A recent article in the Archives of Neurology details how a rare but important disorder called Creutzfeldt-Jakob disease (CJD) is usually initially misdiagnosed. In a cohort of over 300 CJD patients seen at the University of California, San Francisco, there was an average of 3.8 misdiagnoses per person, leading to a 7.9 month delay in receiving an accurate diagnosis.
Those months are particularly important in this disease because CJD causes a rapidly-progressive dementia in which patients sometimes go from being normal to completely debilitated within a few months. While there is no cure for CJD, earlier diagnosis could prevent costly and unnecessary tests and treatments, as well as permit the family to better plan for the future. A delayed diagnosis also increases the risk of unknowingly exposing other people to disease-causing prions, misfolded proteins that can be spread by medical procedures like blood transfusions.
Unfamiliarity with a relatively rare disease is the most likely cause of initial misdiagnosis. The most common incorrect diagnoses provided were viral encephalitis, Alzheimer's disease, peripheral vertigo, paraneoplastic disorder, and depression.
Another factor contributing to misdiagnosis is the misinterpretation of tests used to evaluate someone for CJD. A protein called 14-3-3 is commonly tested in the cerebrospinal fluid, but it is not uncommon for this protein to be undetectable even if CJD is present. The appropriate use of magnetic resonance imaging (MRI) can lead to accurate diagnosis, but due to a lack of familiarity with the disease, MRI findings of CJD are missed up to two-thirds of the time.
Ultimately, a timely and accurate diagnosis will depend on both physicians and patients having an increased awareness of Creutzfeldt-Jakob disease.
Ross W. Paterson, MRCP; Charles C. Torres-Chae, MPA; Amy L. Kuo, MS, RN, GNP; Tim Ando, BA; Elizabeth A. Nguyen, BS; Katherine Wong, BS; Stephen J. DeArmond, MD, PhD; Aissa Haman, MD; Paul Garcia, MD; David Y. Johnson; Bruce L. Miller, MD; Michael D. Geschwind, MD, PhD. Differential Diagnosis of Jakob-Creutzfeldt Disease. Arch Neurol. 2012;():1-5. doi:10.1001/archneurol.2013.79.