Effect of naloxone on posttraumatic ischemia in experimental spinal contusion

1981 ◽  
Vol 55 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Wise Young ◽  
Eugene S. Flamm ◽  
Harry B. Demopoulos ◽  
John J. Tomasula ◽  
Vincent DeCrescito
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Sensory Function ◽  
Thoracic Spinal Cord ◽  
Flow Rates ◽  
Content Type ◽  
Cord Injury ◽  
Fine Print

✓ The effect of naloxone on blood flow and somatosensory evoked potentials was studied in cats subjected to 400 gm-cm contusion injuries of the thoracic spinal cord. Eight cats were treated with 10 mg/kg naloxone 45 to 60 minutes after injury, 11 cats were given 10 ml of saline instead of naloxone, and six cats were neither injured nor treated. Hydrogen clearance was used to measure blood flow in the lateral white columns at the contusion site. Naloxone, given intravenously, significantly improved the blood flow rates in the lateral column white matter. At 2 hours after injury, the mean blood flow in the saline-treated cats fell to 50% (p < 0.01) of preinjury flow rates, whereas it increased 6% (p > 0.50) in naloxone-treated cats, and 12% (p > 0.50) in uninjured cats. At the 3rd hour after injury, the respective flows fell 47% (p < 0.01), and 6% (p > 0.50), and increased 15% (p > 0.50) of the preinjury flow rates. The naloxone-treated cats had striking preservation of sensory function and somatosensory evoked potentials at 24 hours after injury. At 24 hours, responses had returned in all the naloxone-treated cats and in only 11% of the saline-treated cats. The probability of this combination of events occurring by chance is 0.0030. The authors conclude that naloxone may be useful for the treatment of spinal cord injury. The mechanism of the effect is unknown.

Percutaneous flexible bipolar epidural neuroelectrode for spinal cord stimulation

1984 ◽  
Vol 60 (6) ◽  
pp. 1317-1319 ◽  
Author(s):  
Alfred G. Kaschner ◽  
Wilhelm Sandmann ◽  
Heinz Larkamp
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Epidural Space ◽  
Somatosensory Evoked Potentials ◽  
Spinal Cord Stimulation ◽  
Spinal Cord Ischemia ◽  
Aortic Occlusion ◽  
Content Type ◽  
Fine Print

✓ This article describes a new flexible bipolar neuroelectrode which is inserted percutaneously into the epidural space for segmental spinal cord stimulation. This electrode was used in experiments with dogs and monkeys for recording cortical somatosensory evoked potentials in order to identify intraoperative spinal cord ischemia during periods of aortic occlusion.

Spinal blood flow in 24-hour megadose glucocorticoid treatment in awake pigs

2003 ◽  
Vol 99 (3) ◽  
pp. 286-290
Author(s):  
Wolf R. Drescher ◽  
Karen P. Weigert ◽  
Mathias H. Bünger ◽  
Ebbe S. Hansen ◽  
Cody E. Bünger
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Body Weight ◽  
High Dose ◽  
Content Type ◽  
Significant Difference ◽  
Cord Injury ◽  
Methylprednisolone Treatment ◽  
Fine Print

Object. Because of the controversy regarding the benefits of 24-hour administration of methylprednisolone in patients with spinal cord injury (SCI), it is important to investigate its mechanism of action and side effects. This study was conducted to determine if high-dose methylprednisolone modulates neural and vertebral blood flow in an awake large-sized animal model without SCI. Methods. From a group of 18 immature female domestic pigs born to nine different litters, nine animals were randomly allocated to receive methylprednisolone treatment, whereas their nine female siblings served as controls. Drug or placebo was applied in a blinded fashion by a third person not involved in the study. The following treatment for SCI, as suggested by the North American Spinal Cord Injury Study, was administered to the awake pig: methylprednisolone (30 mg/kg of body weight) was infused into the jugular vein during a 15-minute period, followed by a 45-minute pause, and the infusion was maintained over a 23-hour period at a dose of 5.4 mg/kg body weight/hour. By means of the radioactive tracer microsphere technique, spinal cord blood flow (SCBF) was measured in the awake standing pig in the cerebrum, and in spinal gray and white matter, nerve roots, endplates, cancellous bone, cortical shell, and T12—L2 discs. Blood flow was measured before, 1 hour after initiation of infusion, and 24 hours postinfusion. Examination of blood flow in the neural and vertebral tissue samples, as well as of central hemodynamics, revealed no significant difference between the experimental and control groups, and this parity was maintained throughout the experimental phases. Conclusions. In the awake pig model, 24-hour methylprednisolone treatment does not modulate cerebral or SCBF, nor does it increase the risk for vertebral osteonecrosis by producing vertebral ischemia.

