What Promises the CJD Diagnosis in a Case of Rapidly Progressive Dementia?

BACKGROUND: Developing methods for accurately diagnosing prion diseases has been a challenge in the search for successful diagnosis and treatment of rapidly progressive dementia. prion diseases are rare. However, they should be considered in the differential diagnosis. Despite their rarity, several other conditions are often misdiagnosed as prion diseases. Most Alzheimer’s (AD) and Lewy Body Disease (LBD) patients also meet Creutzfeldt-Jakob Disease (CJD) criteria. The similarities in symptomology and pathology between these two patient groups complicates diagnosis and can compromise patient care. Prevalent methods for the diagnosis of CJD lack the heightened sensitivity to conclusively detect CJD. Of all currently available methods, real-time quaking induced conversion (RT-QuIC) analysis provides the highest sensitivity necessary to allow for an accurate diagnosis and yields early, quantitative results. CLINICAL CASE: A 75-year-old woman with rapidly progressing dementia, for which CJD could not be ruled out, appeared for care at a neurological center. Laboratory test results, Magnetic Resonance Imaging (MRI), Cerebrospinal Fluid (CSF) studies, Positron Emission Tomography (PET), and an Electroencephalogram (EEG) proved inadequate to confirm CJD. In addition to AD, LBD, or CJD, other potential, yet improbable, pathologies could have caused the patient’s symptoms. The patient’s diagnosis ultimately was limited to either LBD or prion disease. Spongiform encephalogy was confirmed by a brain biopsy, and further testing confirmed sporadic CJD. CONCLUSION: RT-QuIC offers higher sensitivity than currently prevalent diagnostic methods and appears most promising for CJD diagnosis.