Neurologic Injury (neurologic + injury)

Distribution by Scientific Domains

Selected Abstracts

Estrogen attenuated markers of inflammation and decreased lesion volume in acute spinal cord injury in rats

Eric Anthony Sribnick
Abstract Spinal cord injury (SCI) is a devastating neurologic injury with functional deficits for which the only currently recommended pharmacotherapy is high-dose methylprednisolone, which has limited efficacy. Estrogen is a multiactive steroid that has shown antiinflammatory and antioxidant effects, and estrogen may modulate intracellular Ca2+ and attenuate apoptosis. For this study, male rats were divided into three groups. Sham group animals received a laminectomy at T12. Injured rats received both laminectomy and 40 g · cm force SCI. Estrogen-group rats received 4 mg/kg 17,-estradiol (estrogen) at 15 min and 24 hr post-injury, and vehicle-group rats received equal volumes of dimethyl sulfoxide (vehicle). Animals were sacrificed at 48 hr post-injury, and 1-cm-long segments of the lesion, rostral penumbra, and caudal penumbra were excised. Inflammation was assessed by examining tissue edema, infiltration of macrophages/microglia, and levels of cytosolic and nuclear NF,B and inhibitor of kappa B (I,B,). Myelin integrity was examined using Luxol fast blue staining. When compared to sham, vehicle-treated animals revealed increased tissue edema, increased infiltration of inflammatory cells, decreased cytosolic levels of NF,B and I,B,, increased levels of nuclear NF,B, and increased myelin loss. Treatment of SCI rats with estrogen reduced edema and decreased inflammation and myelin loss in the lesion and penumbral areas, suggesting its potential as a therapeutic agent. Further work needs to be done, however, to elucidate the neuroprotective mechanism of estrogen. © 2005 Wiley-Liss, Inc. [source]

Delayed pharmacological pre-conditioning effect of mitochondrial ATP-sensitive potassium channel opener on neurologic injury in a rabbit model of spinal cord ischemia

Background: Diazoxide, pharmacological openers of mitochondrial ATP-sensitive potassium channels have been shown to induce early pre-conditioning in the spinal cord. Here, the authors investigated whether diazoxide also induce delayed pre-conditioning and thereby reduce neurologic complications using a rabbit model of spinal cord ischemia. Methods: Infrarenal blood flow was interrupted for 20 min in 21 rabbits. Non-treated control animals received no pre-treatment. Diazoxide (5 mg/kg) were given 48 h before 20 min ischemia in the 48-h DZ group, whereas 15-min DZ group received diazoxide (5 mg/kg) 15 min before 20-min ischemia. Neurological functions were evaluated using Johnson scores for 3 days after reperfusion, after which, spinal cords were procured for hematoxylin and eosin staining for cell counting. Results: Johnson scores revealed a marked improvement in both the diazoxide-treated groups vs. the non-treated control group at 3, 24, 48, and 72 h after reperfusion (P<0.01). The histologic changes were proportional to the Johnson scores, with better preservation of motor neuron numbers in the animals of the 48-h DZ and 15-min DZ group relative to the non-treated controls (81±12, 90±10, 50±23 motor neurons, respectively, P<0.01). No difference was found between the 48-h DZ group and 15-min DZ group with respect to the Johnson scores or neuron numbers. Conclusions: The study demonstrates that pre-treatment with diazoxide 48 h before ischemia, induce delayed pharmacological pre-conditioning, thereby significantly improving clinical neurologic scores and histologic findings in this animal model. [source]

Neuropathological changes in vibration injury: An experimental study

MICROSURGERY, Issue 1 2005
Hani S. Matloub M.D.
Vibration syndrome, a clinical condition arising from chronic use of vibrating tools, is associated with a spectrum of neurovascular symptoms. To date, only its vascular pathology has been extensively studied; we sought to determine what direct neurologic injury, if any, is caused by vibration. Hindlimbs of anesthetized rats were affixed to a vibrating platform 4 h a day for 7 days. Study animals were vibrated with set parameters for frequency, acceleration, velocity, and amplitude; control animals were not vibrated. On day 7, nerves were studied by light and electron microscopy. While light microscopy showed minimal histologic differences between vibrated (n = 12) and control (n = 12) nerves, electron microscopic changes were dramatic. Splitting of the myelin sheath and axonal damage (e.g., myelin balls and "finger ring") were consistently seen in both myelinated and nonmyelinated axons. Despite relatively short vibration, definite pathology was demonstrated, suggesting that vibration syndrome has a direct neurologic component. © 2005 Wiley-Liss, Inc. Microsurgery 25:71,75, 2005. [source]

Who Will Consent to Emergency Treatment Trials for Subarachnoid Hemorrhage?

