DTI changes of CSA-CSR patients were most prominent in the brainstem. Subtle microstructural changes in the brainstem might be a neuroanatomical correlate of CSA-CSR in patients at risk of WML. Common predisposing factors for CSA-CSR are enhanced central and peripheral chemosensitivity. It was suggested that the increased sensitivity to CO2 results from bilateral supramedullary brain lesions that disinhibit neural stimulatory input into the brainstem respiratory center.
Voxel-wise differences in FA and gray matter values between all FD patients and healthy controls were statistically evaluated by analysis of covariance (ANCOVA), modeling age as a covariate to account for the age dependency of FA and gray matter. Statistical threshold for the correlation analysis was set at P<0.001, corrected for multiple comparison using the false discovery rate method (FDR-correction, minimum cluster size 50 voxels), which is a standard approach in Statistical Parametric Mapping. In addition, voxel-wise FA and gray matter analyses of patients were performed as separate groups (with and without CSA-CSR), relative to the healthy controls, by using the same statistical parameters.
