Abstract
We investigated associations between DTI indices of three brainstem white matter tracts, traumatic brain injury (TBI) injury characteristics, and postconcussive symptomatology (PCS) in a well-characterized sample of veterans with history of mild to moderate TBI (mTBI). 58 military veterans (mTBI: n = 38, mean age = 33.2, mean time since injury = 90.9 months; military controls [MC]; n = 20; mean age = 29.4) were administered 3T DTI scans as well as a comprehensive neuropsychiatric evaluation including evaluation of TBI injury characteristics and PCS symptoms (e.g., negative mood, dizziness, balance and coordination difficulties). Tractography was employed by seeding ROIs along 3 brainstem white matter tracts (i.e., medial lemniscus-central tegmentum tract [ML-CTT]; corticospinal tracts [CST], and pontine tegmentum [PT]), and mean DTI values were derived from fractional anisotropic (FA) maps. Results showed that there were no significant difference in FA between the MC and TBI groups across the 3 regions of interest; however, among the TBI group, CST FA was significantly negatively associated with LOC duration. Additionally, lower FA of certain tracts—most especially the PT—was significantly associated with increased PCS symptoms (i.e., more severe vestibular symptoms, poorer physical functioning, and greater levels of fatigue), even after adjusting for PTSD symptoms. Our findings show that, in our sample of veterans with mTBI, tractography-based DTI indices of brainstem white matter tracts of interest are related to the presence and severity of PCS symptoms. Findings are promising as they show linkages between brainstem white matter integrity and injury severity (LOC), and they raise the possibility that the pontine tegmentum in particular may be a useful marker of PCS symptoms. Collectively, these data point to important neurobiological substrates of the chronic and complex constellation of symptoms following the ‘signature injury’ of our combat-exposed veterans.
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References
Adams, J. H., Mitchell, D. E., Graham, D. I., & Doyle, D. (1977). Diffuse brain damage of immediate impact type: Its relationship to primary brainstem damage in head injury. Brain, 100, 489–502.
Adams, J. H., Jennett, B., Murray, L. S., Teasdale, G. M., Gennarelli, T. A., & Graham, D. I. (2011). Neuropathological findings in disabled survivors of a head injury. Journal of Neurotrauma, 28(5), 701–709.
Andreasen, N. C., O’Leary, D. S., Cizadlo, T., Arndt, S., Rezai, K., Ponto, L. L., & Hichwa, R. D. (1996). Schizophrenia and cognitive dysmetria: a positron-emission tomography study of dysfunctional prefrontal-thalamic-cerebellar circuitry. Proceedings of the National Academy of Sciences, 93(18), 9985–9990.
Aoki, Y., Inokuchi, R., Gunshin, M., Yahagi, N., & Suwa, H. (2012). Diffusion tensor imaging studies of mild traumatic brain injury: a meta-analysis. Journal of Neurology, Neurosurgery & Psychiatry, 83(9), 870–876.
Bammer, R., Auer, M., Keeling, S. L., Augustin, M., Stables, L. A., Prokesch, R. W., & Fazekas, F. (2002). Diffusion tensor imaging using single‐shot SENSE‐EPI. Magnetic Resonance in Medicine, 48(1), 128–136.
Bayly, P. V., Cohen, T. S., Leister, E. P., Ajo, D., Leuthardt, E. C., & Genin, G. M. (2005). Deformation of the human brain induced by mild acceleration. Journal of Neurotrauma, 22, 845–856.
Bazarian, J. J., Zhong, J., Blyth, B., Zhu, T., Kavcic, V., & Peterson, D. (2007). Diffusion tensor imaging detects clinically important axonal damage after mild traumatic brain injury: a pilot study. Journal of Neurotrauma, 24(9), 1447–1459.
Beck, A. T., Epstein, N., Brown, G., & Steer, R. A. (1988). An inventory for measuring clinical anxiety: psychometric properties. Journal of Consulting and Clinical Psychology, 56(6), 893.
Beck, A. T., Steer, R. A., & Brown, G. K. (1996). Manual for the beck depression inventory-II. San Antonio: Psychological Corporation.
Bendlin, B. B., Ries, M. L., Lazar, M., Alexander, A. L., Dempsey, R. J., Rowley, H. A., & Johnson, S. C. (2008). Longitudinal changes in patients with traumatic brain injury assessed with diffusion-tensor and volumetric imaging. NeuroImage, 42(2), 503–514.
