Coexisting diffuse axonal injury (DAI) and outcome of severe head injury.

The importance of coexisting diffuse axonal injury (DAI) and outcome were studied in 107 patients with diffuse and focal brain injury. Comprehensive neuropathological study was undertaken in 26 fatal patients. There was a clear rank order of the mortality rate in the lesion type. The rank order of good recovery and moderate disability was also similar to the inverse of the mortality ranking. The pathological "marker" of DAI, macroscopic lesions in the corpus callosum and dorsolateral quadrant of the upper brainstem and histological evidence of axonal retraction balls, were commonly found not only in patients with diffuse brain injury but also in focal brain injury. The type of intracranial lesion in severe head injury is thus an important factor in determining outcomes and DAI of varying severity is the common subjacent lesion in the fatal patients.