvement with steroid therapy can be achieved.


Hashimoto's encephalopathy (HE) is a rare, underrecognized disorder, more common in women which presents with sub‐acute onset of confusion, cognitive deterioration, psychiatric symptoms, and seizures. It can present with myoclonus, ataxia and personality changes. The precise etiology and pathophysiologic mechanisms are not known although autoimmune phenomenon has been postulated. MRI, EEG, and CSF analysis are essential to exclude other causes of encephalopathy. There is no gold standard diagnostic test and serological marker for the disease. The finding of elevated anti‐TPO antibody or antithyroglobulin antibody in patients with compatible clinical presentation is required for the diagnosis of HE. Improvement in cognitive impairment with steroid is suggestive of diagnosis. Neurologic investigation shows diffusely abnormal nonspecific slowing of background EEG, high CSF protein level without pleocytosis and normal brain CT. The long‐term prognosis is favorable with steroid treatment. Immunosuppressive therapy can be useful in patients who fail to improve with steroid therapy.


(1) HE is a rare form of reversible encephalopathy, occurring in patients with or without overt thyroid disease. The presentations are varied but diffuse cognitive decline is a common manifestation. (2) Considering the myriad neurologic manifestations of this disease and a lack of well‐defined diagnostic criteria, the disease appears to be underdiagnosed. Nevertheless, a timely diagnosis is crucial as it is often completely reversible. (3) Anyone presenting with rapidly progressive cognitive dysfunction with or without a history of thyroid disease should be considered for a possibility of HE and assessed for the presence of antithyroid antibodies.

To cite this abstract:

Aryal M. Not Just Another Cause of Confusion — a Rare Case of Steroid‐Responsive Encephalopathy. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 459. Journal of Hospital Medicine. 2013; 8 (suppl 2). Accessed March 31, 2020.

« Back to Hospital Medicine 2013, May 16-19, National Harbor, Md.