Structural and Volumetric Brain MRI Findings in Mild Traumatic Brain Injury

Abstract

BACKGROUND AND PURPOSE: Routine MR imaging findings are frequently normal following mild traumatic brain injury and have a limited role in diagnosis and management. Advanced MR imaging can assist in detecting pathology and prognostication but is not readily available outside research settings. However, 3D isotropic sequences with 1-mm 3 voxel size are available on community MR imaging scanners. Using such sequences, we compared radiologists' findings and quantified regional brain volumes between a mild traumatic brain injury cohort and non-brain-injured controls to describe structural imaging findings associated with mild traumatic brain injury. MATERIALS AND METHODS:Seventy-one military personnel with persistent symptoms and 75 controls underwent 3T MR imaging. Three neuroradiologists interpreted the scans using common data elements. FreeSurfer was used to quantify regional gray and white matter volumes.RESULTS: WM hyperintensities were seen in 81% of the brain-injured group versus 60% of healthy controls. The odds of $1 WM hyperintensity in the brain-injured group was about 3.5 times the odds for healthy controls (95% CI, 1.58-7.72; P = .002) after adjustment for age. A frontal lobe-only distribution of WM hyperintensities was more commonly seen in the mild traumatic brain injury cohort. Furthermore, 7 gray matter, 1 white matter, and 2 subcortical gray matter regions demonstrated decreased volumes in the brain-injured group after multiple-comparison correction. The mild traumatic brain injury cohort showed regional parenchymal volume loss.CONCLUSIONS: White matter findings are nonspecific and therefore a clinical challenge. Our results suggest that prior trauma should be considered in the differential diagnosis of multifocal white matter abnormalities with a clinical history of mild traumatic brain injury, particularly when a frontal predilection is observed.ABBREVIATIONS: DAI 4 diffuse axonal injury; mTBI 4 mild traumatic brain injury; TAI 4 traumatic axonal injury; TBI 4 traumatic brain injury; WMH 4 white matter hyperintensity

Occupational and domestic exposure associations with cerebral small vessel disease and vascular dementia: A systematic review and meta‐analysis

“…Two studies detected microbleeds in 43/603 (7·6%) active duty members (mean age = 33·8) with chronic TBI 78 and in 60/834 (7·2%) TBI participants versus 0/42 controls (OR = 6·64, 95% CI = 0·4‐198·2), 81 whereas one study reported no microbleeds in veterans with chronic blast‐related TBI 79 . WMH and TBI/blast exposure were not associated in one study 82 but were associated in three 80,81,84 . Two studies showed possible TBI‐PVS associations 81,83 .…”

“…Exposures included carbon monoxide (29 studies, n = 1,409; 28 studies/ n = 1,373 in meta‐analysis), 15–43 carbon disulfide (4 studies, n = 797; 3 studies/ n = 131 in meta‐analysis), 44–47 1,2‐dichloroethane (4 studies, n = 40, n = 40 in meta‐analysis), 48–51 toluene (4 studies, n = 64/ n = 64 in meta‐analysis), 52–55 diving (4 studies, n = 266; 4 studies/ n = 172 in meta‐analysis), 56–59 high altitude (11 studies, n = 950; 5 studies/ n = 164 in meta‐analysis), 60–70 contact sports (3 studies, n = 629; not meta‐analyzable), 71–73 lead (2 studies, n = 423, not meta‐analyzable), 74,75 military (10 studies, n = 18,893, not meta‐analyzable), 76–85 pesticides/fertilizers (1 study, n = 8623, not meta‐analyzable), 86 miscellaneous solvents (4 studies, n = 251, not meta‐analyzable), 87–90 and broad occupational categories in population‐based dementia studies (9 studies, n = 15,118, not meta‐analyzable) 91–99 …”

“…(2 studies, n = 423, not meta-analyzable), 74,75 military (10 studies, n = 18,893, not meta-analyzable), [76][77][78][79][80][81][82][83][84][85] pesticides/fertilizers (1 study, n = 8623, not meta-analyzable), 86 miscellaneous solvents (4 studies, n = 251, not meta-analyzable), [87][88][89][90] and broad occupational categories in population-based dementia studies (9 studies, n = 15,118, not meta-analyzable). [91][92][93][94][95][96][97][98][99] Imaging-exposure interval was ongoing/recent (same day-3 months) in 46, past (≥3 months-years) in 25, and unspecified in 14 studies; range same day to 33 years; not reported in 31/85.…”

“…We identified 10 studies (n = 18,893) assessing SVD in military occupations (Supplementary Table 1H). [76][77][78][79][80][81][82][83][84][85] 77 There were conflicting microbleed findings in three studies of military members with traumatic brain injury (TBI) in their 30s. 78,79,81 Two studies detected microbleeds in 43/603 (7⋅6%) active duty members (mean age = 33⋅8) with chronic TBI 78 and in 60/834 (7⋅2%) TBI participants versus 0/42 controls (OR = 6⋅64, 95% CI = 0⋅4-198⋅2), 81 whereas one study reported no microbleeds in veterans with chronic blast-related TBI.…”

Brain glucose metabolism and gray matter volume in the evaluation of chronic traumatic encephalopathy in retired professional soccer players: a cross-sectional [18F]FDG-PET/MRI study

“…Several studies with military personnel, boxers, and American football players (4,30),( 8),( 31), (32) (33,34) have shown mild TBI-related hypometabolism in the cerebellum, pons, temporal and frontal regions, posterior cingulate, and thalamus. In RSP, however, the clusters of cortical hypometabolism are less extensive and widespread than reported in those populations.…”