Dynamic changes in white matter following traumatic brain injury and how diffuse axonal injury relates to cognitive domain.

Objective: The goal is to evaluate longitudinally with diffusion tensor imaging (DTI) the integrity of cerebral white matter in patients with moderate and severe DAI and to correlate the DTI findings with cognitive deficits.Methods: Patients with DAI (n = 20) were scanned at three timepoints (2, 6 and 12 months) after trauma. A healthy control group (n = 20) was evaluated once with the same high-field MRI scanner. The corpus callosum (CC) and the bilateral superior longitudinal fascicles (SLFs) were assessed by deterministic tractography with ExploreDTI. A neuropschychological evaluation was also performed.Results: The CC and both SLFs demonstrated various microstructural abnormalities in between-groups comparisons. All DTI parameters demonstrated changes across time in the body of the CC, while FA (fractional anisotropy) increases were seen on both SLFs. In the splenium of the CC, progressive changes in the mean diffusivity (MD) and axial diffusivity (AD) were also observed. There was an improvement in attention and memory along time. Remarkably, DTI parameters demonstrated several correlations with the cognitive domains.Conclusions: Our findings suggest that microstructural changes in the white matter are dynamic and may be detectable by DTI throughout the first year after trauma. Likewise, patients also demonstrated improvement in some cognitive skills.

Biological markers and severe head trauma. Where are we? / Marcadores biológicos e traumatismo craniano grave. Onde estamos?

Traumatic brain injury (TBI) constitutes a major health and socioeconomic problem throughout theworld. Despite the signi!cant advances in neuroradiology and cerebral monitoring it is still dif!cult tomeasure the degree of primary brain injury and continuing secondary damage with Glasgow ComaScale score or the initial computed tomography. Predicting prognosis of TBI patients in early stages hasa vital importance and is dif!cult in some instances. The present review shows that there has been anincreasing interest in biochemical markers for traumatic brain injury during the last years. The potentialcorrelation of markers with injury and outcome measures in severe head injury is promising.

O traumatismo cranioencefálico constitui um grave problema socioeconômico em todo o mundo. Apesar dos avanços em neurorradiologia e neuromonitorização, ainda é difícil mensurar a injúria primária e prever os danos secundários dos pacientes com base somente na Escala de Coma de Glasgow ou natomogra!a de crânio da admissão. Predizer o prognóstico dos pacientes ainda em uma fase inicial é devital importância, porém muitas vezes difícil. A presente revisão mostra que há interesse cada vez maiornos marcadores biológicos relacionados ao trauma decrânio. A potencial correlação dos biomarcadoresda injúria primária com o desfecho dos pacientes com traumatismo craniano grave é promissora.