Bhattarcharjee, Y. (2008). Shell shock revisited: solving the puzzle of blast trauma. Science, 319(5862), 406–408.
Bigler, E. D. (2008). Neuropsychology and clinical neuroscience of persistent post-concussive syndrome. Journal of the International Neuropsychological Society, 14(1), 1–22.
Bigler, E. D., & Bazarian, J. J. (2010). Diffusion tensor imaging A biomarker for mild traumatic brain injury? Neurology, 74(8), 626–627.
Bigler, E. D., & Maxwell, W. L. (2011). Neuroimaging and neuropathology of TBI. NeuroRehabilitation, 28, 63–74.
Bigler, E. D., & Maxwell, W. L. (2012). Neuropathology of mild traumatic brain injury: relationship to neuroimaging findings. Brain Imaging and Behavior, 6(2), 108–136.
Bigler, E. D., Ryser, D. K., Gandhi, P., Kimball, J., & Wilde, E. A. (2006). Day-of-injury computerized tomography, rehabilitation status, and development of cerebral atrophy in persons with traumatic brain injury. American Journal of Physical Medicine & Rehabilitation, 85(10), 793–806.
Blennow, K., Hardy, J., & Zetterberg, H. (2012). The neuropathology and neurobiology of traumatic brain injury. Neuron, 76(5), 886–899.
Blumbergs, P. C., Scott, G., Manavis, J., Wainwright, H., Simpson, D. A., & McLean, A. J. (1994). Staining of amyloid precursor protein to study axonal damage in mild head injury. Lancet, 344(8929), 1055–1056.
Browne, K. D., Chen, X.-H., Meaney, D. F., & Smith, D. H. (2011). Mild traumatic brain injury and diffuse axonal injury in swine. Journal of Neurotrauma, 28(9), 1747–1755.
Büki, A., & Povlishock, J. T. (2006). All roads lead to disconnection?–Traumatic axonal injury revisited. Acta Neurochirurgica, 148(2), 181–194.
Cernak, I., Wang, Z., Jiang, J., Bian, X., & Savic, J. J. (2001). Ultrastructural and functional characteristics of blast injury-induced neurotrauma. Journal of Trauma, 50(4), 695–706.
Chason, J. L., Hardy, W. G., Webster, J. E., & Gurjian, E. S. (1958). Alterations in cell structure of the brain associated with experimental concussion. Journal of Neurosurgery, 15, 135–139.
Chatelin, S., Deck, C., Renard, F., Kremer, S., Heinrich, C., Armspach, J. P., & Willinger, R. (2011). Computation of axonal elongation in head trauma finite element simulation. Journal of the Mechanical Behavior of Biomedical Materials, 4(8), 1905–1919.
Cicerone, K. (1995). The neurobehavioral symptom inventory. Journal of Head Trauma Rehabilitation, 10(3), 1–17.
Denny-Brown, D., & Russell, W. R. (1941). Experimental cerebral concussion. Brain, 64, 95–164.
Dixon, C. E., & Hayes, R. L. (1995). Rodent models of traumatic brain injury and motor function assessment: Controlled cortical impact and fluid percussion models of traumatic brain injury. In S. T. Ohnishi & T. Ohnishi (Eds.), Central nervous system trauma (pp. 255–265). New York: CRC.
Foltz, E. L., & Schmidt, R. P. (1956). The role of the reticular formation in the coma of head injury. Journal of Neurosurgery, 13, 145–154.
Foltz, E. L., Jenkner, F. L., & Ward, A. A. (1953). Experimental cerebral concussion. Journal of Neurosurgery, 10, 342–352.
Fork, M., Bartels, C., Ebert, A. D., Grubich, C., Synowitz, H., & Wallesch, C. W. (2005). Neuropsychological sequelae of diffuse traumatic brain injury. Brain Injury, 19(2), 101–108.
Garman, R. H., Jenkins, L. W., Switzer, R. C., III, Bauman, R. A., Tong, L. C., Swauger, P. V., & Kochanek, P. M. (2011). Blast exposure in rats with body shielding is characterized primarily by diffuse axonal injury. Journal of Neurotrauma, 28(6), 947–959.
