Treatable Neurological Disorders Misdiagnosed as Creutzfeldt-Jakob Disease

A case of primary CNS angiitis thought to be sCJD

Dr. Mark Cohen and a team of workers at Case Medical Center in Cleveland, Ohio have published an important article in the Annals of Neurology entitled Treatable Neurological Disorders Misdiagnosed as Creutzfeldt-Jakob Disease (Ann Neurol 2011;70:437–444). Why is this article important? Well, because mistaking a survivable, treatable disorder for a fatal, non-treatable disorder is not optimal. Cohen's team reviewed the pathologic diagnoses of 1,106 patients who were referred for potential prion disease to the National Prion Disease Pathology Surveillance Center (NPDPSC) at Case Western Reserve University from 2006 to 2009. About one-third of the cases did not have prion disease, with Alzheimer disease and vascular disease being the most common conditions accounting for dementia. Further, about one-quarter of the non-prion cases had treatable diseases, including immune-mediated disorders, neoplastic disorders such as lymphoma, as well as infectious and metabolic disorders. The immune-mediated disorders included primary angiitis of the CNS, acute disseminated encephalomyelitis, limbic encephalitis, neurosarcoidosis, paraneoplastic cerebellar degeneration, and one case of Wegener granulomatosis. Of note, more than half of patients with a treatable dementia had a positive CSF 14-3-3 protein test, highlighting the danger of relying too heavily on this test in making a diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). It turns out that the most specific test for distinguishing CJD from other diseases was magnetic resonance imaging. Drs. David Perry and Michael Geschwind, in a review of this study in the September 2011 issue of Nature Reviews Neurology, (Perry, D. C. & Geschwind, M. D. Nat. Rev. Neurol. 2011:7, 479–480) write: "The fact that many of the non-prion diagnoses in the present study were potentially treatable RPDs [rapidly progressive dementias] should prompt thorough diagnostic testing in patients who are suspected of having sCJD, in order to rule out mimics. The use of CSF testing, contrast-enhanced MRI, and autoimmune antibody screening is supported by this study."