Effect of aminophylline and isoproterenol on spinal cord blood flow after impact injury

1980 ◽  
Vol 53 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Diana Dow-Edwards ◽  
Vincent DeCrescito ◽  
John J. Tomasula ◽  
Eugene S. Flamm
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Adenosine Monophosphate ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury ◽  
Matter Flow

✓ A study of the effects of spinal cord injury upon spinal cord blood flow was carried out in cats. A 400 gm-cm impact produced an overall reduction in spinal cord blood flow of 24% in the white matter and 30% in the gray matter, as determined by 14C-antipyrine autoradiography. At the level of the injury, white-matter flow was 8.1 ml/100 gm/min, a reduction of 49%, and in the gray matter, 12.5 ml/100 gm/min, a reduction of 76%. Treatment with aminophylline and isoproterenol improved the overall blood flow in the spinal cord. At the level of the injury, white-matter flow after this treatment was no longer significantly different from control values. The gray-matter flow remained decreased to 26.2 ml/100 gm/min, a reduction of only 47%. It is proposed that aminophylline and isoproterenol may increase cyclic adenosine monophosphate (AMP) and prevent platelet aggregation along the endothelial surfaces of the microcirculation, and may thereby help to maintain improved perfusion of the injured spinal cord.

Effect of acute spinal cord compression injury on regional spinal cord blood flow in primates

1976 ◽  
Vol 45 (6) ◽  
pp. 660-676 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Regional Blood Flow ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury

✓ Spinal cord blood flow (SCBF) was measured in 24 rhesus monkeys after injury to the cord produced by the inflatable circumferential extradural cuff technique. Measurement of regional blood flow in the white and gray matter of the cord in areas of 0.1 sq mm was achieved with the 14C-antipyrine autoradiographic technique and a scanning microscope photometer. After moderate cord injury (400 mm Hg pressure in the cuff maintained for 5 minutes), which produced paraplegia in 50% of animals and moderate to severe paresis in the other 50%, mean white matter SCBF was significantly decreased for up to 1 hour. White matter blood flow then rose to normal levels by 6 hours posttrauma and was significantly increased by 24 hours posttrauma. Gray matter SCBF was significantly decreased for the entire 24-hour period post-trauma. After severe cord injury (150 mm Hg pressure in the cuff maintained for 3 hours), which produced total paraplegia in almost all animals, SCBF in white and gray matter was reduced to extremely low levels for 24 hours posttrauma. In addition, focal decreases in SCBF were seen in white and gray matter for considerable distances proximal and distal to the injury site. It is concluded that acute compression injury of the spinal cord is associated with long-lasting ischemia in the cord that increases in severity with the degree of injury.

Regional spinal cord blood flow in rats after severe cord trauma

1978 ◽  
Vol 49 (6) ◽  
pp. 844-853 ◽  
Author(s):  
Alex S. Rivlin ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Gray Matter ◽  
Albino Rats ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Compression Technique ◽  
Content Type ◽  
Cord Injury

✓ Spinal cord blood flow (SCBF) was measured in 12 albino rats following acute cord injury produced by the extradural clip compression technique. Severe injury was produced with the clip compressing the cord with a force of 180 gm for 5 minutes, an injury previously shown to produce a severe functional deficit. Regional SCBF was measured 15 minutes, 2 hours, and 24 hours after injury by the 14C-antipyrine autoradiographic technique and a scanning microscope photometer. At 15 minutes and 2 hours, white and gray matter blood flow was severely diminished, and, at 24 hours, there was only minimal improvement. Focal decreases in blood flow were seen in white and gray matter for a considerable distance proximal and distal to the site of cord trauma. Thus, it has been confirmed in this model that severe cord compression injury produces severe posttraumatic ischemia in the cord which lasts for at least 24 hours.

