Studies in experimental spinal cord trauma

1974 ◽  
Vol 40 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Lynn S. Hedeman ◽  
M. Kent Shellenberger ◽  
J. H. Gordon
Keyword(s):  
Spinal Cord ◽  
Pilot Study ◽  
Spinal Cord Trauma ◽  
Significant Elevation ◽  
Small Pilot Study ◽  
Content Type ◽  
Essentially Normal ◽  
Before And After ◽  
Fine Print

✓ The authors report a study of levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT) in the traumatized spinal cords of dogs, and with alpha-mehtyltyrosine before and after injury. There was a significant elevation of DA 15 to 45 minutes after injury. NE was significantly reduced. Twenty-four hours of pretreatment with alpha-methyltyrosine depleted cord catecholamines and prevented trauma-induced DA elevation. Alpha-methyltyrosine given 15 minutes after the trauma did not prevent this trauma-related DA elevation. In a small pilot study in cats, DA was elevated and NE remained essentially normal.

Pathological findings in acute experimental spinal cord trauma

1971 ◽  
Vol 35 (6) ◽  
pp. 700-708 ◽  
Author(s):  
Thomas B. Ducker ◽  
Glenn W. Kindt ◽  
Ludwig G. Kempe
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Clinical Improvement ◽  
Spinal Cord Trauma ◽  
Pathological Findings ◽  
Pathological Changes ◽  
Content Type ◽  
Acute Trauma ◽  
Central Gray ◽  
Fine Print

✓ This study shows that spinal cord pathology secondary to acute trauma in monkeys evolves with stepwise sequential changes. The acute damage is more central than peripheral. Depending on the amount of trauma, the subacute damage may be limited to central gray necrosis or may progress or evolve to include the neighboring white matter. These pathological changes may be taking place even in the presence of clinical improvement.

The effect of norepinephrine on the spinal cord circulation and its possible implications in the pathogenesis of acute spinal trauma

1977 ◽  
Vol 47 (4) ◽  
pp. 567-576 ◽  
Author(s):  
Robert A. Crawford ◽  
Ian R. Griffiths ◽  
James McCulloch
Keyword(s):  
Spinal Cord ◽  
Bolus Injection ◽  
Spinal Injury ◽  
Spinal Cord Blood Flow ◽  
Arterial Infusion ◽  
Content Type ◽  
Barrier Disruption ◽  
Before And After ◽  
Hydrogen Clearance ◽  
Fine Print

✓ The effect of intra-arterially administered norepinephrine (NE) upon spinal cord blood flow (SCBF), before and after disruption of the blood-cord barrier was studied in dogs. Barrier disruption was accomplished with an intra-arterial bolus injection of 2.5 M urea. Multiple ligations of branches of the posterior aorta and cannula placements ensured that the urea was directed to the lumbar and sacral segments of the cord. The SCBF was measured by the hydrogen clearance method. Intra-arterial urea by itself had no significant effect on SCBF. The intra-arterial infusion of NE (12 µg/min and 30 µg/min) was without overall effect on SCBF. However, if the blood-cord barrier had been previously disrupted with hypertonic urea, both concentrations of NE resulted in large reductions in SCBF. No such reductions in SCBF were seen with blood-cord barrier disruption and NE if the animals had been pre-treated with the α-blocker, phenoxybenzamine (1.5 mg/kg). Some aspects of the possible involvement of NE in the pathophysiology of acute spinal injury are discussed.

Norepinephrine levels in experimental spinal cord trauma

1977 ◽  
Vol 46 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Stephen E. Rawe ◽  
Robert H. Roth ◽  
Margaret Boadle-Biber ◽  
William F. Collins
Keyword(s):  
Spinal Cord ◽  
Tyrosine Hydroxylase ◽  
Concentration Gradient ◽  
Neurological Function ◽  
Spinal Cord Tissue ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Spinal Cord Segment ◽  
Fine Print

✓ Levels of norepinephrine (NE) in the spinal cord tissue of nontraumatized cats are highest in the cervical and lumbar enlargements. A rather uniform but slightly increasing concentration gradient from cephalad to caudad is observed in the thoracic segments. A 500 gm-cm trauma at the T-5 or C-7 spinal cord segment did not demonstrate any significant increase in NE levels measured sequentially over a 4-hour period after trauma. Dopamine levels could not be detected in the nontraumatized or traumatized cat spinal cords. Four traumatized cats treated with alpha methyl tyrosine, a tyrosine hydroxylase inhibitor, and followed clinically for 5 months showed no improvement in neurological function when compared to untreated traumatized cats. This study does not support the norepinephrine hypothesis of experimental spinal cord trauma.

