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

Abstract

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). 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. 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. Regardless of the number of lesions, the existence of a genu lesion suggested disability 1 year after TBI in patients with DAI.