The Progression of Memory Loss Secondary to TBI-Induced White Matter Attenuation: a Review of the Literature and Case Exemplar

While it is axiomatic that the major cognitive symptomology of a traumatic brain injury (TBI) of any severity appears shortly after the insult, there is increasing evidence that suggests that, for a subset of individuals with TBI, the course post-injury does not follow what has been traditionally anticipated. Increasingly, longitudinal studies of neurocognitive and neurobehavioral outcomes from TBI demonstrate a highly variable course, which for some continue for a much longer time after the damage associated with TBI lesions would be assumed to have reached a steady state. Chronic neuroinflammatory processes have been identified as one potential source of the continuing decline. We review the literature on chronic inflammatory processes and, in addition, report on the case of a 12-year-old male who sustained a left-temporal lobe displaced skull fracture, with an underlying hemorrhage, when he was hit in the left temporal region of the head by a thrown baseball. Although the youth reported difficulty with memory immediately post-injury, the initial neuropsychological evaluation conducted 6 weeks post-injury yielded data demonstrating that the memory functioning was unaffected by the injury. Testing 3 years later indicated significant memory loss. The course of decline in memory functioning in this instance challenges commonly held conceptualizations concerning the immediacy of memory loss post-TBI and our ability to accurately measure the process as it unfolds.