Diffusion tensor imaging differences relate to memory deficits in diffuse traumatic brain injury
1 Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
2 Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain
3 Department of Neuropsychology, Institut Universitari de Neurorehabilitació Guttmann, Badalona, Spain
4 Centre de Diagnòstic per la Imatge Hospital Clínic de Barcelona (CDIC), Hospital Clínic de Barcelona, Spain
BMC Neurology 2011, 11:24 doi:10.1186/1471-2377-11-24Published: 23 February 2011
Memory is one of the most impaired functions after traumatic brain injury (TBI). We used diffusion tensor imaging (DTI) to determine the structural basis of memory deficit. We correlated fractional anisotropy (FA) of the fasciculi connecting the main cerebral regions that are involved in declarative and working memory functions.
Fifteen patients with severe and diffuse TBI and sixteen healthy controls matched by age and years of education were scanned. The neuropsychological assessment included: Letter-number sequencing test (LNS), 2-back task, digit span (forwards and backwards) and the Rivermead profilet. DTI was analyzed by a tract-based spatial statics (TBSS) approach.
Whole brain DTI analysis showed a global decrease in FA values that correlated with the 2-back d-prime index, but not with the Rivermead profile. ROI analysis revealed positive correlations between working memory performance assessed by 2-back d-prime and superior longitudinal fasciculi, corpus callosum, arcuate fasciculi and fornix. Declarative memory assessed by the Rivermead profile scores correlated with the fornix and the corpus callosum.
Diffuse TBI is associated with a general decrease of white matter integrity. Nevertheless deficits in specific memory domains are related to different patterns of white matter damage.