Reversible spinal cord trauma: a model for electrical monitoring of spinal cord function

1972 ◽  
Vol 36 (4) ◽  
pp. 402-406 ◽  
Author(s):  
Thomas J. Croft ◽  
Jerald S. Brodkey ◽  
Frank E. Nulsen
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Sensitive Indicator ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Cortical Evoked Potentials ◽  
Spinal Cord Damage ◽  
Sensory Transmission ◽  
Spinal Cord Function ◽  
Fine Print

✓ Cortical evoked potentials in anesthetized cats were recorded by a noninvasive averaging technique as a means of estimating spinal cord damage. Graded pressure on the spinal cord produced reversible blocking of these potentials. With this type of trauma, block of motor transmission through the cord paralleled the block of sensory transmission, and each seemed to be a sensitive indicator of spinal cord function. The possible use of such monitoring in anesthetized patients undergoing spinal operations is discussed.

Biogenic amine concentrations in traumatized spinal cords of cats

1974 ◽  
Vol 40 (1) ◽  
pp. 52-57 ◽  
Author(s):  
N. Eric Naftchi ◽  
Margaret Demeny ◽  
Vincent DeCrescito ◽  
John J. Tomasula ◽  
Eugene S. Flamm ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Biogenic Amines ◽  
Biogenic Amine ◽  
Sodium Succinate ◽  
Aminocaproic Acid ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Methyl Prednisolone ◽  
Epsilon Aminocaproic Acid ◽  
Fine Print

✓ Concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT), and histamine (HIST) were determined in spinal cords of five groups of cats. One group underwent laminectomy only; a second untreated group received a 400 gm-cm impact at the T-9 level. These were compared with three groups treated with epsilon aminocaproic acid (EACA), methyl prednisolone sodium succinate (MP), and a combination of EACA and MP after similar trauma. The biogenic amines were measured in three 1-cm segments of the cord, rostral, middle, and caudal, 1 hour after trauma. There was no change in NE concentration in any of the three segments after impact compared with laminectomized controls, nor was the NE concentration in the impacted (middle) area higher than that in the rostral or caudal sites. Although the NE content of the cord in treated animals decreased compared to that of laminectomized controls, the decrease was not significant. The concentration of DA, however, significantly increased after impact and significantly decreased after treatment with EACA and EACA plus MP. There was no significant change in 5-HT levels, but the level of HIST increased significantly after impact and was lowered by treatment with EACA and EACA with MP. The implications of these changes in biogenic amines in spinal cord trauma are discussed.

Value of normothermic perfusion, hypothermic perfusion, and durotomy in the treatment of experimental acute spinal cord trauma

1973 ◽  
Vol 39 (1) ◽  
pp. 52-64 ◽  
Author(s):  
Charles H. Tator ◽  
Lüder Deecke
Keyword(s):  
Spinal Cord ◽  
Beneficial Effect ◽  
Cord Compression ◽  
Spinal Cord Trauma ◽  
Compression Force ◽  
Content Type ◽  
Hypothermic Perfusion ◽  
Normothermic Perfusion ◽  
Therapeutic Value ◽  
Fine Print

✓ Investigations were performed to determine the relative therapeutic value of local hypothermic perfusion, local normothermic perfusion, and durotomy in monkeys injured by circumferential compression of the spinal cord at T9–10. A new method of cord compression was used consisting of an inflatable Silastic cuff which was passed around the cord extradurally and inflated to either 350 or 400 mm Hg. At the lower compression force, both hypothermic and normothermic perfusion improved the neurological recovery compared to that in control animals. However, at the higher degree of compression only normothermic perfusion produced significantly better recovery. Durotomy was excluded as a contributing factor. The results indicate that normothermic perfusion is a better method of treatment and that the beneficial effect of hypothermic perfusion is probably due to the perfusion rather than the hypothermia. The mechanism by which perfusion exerts its beneficial effect is unknown, but it is suggested that dialysis of noxious substances from the injured cord may play a role.

