Preserved autoregulation in the rhesus spinal cord after high cervical cord section

1976 ◽  
Vol 44 (4) ◽  
pp. 425-428 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Thomas F. Doyle ◽  
Norwyn Newby ◽  
Hugo V. Rizzoli

✓ The authors studied the effect of high cervical cord section on the phenomenon of autoregulation in the rhesus monkey with the hydrogen clearance method to measure focal spinal cord blood flow (SCBF). Laminectomies were performed at T7–11 and C1–2. The spinal cord was completely severed at C1–2. Under normocapnic conditions, SCBF was then measured in the thoracic spinal cord over a wide range of blood pressures (MAP). The MAP was either lowered by bleeding or raised by the intravenous infusion of angiotensin. Autoregulation was found to be intact between 50 and 125 mm Hg, following a pattern similar to the one observed in the intact animal.

1977 ◽  
Vol 46 (3) ◽  
pp. 336-341 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Delbert E. Evans ◽  
Hugo V. Rizzoli

✓ Spinal cord blood flow (SCBF) was measured over a wide range of artificially varied mean systemic arterial blood pressures (MAP) in a group of monkeys with alpha adrenergic receptors blocked by the intravenous administration of phenoxybenzamine (Dibenzyline). The SCBF was found to vary linearly with changes in MAP. Autoregulation appeared to have been abolished. These data are cited as evidence for a dominant role of the sympathetic nervous system in control of the spinal circulation.


1976 ◽  
Vol 45 (6) ◽  
pp. 647-659 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator

✓ 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.


1998 ◽  
Vol 89 (4) ◽  
pp. 659-666 ◽  
Author(s):  
Francesco M. Salpietro ◽  
Concetta Alafaci ◽  
Olga Gervasio ◽  
Giovanni La Rosa ◽  
Ambrogia Baio ◽  
...  

✓ Primary intramedullary melanoma is a very rare tumor that occurs most frequently in the middle or lower thoracic spinal cord. The authors present a case of primary cervical cord melanoma that developed in a 62-year-old man who was surgically treated and subsequently underwent radiation therapy. Clinical and histogenetic features of this neoplasm and results of chemo-, radio-, and immunotherapy are reported. Both “dysembryogenetic” and “mesodermal” hypotheses on the origin of primary spinal melanoma are discussed.


1976 ◽  
Vol 44 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Thomas F. Doyle ◽  
Hugo V. Rizzoli

✓ The authors used the hydrogen clearance method to measure focal spinal cord blood flow (SCBF) in the rhesus monkey over a wide range of mean arterial blood pressures (MAP) in an attempt to test the hypothesis of autoregulation. The MAP was either lowered by bleeding or raised by the intravenous infusion of norepinephrine or angiotensin. The SCBF remained constant and in the normal range with an MAP of 50 to 135 mm Hg, indicating the presence of autoregulation. Below 50 mm Hg, SCBF fell passively with further decreases in MAP. At MAP values above 135 mm Hg, vasodilatation occurred which resulted in a breakthrough of autoregulation and marked increases in SCBF with further increases in the MAP.


2004 ◽  
Vol 1 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Ryder Gwinn ◽  
Fraser Henderson

✓ Anterior spinal cord herniation is a well-documented condition in which the thoracic cord becomes tethered within a defect in the anterior dura mater. Typical procedures have involved a posterior approach with direct manipulation of the thoracic cord to expose and blindly release its point of tethering. The authors report three cases in which a novel approach for the treatment of anterior thoracic cord herniation was performed, cord manipulation and traction are minimized, and direct dural repair of the defect is performed.


1991 ◽  
Vol 75 (6) ◽  
pp. 911-915 ◽  
Author(s):  
Thomas H. Milhorat ◽  
David E. Adler ◽  
Ian M. Heger ◽  
John I. Miller ◽  
Joanna R. Hollenberg-Sher

✓ The pathology of hematomyelia was examined in 35 rats following the stereotactic injection of 2 µl blood into the dorsal columns of the thoracic spinal cord. This experimental model produced a small ball-hemorrhage without associated neurological deficits or significant tissue injury. Histological sections of the whole spinal cord were studied at intervals ranging from 2 hours to 4 months after injection. In acute experiments (2 to 6 hours postinjection), blood was sometimes seen within the lumen of the central canal extending rostrally to the level of the fourth ventricle. Between 24 hours and 3 days, the parenchymal hematoma became consolidated and there was an intense proliferation of microglial cells at the perimeter of the lesion. The cells invaded the hematoma, infiltrated its core, and removed erythrocytes by phagocytosis. Rostral to the lesion, the lumen of the central canal was found to contain varying amounts of fibrin, proteinaceous material, and cellular debris for up to 15 days. These findings were much less prominent in the segments of the canal caudal to the lesion. Healing of the parenchymal hematoma was usually complete within 4 to 6 weeks except for residual hemosiderin-laden microglial cells and focal gliosis at the lesion site. It is concluded that the clearance of atraumatic hematomyelia probably involves two primary mechanisms: 1) phagocytosis of the focal hemorrhage by microglial cells; and 2) drainage of blood products in a rostral direction through the central canal of the spinal cord.


