Central nervous system trauma : journal of the American Paralysis Association
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Cent Nerv Syst Trauma · Jan 1987
Conductivity of dorsal column fibers during experimental spinal cord compression and after decompression at various stimulus frequencies.
The effects of spinal cord compression on conduction of dorsal column fibers at various stimulus frequencies were analyzed in pentobarbital anesthetized cats. The responses to L6 dorsal root stimulation at 1 to 500 Hz were recorded from the L2 cord dorsum. The L4 cord segment was compressed gradually until the compound action potential (CAP) at 1 Hz was flat. ⋯ The conduction failure at high stimulus frequency indicates incomplete impairment of spike generation in axons injured by mechanical compression and that these axons can transmit impulses at a low stimulus frequency. High frequency stimulation may be useful for monitoring of the function of the CNS axons. The mechanism underlying the augmentation of CAPs at moderately high stimulus frequency is briefly discussed.
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Cent Nerv Syst Trauma · Jan 1987
Comparative StudyPost-traumatic spinal cord ischemia: relationship to injury severity and physiological parameters.
Alterations in lumbar spinal cord white matter blood flow (SCBF) during the initial 4 hours following contusion injury were examined in cats anesthetized with either dial-urethane or sodium pentobarbital and correlated with changes in cardiovascular parameters (MAP, HR), blood gases (pCO2, pO2), and pH. In the dial-urethane anesthetized cats, the effect of a severe 500 g-cm contusion on SCBF was determined at the center of the injury site vs. an adjacent site 3 mm away. At the injury site, SCBF fell progressively from a pre-injury mean of 13.9 +/- 0.8 (S. ⋯ In addition, a significant difference in SCBF may exist between the injury site and adjacent spinal tissue only a few mm away. No correlation between the increase or decrease in SCBF and change in cardiovascular parameters or blood gases following injury is demonstrable nor does anesthetic choice seem to make a significant difference. Thus, post-traumatic changes in SCBF appear to be due to the elaboration of local mediators for the most part unrelated to concomitant alterations in spinal cord perfusion pressure.
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Cent Nerv Syst Trauma · Jan 1985
Comparative StudyChanges in norepinephrine and histamine in monkey spinal cords traumatized by weight drop and compression.
Changes in norepinephrine and histamine levels in the spinal cord of monkeys at 1/2, 2, and 4 hours after 200 g cm of contusion injury, 50 g of compression injury, and 2 hours of decompression following 4 hours of compression were studied in the traumatized and an adjacent nontraumatized segment. Norepinephrine levels were elevated in the traumatized segment at 1/2, 2, and 4 hours after contusion injury and in the adjacent nontraumatized segment at 1/2 hour. Compression of 1/2 and 2 hours caused elevation of norepinephrine in both the traumatized and nontraumatized segments. ⋯ Histamine content increased in the traumatized segment at 2 and 4 hours after contusion injury and in the adjacent nontraumatized segment at 2 hours. Compression injury did not change histamine levels, but decompression caused an increase. The possible influence of simultaneous changes in norepinephrine and histamine levels on the vessels following injury is discussed.
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Cent Nerv Syst Trauma · Jan 1985
Spinal cord edema, 5-hydroxytryptamine, lipid peroxidation, and lysosomal enzyme release after acute contusion and compression injury in primates.
Physical and biochemical changes in the spinal cord of monkeys at 1/2, 2, and 4 hours following 200 g cm contusion injury and 50 g of compression injury and 2 hours of decompression following 4 hours of compression were studied. The pathophysiologic changes were milder in compression compared to contusion injury. Following contusion injury, at 1/2 and 2 hours there was significant increase in % water content, lipid peroxidation, and alpha-L-fucosidase. alpha-D-Mannosidase was significantly increased at all time periods, and beta-D-hexosaminidase was increased at 1/2 and 4 hours. ⋯ Lipid peroxidation had increased at all time periods, whereas B-D-hexosaminidase, beta-D-galactosidase, and 5-HIAA were increased at 2 hours. alpha-D-Mannosidase had increased at 1/2 and 2 hours, and alpha-L-fucosidase had increased at 4 hours. After 2 hours decompression following 4 hours compression, water content, beta-D-galactosidase, and alpha-D-Mannosidase were significantly increased. An attempt was made to correlate the findings and to understand the sequential pathophysiologic changes in the first 4 hours following spinal cord trauma, providing a baseline for evaluation of the efficacy of any therapeutic maneuvers.
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Major sources of data on incidence and prevalence of spinal cord injury (SCI) in the United States were reviewed, including many federal government agencies, state level rehabilitation and health departments, regional SCI systems, private voluntary organizations, available literature, and several unpublished studies. With the exception of the Veterans Administration, many of the federal databases did not prove helpful. ⋯ Data from the Florida and Virginia Central Registries of SCI suggest a decrease in traumatic SCI incidence in recent years. Based on data abstracted from a regional study, the California Disability Survey, we estimate the prevalence of traumatic SCI to be about 238,000 in the United States for 1984.