Mild traumatic brain injury

The spectrum captured: a methodological approach to studying incidence and outcomes of traumatic brain injury on a population level

Authors: Theadom A, Barker-Collo S, Feigin VL, Starkey NJ, Jones K, Jones A, Ameratunga S, Barber PA; BIONIC Research Group.

OBJECTIVE: Drawing on the experience of conducting the Brain Injury Incidence and Outcomes New Zealand in the Community study, this article aims to identify the issues arising from the implementation of proposed guidelines for population-based studies of incidence and outcomes in traumatic brain injury (TBI).
STUDY DESIGN AND SETTING: All new cases of TBI (all ages and severities) were ascertained over a 1-year period, using overlapping prospective and retrospective sources of case ascertainment in New Zealand. All eligible TBI cases were invited to participate in a comprehensive assessment at baseline and at 1-month follow-up.
RESULTS: Our experience to date has revealed the feasibility of case ascertainment methods. Consultation with community health services and professionals resulted in feasible referral pathways to support the identification of TBI cases. 'Hot pursuit' methods of recruitment were essential to ensure complete case ascertainment for this population with few additional cases of TBI identified through cross-checks.
CONCLUSION: This review of proposed guidelines in relation to practical study methodology provides a framework for future comparable population-based epidemiological studies of TBI incidence and outcomes in developed countries.

Traumatic Brain Injury, Shell Shock, and Posttraumatic Stress Disorder in the Military—Past, Present, and Future

Authors: Shively, Sharon B. MD, PhD; Perl, Daniel P. MD

With preferential use of high explosives in modern warfare, traumatic brain injury (TBI) has become a common injury for troops. Most TBIs are classified as “mild,” although military personnel with these injuries can have persistent symptoms such as headache, memory impairment, and behavioral changes. During World War I, soldiers in the trenches, undergoing unrelenting artillery bombardment, suffered from similar symptoms, designated at the time as “shell shock.” Dr Frederick Mott proposed studying the brains of deceased soldiers to elucidate the neuropathology of this clinical entity. Subsequent to a British government enquiry after World War I, the term “shell shock” was banned and further investigation into a possible organic cause for these symptoms was discontinued. Nevertheless, similar clinical entities, such as combat or battle fatigue and posttraumatic stress disorder, continue to be encountered by combatants in subsequent military conflicts. To this day, there exists a paucity of neuropathology studies investigating the effects of high explosives on the human brain. By analogy, studies have recently revealed that athletes with repeated head trauma can develop a neurodegenerative disease, chronic traumatic encephalopathy, who present with similar clinical features. Given current circumstance, we propose completing the work envisioned by Dr Mott almost 100 years ago.

Neuropsychological outcomes of mild traumatic brain injury, post-traumatic stress disorder and depression in Iraq-deployed US Army soldiers

Authors: Vasterling JJ, Brailey K, Proctor SP, Kane R, Heeren T, Franz M.

BACKGROUND: Traumatic brain injury (TBI) is a concern of contemporary military deployments. Whether milder TBI leads to enduring impairment remains controversial.
AIMS: To determine the influence of deployment TBI, and post-traumatic stress disorder (PTSD) and depression symptoms on neuropsychological and functional outcomes.
METHOD: A sample of 760 US Army soldiers were assessed pre- and post-deployment. Outcomes included neuropsychological performances and subjective functional impairment.
RESULTS: In total, 9% of the participants reported (predominantly mild) TBI with loss of consciousness between pre- and post-deployment. At post-deployment, 17.6% of individuals with TBI screened positive for PTSD and 31.3% screened positive for depression. Before and after adjustment for psychiatric symptoms, TBI was significantly associated only with functional impairment. Both PTSD and depression symptoms adjusted for TBI were significantly associated with several neuropsychological performance deficits and functional impairment.
CONCLUSIONS: Milder TBI reported by deployed service members typically has limited lasting neuropsychological consequences; PTSD and depression are associated with more enduring cognitive compromise.

Abnormal whole-brain functional networks in homogeneous acute mild traumatic brain injury

Authors: Shumskaya E, Andriessen TM, Norris DG, Vos PE.

