Journal of neurotrauma
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Journal of neurotrauma · May 2016
Serial Diffusion Tensor imaging In Vivo Predicts Long-Term Functional Recovery in Rats Following Spinal Cord Injury.
The current study demonstrates the feasibility of using serial magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in vivo to quantify temporally spinal cord injury (SCI) pathology in adult female Sprague-Dawley rats that were scanned prior to a moderate or severe upper lumbar contusion SCI. Injured rats were behaviorally tested for hind limb locomotion (Basso, Beattie, Bresnahan [BBB] scores) weekly for 4 weeks and scanned immediately after each session, ending with terminal gait analyses prior to euthanasia. As a measure of tissue integrity, fractional anisotropy (FA) values were significantly lower throughout the spinal cord in both injury cohorts at all time-points examined versus pre-injury. ⋯ Critically, quantified FA values at subacute (24 h) and all subsequent time-points were highly predictive of terminal behavior, reflected in significant correlations with both weekly BBB scores and terminal gait parameters. Critically, the finding that clinically relevant subacute (24 h) FA values accurately predict long-term functional recovery may obviate long-term studies to assess the efficacy of therapeutics tested experimentally or clinically. In summary, this study demonstrates a reproducible serial MRI procedure to predict the long-term impact of contusion SCI on both behavior and histopathology using subacute DTI metrics obtained in vivo to accurately predict multiple terminal outcome measures, which can be particularly valuable when comparing experimental interventions.
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Journal of neurotrauma · May 2016
Chronic contusion spinal cord injury impairs ejaculatory reflexes in male rats: Partial recovery by systemic infusions of dopamine D3 receptor agonist 7OHDPAT.
Chronic spinal cord injury (SCI) causes major disruption of ejaculatory function in men. Ejaculation is a reflex and the spinal generator for ejaculatory reflexes in the rat has been located in the lumbosacral spinal cord. The effects of SCI on the rat spinal ejaculation generator and ejaculatory reflexes remain understudied. ⋯ Male rats received a contusion injury at T6-T7 and effects of systemic administration of 7OHDPAT (1 mg/kg) were tested 4-5 weeks following injury. Results showed that 7OHDPAT administration facilitated ejaculatory reflexes in SCI males with or without DPN stimulation, provided that supraspinal inputs to the lumbar cord were severed by transection just prior to evaluating the reflex. Thus, 7OHDPAT administration in SCI males was able to overcome the detrimental effects of SCI on ejaculatory reflexes.
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Journal of neurotrauma · May 2016
The Evolution of Posttraumatic Stress Disorder following Moderate to Severe Traumatic Brain Injury.
Increasing evidence indicates that post-traumatic stress disorder (PTSD) may develop following traumatic brain injury (TBI), despite most patients having no conscious memory of their accident. This prospective study examined the frequency, timing of onset, symptom profile, and trajectory of PTSD and its psychiatric comorbidities during the first 4 years following moderate-to-severe TBI. Participants were 85 individuals (78.8% male) with moderate or severe TBI recruited following admission to acute rehabilitation between 2005 and 2010. ⋯ The majority of subjects with PTSD experienced a chronic symptom course and all developed one or more than one comorbid psychiatric disorder, with mood, other anxiety, and substance-use disorders being the most common. Despite event-related amnesia, post-traumatic stress symptoms, including vivid re-experiencing phenomena, may develop following moderate-to-severe TBI. Onset is typically delayed and symptoms may persist for several years post-injury.
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Journal of neurotrauma · May 2016
Coated-platelet levels increase with number of injuries in patients with mild traumatic brain injury.
Coated-platelets are procoagulant platelets that are elevated in stroke and are associated with stroke recurrence. In a previous study, prompted by data showing an increased risk for stroke following traumatic brain injury (TBI), we found that coated-platelet levels are elevated in patients with combat-related mild TBI (mTBI) several years after the injury, compared with controls. We now investigate in an expanded patient population whether parameters commonly recorded in mTBI are related to increased coated-platelet potential. ⋯ A multi-variable linear model analysis, including these three parameters and an additional three parameters (race/ethnicity, smoking, and mechanism of injury) that reached a p value of <0.2, showed that the number of injuries were predictive of coated-platelet levels (p = 0.004). These results support a mechanistic link between increased coated-platelet levels and repeated injuries in mTBI. Long-term studies will be required to determine the impact of increased prothrombotic potential in mTBI patients.