Assessing the Relationship between Neurocognitive Performance and Brain Volume in Chronic Moderate-Severe Traumatic Brain Injury.

Nikos Konstantinou,Andrew C Papanicolaou,Ioannis Seimenis,Eva Pettemeridou,Savvas S Papacostas,Eleni Eracleous,Fofi Constantinidou

doi:10.3389/fneur.2016.00029

Abstract

Characterize the scale and pattern of long-term atrophy in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in chronic moderate-severe traumatic brain injury (TBI) and its relationship to neurocognitive outcomes. The TBI group consisted of 17 males with primary diagnosis of moderate-severe closed head injury. Participants had not received any systematic, post-acute rehabilitation and were recruited on average 8.36 years post-injury. The control group consisted of 15 males matched on age and education. Neurocognitive battery included widely used tests of verbal memory, visual memory, executive functioning, and attention/organization. GM, WM, and CSF volumes were calculated from segmented T1-weighted anatomical MR images. Voxel-based morphometry was employed to identify brain regions with differences in GM and WM between TBI and control groups. Chronic TBI results in significant neurocognitive impairments, and significant loss of GM and WM volume, and significant increase in CSF volume. Brain atrophy is not widespread, but it is rather distributed in a fronto-thalamic network. The extent of volume loss is predictive of performance on the neurocognitive tests. Significant brain atrophy and associated neurocognitive impairments during the chronic stages of TBI support the notion that TBI results in a chronic condition with lifelong implications.

Highlights

Traumatic brain injury (TBI) has been historically considered as a single event that requires rehabilitation during the months after the injury and results in a static course thereafter [1]
In order to further investigate the relationship between brain volume and neurocognitive performance, we investigated whether brain regions that exhibited significant differences between the TBI and the control groups in the voxel-based morphometry (VBM) analysis hold any predictive value for neurocognitive performance
The current study investigated the chronic outcomes of moderate–severe TBI in a homogeneous group of male survivors of TBI that had not received any systematic post-acute rehabilitation and were recruited several years post-injury

Summary

Introduction

Traumatic brain injury (TBI) has been historically considered as a single event that requires rehabilitation during the months after the injury and results in a static course thereafter [1]. Neuropsychological research indicates that following an acute recovery phase many patients with moderate–severe TBI sustain significant cognitive deficits lasting for many years postinjury [5,6,7,8]. Neuroimaging studies demonstrated that these effects extend beyond the first year post-injury and individuals with TBI exhibit significant brain volume loss in both the subacute and chronic phases [3, 4, 14,15,16,17,18] that continues for years after the injury [3, 5, 15, 19]. Recent reports demonstrated GM and WM volume loss for up to approximately 4 years post-injury [17]

Objectives

Results

Conclusion