Effects of anesthesia and laminectomy on regional spinal cord blood flow in conscious sheep

1981 ◽  
Vol 54 (5) ◽  
pp. 620-626 ◽  
Author(s):  
J. Robert S. Hales ◽  
John D. Yeo ◽  
Stefanie Stabback ◽  
Alan A. Fawcett ◽  
Raymond Kearns
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Sodium Pentobarbital ◽  
Spinal Cord Blood Flow ◽  
Regional Variations ◽  
Content Type ◽  
Conscious Sheep

✓ Blood flow for the whole spinal cord (SCBF), central cord (largely gray matter), and peripheral cord (largely white matter) has been measured at all segmental levels using radioactive microspheres in conscious sheep. Whole SCBF was greatest in the lower cervical and lumbar enlargements and least in the upper cervical and thoracic regions. This was attributable partly to regional variations in gray-matter blood flow but principally to regional variations in the proportion of gray and white matter present. Whole SCBF for the total cord was 14.5 ± 0.8 ml/100 gm/min, central cord flow was 40.6 ± 3.5 ml/100 gm/min, and peripheral cord flow was 9.7 ± 1.9 ml/100 gm/min. Blood flow was not affected by sodium pentobarbital provided the level of anesthesia, arterial pressure, and blood gases was carefully regulated. Laminectomy usually resulted in a marked increase in central cord blood flow at the site of cord exposure, lasting about 90 minutes; this increase was not necessarily reflected in whole SCBF because of the absence of any change in blood flow in the relatively large proportion of peripheral cord. This effect of laminectomy could adversely influence results obtained from studies using invasive techniques to measure SCBF.

Spinal Cord Blood Flow in Experimental Transient Traumatic Paraplegia

1980 ◽  
Vol 52 (3) ◽  
pp. 335-345 ◽  
Author(s):  
Dean C. Lohse ◽  
Howard J. Senter ◽  
John S. Kauer ◽  
Richard Wohns
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Spinal Cord Blood Flow ◽  
Flow Measurements ◽  
Content Type ◽  
The Mean ◽  
Blood Flow Measurements ◽  
Fine Print

✓ Blood flow in the lateral funiculus of the thoracic spinal cord was measured in 24 anesthetized cats using the hydrogen clearance method. In a control series of eight nontraumatized animals, blood flow measurements were taken from the T-5 and T-6 segments for 6 consecutive hours. The mean spinal cord blood flow (SCBF) in the control group was 12.8 ± 3.51 (SD) ml/min/100 gm on the basis of 107 measurements over 6 hours. In the experimental groups, 16 animals were similarly prepared. The spinal cords of these animals were then traumatized by dropping a 20-gm weight 5 cm (100 gm-cm trauma) or 13 cm (260 gm-cm trauma) onto the T-5 segment. Previous experiments have shown that these trauma levels lead to a transient paraplegia of less than 10 and 30 days' duration, respectively. Two hundred blood flow measurements from T-5 and T-6 were taken over the 6 hours following trauma. In the seven animals of the 100 gm-cm group, mean SCBF after trauma from the T-5 segment was 12.6 ± 3.45 (SD) ml/min/100 gm on the basis of 50 measurements taken over 6 hours; not significantly different from the controls (p > 0.70). In the 260 gm-cm group, mean SCBF from T-5 for 6 hours after trauma was 17.3 ± 6.60 (SD) ml/min/100 gm; significantly higher than controls (p < 0.001). Mean SCBF 3 to 6 hours after trauma was significantly elevated over controls (p < 0.05). The mean hyperemia in the 260 gm-cm group was found to be due to marked hyperemia in only four animals of the series, while five animals maintained blood flows in the normal range. This experiment provides quantitative evidence that white matter ischemia does not occur in spinal cord injuries that can be expected to produce only transient paraplegia. The data support the concept that white matter ischemia in the acute phase of severe spinal cord trauma may be related to secondary injury and subsequent permanent paraplegia.

Spinal Cord Blood Flow in the Rat under Normal Physiological Conditions

Neurosurgery ◽  
1990 ◽  
Vol 27 (6) ◽  
pp. 882-886 ◽  
Author(s):  
Avraham Rubinstein ◽  
Ehud Arbit
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Spinal Cord Blood Flow ◽  
Passive Flow ◽  
Blood Pressure Range ◽  
Hydrogen Clearance

Abstract Regional spinal cord blood flow (SCBF) was measured in a group of rats under conditions of normothermia, normocarbia, normoxia, and normal blood pressure, using the hydrogen clearance technique. Regional SCBF in the cervical white matter was 26.8 ± 1 (SE) ml/100 g/min and in the cervical gray matter 53.6 ± 2.5; in the thoracic white matter it was 22.2 ± 2.4 ml/100 g/min and in the thoracic gray matter 41.2 ± 12/6 ml/100 g/min; and in the lumbar gray matter it was 52.3 ± 1.9 ml/100 g/min. The effect of changes in blood pressure on SCBF (autoregulation) was investigated in nine rats. We have observed that SCBF remains relatively constant in the blood pressure range of 45 to 165 mm Hg and assumes a passive flow below or above this range.

