Pathologic correlates of diffusion MRI changes in Creutzfeldt-Jakob disease

Objective: The cause of hyperintense magnetic resonance changes and reduced apparent diffusion coefficient (ADC) in specific brain regions of patients with Creutzfeldt-Jakob disease (CJD) is unknown. Our aim was to determine the neuropathologic correlates of antemortem water ADC and normalized T2-weighted changes in patients with CJD. Method: Ten patients with CJD and 10 sex- and age-matched healthy controls were studied by DWI and T2-weighted echoplanar MRI. At postmortem, patients with CJD were evaluated for semiquantitative assessment of gliosis and neuronal loss, spongiform changes, and abnormal PrP protein deposition in four cortical regions (occipital, parietal, and temporal cortex, and cingulate gyrus), thalamus, and striatum for a total of 60 regions of interest (ROI). Results: Gliosis and neuronal loss correlated very highly with each other in the 60 ROIs. Where status spongiosus was absent, spongiform change correlated very highly with gliosis and neuronal loss in the cortex, but not in deep gray matter. Spongiform change was also significantly correlated with PrPSc load in both cortical and deep gray ROIs. In deep gray matter, ADC decreased with increasing spongiform change (R-2 = 0.78; p < 0.001) and PrPSc load (R-2 = 0.51; p = 0.003). In the cortex, ADC decreased with increases in all three, highly correlated, pathologic scores. Conclusion: Antemortem reductions in ADC values, typically found in patients with Creutzfeldt-Jakob disease (CJD), are correlated with spongiform changes seen at autopsy. This could be clearly established in the striatum and thalamus of our patients with CJD where the extent of spongiform change was not significantly correlated with gliosis or neuronal loss. Neurology(R) 2009; 72: 1425-1431