Hashimoto's encephalopathy. Steroid-responsive encephalopathy associated with Hashimoto's thyroiditis

Hashimoto's encephalopathy is a steroid-responsive, relapsing or progressiv e encephalopathy associated with Hashimoto's thyroiditis. Characteristic cl inical features are confusion, seizures, alteration in conscious level, str oke-like episodes, myoclonus, and tremulousness. High CSF protein levels wi thout pleocytosis and a diffusely abnormal EEG are typical findings. Brain CT and MRI and cerebral angiogram are usually normal. We present two case r eports of Hashimoto's encephalopathy in 55- and 77-year-old patients who bo th responded well to steroid therapy,and review the literature.