White Matter Damage in Carbon Monoxide Intoxication Assessed in Vivo Using Diffusion

BACKGROUND AND PURPOSE: White matter (WM) injury in carbon monoxide (CO) intoxication is thought to be related to delayed cognitive sequelae. To determine if microstructural changes in WM are responsible for the delayed onset of cognitive symptoms, we performed diffusion tensor imaging (DTI) in patients with CO intoxication. MATERIALS AND METHODS: DTI was performed in 14 patients with delayed sequelae after CO intoxication and in 16 sex- and age-matched healthy volunteers. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of several WM regions were measured. We also determined the correlation between FA of the selected WM and neuropsychological rating scores for the CO intoxi-cation group. RESULTS: FA of patients with CO intoxication decreased in the corpus callosum, orbitofrontal WM, high frontal WM, parietal WM, and temporal lobes in comparison with the corresponding regions of healthy controls. FA of the WM in the occipital lobe and internal capsule of patients was not significantly different from that in controls. ADCs of all measuredWM increased significantly in patients exposed to CO. High correlations were found between the FA of all selected WM and the Mini-Mental State Examina-tion score ( 0.631, P .016) and the digit span backward task ( 0.759, P .001)