Evoked potentials from direct cerebellar stimulation for monitoring of the rodent spinal cord

1992 ◽  
Vol 76 (2) ◽  
pp. 280-291 ◽  
Author(s):  
R. John Hurlbert ◽  
Charles H. Tator ◽  
Michael G. Fehlings ◽  
Greg Niznik ◽  
R. Dean Linden
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Posterior Fossa ◽  
Evoked Potential ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Thoracic Spinal ◽  
Ventral Funiculus ◽  
Fine Print ◽  
Cerebellar Stimulation

✓ Although the assessment of spinal cord function by electrophysiological techniques has become important in both clinical and research environments, current monitoring methods do not completely evaluate all tracts in the spinal cord. Somatosensory and motor evoked potentials primarily reflect dorsal column and pyramidal tract integrity, respectively, but do not directly assess the status of the ventral funiculus. The present study was undertaken to evaluate the use of evoked potentials, elicited by direct cerebellar stimulation, in monitoring the ventral component of the rodent spinal cord. Twenty-nine rats underwent epidural anodal stimulation directly over the cerebellar cortex, with recording of evoked responses from the lower thoracic spinal cord, both sciatic nerves, and/or both gastrocnemius muscles. Stimulation parameters were varied to establish normative characteristics. The pathways conducting these “posterior fossa evoked potentials” were determined after creation of various lesions of the cervical spinal cord. The evoked potential recorded from the thoracic spinal cord consisted of five positive (P1 to P5) and five negative (N1 to N5) peaks. The average conduction velocity (± standard deviation) of the earliest wave (P1) was 53 ± 4 m/sec, with a latency of 1.24 ± 0.10 msec. The other components followed within 4 msec from stimulus onset. Unilateral cerebellar stimulation resulted in bilateral sciatic nerve and gastrocnemius muscle responses; there were no significant differences (p > 0.05) in the thresholds, amplitudes, or latencies of these responses elicited by right- versus left-sided stimulation. Recordings performed following creation of selective lesions of the cervical cord indicated that the thoracic response was carried primarily in the ventral funiculus while the sciatic and gastrocnemius responses were mediated through the dorsal half of the spinal cord. It is concluded that the posterior fossa evoked potential has research value as a method of monitoring pathways within the ventral spinal cord of the rat, and should be useful in the study of spinal cord injury.

Effects of epidural hypothermic saline infusion on locomotor outcome and tissue preservation after moderate thoracic spinal cord contusion in rats

2005 ◽  
Vol 2 (3) ◽  
pp. 308-318 ◽  
Author(s):  
Carlos E. Casas ◽  
Loren P. Herrera ◽  
Chad Prusmack ◽  
Gladys Ruenes ◽  
Alexander Marcillo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Gray Matter ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Treatment Groups ◽  
Thoracic Spinal ◽  
Cord Injury ◽  
Spinal Cord Contusion ◽  
Tissue Sparing ◽  
Fine Print

Object. Regionally delivered hypothermia has advantages over systemic hypothermia for clinical application following spinal cord injury (SCI). The effects of local hypothermia on tissue sparing, neuronal preservation, and locomotor outcome were studied in a moderate thoracic spinal cord contusion model. Methods. Rats were randomized to four treatment groups and data were collected and analyzed in a blinded fashion. Chilled saline was perfused into the epidural space 30 minutes postcontusion to achieve the following epidural temperatures: 24 ± 2.3°C (16 rats), 30 ± 2.4°C (13 rats), and 35 ± 0.9°C (13 rats). Hypothermia was continued for 3 hours when a 45-minute period of rewarming was instituted. In a fourth group a moderate contusion only was induced in 14 animals. Rectal (core) and T9–10 (epidural) temperatures were measured continuously. Locomotor testing, using the Basso-Beattie-Bresnahan (Ba-Be-Br) scale, was performed for 6 weeks, and rats were videotaped for subsequent analysis. The lesion/preserved tissue ratio was calculated throughout the entire lesion cavity and the total lesion, spinal cord, and spared tissue volumes were determined. The rostral and caudal extent of gray matter loss was also measured. At 6 weeks locomotor recovery was similar in all groups (mean Ba-Be-Br Scale scores 14.88 ± 3.71, 14.83 ± 2.81, 14.50 ± 2.24, and 14.07 ± 2.39 [p = 0.77] for all four groups, respectively). No significant differences in spared tissue volumes were found when control and treatment groups were compared, but gray matter preservation was reduced in the infusion-treated groups. Conclusions. Regional cooling applied 30 minutes after a moderate contusive SCI was not beneficial in terms of tissue sparing, neuronal preservation, or locomotor outcome. This method of cooling may reduce blood flow in the injured spinal cord and exacerbate secondary injury.

