Journal of neurotrauma
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Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). ⋯ Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7 rad/sec(2) and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.
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Journal of neurotrauma · Oct 2011
Intracranial pressure changes following traumatic brain injury in rats: lack of significant change in the absence of mass lesions or hypoxia.
Traumatic brain injury (TBI) often causes raised intracranial pressure (ICP), with >50% of all TBI- related deaths being associated with this increase in ICP. To date, there is no effective pharmacological treatment for TBI, partly because widely used animal models of TBI may not replicate many of the pathophysiological responses observed in humans, and particularly the ICP response. Generally, rodents are the animal of choice in neurotrauma research, and edema formation has been demonstrated in rat models; however, few studies in rats have specifically explored the effects of TBI on ICP. ⋯ At all other times, changes in CPP were the result of changes in MABP and not ICP. Our results suggest that rats may be able to compensate for the intracranial expansion associated with cerebral edema after TBI, and that they only develop a consistent post-traumatic increase in ICP in the presence of a mass lesion. Therefore, they are an inappropriate model for the investigation of ICP changes after TBI, and for the development of therapies targeting ICP.
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Journal of neurotrauma · Oct 2011
Decompressive craniectomy for elderly patients with traumatic brain injury: it's probably not worth the while.
Decompressive craniectomy (DC) has been regarded as an ultima ratio measure in the treatment of refractory intracranial hypertension after brain injury. Most discussion about its benefits is based on studies performed in patients who are <65 years of age. The aim of this study was to identify patients aged ≥66 years who underwent DC after traumatic brain injury (TBI), in order to assess patient outcome and to correlate the values of potential predictors of survival on prognosis. ⋯ Patients who survived had a higher mean post-resuscitation GCS score (p=0.02). Logistical regression analysis indicated post-resuscitation GCS score as the only independent predictive factor for outcome. None of the 22 patients with a post-resuscitation GCS score of 3-5 had a good outcome, 2/10 (20%) patients with a post-resuscitation GCS score of 6-8 and 6/12 patients (50%) with a post-resuscitation GCS score ≥9 had a good outcome.
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Journal of neurotrauma · Oct 2011
No evidence for a cumulative impact effect on concussion injury threshold.
Recent studies using a helmet-based accelerometer system (Head Impact Telemetry System [HITS]) have demonstrated that concussions result from a wide range of head impact magnitudes. Variability in concussion thresholds has been proposed to result from the cumulative effect of non-concussive head impacts prior to injury. We used the HITS to collect biomechanical data representing >100,000 head impacts in 95 high school football players over 4 years. ⋯ No differences were present in any impact history variable between the concussive and non-concussive high magnitude impacts. These analyses included the number of head impacts, cumulative HIT severity profile value, cumulative linear acceleration, and cumulative rotational acceleration during the same practice or game session, as well as over the 30 min and 1 week preceding these impacts. Our data do not support the proposal that impact volume or intensity influence concussion threshold in high school football athletes.