title: Diffuse Disconnectivity in tBi: a resting state fMri anD Dti stuDy.
abstract: Diffuse axonal injury is a common pathological consequence of Traumatic Brain Injury (TBI). Diffusion Tensor Imaging is an ideal technique to study white matter integrity using the Fractional Anisotropy (FA) index which is a measure of axonal integrity and coherence. There have been several reports showing reduced FA in individuals with TBI, which suggest demyelination or reduced fiber density in white matter tracts secondary to injury. Individuals with TBI are usually diagnosed with cognitive deficits such as reduced attention span, memory and executive function. In this study we sought to investigate correlations between brain functional networks, white matter integrity, and TBI severity in individuals with TBI ranging from mild to severe. A resting state functional magnetic resonance imaging protocol was used to study the default mode network in subjects at rest. FA values were decreased throughout all white matter tracts in the mild to severe TBI subjects. FA values were also negatively correlated with TBI injury severity ratings. The default mode network showed several brain regions in which connectivity measures were higher among individuals with TBI relative to control subjects. These findings suggest that, subsequent to TBI, the brain may undergo adaptation responses at the cellular level to compensate for functional impairment due to axonal injury.
authors: Department of Radiology, Mount Sinai School of Medicine, New York, NY 10029 USA ; Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029 USA.
authors: Cheuk Ying
authors: CY
authors: Tang
authors: Emily
authors: E
authors: Eaves
authors: Kristen
authors: K
authors: Dams-O'Connor
authors: Lap
authors: L
authors: Ho
authors: Eric
authors: E
authors: Leung
authors: Edmund
authors: E
authors: Wong
authors: David
authors: D
authors: Carpenter
authors: Johnny
authors: J
authors: Ng
authors: Wayne
authors: W
authors: Gordon
authors: Giulio
authors: G
authors: Pasinetti
keywords: Cognitive Function; DTI; Functional magnetic resonance imaging (fMRI); Traumatic Brain Injury (TBI)