Journal of neurotrauma
-
Journal of neurotrauma · May 2012
Comparative StudyDifferential effects of voluntary and forced exercise on stress responses after traumatic brain injury.
Voluntary exercise increases levels of brain-derived neurotrophic factor (BDNF) after traumatic brain injury (TBI) when it occurs during a delayed time window. In contrast, acute post-TBI exercise does not increase BDNF. It is well known that increases in glucocorticoids suppress levels of BDNF. ⋯ Forced exercise did not increase levels of BDNF in any group. It did, however, decrease hippocampal glucocorticoid receptors in the control group. The results suggest that exercise regimens with strong stress responses may not be beneficial during the early post-injury period.
-
Journal of neurotrauma · May 2012
Comparative StudyPrognostic value of diffusion tensor imaging parameters in severe traumatic brain injury.
Diffusion tensor imaging (DTI) has recently emerged as a useful tool for assessing traumatic brain injury (TBI). In this study, the prognostic value of the relationship between DTI measures and the clinical status of severe TBI patients, both at the time of magnetic resonance imaging (MRI), and their discharge to acute TBI rehabilitation, was assessed. Patients (n=59) admitted to the trauma center with severe closed head injuries were retrospectively evaluated after approval from the institution's institutional review board, to determine the prognostic value of DTI measures. ⋯ The inclusion of regional and global DTI measures improved the accuracy of prognostic models, when adjusted for admission GCS score and age (p<0.05). Whole brain white matter and regional DTI measures are sensitive markers of TBI, and correlate with neurological status both at MRI and discharge to rehabilitation. The addition of DTI measures adjusted for age, gender, and admission GCS score significantly improved prognostic models.
-
Journal of neurotrauma · May 2012
Trends in the incidence of physician-diagnosed mild traumatic brain injury among active duty U.S. military personnel between 1997 and 2007.
Mild traumatic brain injury (mTBI) has been described as the most common form of traumatic brain injury within military populations; however, few epidemiologic studies have examined incidence rates for mTBI in this population. The objective of this study was to examine trends in the incidence of mTBI among active-duty U. S. service members between 1997 and 2007. ⋯ Overall, for 2006-2007 versus 1997-2005, the rate ratio was 1.61 (95% CI 1.58,1.65). The greatest increase in the rate of mTBI was observed among those serving in Iraq, who experienced a 38.4% (95% CI 35.4%,41.1%) annual increase in new cases. The observed increase in the incidence of mTBI in this population has significant policy implications in terms of allocating appropriate health care resources.
-
Journal of neurotrauma · May 2012
Paroxysmal sympathetic hyperactivity after traumatic brain injury: clinical and prognostic implications.
A proportion of patients surviving severe traumatic brain injury (TBI) have symptoms suggestive of excessive sympathetic discharge, here termed paroxysmal sympathetic hyperactivity (PSH). The goals of this study were: (1) to describe the clinical associations and radiological findings of PSH, its incidence, and features in subjects with severe TBI in the intensive care unit (ICU); (2) to investigate the potential role of increased intracranial pressure in the pathogenesis of PSH; and (3) to determine the prognostic influence of PSH during the ICU stay, on discharge from the ICU, and at 12 months post-injury. A prospective cohort study was undertaken of all ICU admissions with severe TBI older than 14 years over an 18-month period. ⋯ At 1 year post-injury, 20% of this group demonstrated ongoing PSH episodes. Over 18 months, 10.1% of admissions following severe TBI demonstrated PSH features in ICU. Subjects with PSH had a longer ICU stay and higher rate of complications, although this did not appear to compromise their long-term neurological recovery.
-
Journal of neurotrauma · May 2012
Effect of blast exposure on the brain structure and cognition in Macaca fascicularis.
Blast injury to the brain is one of the major causes of death and can also significantly affect cognition and physical and psychological skills in survivors of blast. The complex mechanisms via which blast injury causes impairment of cognition and other symptoms are poorly understood. In this study, we investigated the effects of varying degrees of primary blast overpressure (BOP; 80 and 200 kPa) on the pathophysiological and magnetic resonance imaging (MRI) changes and neurocognitive performance as assessed by the monkey Cambridge Neuropsychological Test Automated Battery (mCANTAB) in non-human primates (NHP). ⋯ Increased apoptosis appeared to involve astrocytes and oligodendrocytes in the animals following blast exposure. The small sample size could have contributed to the non-significant outcome in cognitive performance post-blast and limited quantitative analyses. Nevertheless, the study has provided initial descriptive changes for establishing a primary BOP threshold for brain injury to serve as a useful platform for future investigations that aim to estimate brain injury potential and set safe limits of exposure.