A quantitative review of the effects of traumatic brain injury on cognitive functioning.

Changes in cognitive functioning often result from traumatic brain injury (TBI) and predict other important aspects of psychosocial recovery. Despite this pivotal role, no quantitative review of cognitive functioning across the spectrum of TBI severity has been reported. We therefore conducted a meta-analysis of 39 mostly cross-sectional studies of the cognitive effects of mild head injury (MHI) and moderate-severe TBI from the acute phase through long-term follow-up.