Cingulum injury in patients with diffuse axonal injury: a diffusion tensor imaging study.

Accurate assessment of the cingulum is difficult, because it is a long neural tract that extends from the orbitofrontal cortex to the medial temporal lobe. We divided the cingulum into five parts and investigated changes caused by injury in these regions in patients with diffuse axonal injury (DAI) using diffusion tensor tractography (DTT). Twenty-one patients with DAI and 21 control subjects were recruited. The cingulum was divided into; the anterior, superior (the anterior and posterior portions), posterior, and inferior regions. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and tract number were measured in each region. FA values and tract numbers in the patient group were lower in the anterior superior cingulum than in controls (p<0.05); whereas the ADC values in the patient group were higher in the anterior and posterior superior cingulum than in controls (p<0.05). In the superior cingulum, increases in the ADC values of the anterior portion (Δ8.1%) were higher than those of the posterior portion (Δ5.5%). We found that the superior cingulum was injured in patients with DAI, and that the anterior portion of the superior cingulum was more injured than the posterior portion. Consequently, the superior cingulum appears to be a vulnerable area and the anterior superior cingulum appears more vulnerable than the posterior superior cingulum in DAI.