Guideline Examines Diagnostic Accuracy of CSF 14-3-3 Protein in sCJD

Usefulness of Test Depends on Clinician’s Judgment of Probability of sCJD Before Testing

Testing for 14-3-3 protein in spinal fluid may support the clinical diagnosis and other diagnostic tests used to diagnose sporadic Creutzfeldt-Jakob disease (sCJD) in patients who present with rapidly progressive dementia and are suspected of having sCJD. This is the primary finding in “Diagnostic Accuracy of CSF 14-3-3 Protein in Sporadic Creutzfeldt-Jakob Disease,” a new guideline from the AAN that was published electronically ahead of print on September 19, 2012, and appears in the October 2, 2012, print edition of Neurology^®. 

While the test may help when used in cases where doctors suspect sCJD may be present, the test is not accurate enough either to diagnose the disease or to rule out the disease with absolute certainty.

The usefulness of the 14-3-3 test will largely depend on a clinician’s judgment of the pretest probability of sCJD for a given patient. Such judgments will reasonably consider the rarity of sCJD (incidence 1 per million per year), the patient’s clinical presentation, and the results of already obtained ancillary tests such as brain MRI. However, how the test should be used in conjunction with EEG and MRI findings suggestive of sCJD needs further investigation. The authors contend that only physicians experienced in diagnosing dementia should determine whether the 14-3-3 protein test is needed and how results should be understood.

Read the guideline and access PDF summaries for clinicians and patients, a slide presentation, and a clinical example. For more information, contact Julie Cox at jcox@aan.com or (612) 928-6069.