The effect of nimodipine and dextran on axonal function and blood flow following experimental spinal cord injury

1989 ◽  
Vol 71 (3) ◽  
pp. 403-416 ◽  
Author(s):  
Michael G. Fehlings ◽  
Charles H. Tator ◽  
R. Dean Linden
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Dextran 40 ◽  
Treatment Groups ◽  
Cord Injury ◽  
Fine Print

✓ There is evidence that posttraumatic ischemia is important in the pathogenesis of acute spinal cord injury (SCI). In the present study spinal cord blood flow (SCBF), measured by the hydrogen clearance technique, and motor and somatosensory evoked potentials (MEP and SSEP) were recorded to evaluate whether the administration of nimodipine and dextran 40, alone or in combination, could increase posttraumatic SCBF and improve axonal function in the cord after acute SCI. Thirty rats received a 53-gm clip compression injury on the cord at T-1 and were then randomly and blindly allocated to one of six treatment groups (five rats in each). Each group was given an intravenous infusion of one of the following over 1 hour, commencing 1 hour after SCI: placebo and saline; placebo and dextran 40; nimodipine 0.02 mg/kg and saline; nimodipine 0.02 mg/kg and dextran 40; nimodipine 0.05 mg/kg and saline; and nimodipine 0.05 mg/kg and dextran 40. The preinjury physiological parameters, including the SCBF at T-1 (mean ± standard error of the mean: 56.84 ± 4.51 ml/100 gm/min), were not significantly different (p > 0.05) among the treatment groups. Following SCI, there was a significant decrease in the SCBF at T-1 (24.55 ± 2.99 ml/100 gm/min; p < 0.0001) as well as significant changes in the MEP recorded from the spinal cord (MEP-C) (p < 0.0001), the MEP recorded from the sciatic nerve (MEP-N) (p < 0.0001), and the SSEP (p < 0.002). Only the combination of nimodipine 0.02 mg/kg and dextran 40 increased the SCBF at T-1 (43.69 ± 6.09 ml/100 gm/min; p < 0.003) and improved the MEP-C (p < 0.0001), MEP-N (p < 0.04), and SSEP (p < 0.002) following SCI. With this combination, the changes in SCBF were significantly related to improvement in axonal function in the motor tracts (p < 0.0001) and somatosensory tracts (p < 0.0001) of the cord. This study provides quantitative evidence that an increase in posttraumatic SCBF can significantly improve the function of injured spinal cord axons, and strongly implicates posttraumatic ischemia in the pathogenesis of acute SCI.

Combined medical and surgical treatment after acute spinal cord injury: results of a prospective pilot study to assess the merits of aggressive medical resuscitation and blood pressure management

1997 ◽  
Vol 87 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Fernando L. Vale ◽  
Jennifer Burns ◽  
Amie B. Jackson ◽  
Mark N. Hadley
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Bladder Function ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Arterial Blood ◽  
Thoracic Spinal ◽  
Cord Injury ◽  
Fine Print

✓ The optimal management of acute spinal cord injuries remains to be defined. The authors prospectively applied resuscitation principles of volume expansion and blood pressure maintenance to 77 patients who presented with acute neurological deficits as a result of spinal cord injuries occurring from C-1 through T-12 in an effort to maintain spinal cord blood flow and prevent secondary injury. According to the Intensive Care Unit protocol, all patients were managed by using Swan—Ganz and arterial blood pressure catheters and were treated with immobilization and fracture reduction as indicated. Intravenous fluids, colloid, and vasopressors were administered as necessary to maintain mean arterial blood pressure above 85 mm Hg. Surgery was performed for decompression and stabilization, and fusion in selected cases. Sixty-four patients have been followed at least 12 months postinjury by means of detailed neurological assessments and functional ability evaluations. Sixty percent of patients with complete cervical spinal cord injuries improved at least one Frankel or American Spinal Injury Association (ASIA) grade at the last follow-up review. Thirty percent regained the ability to walk and 20% had return of bladder function 1 year postinjury. Thirty-three percent of the patients with complete thoracic spinal cord injuries improved at least one Frankel or ASIA grade. Approximately 10% of the patients regained the ability to walk and had return of bladder function. As of the 12-month follow-up review, 92% of patients demonstrated clinical improvement after sustaining incomplete cervical spinal cord injuries compared to their initial neurological status. Ninety-two percent regained the ability to walk and 88% regained bladder function. Eighty-eight percent of patients with incomplete thoracic spinal cord injuries demonstrated significant improvements in neurological function 1 year postinjury. Eighty-eight percent were able to walk and 63% had return of bladder function. The authors conclude that the enhanced neurological outcome that was observed in patients after spinal cord injury in this study was in addition to, and/or distinct from, any potential benefit provided by surgery. Early and aggressive medical management (volume resuscitation and blood pressure augmentation) of patients with acute spinal cord injuries optimizes the potential for neurological recovery after sustaining trauma.