The effect of spinal distraction on regional spinal cord blood flow in cats

1980 ◽  
Vol 53 (6) ◽  
pp. 756-764 ◽  
Author(s):  
Eugen J. Dolan ◽  
Ensor E. Transfeldt ◽  
Charles H. Tator ◽  
Edward H. Simmons ◽  
Kenneth F. Hughes
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cord Blood ◽  
Spinal Cord Injuries ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury ◽  
Autoradiographic Technique ◽  
Fine Print

✓ Distraction is considered to be a factor in many spinal cord injuries. With a specially designed distraction apparatus and the 14C-antipyrine autoradiographic technique, the effect of distraction on spinal cord blood flow (SCBF) in cats was studied. Distraction was performed at L2–3 at a rate of 0.25 cm/10 min, and the spinal evoked response (SER) was monitored by stimulating the sciatic nerve and recording at T-13. The SCBF was assessed in five control animals, four animals in whom the SER was markedly altered by distraction, and five animals after the SER had been abolished and an additional 0.5 cm distraction applied. Control cats had gray- and white-matter flows of 44.5 ± 1.4 (SEM) and 10.5 ± 0.4 ml/100 gm/min, respectively. Distraction to the point of marked SER alteration caused a 50% loss of SCBF at and caudal to the distraction site. An additional 0.5 cm distraction produced total abolition of SCBF at the distraction site and for a considerable distance rostral and caudal to it. Thus, it is shown that spinal distraction causes cord ischemia similar to that seen with other types of spinal cord injury. In addition, distraction severe enough to cause loss of the SER has already produced severe cord ischemia.

Review of the secondary injury theory of acute spinal cord trauma with emphasis on vascular mechanisms

1991 ◽  
Vol 75 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Charles H. Tator ◽  
Michael G. Fehlings
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cord Blood ◽  
Volume Expansion ◽  
Acute Spinal Cord Injury ◽  
Secondary Injury ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury

✓ In patients with spinal cord injury, the primary or mechanical trauma seldom causes total transection, even though the functional loss may be complete. In addition, biochemical and pathological changes in the cord may worsen after injury. To explain these phenomena, the concept of the secondary injury has evolved for which numerous pathophysiological mechanisms have been postulated. This paper reviews the concept of secondary injury with special emphasis on vascular mechanisms. Evidence is presented to support the theory of secondary injury and the hypothesis that a key mechanism is posttraumatic ischemia with resultant infarction of the spinal cord. Evidence for the role of vascular mechanisms has been obtained from a variety of models of acute spinal cord injury in several species. Many different angiographic methods have been used for assessing microcirculation of the cord and for measuring spinal cord blood flow after trauma. With these techniques, the major systemic and local vascular effects of acute spinal cord injury have been identified and implicated in the etiology of secondary injury. The systemic effects of acute spinal cord injury include hypotension and reduced cardiac output. The local effects include loss of autoregulation in the injured segment of the spinal cord and a marked reduction of the microcirculation in both gray and white matter, especially in hemorrhagic regions and in adjacent zones. The microcirculatory loss extends for a considerable distance proximal and distal to the site of injury. Many studies have shown a dose-dependent reduction of spinal cord blood flow varying with the severity of injury, and a reduction of spinal cord blood flow which worsens with time after injury. The functional deficits due to acute spinal cord injury have been measured electrophysiologically with techniques such as motor and somatosensory evoked potentials and have been found proportional to the degree of posttraumatic ischemia. The histological effects include early hemorrhagic necrosis leading to major infarction at the injury site. These posttraumatic vascular effects can be treated. Systemic normotension can be restored with volume expansion or vasopressors, and spinal cord blood flow can be improved with dopamine, steroids, nimodipine, or volume expansion. The combination of nimodipine and volume expansion improves posttraumatic spinal cord blood flow and spinal cord function measured by evoked potentials. These results provide strong evidence that posttraumatic ischemia is an important secondary mechanism of injury, and that it can be counteracted.

