Longitudinal Changes in Structural and Functional Brain Imaging and Their Association with Cognitive and Neuropsychiatric Symptoms in Hashimoto Encephalopathy with Anti-NAE Antibody.

Few studies have longitudinally evaluated Hashimoto's encephalopathy with anti-NH2-terminal α-enolase (anti-NAE) antibodies using detailed imaging and neuropsychological assessments. We present the case of a man in his 50s who presented with acute hallucinations, catatonia, seizures, and cognitive decline. Initial MRI revealed diffuse white matter hyperintensities, and SPECT revealed widespread hypoperfusion. These symptoms improved with immunotherapy, but progressive frontal and temporal atrophy and residual hypoperfusion appeared over 33 months. His cognitive function improved, but he remained impaired, with persistent disinhibition and perseveration. This case suggests that Hashimoto's encephalopathy with anti-NAE antibodies can cause lasting structural and functional brain abnormalities and cognitive impairments, requiring long-term neuroimaging and neuropsychological follow-up.