Journal article
Scale and pattern of atrophy in the chronic stages of moderate-severe TBI
Frontiers in human neuroscience, Vol.8, p.67
03/31/2014
DOI: 10.3389/fnhum.2014.00067
PMCID: PMC3978360
PMID: 24744712
Abstract
Background: Moderate-severe traumatic brain injury (TBI) is increasingly being understood as a progressive disorder, with growing evidence of reduced brain volume and white matter (WM) integrity as well as lesion expansion in the chronic phases of injury. The scale of these losses has yet to be investigated, and pattern of change across structures has received limited attention.
Objectives: (1) To measure the percentage of patients in our TBI sample showing atrophy from 5 to 20 months post-injury in the whole brain and in structures with known vulnerability to acute TBI, and (2) To examine relative vulnerability and patterns of volume loss across structures.
Methods: Fifty-six TBI patients [complicated mild to severe, with mean Glasgow Coma Scale (GCS) in severe range] underwent MRI at, on average, 5 and 20 months post-injury; 12 healthy controls underwent MRI twice, with a mean gap between scans of 25.4 months. Mean monthly percent volume change was computed for whole brain (ventricle-to-brain ratio; VBR), corpus callosum (CC), and right and left hippocampi (HPC).
Results: (1) Using a threshold of 2 z-scores below controls, 96% of patients showed atrophy across time points in at least one region; 75% showed atrophy in at least 3 of the 4 regions measured. (2) There were no significant differences in the proportion of patients who showed atrophy across structures. For those showing decline in VBR, there was a significant association with both the CC and the right HPC (P < 0.05 for both comparisons). There were also significant associations between those showing decline in (i) right and left HPC (P < 0.05); (ii) all combinations of genu, body and splenium of the CC (P < 0.05), and (iii) head and tail of the right HPC (P < 0.05 all sub-structure comparisons).
Conclusions: Atrophy in chronic TBI is robust, and the CC, right HPC and left HPC appear equally vulnerable. Significant associations between the right and left HPC, and within substructures of the CC and right HPC, raise the possibility of common mechanisms for these regions, including transneuronal degeneration. Given the 96% incidence rate of atrophy, a genetic explanation is unlikely to explain all findings. Multiple and possibly synergistic mechanisms may explain findings. Atrophy has been associated with poorer functional outcomes, but recent findings suggest there is potential to offset this. A better, understanding of the underlying mechanisms could permit targeted therapy enabling better long-term outcomes.
Details
- Title: Subtitle
- Scale and pattern of atrophy in the chronic stages of moderate-severe TBI
- Creators
- Robin E. A. Green - CognITBrenda Colella - Toronto Rehabilitation InstituteJerome J. Maller - Monash Alfred Psychiatry Research centreMark Bayley - Toronto Rehabilitation InstituteJoanna Glazer - Toronto Rehabilitation InstituteDavid J. Mikulis - University of Toronto
- Resource Type
- Journal article
- Publication Details
- Frontiers in human neuroscience, Vol.8, p.67
- DOI
- 10.3389/fnhum.2014.00067
- PMID
- 24744712
- PMCID
- PMC3978360
- NLM abbreviation
- Front Hum Neurosci
- ISSN
- 1662-5161
- eISSN
- 1662-5161
- Publisher
- Frontiers Media Sa
- Number of pages
- 9
- Grant note
- Ontario Neurotrauma Foundation Canadian Institute of Health Research; Canadian Institutes of Health Research (CIHR) Canada Research Chairs Program; Canada Research Chairs Physicians Services Incorporated Foundation
- Language
- English
- Date published
- 03/31/2014
- Academic Unit
- Radiology
- Record Identifier
- 9984848428102771
Metrics
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