Genu of corpus callosum in diffuse axonal injury induces a worse 1-year outcome in patients with traumatic brain injury

Previous studies have shown a relationship between diffuse axonal injury (DAI) and unfavorable clinical outcome in patients with traumatic brain injury (TBI), but it remains unclear whether the type of DAI lesion influences outcome after TBI. The aim of the present study was to investigate whether 1-year outcome after TBI differed between patients with different types of lesions. A retrospective, single-institution study involving 261 patients with TBI was carried out between April 2003 and December 2009. Outcome was measured using the Glasgow Outcome Scale (GOS) 1 year after TBI. DAI lesions occurred in the lobar region, corpus callosum (CC), and brainstem. CC lesions were subdivided into three types: genu, body, and splenium. Univariate and multivariate logistic regression analyses were performed to evaluate the relationships between clinical characteristics and outcome for each type of DAI lesion and each type of CC lesion in patients with TBI. Sixty-nine patients had DAI lesions: 34 in the lobar region, 30 in the CC, and five in the brainstem. Of the 30 patients with CC lesions, ten each were found in the genu, body, and splenium. Each DAI, CC, and genu lesion was significantly associated with unfavorable outcome 1 year after TBI by multivariate analysis using variables that were significantly associated with unfavorable outcome as determined by univariate analysis after adjustment for age. CC lesions, especially those in the genu, were related to unfavorable 1-year outcome in patients with TBI.