Gean, A. D. (1994). Imaging of head trauma. New York: Raven.
Habas, C., & Cabanis, E. A. (2007). Anatomical parcellation of the brainstem and cerebellar white matter: a preliminary probabilistic tractography study at 3T. Neuroradiology, 49(10), 849–863.
Haber, A. H., & Fichtenberg, N. L. (2006). Replication of the Test of Memory Malingering (TOMM) in a traumatic brain injury and head trauma sample. The Clinical Neuropsychologist, 20(3), 524–532.
Håberg, A.K., Olsen, A., Moen, K.G., Schirmer-Mikalsen, K., Visser, E., Finnanger, T.G., et al. (2014). White matter microstructure in chronic moderate-to-severe traumatic brain injury: Impact of acute-phase injury-related variables and associations with outcome measures. Journal of Neuroscience Research, 93, 1109–1126.
Haines, D. H. (2000). Neuroanatomy. An atlas of structures, sections and systems (5th ed.). New York: Lippincott Williams & Wilkins.
Heitger, M.H., Jones, R.D., Macleod, A.D., Snell, D.L., Frampton, C.M., & Anderson, T.J. (2009). Impaired eye movements in post-concussion syndrome indicate suboptimal brain function beyond the influence of depression, malingering or intellectual ability. Brain, awp181.
Helton, K. J., Phillips, N. S., Khan, R. B., Boop, F. A., Sanford, R. A., Zou, P., & Ogg, R. J. (2006). Diffusion tensor imaging of tract involvement in children with pontine tumors. American Journal of Neuroradiology, 27(4), 786–793.
Inoue, T., Ogasawara, K., Beppu, T., Ogawa, A., & Kabasawa, H. (2005). Diffusion tensor imaging for preoperative evaluation of tumor grade in gliomas. Clinical Neurology and Neurosurgery, 107, 174–180.
Johnson, V. E., Stewart, W., & Smith, D. H. (2013). Axonal pathology in traumatic brain injury. Experimental Neurology, 246, 35–43.
Jones, D. K., Horsfield, M. A., & Simmons, A. (1999). Optimal strategies for measuring diffusion in anisotropic systems by magnetic resonance imaging. Magnetic Resonance in Medicine, 42(3), 515–525.
Kinnunen, K. M., Greenwood, R., Powell, J. H., Leech, R., Hawkins, P. C., Bonnelle, V., Patel, M. C., Counsell, S. J., & Sharp, D. J. (2010). White matter damage and cognitive impairment after traumatic brain injury. Brain, 134(2), 449–463.
Kou, Z., Wu, Z., Tong, K. A., Holshouser, B., Benson, R. R., Hu, J., & Haacke, E. M. (2010). The role of advanced MR imaging findings as biomarkers of traumatic brain injury. The Journal of Head Trauma Rehabilitation, 25(4), 267–282.
Levin, H., & Smith, D. (2013). Traumatic brain injury: networks and neuropathology. Lancet Neurology, 12(1), 15–16.
Levin, H. S., Benton, A. L., & Grossman, R. G. (1982). Neurobehavioral consequences of closed head injury. New York: Oxford University Press.
Lin, W. M., Chen, M. H., Wang, H. C., Lu, C. H., Chen, P. C., Chen, H. L., & Lin, W. C. (2014). Association between peripheral oxidative stress and white matter damage in acute traumatic brain injury. BioMed Research International, 2014, 340–936.
Lui, Y. W., Law, M., & Chacko, M. J. (2007). Brainstem corticospinal tract diffusion tensor imaging in patients with primary posterior fossa neoplasm stratified by tumor type. Neurosurgery, 61, 1199–1207.
Mac Donald, C. L., Johnson, A. M., Cooper, D., Nelson, E. C., Werner, N. J., Shimony, J. S., Snyder, A. Z., Raichle, M. E., Witherow, J. R., Fang, R., Flaherty, S. F., & Brody, D. L. (2011). Detection of blast-related traumatic brain injury in U.S. military personnel. The New England Journal of Medicine, 364(22), 2091. doi:10.1056/NEJMoa1008069.
Mac Donald, C. L., Adam, O. R., Johnson, A. M., Nelson, E. C., Werner, N. J., Rivet, D. J., & Brody, D. L. (2015). Acute post-traumatic stress symptoms and age predict outcome in military blast concussion. Brain, 138(5), 1314–1326.
