Diffusion tensor imaging abnormalities in patients with mild traumatic brain injury and neurocognitive impairment.
OBJECTIVE
To determine if diffusion tensor imaging can differentiate patients with chronic cognitive impairment after mild traumatic brain injury (TBI) from normal controls.


METHODS
Ten patients with persistent cognitive impairment after mild TBI were evaluated at least 2 years after injury. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured at white matter regions susceptible to axonal injury after TBI. Comparison was made to 10 normal controls.


RESULTS
Fractional anisotropy was significantly lower (4.5%; P = 0.01) and ADC higher (7.1%; P = 0.04) in patients at the left side of the genu of the corpus callosum. The mild TBI group also demonstrated a significant increase in FA within the posterior limb of the internal capsule bilaterally (left, 5.1%; P = 0.03; right, 1.9%; P = 0.04).


CONCLUSIONS
These results demonstrate low FA and high ADC in the genu of the corpus callosum of mild TBI patients with persistent cognitive impairment, suggesting that permanent white matter ultrastructural damage occurs in mild TBI, and that such damage may be associated with persistent cognitive disability. Further longitudinal studies are warranted to elucidate the full importance of the findings.
Lo
Calvin
C
Department of Radiology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY 10467, USA.
Shifteh
Keivan
K
Gold
Tamar
T
Bello
Jacqueline A
JA
Lipton
Michael L
ML
D000328:Adult; D016880:Anisotropy; D001930:Brain Injuries / Q000150:complications* / Q000175:diagnosis*; D002908:Chronic Disease; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D003337:Corpus Callosum / Q000473:pathology* / Q000648:ultrastructure; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D020772:Internal Capsule / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012016:Reference Values