Angela Del Giudice MD
Abstract Objectives:, Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disorder that still requires much clinical study. However, the decision to participate in a randomized clinical trial, particularly a neuroemergency trial, is a complex one. The purposes of this survey were to determine who would participate in a randomized clinical trial that intended to examine transfusion practices after SAH, to identify who could serve as potential proxy decision-makers, and to find which patient characteristics were associated with the decision to participate. Methods:, This was a cross-sectional study using a self-administered questionnaire, composed of a brief description of the proposed trial followed by questions about participation using a 5-point Likert scale. Information sought included potential decision-maker, demographic data, setting and reason for current health care access, and personal or family history of neurologic injury. Results:, Nine-hundred five subjects were enrolled during emergency department (ED) visits, office visits, hospital admissions, or online, during a 1-month period: 63% were women and 46% were white. Nonneurologic problems were the leading reason (90%) for health care access, but 45% had a personal or family history of neurologic injury. Overall, 54% (95% confidence interval [CI] = 51% to 57%) of subjects stated they would definitely or probably consent to participate. No subject characteristics were associated with this decision: age (p = 0.28), sex (p = 0.16), race/ethnicity (p = 0.07), education (p = 0.44), religion (p = 0.42), clinical setting (p = 0.14), reason for visit (p = 0.58), and/or history of neurologic injury (p = 0.33). The vast majority (88%) identified a family member as the proxy decision-maker, again without differences among groups. Conclusions:, Greater than half of respondents stated they would participate in a proposed emergency treatment trial for SAH. Our survey suggests that the decision to participate is highly individualized, because no demographic, pathologic, historical, or access-related predictors of choice were found. Educational materials designed for this type of trial would need to be broad-based. Family members should be considered as proxy decision-makers where permitted by federal and local regulations. [source]

Mechanical Ventilation Was Associated with Acidemia in a Case Series of Salicylate-poisoned Patients

Andrew I. Stolbach MD
Abstract Objectives:, Despite little empiric evidence, mechanical ventilation (MV) in the setting of salicylate poisoning is considered by many to be harmful. When salicylate-poisoned patients are ventilated at conventional settings, the respiratory alkalosis is abolished, more salicylate is able to pass into the central nervous system (CNS), and neurotoxicity worsens. The objective of this study was to identify a relationship between MV, acidosis, and outcome in salicylate-poisoned patients. Methods:, The authors electronically searched a poison control center (PCC) database (2001,2007) for patients with salicylate poisoning, defined as a serum concentration >50 mg/dL, who had MV listed as a therapy. For the 7-year study period, a total of 3,144 salicylate-poisoning cases were identified. Eleven patients met the inclusion criteria of having both salicylate concentrations >50 mg/dL and required MV; only 7 of them had post-MV data available. Results:, In all seven patients with post-MV blood gas data, the post-MV pH was <7.4. In five of six patients with recorded PCO2, the post-MV PCO2 was >50 mm Hg. Two of the seven patients in the study group died following intubation (two patients died within 3 hours [serum salicylate concentrations, 85 and 79 mg/dL, respectively]). Another patient sustained severe neurologic injury (serum salicylate concentration, 84 mg/dL). The other four patients were ultimately discharged home. In the three patients with the worst clinical outcome, deterioration was reported within hours of intubation. Conclusions:, Inadequate MV of patients with salicylate poisoning is associated with respiratory acidosis, acidemia, and clinical deterioration in this series of cases. This supports warnings about the danger of improper MV in patients with salicylate poisoning. A prospective study should be performed. [source]

Induced hypothermia following out-of-hospital cardiac arrest; initial experience in a community hospital

Brook D. Scott M.D.
Abstract Background Successful resuscitation from sudden cardiac death is frequently accompanied by severe and often fatal neurologic injury. Induced hypothermia (IH) may attenuate the neurologic damage observed in patients after cardiac arrest. Hypothesis This study examined a population of nonselected patients presenting to a community hospital following successful resuscitation of sudden cardiac death. We sought to determine whether a program of induced hypothermia would improve the clinical outcome of these critically ill patients. Methods We initiated a protocol of IH at the Oklahoma Heart Hospital in August of 2003. Study patients were consecutive adults admitted following successful resuscitation of out-of-hospital cardiac arrest. Moderate hypothermia was induced by surface cooling and maintained for 24 to 36 h in the Intensive Care Unit with passive rewarming over 8 h. Results Forty-nine patients who were resuscitated and had the return of spontaneous circulation completed the hypothermia protocol. The cause of cardiac arrest was acute myocardial infarction in 24 patients and cardiac arrhythmias in 19 patients. Nineteen patients (39%) survived and were discharged. Sixteen of the patients discharged had no or minimal residual neurologic dysfunction and 3 patients had clinically significant residual neurologic injury. Conclusion A program of induced hypothermia based in a community hospital is feasible, practical, and requires limited additional financial and nursing resources. Survival and neurologic recovery compare favorably with clinical trial outcomes. Copyright © 2006 Wiley Periodicals, Inc. Wiley Periodicals, Inc. [source]

Spectrum of outcome in infants with extreme neonatal jaundice

E Hankų
The increasing number of case reports on neurologic sequelae related to hyperbilirubinaemia may represent a re-emergence of kernicterus in the industrialized world. However, not much has been written about infants who survived extreme levels of serum bilirubin without neurologic damage. We present three cases of extreme neonatal hyperbilirubinaemia, all with peak serum bilirubin levels >600 mmol/L. Two of the infants developed neurologic sequelae, but the third infant did not. In contrast to the two with sequelae, the infant without sequelae was female, had a positive Coombs' test, less clinical signs compatible with bilirubin encephalopathy, and a shorter exposure to serum bilirubin values >400 mmol/L. Conclusion: The basic mechanism of bilirubin neurotoxicity remains unknown, and it is not clear why some infants do not develop neurologic injury at serum bilirubin levels at which others do. We speculate that a comparison between patients with sequelate and those without may yield important information. [source]