This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objectives: To identify structural connectivity change occurring during the first 6 months after traumatic brain injury and to evaluate the utility of diffusion tensor tractography for predicting long-term outcome.
Methods: The participants were 28 patients with mild to severe traumatic axonal injury and 20 age- and sex-matched healthy control subjects. Neuroimaging was obtained 0–9 days postinjury for acute scans and 6–14 months postinjury for chronic scans. Long-term outcome was evaluated on the day of the chronic scan. Twenty-eight fiber regions of 9 major white matter structures were reconstructed, and reliable tractography measurements were determined and used.
Results: Although most (23 of 28) patients had severe brain injury, their long-term outcome ranged from good recovery (16 patients) to moderately (5 patients) and severely disabled (7 patients). In concordance with the diverse outcome, the white matter change in patients was heterogeneous, ranging from improved structural connectivity, through no change, to deteriorated connectivity. At the group level, all 9 fiber tracts deteriorated significantly with 7 (corpus callosum, cingulum, angular bundle, cerebral peduncular fibers, uncinate fasciculus, and inferior longitudinal and fronto-occipital fasciculi) showing structural damage acutely and 2 (fornix body and left arcuate fasciculus) chronically. Importantly, the amount of change in tractography measurements correlated with patients' long-term outcome. Acute tractography measurements were able to predict patients' learning and memory performance; chronic measurements also determined performance on processing speed and executive function.
Conclusions: Diffusion tensor tractography is a valuable tool for identifying structural connectivity changes occurring between the acute and chronic stages of traumatic brain injury and for predicting patients' long-term outcome.
GLOSSARY
- AB=
- angular bundle;
- AF=
- arcuate fasciculus;
- CB=
- cingulum bundle;
- CC=
- corpus callosum;
- CCab=
- anterior body of the corpus callosum;
- CCg=
- genu of the corpus callosum;
- CCpb=
- posterior body of the corpus callosum;
- CCs=
- splenium of the corpus callosum;
- CPF=
- cerebral peduncular fibers;
- CPpa=
- cerebral peduncular fibers to the parietal lobes;
- CVLT-II=
- California Verbal Learning Test–II;
- DCA=
- discriminant correspondence analysis;
- DTI=
- diffusion tensor imaging;
- FA=
- fractional anisotropy;
- FB=
- fornix body;
- FC=
- fornix crus;
- GCS=
- Glasgow Coma Scale;
- IFO=
- inferior fronto-occipital fasciculus;
- ILF=
- inferior longitudinal fasciculus;
- MD=
- mean diffusivity;
- PLS=
- partial least-squares;
- ROI=
- region of interest;
- TAI=
- traumatic axonal injury;
- TBI=
- traumatic brain injury;
- UF=
- uncinate fasciculus
Footnotes
-
Study funding: Supported by the NIH (R01-HD48179 and U01-HD042652 to R.D.-A. and K23-NS060827 to C.D.M.) and the US Department of Education (H133 A020526 to R.D.-A.).
-
Editorial, page 810
-
Supplemental data at www.neurology.org
- Received December 13, 2010.
- Accepted March 22, 2011.
- Copyright © 2011 by AAN Enterprises, Inc.
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Disputes & Debates: Rapid online correspondence
REQUIREMENTS
If you are uploading a letter concerning an article:
You must have updated your disclosures within six months: http://submit.neurology.org
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.