Delayed Diagnosis of Sporadic Creutzfeldt-Jakob Disease in a Patient with Schizophrenia

Abstract

Human transmissible spongiform encephalopathies, also known as prion diseases, are caused by abnormal folding of normal prion proteins in the brain. Sporadic Creutzfeldt-Jakob Disease (sCJD), the most common prion disease, occurs at an annual rate of one in 1 million and often leads to a fatal outcome within a year. The mean age of onset is 55 to 75 years old. sCJD is a cause of rapidly progressive dementia but because of its rarity, may not be on the differential diagnosis in its earlier stages of manifestation, particularly if a patient lacks other neurological symptoms. Patients with sCJD often present with early cognitive and psychiatric manifestations, such as memory loss, irritability, depression, ataxia, extrapyramidal symptoms, and in rarer instances, psychosis. Later symptoms include myoclonus, cortical blindness, seizures, and in its final stage, akinetic mutism. We report a patient ultimately found to have sCJD whose presentation was initially mistaken for an exacerbation of his chronic schizophrenia, delaying his diagnosis.