Differences in corpus callosum injury between cerebral concussion and diffuse axonal injury

Background: We investigated differences in corpus callosum (CC) injuries between patients with concussion and those with diffuse axonal injury (DAI) by using diffusion tensor tractography (DTT). Methods: Twenty-nine patients with concussion, 21 patients with DAI, and 25 control subjects were recruited. We reconstructed the whole CC and 5 regions of the CC after applying Hofer classification (I, II, III, IV, and V). The whole CC and each region of the CC were analyzed to measure DTT parameters (fractional anisotropy [FA], apparent diffusion coefficient [ADC], and fiber number [FN]). Results: In the whole CC, significant differences were observed in all DTT parameters between the concussion and control groups and the DAI and control groups (P<.05). Among the 5 regions of the CC, significant differences were observed in FA and ADC between the concussion and control groups and the DAI and control groups (P<.05). Significant differences in FN were observed in CC regions I and II (connected with the prefrontal lobe and secondary motor area) between the concussion and control groups, in CC regions I, II, III, and IV (connected with the frontoparietal lobes) between the DAI and control groups, and in CC regions III, IV (connected with the motor-sensory cortex) between the concussion and DAI groups (P<.05). Conclusion: It was observed that both concussion and DAI patients showed diffuse neural injuries in the whole CC and all 5 regions of the CC. Neural FN results revealed that concussion patients appeared to be specifically injured in the anterior part of the CC connected with the frontal lobe, whereas DAI patients were injured in more diffuse regions connected with whole frontoparietal lobes.