OBJECTIVES: To evaluate the whole-brain resting-state networks in a homogeneous group of patients with acute mild traumatic brain injury (MTBI) and to identify alterations in functional connectivity induced by MTBI.
METHODS: Thirty-five patients with acute MTBI and 35 healthy control subjects, matched in age, gender, handedness, and education, underwent resting-state fMRI, susceptibility weighted imaging, neuropsychological, and postconcussive symptom assessments. We ensured the homogeneity of the patient group by limiting the injury mechanism to fronto-occipital impacts. Alterations in functional connectivity were analyzed by using data-driven independent component analysis, which is not biased by a priori region selection.
RESULTS: We found a decrease in functional connectivity within the motor-striatal network in the MTBI group. At the same time, patients showed deficits in psychomotor speed as well as in speed of information processing. We propose that although disorders in motor function after MTBI are rarely reported, injury still has an effect on motor functioning, which in its turn may also explain the reduction in speed of information processing. Further, we found a cluster of increased functional connectivity in the right frontoparietal network in the MTBI group. We suggest that this abnormal increased connectivity might reflect increased awareness to external environment and explain excessive cognitive fatigue reported by patients with MTBI. It might also underlie the physical postconcussive symptoms, such as headache and increased sensitivity to noise/light.
CONCLUSIONS: We proved that whole-brain functional connectivity is altered early (within 4 weeks) after MTBI, suggesting that changes in functional networks underlie the cognitive deficits and postconcussive complaints reported by patients with MTBI.

Effects of chronic mild traumatic brain injury on white matter integrity in Iraq and Afghanistan war veterans

Authors: Morey RA, Haswell CC, Selgrade ES, Massoglia D, Liu C, Weiner J, Marx CE, Cernak I, McCarthy G; MIRECC Work Group.

Mild traumatic brain injury (TBI) is a common source of morbidity from the wars in Iraq and Afghanistan. With no overt lesions on structural MRI, diagnosis of chronic mild TBI in military veterans relies on obtaining an accurate history and assessment of behavioral symptoms that are also associated with frequent comorbid disorders, particularly posttraumatic stress disorder (PTSD) and depression. Military veterans from Iraq and Afghanistan with mild TBI (n = 30) with comorbid PTSD and depression and non-TBI participants from primary (n = 42) and confirmatory (n = 28) control groups were assessed with high angular resolution diffusion imaging (HARDI). White matter-specific registration followed by whole-brain voxelwise analysis of crossing fibers provided separate partial volume fractions reflecting the integrity of primary fibers and secondary (crossing) fibers. Loss of white matter integrity in primary fibers (P < 0.05; corrected) was associated with chronic mild TBI in a widely distributed pattern of major fiber bundles and smaller peripheral tracts including the corpus callosum (genu, body, and splenium), forceps minor, forceps major, superior and posterior corona radiata, internal capsule, superior longitudinal fasciculus, and others. Distributed loss of white matter integrity correlated with duration of loss of consciousness and most notably with "feeling dazed or confused," but not diagnosis of PTSD or depressive symptoms. This widespread spatial extent of white matter damage has typically been reported in moderate to severe TBI. The diffuse loss of white matter integrity appears consistent with systemic mechanisms of damage shared by blast- and impact-related mild TBI that involves a cascade of inflammatory and neurochemical events. Hum Brain Mapp , 2012. © 2012 Wiley Periodicals, Inc.

Traumatic brain injury: special problem, special care

Author: Wick JY.

External physical insult, an accidental blow, acceleration followed by rapid deceleration, or explosive blasts can cause traumatic brain injury (TBI). During the last few years, experts have realized that even mild blows to the head can cause lasting damage. Better understanding of how TBI occurs has improved the probability of survival for those with the most serious injuries. Graded using the Glasgow Coma Scale, TBI may leave its sufferers awake, in periods of alertness interspersed with cognitive confusion, or deep in coma. Falls recently displaced motor vehicle accidents as the leading cause of TBI. Elders are at high risk for falls and TBI, and they may be unaware of possible lasting complications. Pharmacologic therapies for patients who have suffered TBI are, by necessity, individualized.

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