Detection of 14-3-3 protein in the CSF of a patient with Hashimoto’s encephalopathy

The clinical features of Hashimoto’s encephalopathy may be confused with those of Creutzfeldt–Jakob disease (CJD).1 The diagnosis of encephalopathy associated with Hashimoto’s thyroiditis is established by the detection of antithyroid antibodies and variable degrees of thyroid dysfunction.1,2 The definitive diagnosis of CJD requires histologic confirmation. Nevertheless, in an adequate clinical setting, the presence of 14-3-3 protein in the CSF is a useful marker for the in vivo diagnosis of CJD, because false-positive results are seen in disorders that are usually not considered in the differential diagnosis.3,4 We report a patient with Hashimoto’s encephalopathy with two unusual features: the presence of opsoclonus and the detection of 14-3-3 brain protein in the CSF. A 41-year-old woman was admitted in January 1997 because of a generalized epileptic seizure. She had been well until November 1996, when her family noticed abnormal behavior with irritability, paranoid ideation, and insomnia. During the ensuing weeks, she developed memory loss and reduced speech that led to mutism. One week before admission, her gait became unsteady, and she developed focal epileptic seizures in the right arm and uncoordinated ocular …