Serial brain MRI changes related to autoimmune pathophysiology in Hashimoto encephalopathy with anti-NAE antibodies: A case-series study.

PURPOSE:Hashimoto encephalopathy (HE) is an autoimmune-mediated encephalopathy associated with anti-thyroid antibodies. We previously discovered serum autoantibodies against the NH2-terminal of α-enolase (NAE), which serve as a specific diagnostic biomarker for HE and may be involved in the autoimmune pathophysiology of HE, including vasculitis. Although the common findings of brain magnetic resonance imaging (MRI) in HE have been recognized as normal or non-specific white matter lesions, serial MRI changes have been less well studied. The aim of this study was to clarify detailed and longitudinal MRI changes in HE associated with anti-NAE antibodies. METHODS:We investigated serial brain MR images in 12 Japanese patients with HE who had serum anti-NAE antibodies. RESULTS:Brain MRI showed diffuse white matter abnormalities and/or multiple small subcortical lesions in 10 patients. These lesions were apparently non-specific; however, in 7 of these patients we observed expanding and diminishing white matter lesions, emerging subcortical high-intensity spots on diffusion-weighted images, or reversible limbic lesions, which worsened at relapse and improved after recovery following immunotherapies. CONCLUSION:MRI lesions that fluctuate according to the disease condition were frequently observed in HE patients with anti-NAE antibodies, which suggests that these fluctuation may be associated with the autoimmune pathophysiology of HE.