Evoked cortical potentials in experimental spinal cord trauma

1973 ◽  
Vol 38 (3) ◽  
pp. 332-336 ◽  
Author(s):  
Charles M. D'Angelo ◽  
John C. VanGilder ◽  
Arthur Taub
Keyword(s):  
Spinal Cord ◽  
Evoked Potential ◽  
Tibial Nerve ◽  
Cervical Spinal Cord ◽  
Evoked Response ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Tibial Nerve Stimulation ◽  
Fine Print ◽  
Evoked Cortical Potentials

✓ The somatosensory cortical evoked response following tibial nerve stimulation was recorded for 4 hours in cats sustaining 100, 300, and 500 gm-cm impact injuries to the posterior thoracic, posterior cervical, and anterior cervical spinal cord. The return of the evoked response could be correlated with the severity of pathological damage to the spinal cord. The evoked potential returned almost immediately in animals sustaining only gray matter petechial hemorrhages, was delayed until 1 hour in animals with perigray white matter hemorrhages, and did not return at all in animals with central cavitation and posterior column fragmentation.

The H-reflex in experimental spinal cord trauma

1973 ◽  
Vol 39 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Charles M. D'Angelo
Keyword(s):  
Spinal Cord ◽  
Gray Matter ◽  
Stretch Reflex ◽  
H Reflex ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Hematoma Formation ◽  
Cervical Segment ◽  
Fine Print ◽  
Impact Injuries

✓ The H-reflex, the electrical correlate of the monosynaptic stretch reflex, recorded from the median nerve was monitored in cats sustaining controlled impact injuries to the eighth cervical segment of the spinal cord. The H-wave was unchanged in cats that showed only scattered gray matter petechial hemorrhages, whereas the H-wave could not be recorded in cats with central hematoma formation and central cavitation. With intermediate impact injuries that produced a coalescence of gray matter hemorrhages, the H-wave, although initially present, gradually diminished in amplitude and disappeared completely in approximately 2 hours.

Review of the effect of spinal cord trauma on the vessels and blood flow in the spinal cord

1976 ◽  
Vol 45 (6) ◽  
pp. 638-646 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Species Variation ◽  
Spinal Cord Trauma ◽  
Compression Injury ◽  
Content Type ◽  
Cord Injury ◽  
Fine Print

✓ The effect of spinal cord trauma on the vasculature and blood flow of the spinal cord is reviewed. Both quantitative and nonquantitative studies are critically discussed and reasons sought for some of the major controversies that have arisen. Differences in methodology, species variation, and variation in the degree and type of cord injury may all be important factors in producing the conflicting results reported in the literature. In general, it can be said that trauma has a profound effect on the vasculature and blood flow in the cord and that severe compression injury of the cord causes marked ischemia in the gray and white matter.

Electrospinogram and spinal and cortical evoked potentials in experimental spinal cord trauma

1975 ◽  
Vol 43 (6) ◽  
pp. 737-741 ◽  
Author(s):  
Glenn Morrison ◽  
Ronald J. Lorig ◽  
Jerald S. Brodkey ◽  
Frank E. Nulsen
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Spinal Cord Compression ◽  
Evoked Potential ◽  
Cord Compression ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Cortical Evoked Potentials ◽  
Acute Changes ◽  
Fine Print

✓ Studies in 28 traumatized cats showed the following acute changes after spinal cord compression in the cord segment below the trauma: 1) increase in size of the spinal cord evoked potential; 2) increase in size of the electrospinogram; and 3) increase in frequency of the electrospinogram.

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