Journal of neurotrauma
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Journal of neurotrauma · Jun 2014
Daily passive cycling attenuates the hyperexcitability and restores the responsiveness of the extensor monosynaptic reflex to quipazine in the chronic spinal transected rat.
Activity-based interventions such as locomotor training or passive cycling have a positive influence on the spinal circuitry and recovery following a spinal cord injury (SCI). The use of quipazine in combination with exercise training has demonstrated a greater functional recovery than has exercise training alone. However, the influence of exercise or training on the responsiveness of the spinal cord to quipazine has not been examined following a chronic spinal transection. ⋯ With daily passive cycling, the extensor MSR hyperexcitability was attenuated, and the MSR amplitude increased 72% following quipazine injection (p<0.004), which was comparable to the extensor MSR response (94%) in the control group. For both chronic spinal transection groups, the flexor MSR amplitudes were not altered following quipazine injection, whereas in the control group the flexor MSR amplitude increased 86% in response to quipazine (p<0.004). These results demonstrate that passive cycling attenuates the hyperreflexive response of the extensor MSR following a chronic SCI, and restores the MSR response to quipazine.
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Journal of neurotrauma · Jun 2014
Increased central arterial stiffness explains baroreflex dysfunction in spinal cord injury.
After cervical spinal cord injury (SCI), orthostatic hypotension and intolerance commonly ensue. The cardiovagal baroreflex plays an important role in the acute regulation of blood pressure (BP) and is associated with the onset of presyncope. The cardiovagal baroreflex is dysfunctional after SCI; however, this may be influenced by either increased stiffening of the arteries containing the stretch-receptors (which has been shown in SCI) or a more downstream neural mechanism (i.e., solitary nucleus, sinoatrial node). ⋯ Further, β-stiffness index was negatively related to reduced BRS in those with SCI when upright (R2=0.55; p<0.05), but not in able-bodied persons. Normalizing BP did not improve BRS or CCA stiffness. This study clearly shows that reduced BRS is closely related to increased arterial stiffness in the population with SCI.
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Journal of neurotrauma · Jun 2014
Restraints and peripheral nerve injuries in adult victims of motor vehicle crashes.
The pattern of injuries in restrained victims of motor vehicle crashes (MVCs) remains an issue of debate. We investigated the association of peripheral nerve injuries with the use of protective devices (seat belt and air bag) during MVCs. We performed a retrospective cohort study of 384,539 adult MVC victims who were registered in the National Trauma Data Bank (NTDB) between 2009 and 2011. ⋯ The location of the patient in the vehicle did not seem to affect the risk of peripheral nerve injury, with drivers demonstrating no association with nerve injuries (OR, 0.94; 95% CI, 0.87-1.02) in comparison with non-drivers. On the contrary, alcohol consumption was associated with increased incidence of peripheral nerve injuries (OR, 1.10; 95% CI, 1.01-1.20). In summary, restraint use was associated with decreased risk of peripheral nerve injury in MVC victims, after controlling for confounders.
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Despite an increased incidence of depression in patients after spinal cord injury (SCI), there is no animal model of depression after SCI. To address this, we used a battery of established tests to assess depression after a rodent contusion injury. Subjects were acclimated to the tasks, and baseline scores were collected before SCI. ⋯ Fluoxetine significantly decreased immobility in the forced swim test (FST) in depressed subjects identified with the equation. Subjects that were depressed and treated with saline displayed significantly increased immobility on the FST, relative to not depressed, saline-treated controls. These initial experiments validate our tests of depression, generating a powerful model system for further understanding the relationships between molecular changes induced by SCI and the development of depression.