Hashimoto's encephalopathy: South Korean experiences.

Hashimoto's encephalopathy (HE) is a rare neurological disorder. Early diagnosis and treatment are critical to prevent irreversible brain damage. In the present study, we aimed to describe and classify HE on the basis of clinical, neuroimaging, and EEG findings. We retrospectively reviewed the clinical, radiological, and electrophysiological findings in patients who showed both neurological symptoms and high titers of anti-thyroid antibodies, and who were admitted between 2006 and 2012. Our patients were classified into two groups: those presenting seizures (group 1) and those with diffuse encephalopathies (group 2). Group 1 contained two patients. Patient 1, who showed verbal memory disturbance, focal MRI lesions, and partial seizure activity on EEG, recovered with antiepileptic and steroid treatments. Five of six patients assigned to group 2 were treated with steroids and showed significant improvement. One patient treated with azathioprine showed moderate improvement. Four of these patients had accompanying metabolic disturbances. HE is a treatable neurologic disorder with different subtypes, each with its own clinical manifestations and treatment options. HE can be difficult to identify and requires careful and attentive clinical observation for diagnosis.