Hashimoto’s Encephalopathy with Reversible Diffuse Leukoencephalopathy

Background The magnetic resonance imaging (MRI) findings of Hashimoto's encephalopathy (HE) are variable; images range from having a normal appearance, to showing ischemic lesions, demyelination, or vasogenic edema. Case Report A 57-year-old woman presented with a sudden onset of dysarthria and dizziness. Routine blood tests were normal and the MRI was unremarkable. After admission, she developed aphasic seizures and myoclonus, and eventually became comatose. A follow up MRI showed diffuse high signal intensities at the bilateral cerebral white matter on fluid attenuated inversion recovery imaging. The serum titers of the anti-thyroglobulin antibody and anti-thyroperoxidase antibody were increased. After 5 days of 1,000 mg/day of intravenous methylprednisolone infusion, she recovered rapidly. Conclusion We propose that repeated brain MRIs are necessary for the diagnosis of HE. Diffuse leukoencephalopathy may be a pathologic finding on MRI and, in this case study, was shown to be reversible after applying an appropriate treatment