Regional spinal cord blood flow in primates

1976 ◽  
Vol 45 (6) ◽  
pp. 647-659 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Gray Matter ◽  
Mean Value ◽  
Spinal Cord Blood Flow ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Arterial Blood ◽  
Thoracic Spinal

✓ Spinal cord blood flow (SCBF) was measured in the primate thoracic spinal cord using the 14C-antipyrine autoradiographic technique that allowed clear differentiation between white and gray matter blood flow. Individual SCBF values were obtained for 0.1-sq mm areas of the thoracic cord cross section. White matter blood flow was homogeneous throughout with a mean value of 10.3 ± 0.2 ml/100 gm/min. Graymatter flow was more variable with lower values in the dorsal horns and higher values in the central gray and anterior horns. Mean gray-matter flow was 57.6 ± 2.3 ml/100 gm/min. Arterial pO2 was 123 ± 2 torr, pCO2 was 40.2 ± 0.5 torr and pH was 7.327 ± 0.010. Mean arterial blood pressure was 113 ± 3 mm Hg and core temperature was 36.4° ± 0.1° C.

Comparison of hydrogen clearance and 14C-antipyrine autoradiography in the measurement of spinal cord blood flow after severe impact injury

1980 ◽  
Vol 52 (6) ◽  
pp. 801-807 ◽  
Author(s):  
David F. Cawthon ◽  
Howard J. Senter ◽  
William B. Stewart
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Flow Patterns ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Thoracic Cord ◽  
Impact Injury ◽  
Hydrogen Clearance

✓ Spinal cord blood flow was measured by two different techniques in normal and traumatized cat spinal cord. Flow was measured in the thoracic cord after severe (500 gm-cm) impact injury at T-6. Blood flow was measured sequentially at two sites for 7 hours after trauma using the hydrogen clearance technique, and spatially at many sites but at selected times by means of the 14C-antipyrine autoradiographic method. The two techniques gave similar results. Control white-matter blood flow in the lateral funiculus was 11.13 ± 1.29 ml/min/100 gm in the hydrogen clearance series, and 11.07 ± 3.16 gm blood/min/100 gmin the antipyrine series. Following injury, blood flow remained in the control range until 1 hour after trauma, when ischemia became the major pattern. From 4 to 8 hours following trauma, several categories of flow patterns emerged. In one group of animals, white-matter blood flow returned to control levels at some points along the length of cord surveyed, but remained depressed at adjacent cord levels. In another category of animals, most sites in the white matter had flows approaching control levels by 7 to 8 hours. In yet another group, all sites examined, although a limited number, showed ischemia. In contrast, gray-matter ischemia appeared earlier (25% of control levels at 1 hour), had a sharper focus, and persisted in the period examined. The differences in blood flow between gray and white matter and the longitudinal variation in white-matter flow suggested that the hydrogen clearance method should be verified by autoradiography for accuracy of spatial flow patterns.

Spinal cord blood flow patterns in experimental traumatic paraplegia

1973 ◽  
Vol 38 (1) ◽  
pp. 52-58 ◽  
Author(s):  
George J. Dohrmann ◽  
Katherine M. Wick ◽  
Paul C. Bucy
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Flow Patterns ◽  
Circulation Time ◽  
Spinal Cord Blood Flow ◽  
Thioflavine S ◽  
Blood Flow Patterns

✓ Alterations in spinal cord blood flow patterns in experimental traumatic paraplegia were studied by using thioflavine S, a fluorescent dye that stains the endothelium of blood vessels. Feline spinal cords, exposed by laminectomy, were traumatized with a 400 gm-cm contusion, and a rapid intravenous injection of thioflavine S administered. The spinal cords were excised within one circulation time after the injection, and the resulting spinal cord sections were examined under ultraviolet light. As thioflavine S is a fluorescent substance that binds to the blood vessel walls and as the spinal cord was excised within one circulation time, it was possible to determine in which vessels blood was flowing at the time of injection. Control animals showed blood flow in all parts of the spinal cord. At 15 min postcontusion there was a marked decrease in the number of vessels perfused in the white matter; however, at 30 min many of the vessels had evidence of renewed blood flow. By 1 hr postcontusion the entire gray matter showed hemorrhagic infarction. The number of fluorescing vessels in the white matter decreased considerably between 1 and 8 hrs postcontusion. At 8 hrs the thioflavine S-stained vessels were limited to the peripheral half of the white matter; however, by 24 hrs most of the vessels again fluoresced, but the gray matter remained without perfusion. In this experimentally-produced lesion, the gray matter of the spinal cord was infarcted by 1 hr postcontusion; the white matter was ischemic between 1 and 8 hrs with resumed blood flow by 24 hrs.

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