A case of refractory hashimoto’s encephalopathy demonstrating improvement with plasmapheresis

Abstract

Hashimoto's encephalopathy (HE) can present with multiple neurologic manifestations and various neuroimaging findings. While its progressive form is often well-recognized, patients with a waxing and waning course may provide diagnostic difficulty. Treatment with corticosteroids has been well-documented, but the benefit of immune-related therapies such as plasmapheresis has not been solidified. Here we describe a patient with waxing and waning signs and symptoms as well as significant fluctuations in neuroimaging findings that initially caused uncertainty regarding her diagnosis. After several largely negative tests including two brain biopsies, she was found to have high levels of anti-thyroid antibodies. Though sometimes found in disorders such as Hashimoto's thyroiditis and Graves' disease, these laboratory values in the setting of unremarkable thyroid function tests and her symptoms and their initial responsiveness to corticosteroids helped solidify her diagnosis as HE. However, due to refractory symptoms and signs, this patient required plasmapheresis. We demonstrate clinical, serological, and radiological improvement with this yet unconfirmed therapy, thus raising questions about the appropriateness of the term "steroid-responsive encephalopathy".