Imperial College London
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Adriana M. Azor

Faculty of Medicine, Department of Brain Sciences

Honorary Research Associate
 
 
 
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Contact

 

+44 (0)7873 719 812adriana.azor16

 
 
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Location

 

Burlington DanesHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jolly:2021:brain/awaa372,
author = {Jolly, AE and Balaet, M and Azor, A and Friedland, D and Sandrone, S and Graham, NSN and Zimmerman, K and Sharp, DJ},
doi = {brain/awaa372},
journal = {Brain: a journal of neurology},
pages = {92--113},
title = {Detecting axonal injury in individual patients after traumatic brain injury.},
url = {http://dx.doi.org/10.1093/brain/awaa372},
volume = {144},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Poor outcomes after traumatic brain injury (TBI) are common yet remain difficult to predict. Diffuse axonal injury is important for outcomes, but its assessment remains limited in the clinical setting. Currently, axonal injury is diagnosed based on clinical presentation, visible damage to the white matter or via surrogate markers of axonal injury such as microbleeds. These do not accurately quantify axonal injury leading to misdiagnosis in a proportion of patients. Diffusion tensor imaging provides a quantitative measure of axonal injury in vivo, with fractional anisotropy often used as a proxy for white matter damage. Diffusion imaging has been widely used in TBI but is not routinely applied clinically. This is in part because robust analysis methods to diagnose axonal injury at the individual level have not yet been developed. Here, we present a pipeline for diffusion imaging analysis designed to accurately assess the presence of axonal injury in large white matter tracts in individuals. Average fractional anisotropy is calculated from tracts selected on the basis of high test-retest reliability, good anatomical coverage and their association to cognitive and clinical impairments after TBI. We test our pipeline for common methodological issues such as the impact of varying control sample sizes, focal lesions and age-related changes to demonstrate high specificity, sensitivity and test-retest reliability. We assess 92 patients with moderate-severe TBI in the chronic phase (≥6 months post-injury), 25 patients in the subacute phase (10 days to 6 weeks post-injury) with 6-month follow-up and a large control cohort (n = 103). Evidence of axonal injury is identified in 52% of chronic and 28% of subacute patients. Those classified with axonal injury had significantly poorer cognitive and functional outcomes than those without, a difference not seen for focal lesions or microbleeds. Almost a third of patients with unremarkable standard MRIs had evidence o
AU  - Jolly,AE
AU  - Balaet,M
AU  - Azor,A
AU  - Friedland,D
AU  - Sandrone,S
AU  - Graham,NSN
AU  - Zimmerman,K
AU  - Sharp,DJ
DO  - brain/awaa372
EP  - 113
PY  - 2021///
SN  - 0006-8950
SP  - 92
TI  - Detecting axonal injury in individual patients after traumatic brain injury.
T2  - Brain: a journal of neurology
UR  - http://dx.doi.org/10.1093/brain/awaa372
UR  - https://www.ncbi.nlm.nih.gov/pubmed/33257929
UR  - https://academic.oup.com/brain/article/144/1/92/6012956
UR  - http://hdl.handle.net/10044/1/85588
VL  - 144
ER  -
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