Journal of neurotrauma
-
Journal of neurotrauma · Jan 2017
Hemolysed blood elicits - calcium antagonist and high CO2 reversible - constrictions via elevation of Ca2+ in isolated cerebral arteries.
During acute subarachnoid hemorrhage, blood is hemolyzed, which is followed by a significant cerebrovascular spasm resulting in a serious clinical condition. Interestingly, however, the direct vasomotor effect of perivascular hemolyzed blood (HB) has not yet been characterized, preventing the assessment of contribution of vasoconstrictor mechanisms deriving from brain tissue and/or blood and development of possible treatments. We hypothesized that perivascular HB reduces the diameter of the cerebral arteries (i.e., basilar artery [BA]; middle cerebral artery [MCA]) by elevating vascular tissue [Ca2+]i level. ⋯ After washout of HB, nitric oxide-mediated dilations remained significantly reduced compared to control. HB significantly increased the ratiometric Ca signal, which returned to control level after washout. In conclusion, perivascular hemolyzed blood elicits significant-nifedipine and high CO2 reversible-constrictions of isolated BAs and MCAs, primarily by increasing intracellular Ca2+, findings that can contribute to the refinement of local treatment of subarachnoid hemorrhage.
-
Journal of neurotrauma · Jan 2017
Comprehensive Profiling of Modulation of Nitric Oxide levels and Mitochondrial Activity in Injured Brain: An Experimental Study based on the Fluid Percussion Injury Model in Rats.
Nitric oxide (NO) has frequently been associated with secondary damage after brain injury. However, average NO levels in different brain regions before and after traumatic brain injury (TBI) and its role in post-TBI mitochondrial dysfunction remain unclear. In this comprehensive profiling study, we demonstrate for the first time that basal NO levels vary significantly in the healthy cortex (0.44 ± 0.04 μM), hippocampus (0.26 ± 0.03 μM), and cerebellum (1.24 ± 0.08 μM). ⋯ NO-mediated impairment of mitochondrial state 3 respiration dependent on complex I substrates was transient and confined to the ipsilateral cortex. Our results demonstrate that NO dynamics and associated effects differ in various regions of the injured brain. A potential association between the observed mitochondrial electron flow through complex I, but not complex II, and the modulation of TBI induced NO levels in different brain regions has to be prospectively analyzed in more detail.
-
Journal of neurotrauma · Jan 2017
Multicenter StudyNon-hospitalized patients with mild traumatic brain injury, the forgotten minority?
Non-hospitalized mild traumatic brain injury (mTBI) patients comprise a substantial part of the trauma population. For these patients, guidelines recommend specialized follow-up only in the case of persistent complaints or problems in returning to previous activities. This study describes injury and outcome characteristics of non-hospitalized mTBI patients, and the possibility of predicting which of the non-hospitalized patients will return to the outpatient neurology clinic. ⋯ Twenty-five percent of the non-hospitalized patients returned to the outpatient neurology clinic within 6 months after injury, of which one third had not completely resumed pre-injury activities. Regression analyses showed an increased risk for outpatient follow-up for patients scoring above the cutoff value for anxiety (odds ratio [OR] = 3.0), depression (OR = 3.5), or both (OR = 3.7) 2 weeks after injury. Our findings underline that clinicians and researchers should be aware of recovery for all mTBI patients, preventing their transition into a forgotten minority.
-
Journal of neurotrauma · Jan 2017
Review Meta AnalysisSystematic review and meta-analysis: Is pre-injury antiplatelet therapy associated with traumatic intracranial hemorrhage?
The objective of this systematic review and meta-analysis is to evaluate whether the pre-injury use of antiplatelet therapy (APT) is associated with increased risk of traumatic intracranial hemorrhage (tICH) on CT scan. PubMed, Medline, Embase, Cochrane Central, reference lists, and national guidelines on traumatic brain injury were used as data sources. Eligible studies were cohort studies and case-control studies that assessed the relationship between APT and tICH. ⋯ The results were robust to sensitivity analysis on study quality. In summary, APT in patients with head injury is associated with increased risk of tICH; this association is most relevant in patients with mTBI. Whether this association is the result of a causal relationship and whether this relationship also exists for patients receiving aspirin monotherapy cannot be established with the current review and meta-analysis.