1978 ◽  
Vol 48 (6) ◽  
pp. 1002-1007 ◽  
Author(s):  
Stephen E. Rawe ◽  
William A. Lee ◽  
Phanor L. Perot

✓ The early sequential histopathological alterations following a concussive paraplegic injury to the posterior thoracic spinal cord in cats were studied. The lack of significant progression of hemorrhages over a 4-hour period after injury indicates that most hemorrhages probably occur within the first hour. The marked enhancement or retardation of hemorrhages in the post-injury period, when the blood pressure was increased or decreased, respectively, demonstrates the loss of autoregulation of spinal cord vasculature at the trauma site after a concussive paraplegic injury. Progressive edema formation was evident over a 4-hour period following injury, and it could be enhanced or retarded by elevation or reduction of the systemic blood pressure.


1984 ◽  
Vol 61 (4) ◽  
pp. 761-766 ◽  
Author(s):  
Michael Salcman ◽  
Ernesto Botero ◽  
Krishna C. V. Rao ◽  
Richard D. Broadwell ◽  
Eric Scott

✓ The development of a transplantable model brain tumor in the neonatal dog, the adaptation of the tumor to tissue culture, and the successful growth of the tumor in adult mongrel dogs has been adapted to producing similar tumors in the thoracic spinal cord of the adult dog. Ten adult dogs, weighing 4 to 25.4 kg each, were subjected to formal laminectomy. The tumor cell suspension was injected by hand with a Hamilton syringe at two or three sites over a distance of 1 cm; each site received an injection volume to 0.02 to 0.05 cc of the cell suspension after the dura had been opened. Immediately after injection the field was copiously irrigated and the puncture area sealed with a single drop of ethyl cyanoacrylate. Tumor cells for injection were obtained by thawing ampules stored at −195°C in a mixture of 10% dimethyl sulfoxide and RPMI 1640 culture medium. Cells were resuspended in Hank's balanced salt solution and 15% fetal calf serum on ice. Solutions had 90% cell viability, and animals received a dose in the range of 3 to 13 × 106 cells. Eight animals developed tumors and became paraparetic on the 9th to 14th postinjection day. Metrizamide myelography in three animals revealed complete blocks; two animals underwent spinal computerized tomography (CT) and demonstrated syringohydromyelia. Histology revealed the tumors to be highly vascular primitive neoplasms that invaded the surrounding cord. This spinal cord tumor model is large enough to be operated on, studied by CT and myelography, and subjected to pharmacological, electrophysiological, and blood flow study.


1998 ◽  
Vol 4 (5) ◽  
pp. E6 ◽  
Author(s):  
Francesco M. Salpietro ◽  
Concetta Alafaci ◽  
Olga Gervasio ◽  
Giovanni La Rosa ◽  
Francesco Tomasello ◽  
...  

Primary intramedullary melanoma is a very rare tumor, most frequently occurring in the middle or lower thoracic spinal cord. The authors present a new case of primary cervical cord melanoma that developed in a 62-year-old man whose tumor was surgically treated and subsequently received radiation therapy. Clinical and histogenetic features of this neoplasm, results of chemo-, radio-, and immunotherapy are reported. Both “disembryogenetic” and “mesodermal” hypotheses on the origin of primary spinal melanoma are discussed.


2000 ◽  
Vol 92 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Federico Roncaroli ◽  
Bernd W. Scheithauer ◽  
H. Gordon Deen

✓ A case of multiple hemangiomas of the cauda equina nerve roots, conus medullaris, and lower spinal cord is described. The 74-year-old male patient presented with a 9-month history of progressive bilateral leg weakness. He had a history of lymphoma at the age of 39 years and renal cell carcinoma in his early 40s. Neither disease was evident at the time of this presentation. A magnetic resonance image revealed multiple enhancing nodules in the cauda equina region as well as on the pial surface of the lower thoracic spinal cord and conus medullaris. The patient underwent an L2–3 laminectomy. Cauda equina nerve roots were found to be studded with numerous purple nodules, the largest measuring 6 to 8 mm. The nodules were adherent to nerve roots from which they could not be resected. Two lesions were histologically examined and found to be capillary hemangiomas. Twelve months into an uneventful postoperative course, the patient is neurologically unchanged. This unique case might represent a distinct form of hemangiomatosis confined to the cauda equina nerve roots and spinal cord.


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