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

Diffuse axonal injury (DAI) is a severe head injury, which exhibits symptoms of consciousness disturbance and is thought to occur through rotational angular acceleration. This paper analyzes the occurrence of DAI when direct impacts with translational accelerations are applied to two-dimensional head models. We constructed a human model reproducing the human head structure, as well as modified human models with some internal head structures removed. Blunt direct impacts were applied from a lateral direction to the bottom of the third ventricle, considered to be the center of impact, using an impactor. The analysis was done by comparing the macroscopic manifestation of DAI with the shear stress as the engineering index. In the analytical data obtained from the human model, shear stresses were concentrated on the corpus callosum and the brain stem, in the deep area. This agrees with regions of the DAI indicated by small hemorrhages in the corpus callosum and the brain stem. The analytical data obtained by the modified human models show that the high shear stress on the corpus callosum is influenced by the falx cerebri, while the high shear stress on the brain stem is influenced by the tentorium cerebelli and the shape of the brain. These results indicate that DAI, generally considered to be influenced by angular acceleration, may also occur through direct impact with translational acceleration. We deduced that the injury mechanism of DAI is related to the concentration of shear stress on the core of the brain, since the internal head structures influence the impact stress concentration.

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Teaching NeuroImages: Restricted diffusion in the corpus callosum after traumatic diffuse axonal injury

Neurology ◽

10.1212/wnl.0b013e3181f962d7 ◽

2010 ◽

Vol 75 (17) ◽

pp. e69-e69

Author(s):

B. L. Edlow ◽

E. L. Diamond

Keyword(s):

Corpus Callosum ◽

Axonal Injury ◽

Diffuse Axonal Injury ◽

Restricted Diffusion

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Genu of corpus callosum as a prognostic factor in diffuse axonal injury

Journal of Neurosurgery ◽

10.3171/2011.6.jns11513 ◽

2011 ◽

Vol 115 (5) ◽

pp. 1019-1024 ◽

Cited By ~ 15

Author(s):

Hidetoshi Matsukawa ◽

Masaki Shinoda ◽

Motoharu Fujii ◽

Osamu Takahashi ◽

Daisuke Yamamoto ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Logistic Regression ◽

Regression Analysis ◽

Corpus Callosum ◽

Multinomial Logistic Regression ◽

Axonal Injury ◽

Diffuse Axonal Injury ◽

Regression Analyses ◽

Multivariate Logistic Regression ◽

Multinomial Logistic Regression Analysis

Object Previous studies have shown a relationship between a patient's stage of diffuse axonal injury (DAI) and outcome. However, few studies have assessed whether a specific lesion or type of corpus callosum injury (CCI) influences outcome in patients with DAI. The authors investigated the effect of various DAIs and CCIs on outcome in patients with traumatic brain injury (TBI). Methods The authors retrospectively reviewed 78 consecutive patients with DAI who were seen between May 2004 and March 2010. Outcome was evaluated using the Extended Glasgow Outcome Scale (EGOS) 1 year after TBI. Patients with single DAIs had only 1 of the 3 lesions (lobar, CC, or brainstem). Patients with dual DAIs had 2 of these lesions, and those with triple DAIs had all of these lesions. Furthermore, the authors defined single, dual, and triple CCIs by using 3 lesions (genu, body, splenium) in the same way among patients with single (CC) DAIs. Univariate and multivariate logistic regression analyses were performed to evaluate the relationships between these lesions and outcome in patients with DAI. Results Fifty patients had single DAIs: 34 in the lobar area, 11 in the CC, and 5 in the brainstem. Twenty had dual DAIs, and 8 had triple DAIs. Of the 11 CCIs, 9 were single and 2 were dual CCIs. Among these lesions, only those in the genu were related to disability. The authors dichotomized patients into those with and without genu lesions, regardless of other injuries. Multinomial logistic regression analysis showed that a genu lesion (OR 18, 95% CI 2.2–32; p = 0.0021) and a pupillary abnormality (OR 14, 95% CI 1.6–24; p = 0.0068) were associated with disability (EGOS ≤ 6) in patients with DAI. Conclusions Regardless of the number of lesions, the existence of a genu lesion suggested disability 1 year after TBI in patients with DAI.

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