McHorney, C. A., Ware, J. E., Jr., & Raczek, A. E. (1993). The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Medical Care, 31, 247–263.
McIntosh, T. K., Smith, D. H., Meaney, D. F., Gennarelli, T. A., & Graham, D. I. (1996). Neuropathological sequelae of traumatic brain injury: relationship to neurochemical and biomechanical mechanisms. Laboratory Investatigation, 74(2), 315–342.
Merterko, M., Baker, E., Stolzmann, K. L., Hendricks, A. M., Cicerone, K. D., & Lew, H. L. (2012). Psychometric assessment of the Neurobehavioral Symptom Inventory-22: The structure of persistent postconcussive symptoms following deployment-related mild traumatic brain injury among veterans. Journal of Head Trauma Rehabilitation, 27(1), 55–62.
Moore, B. A., & Donders, J. (2004). Predictors of invalid neuropsychological test performance after traumatic brain injury. Brain Injury, 18(10), 975–984.
Mori, S., & van Zijl, P. C. M. (2002). Fiber tracking: principles and strategies - a technical review. NMR in Biomedicine, 15(7–8), 468–480.
Moruzzi, G., & Magoun, H. W. (1949). Brainstem reticular formation and activation of the EEG. Electroencephalography and Clinical Neurophysiology, 1, 455–473.
Nagae-Poetscher, L. M., Jiang, H., Wakana, S., Golay, X., van Zijl, P. C., & Mori, S. (2004). High-resolution diffusion tensor imaging of the brain stem at 3 T. American Journal of Neuroradiology, 25(8), 1325–1330.
Nilsson, B., Ponten, U., & Voigt, G. (1977). Experimental head injury in the rat. Part 1: mechanics, pathophysiology, and morphology in an impact acceleration trauma model. Journal of Neurosurgery, 47(2), 241–251.
Niogi, S. N., Mukherjee, P., Ghajar, J., Johnson, C., Kolster, R. A., Sarkar, R., et al. (2008). Extent of microstructural white matter injury in postconcussive syndrome correlates with impaired cognitive reaction time: a 3T diffusion tensor imaging study of mild traumatic brain injury. American Journal of Neuroradiology, 29(5), 967–973.
Ommaya, A. K. (1966). Trauma to the nervous system: a clinical and experimental study. ARCS, 38, 317–347.
Oppenheimer, D. R. (1968). Microscopic lesions in the brain following head injury. Journal of Neurology, Neurosurgery, and Psychiatry, 31(4), 299–306.
Plum, R., & Posner, J. B. (1980). The diagnosis of stupor and coma (3rd ed.). Philadelphia: F.A. Davis.
Povlishock, J. T., & Christman, C. W. (1995). The pathobiology of traumatically induced axonal injury in animals and humans: a review of current thoughts. Journal of Neurotrauma, 12(4), 555–564.
Povlishock, J. T., & Katz, D. I. (2005). Update of neuropathology and neurological recovery after traumatic brain injury. Journal of Head Trauma Rehabilitation, 20(1), 76–94.
Povlishock, J. T., Becker, D. P., Miller, J. D., Jenkins, L. W., & Dietrich, W. D. (1979). The morphopathologic substrates of concussion? Acta Neuropathologica, 47(1), 1–11.
Price, J. L. (2003). Comparative aspects of amygdala connectivity. Annals of the New York Academy of Sciences, 985(1), 50–58.
Rabinowitz, A. R., & Levin, H. S. (2014). Cognitive sequelae of traumatic brain injury. Psychiatric Clinics of North America, 37(1), 1–11.
Reep, R. L., & Corwin, J. V. (2009). Posterior parietal cortex as part of a neural network for directed attention in rats. Neurobiology of Learning and Memory, 91(2), 104–113.
Rees, P. M. (2003). Contemporary issues in mild traumatic brain injury. Archives of Physical Medicine and Rehabilitation, 84(12), 1885–1894.
Ruggiero, K. J., Del Ben, K., Scotti, J. R., & Rabalais, A. E. (2003). Psychometric properties of the PTSD Checklist-Civilian Version. Journal of Trauma and Stress, 16(5), 495–502.
