Creutzfeldt-Jakob disease: updated diagnostic criteria, treatment algorithm, and the utility of brain biopsy.

Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative condition with a rapid disease course and a mortality rate of 100%. Several forms of the disease have been described, and the most common is the sporadic type. The most challenging aspect of this disease is its diagnosis-the gold standard for definitive diagnosis is considered to be histopathological confirmation-but newer tests are providing means for an antemortem diagnosis in ways less invasive than brain biopsy. Imaging studies, electroencephalography, and biomarkers are used in conjunction with the clinical picture to try to make the diagnosis of CJD without brain tissue samples, and all of these are reviewed in this article. The current diagnostic criteria are limited; test sensitivity and specificity varies with the genetics of the disease as well as the clinical stage. Physicians may be unsure of all diagnostic testing available, and may order outdated tests or prematurely request a brain biopsy when the diagnostic workup is incomplete. The authors review CJD, discuss the role of brain biopsy in this patient population, provide a diagnostic pathway for the patient presenting with rapidly progressive dementia, and propose newer diagnostic criteria.