Journal of neurotrauma
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Journal of neurotrauma · Jul 2015
A Novel Preclinical Model of Moderate Primary Blast-Induced Traumatic Brain Injury.
Blast-induced traumatic brain injury (bTBI) is the "signature" injury of the recent Iraq and Afghanistan wars. Here, we present a novel method to induce bTBI using shock wave (SW) lithotripsy. Using a lithotripsy machine, Wistar rats (N = 70; 408.3 ± 93 g) received five SW pulses to the right side of the frontal cortex at 24 kV and a frequency of 60 Hz. ⋯ Median hemispheric differences for contrast peak values (obtained from DSA studies) for 24, 72, and 168 h endpoints were 3.45%, 3.05% and 0.2%, respectively, with statistically significant differences at 1 versus 7 d (p<0.05) and 3 versus 7 d (p<0.01). In this study, we successfully established a preclinical rat model of bTBI with characteristics similar to those observed in clinical cases. This new method may be useful for future investigations aimed at understanding bTBI pathophysiology.
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Journal of neurotrauma · Jul 2015
Static and Dynamic Intrinsic Connectivity following Mild Traumatic Brain Injury.
Mild traumatic brain injury (mTBI) is the most common neurological disorder and is typically characterized by temporally limited cognitive impairment and emotional symptoms. Previous examinations of intrinsic resting state networks in mTBI have primarily focused on abnormalities in static functional connectivity, and deficits in dynamic functional connectivity have yet to be explored in this population. Resting-state data was collected on 48 semi-acute (mean = 14 days post-injury) mTBI patients and 48 matched healthy controls. ⋯ Reduced (HC > mTBI patients) static connectivity was observed in the DMN at uncorrected (p < 0.005) thresholds. Finally, a trend (p = 0.07) for decreased dynamic connectivity in patients across all ICN was observed during spatially invariant analyses (DisCo-Z). In the semi-acute phase of recovery, mTBI was not reliably associated with abnormalities in static or dynamic functional connectivity within the DMN or sub-cortical structures.
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Journal of neurotrauma · Jul 2015
Associations between a history of traumatic brain injuries and current cigarette smoking, cannabis use, nonmedical opioid use, and elevated psychological distress in a population sample of Canadian adults.
This study describes the prevalence of reported history of traumatic brain injury (TBI) and its association with reports of current substance use, cigarette smoking, and psychological distress among Canadian adults in a population sample. A cross-sectional sample of 1999 Ontario adults 18-93 years of age were surveyed by telephone in 2011 as part of the Center for Addiction and Mental Health's ongoing representative survey of adult mental health and substance use in Ontario, Canada. Loss of consciousness for at least 5 min or at least one overnight hospitalization resulting from symptoms associated with the TBI injury represented minimum criteria for TBI. ⋯ Men had higher prevalence of TBI than women. Adults who reported a history of TBI had higher odds of reported past-year daily smoking (adjusted odds ratio [AOR] = 2.15), using cannabis (AOR = 2.80) and nonmedical opioids (AOR = 2.90), as well as screened significantly for recent elevated psychological distress (AOR = 1.97) in the past few weeks, compared to adults without a history of TBI. Co-occurrence of a history of TBI with current elevated psychological distress and substance use warrants vigilance among medical practitioners to assess the possibility of a history of TBI during reviews of the history leading to the occurrence of these conditions.
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Journal of neurotrauma · Jul 2015
The autonomic system functional state predicts responsiveness in DOC.
Diagnosis and early prognosis of the vegetative state/unresponsive wakefulness syndrome (VS/UWS) and its differentiation from the minimally-conscious state still rest on the clinical observation of responsiveness. The incidence of established clinical indicators of responsiveness also has proven variable in the single subject and is correlated to measures of heart rate variability (HRV) describing the sympathetic/parasympathetic balance. We tested responsiveness when the HRV descriptors nuLF and peakLF were or were not in the ranges with highest incidence of response based on findings from previous studies (10.0-70.0 and 0.05-0.11 Hz, respectively). ⋯ The observed incidence in the "response" condition (visual: 55.1%; auditory: 51.5%) was higher than predicted statistically (32.1%) or described in previous clinical studies; responses were only occasional in the "no-response" condition (visual, 15.9%; auditory, 13.4%). Models validated the predictability with high accuracy. The current clinical criteria for diagnosis and prognosis based on neurological signs should be reconsidered, including variability over time and the autonomic system functional state, which could also qualify per se as an independent indicator for diagnosis and prognosis.
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Journal of neurotrauma · Jul 2015
Moderate Hypothermia Significantly Decreases Hippocampal Cell Death Involving Autophagy Pathway after Moderate Traumatic Brain Injury.
Here, we evaluated changes in autophagy after post-traumatic brain injury (TBI) followed by moderate hypothermia in rats. Adult male Sprague-Dawley rats were randomly divided into four groups: sham injury with normothermia group (37 °C); sham injury with hypothermia group (32 °C); TBI with normothermia group (TNG; 37 °C); and TBI with hypothermia group (THG; 32 °C). Injury was induced by a fluid percussion TBI device. ⋯ Further, ultrastructural observations showed that there was a marked increase of autophagosomes and autolysosomes in ipsilateral hippocampus after post-TBI hypothermia. Our data demonstrated that moderate hypothermia significantly attenuated cell death and increased autophagy in ipsilateral hippocampus after fluid percussion TBI. In conclusion, autophagy pathway may participate in the neuroprotective effect of post-TBI hypothermia.