Differential effects of minocycline on microglial activation and neurodegeneration following closed head injury in the neonate rat.

The role of microglia in the pathophysiology of injury to the developing brain has been extensively studied. In children under the age of 4 who have sustained a traumatic brain injury (TBI), markers of microglial/macrophage activation were increased in the cerebrospinal fluid and were associated with worse neurologic outcome. Minocycline is an antibiotic that decreases microglial/macrophage activation following hypoxic-ischemia in neonatal rodents and TBI in adult rodents thereby reducing neurodegeneration and behavioral deficits. In study 1, 11-day-old rats received an impact to the intact skull and were treated for 3days with minocycline. Immediately following termination of minocycline administration, microglial reactivity was reduced in the cortex and hippocampus (p<0.001) and was accompanied by an increase in the number of fluoro-Jade B profiles (p<0.001) suggestive of a reduced clearance of degenerating cells; however, this effect was not sustained at 7days post-injury. Although microglial reactivity was reduced in the white matter tracts (p<0.001), minocycline treatment did not reduce axonal injury or degeneration. In the thalamus, minocycline treatment did not affect microglial reactivity, axonal injury and degeneration, and neurodegeneration. Injury-induced spatial learning and memory deficits were also not affected by minocycline. In study 2, to test whether extended dosing of minocycline may be necessary to reduce the ongoing pathologic alterations, a separate group of animals received minocycline for 9days. Immediately following termination of treatment, microglial reactivity and neurodegeneration in all regions examined were exacerbated in minocycline-treated brain-injured animals compared to brain-injured animals that received vehicle (p<0.001), an effect that was only sustained in the cortex and hippocampus up to 15days post-injury (p<0.001). Whereas injury-induced spatial learning deficits remained unaffected by minocycline treatment, memory deficits appeared to be significantly worse (p<0.05). Sex had minimal effects on either injury-induced alterations or the efficacy of minocycline treatment. Collectively, these data demonstrate the differential effects of minocycline in the immature brain following impact trauma and suggest that minocycline may not be an effective therapeutic strategy for TBI in the immature brain.

[Optimization of medical-diagnostic process in patients with traumatic brain injury during early rehabilitation].

The problem of cardiovascular disease and cancer, the effects of traumatic brain injury is now one of the major health and social problems. Every year in Ukraine registered 200 thousand cases of the victims of traumatic brain injury. Of these, 30% of people then have persistent signs of disability that results in a disability, sometimes painful existence the patient and his relatives. Therefore, in order to bring man back into society after a traumatic brain injury, to the rehabilitation phase of treatment, immediately after the stabilization of the patient.

Effects of mexiletine, ginkgo biloba extract (EGb 761), and their combination on experimental head injury.

Lipid peroxidation (LP) and brain edema are important factors that produce tissue damage in head injury. The purpose of this study was to investigate the effect of mexiletine, gingko biloba extract (EGb 761), and their combination on LP and edema after moderate head trauma. Forty rats were randomly and blindly divided into four groups of ten animals each: control group (bolus injection of physiological saline), mexiletine group (50 mg/kg per injection), EGb 761 group (30 mg/kg per injection), and mexiletine plus EGb 761 group (50 mg/kg and 30 mg/kg per injection, respectively). The injections were given intraperitoneally at 1 h, 9 h, and 17 h after trauma. Twenty-four hours after injury, the rats were killed, and malondialdehyde (MDA) levels and brain water content were determined. Rats treated with mexiletine, EGb 761, and mexiletine plus EGb 761 had significantly lower MDA levels than the control group (P<0.01). The lowest MDA levels were measured in the mexiletine plus EGb 761 group. However, there was no significant difference in brain water content between treated groups and the control group (P>0.05). These findings show the usefulness of mexiletine and its combination with EGb 761 as a cerebroprotective agent in this model of experimental head injury.

[Therapeutic value of antioxidants and calcium channel blockers in patients in the acute phase of closed head injuries]. / Terapijska vrijednost antioksidanasa i blokatora kalcijumski kanala kod bolesnika sa zatvorenom povredom glave u akutnoj fazi.

Knowing that uncontrolled calcium signalization with excessive production of reactive oxidative matters is present in case of neurotrauma, aim of the investigation was to establish therapeutic value of combined administration of antioxidants (AO) and calcium channel blockers (CCB) in patients with closed head injury (CHI). Investigation comprised 120 patients with CHI who received AO (vitamins C and E) parenterally during 10 days and CCB (nimodipine), and control group was comprised of 60 patients with CHI who did not receive these medicinals in therapeutic program. We have established the influence of the therapy on neurologic and functional deficiency and consciousness disorder, respectively. Results of the investigation confirmed better recovery of all three observed parameters (degree of neurologic deficiency, degree of functional deficiency and consciousness disorder) in a group of patients receiving AO and CCB, which was statistically significant. It can be concluded that the administration of AO and CCB in patients with CHI in the acute phase should be included into therapeutic program of this significant clinical syndrome.