Salamon, N., Cicotte, N., Alger, J., Shattuck, D., Perlman, S., Schultze-Haakh, H., & Salamon, G. (2005). Analysis of the brainstem white matter tracts with diffusion tensor imaging. Neuroradiology, 47, 895–902.
Scheid, R., Preul, C., Gruber, O., Wiggins, C., & Von Cramon, D. Y. (2003). Diffuse axonal injury associated with chronic traumatic brain injury: evidence from T2-weighted gradient-echo imaging at 3T. AJN, 24, 1049–1056.
Shetter, A. G., & Demakas, J. J. (1979). The pathophysiology of concussion: a review. Advances in Neurology, 22, 5–14.
Sidaros, A., Engberg, A. W., Sidaros, K., Liptrot, M. G., Herning, M., Petersen, P., & Rostrup, E. (2008). Diffusion tensor imaging during recovery from severe traumatic brain injury and relation to clinical outcome: a longitudinal study. Brain, 131(2), 559–572.
Smith, D. H., Nonaka, M., Miller, R., Leoni, M., Chen, X. H., Alsop, D., et al. (2000). Immediate coma following inertial brain injury dependent on axonal damage in the brainstem. Journal of Neurosurgery, 93(2), 315–322.
Smith, D. H., Hicks, R., & Povlishock, J. T. (2013). Therapy development for diffuse axonal injury. Journal of Neurotrauma, 30(5), 307–323.
Sorg, M. S. F., Delano-Wood, L., Luc, M. N., Schiehser, D. M., Hanson, K. L., Nation, D. A., Lanni, E., Jak, A. J., Lu, K., Meloy, M. J., Frank, L. R., Lohr, J. B., & Bondi, M. W. (2014). White matter integrity in veterans with mild traumatic brain injury: associations with executive function and loss of consciousness. The Journal of Head Trauma Rehabilitation, 29(1), 21.
Strich, J. (1961). Shearing of nerve fibers as a cause of head injury. Lancet, 2, 443–448.
Sugahara, T., Korogi, Y., Kochi, M., Ikushima, I., Shigematu, Y., Hirai, T., & Takahashi, M. (1999). Usefulness of diffusion‐weighted MRI with echo‐planar technique in the evaluation of cellularity in gliomas. Journal of Magnetic Resonance Imaging, 9(1), 53–60.
Sullivan, E. V. (2003). Compromised pontocerebellar and cerebellothalamocortical systems: speculations on their contributions to cognitive and motor impairment in nonamnesic alcoholism. Alcohol Clinical Experimental Research, 27(9), 1409–1419.
Suskauer, S. J., & Huisman, T. A. (2009). Neuroimaging in pediatric traumatic brain injury: current and future predictors of functional outcome. Developmental Disabilities Research Reviews, 15(2), 117–123.
Taber, K. H., Hurley, R. A., Haswell, C. C., Rowland, J. A., Hurt, S. D., Lamar, C. D., & Morey, R. A. (2015). White matter compromise in veterans exposed to primary blast forces. The Journal of Head Trauma Rehabilitation, 30(1), E15–E25.
Teasdale, G., & Jennett, B. (1974). Assessment of coma and impaired consciousness. A practical scale. Lancet, 2, 81–84.
Tomaiuolo, F., Carlesimo, G. A., Di Paoloa, M., Petrides, M., Fera, F., Bonanni, R., et al. (2004). Gross morphology and morphometric sequelae in the hippocampus, fornix, and corpus callosum of patients with severe non-missile traumatic brain injury without macroscopically detectable lesions: a T1 weighted MRI study. Journal of Neurology, Neurosurgery & Psychiatry, 75, 1314–1322.
Traumatic Brain Injury Task Force (2009). Report to the surgeon general: TBI task force. http://www.healthquality.va.gov/guidelines/Rehab/mtbi/concussion_mtbi_full_1_0.pdf.
Uh, J., Merchant, T. E., Li, Y., Feng, T., Gajjar, A., Ogg, R. J., & Hua, C. (2013). Differences in brainstem fiber tract response to radiation: a longitudinal diffusion tensor imaging study. International Journal of Radiation Oncology Biology Physics, 86(2), 292–297.
Vanderploeg, R. D., Groer, S., & Belanger, H. G. (2012). Initial developmental process of a VA semistructured clinical interview for TBI identification. Journal of Rehabilitation Research and Development, 49(4), 545.
