Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis (SREAT) Masquerading as New-Onset Bipolar Disorder in an Elderly Female

Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis (SREAT) Masquerading as New-Onset Bipolar Disorder in an Elderly Female

¹Dawn Radford D.O., ²Manish Karamchandani M.D., ²McKay Hanna M.D., ³Mini Singh M.D.

¹Medical University of South Carolina; ²Medical University of South Carolina; ³University of Virginia

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), also known as Hashimoto’s Encephalopathy (HE), is an immune-mediated condition that may present with a myriad of neuropsychiatric symptoms, making diagnosis a quandary.
We report a case of a 70-year-old female who presented with subacute onset of mania and cognitive decline, diagnosed as bipolar disorder. She was treated with valproic acid for mood stabilization with minimal improvement in symptoms and six months later presented with new-onset seizures. Interestingly, her seizures started four days after discontinuing valproic acid. Following her admission to our hospital, a diagnosis of autoimmune epilepsy was suspected. EEG revealed multiple focal onset seizures with secondary generalization originating from the right frontocentral area and/or right temporal lobe. MRI revealed asymmetric cortical thickening along the paramedian right anterior frontal region thought to be nonspecific. She was empirically treated with pulse dose steroids and intravenous immunoglobulins. She underwent an extensive work up including neuroimaging studies that were unremarkable as well as serological testing for autoimmune etiologies. A high titer of anti-thyroid peroxidase (anti-TPO) antibodies was detected. She was clinically and biochemically euthyroid. A diagnosis of SREAT was rendered and the patient had significant clinical improvement in symptoms following administration of corticosteroids.
SREAT is a diagnosis of exclusion but is supported by the presence of elevated anti-TPO and steroid responsiveness. Initial presentation may masquerade as a primary mood disorder, as in this case. Prompt diagnosis and treatment fully reverses neurological and psychiatric dysfunction in most cases.

Keywords: neuroimmunology, immunology, neuropsychiatry, geriatric neuropsychiatry, thyroid, SREAT, bipolar disorder, epilepsy, seizures, autoimmune encephalopathy

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How to cite this article:

Dawn Radford, Manish Karamchandani, McKay Hanna, Mini Singh. Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis (SREAT) Masquerading as New-Onset Bipolar Disorder in an Elderly Female. International Journal of Case Reports, 2023, 7:292. DOI: 10.28933/ijcr-2023-06-0806dr

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