Neuroprotective effects of MgSO4 and MgCl2 in closed head injury: a comparative phosphorus NMR study.

Previous studies have shown that free magnesium levels decline after traumatic brain injury and that magnesium salt administration improves posttraumatic outcome. These earlier studies, however, have been limited to models of injury that do not produce a significant degree of diffuse axonal injury and have used either MgSO4 or MgCl2 as the magnesium salt. The present study compares the neuroprotective efficacy of MgSO4 and MgCl2 in a severe model of diffuse axonal injury in rats using phosphorus nuclear magnetic resonance spectroscopy and the rotarod test to monitor effects on metabolism and neurologic outcome, respectively. Both MgSO4 and MgCl2 given as a bolus of 100 micromoles/kg at 30 min after severe, closed head injury significantly improved brain intracellular free magnesium concentration and neurologic outcome. These findings suggest that both salts penetrate the blood-brain barrier after brain trauma, enter injured tissue, and subsequently improve neurologic outcome.

[Neurochemical changes and current pharmacological approaches in craniocerebral trauma]. / Neurochemische Veränderungen und aktuelle pharmakologische Ansätze beim Schädel-Hirn-Trauma.

In recent years, our knowledge concerning pathophysiological changes in brain metabolism after traumatic brain injury (TBI) has greatly expanded. This, in turn, has enabled the development of specific pharmacological strategies for the supplementary treatment of brain-injured patients with the aim of reducing secondary brain damage. The present article focuses on the pathophysiology of TBI and the possibilities for pharmacological intervention. While some of the substances reviewed and presently used in the treatment of TBI, others are under experimental and clinical evaluation at different stages.

Zinc supplementation is associated with improved neurologic recovery rate and visceral protein levels of patients with severe closed head injury.

Sixty-eight patients were entered into a randomized, prospective, double-blinded controlled trial of supplemental zinc versus standard zinc therapy to study the effects of zinc supplementation on neurologic recovery and nutritional/metabolic status after severe closed head injury. One month after injury, the mortality rates in the standard zinc group and the zinc-supplemented group were 26 and 12%, respectively. Glasgow Coma Scale (GCS) scores of the zinc-supplemented group exceeded the adjusted mean GCS score of the standard group at day 28 (p = 0.03). Mean motor GCS score levels of the zinc-supplemented group were significantly higher on days 15 and 21 than those of the control group (p = 0.005, p = 0.02). This trend continued on day 28 of the study (p = 0.09). The groups did not differ in serum zinc concentration, weight, energy expenditure, or total urinary nitrogen excretion after hospital admission. Mean 24-h urine zinc levels were significantly higher in the zinc-supplemented group at days 2 (p = 0.0001) and 10 (p = 0.01) after injury. Mean serum prealbumin concentrations were significantly higher in the zinc-supplemented group (p = 0.003) at 3 weeks after injury. A similar pattern was found for mean serum retinol binding protein level (p = 0.01). A significantly larger number of patients in the standard zinc group had craniotomies for evacuation of hematoma; thus a bias may have been present. The results of this study indicate that zinc supplementation during the immediate postinjury period is associated with improved rate of neurologic recovery and visceral protein concentrations for patients with severe closed head injury.

A trial of the effect of nimodipine on outcome after head injury.

We performed a randomised prospective double blind trial to study the effect of the calcium antagonist nimodipine on the outcome of head injured patients. The subjects were not obeying commands at the time of entry to the study, within 24 hours of injury. One hundred and seventy-five patients received nimodipine IV, 2 mg per hour for up to 7 days and 176 received placebo. The two groups were well matched for important prognostic features. Six months after injury 93 (53%) of the nimodipine group and 86 (49%) of the control group had a favourable outcome (moderate/good recovery). The relative increase in favourable outcomes (8%) was not significant but is compatible (95% C.I.) with an increase in favourable outcomes in treated patients by 33% or a decrease by 12%. Nimodipine was well tolerated and there were few adverse reactions; means of systolic and diastolic blood pressures and the intracranial pressure did not differ between the groups. It is unlikely that nimodipine has a marked effect on outcome (ie an increase in favourable outcome of greater than 15%) after head injury of this severity but the study does not exclude a modest but clinically useful benefit.