scholarly journals Electrophysiological outcomes after spinal cord injury

2008 ◽  
Vol 25 (5) ◽  
pp. E11 ◽  
Author(s):  
James Xie ◽  
Maxwell Boakye
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Motor Evoked Potential ◽  
H Reflex ◽  
Sensory Function ◽  
Reflex Modulation ◽  
Clinical Evaluations ◽  
Cord Injury

Electrophysiological measures can provide information that complements clinical assessments such as the American Spinal Injury Association sensory and motor scores in the evaluation of outcomes after spinal cord injury (SCI). The authors review and summarize the literature regarding tests that are most relevant to the study of SCI recovery—in particular, motor evoked potentials and somatosensory evoked potentials (SSEPs). In addition, they discuss the role of other tests, including F-wave nerve conductance tests and electromyography, sympathetic skin response, and the Hoffman reflex (H-reflex) test as well as the promise of dermatomal SSEPs and the electrical perceptual threshold test, newer quantitative tests of sensory function. It has been shown that motor evoked potential amplitudes improve with SCI recovery but latencies do not. Somatosensory evoked potentials are predictive of ambulatory capacity and hand function. Hoffman reflexes are present during spinal shock despite the loss of tendon reflexes, but their amplitudes increase with time after injury. Further, H-reflex modulation is reflective of changes in spinal excitability. While these tests have produced data that is congruent with clinical evaluations, they have yet to surpass clinical evaluations in predicting outcomes. Continuing research using these methodologies should yield a better understanding of the mechanisms behind SCI recovery and thus provide potentially greater predictive and evaluative power.

Tethered cervical spinal cord

1987 ◽  
Vol 67 (4) ◽  
pp. 600-602 ◽  
Author(s):  
Theodore W. Eller ◽  
Lawrence P. Bernstein ◽  
Richard S. Rosenberg ◽  
David G. McLone
Keyword(s):  
Spinal Cord ◽  
Young Adult ◽  
Evoked Potentials ◽  
Clinical Improvement ◽  
Somatosensory Evoked Potentials ◽  
Imaging Technique ◽  
Cervical Spinal Cord ◽  
Tethered Spinal Cord ◽  
Content Type ◽  
Fine Print

✓ A case of congenital tethered cervical spinal cord is presented in a young adult. Metrizamide computerized tomography was the most useful imaging technique for identifying the tethered spinal cord. Intraoperative somatosensory evoked potentials correlated well with clinical improvement following surgery.

Blood flow in normal and injured monkey spinal cord

1975 ◽  
Vol 43 (2) ◽  
pp. 162-171 ◽  
Author(s):  
W. George Bingham ◽  
Harold Goldman ◽  
Stewart J. Friedman ◽  
Sharon Murphy ◽  
David Yashon ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Gray Matter ◽  
Rhesus Monkeys ◽  
Time Intervals ◽  
Flow Rates ◽  
Content Type ◽  
Macaca Rhesus ◽  
Fine Print

✓ The authors used indicator fractionation techniques to determine blood flow in normal and bluntly traumatized spinal cords of Macaca rhesus monkeys. Normal flow rates were determined for several levels of spinal cord as well as differential values for white and gray matter from representative areas. Flow rates in traumatized tissue, obtained at several different time intervals up to 4 hours after injury, demonstrated marked differences in regional perfusion of the white matter and gray matter after trauma. Gray matter perfusion was nearly obliterated while white matter blood flow persisted and in fact was higher than uninjured controls. The findings do not support the concept of ischemia as a factor in white matter failure. If toxic pathobiochemical alterations are induced by trauma, it may be possible to reverse these changes by exploiting the preserved white matter blood flow for chemotherapeutic intervention.

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