Vanderploeg, R. D., Silva, M. A., Soble, J. R., Curtiss, G., Belanger, H. G., Donnell, A. J., & Scott, S. G. (2015). The structure of postconcussion symptoms on the neurobehavioral symptom inventory: a comparison of alternative models. The Journal of Head Trauma Rehabilitation, 30(1), 1–11.
Verhaal, A. & van ‘T Hooft, F. (1975). Commotio and contusion cerebri (cerebral concussion). In: P.J. Vinken, G.W. Bruyn, & R. Braakman (Eds.), Handbook of Clinical Neurology (pp. 417–444). North-Holland.
Viano, D. C., Casson, I. R., Pellman, E. J., Bir, C. A., Zhang, L., Sherman, D. C., & Boitano, M. A. (2005). Concussion in professional football: comparison with boxing head impacts—Part 10. Neurosurgery, 57(6), 1154–1172.
Wakana, S., Jiang, H., Nagae-Poetscher, L. M., van Zijl, P. C., & Mori, S. (2004). Fiber tract-based atlas of human white matter anatomy. Radiology, 230(1), 77–87.
Wang, R., Benner, T., Soensen, A. G., & Wedeen, V. J. (2007). Diffusion toolkit: a software package for diffusion imaging data processing and tractography. Proceedings on International Society for Magnetic Resonance in Medicine, 15, 3720.
Ward, A. A. (1958). Physiological basis of concussion. Journal of Neurosurgery, 15, 129–134.
Ware, J. E., & Gandek, B. (1998). Overview of the SF-36 health survey and the international quality of life assessment (IQOLA) project. Journal of Clinical Epidemiology, 51(11), 903–912.
Ware, J. E., Kosinski, M., & Keller, S. D. (1994). SF-36 physical and mental health summary scales: A user’s manual. Boston: The Health Institute.
Ware, J. E., Kosinski, M., Gandek, B., Aaronson, N. K., Apolone, G., Bech, P., & Sullivan, M. (1998). The factor structure of the SF-36 Health Survey in 10 countries: Results from the IQOLA Project. Journal of Clinical Epidemiology, 51(11), 1159–1165.
Weathers, F. W., Huska, J. A., & Keane, T. M. (1991). PCL-C for DSM-IV. Boston: National Center for PTSD-Behavioral Science Division.
Wilde, E. A., Chu, Z., Bigler, E. D., Hunter, J. V., Fearing, M. A., Hanten, G., & Levin, H. S. (2006). Diffusion tensor imaging in the corpus callosum in children after moderate to severe traumatic brain injury. Journal of Neurotrauma, 23(10), 1412–1426.
Yeh, P. H., Wang, B., Oakes, T. R., French, L. M., Pan, H., Graner, J., & Riedy, G. (2014). Postconcussional disorder and PTSD symptoms of military‐related traumatic brain injury associated with compromised neurocircuitry. Human Brain Mapping, 35(6), 2652–2673.
Zhang, W., Li, X., Zhang, J., Luft, A., Hanley, D. F., van Zijl, P., & Mori, S. (2009). Landmark-referenced voxel-based analysis of diffusion tensor images of the brainstem white matter tracts: application in patients with middle cerebral artery stroke. NeuroImage, 44(3), 906–913.
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The current study was supported by a VA Clinical Science Research & Development (Career Development Award-2 to L.D-W, D.S.); Department of Defense Investigator-Initiated Research Grant (L.D-W); and VA Merit Review (L.D-W.)
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Lisa Delano-Wood, Katherine Bangen, Scott Sorg, Alexandra Clark, Dawn Schiehser, Norman Luc, Mark Bondi, Madeleine Werhane, Kim, Russell Kim, & Erin Bigler, declare no conflicts of interest. All procedures involved in this study were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975. Informed consent was obtained from all patients included in the study.
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Delano-Wood, L., Bangen, K.J., Sorg, S.F. et al. Brainstem white matter integrity is related to loss of consciousness and postconcussive symptomatology in veterans with chronic mild to moderate traumatic brain injury. Brain Imaging and Behavior 9, 500–512 (2015). https://doi.org/10.1007/s11682-015-9432-2
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DOI: https://doi.org/10.1007/s11682-015-9432-2