Therapeutic model for experimental spinal cord injury in the rat: I. Mortality and motor deficit.
In the course of establishing a therapeutic model for experimental spinal cord injury in the rat, we determined the effects of trauma dose (20, 30, 40, 50, and 60 g-cm) on the mortality and motor deficit in the 4 weeks following injury. Mortality was dependent upon the trauma dose: 20 g-cm, 11%; 30 g-cm, 14%; 40 g-cm, 27%; 50 g-cm, 32%; 60 g-cm, 41%. Statistical analysis by linear regression is highly significant for increasing mortality with increasing trauma dose. The motor deficit determined by a modified Tarlov scale also was dependent upon trauma dose. A trauma dose-response curve based on this study indicates that a drug which reduces the motor deficit from that found at 40 g-cm to that at 30 g-cm may be detected at a significant level of 0.05 with a power of 0.8 if 30 rats are included in each of placebo and treated groups. The same sample size would detect a significant reduction of mortality from that of 40 g-cm to 30 g-cm.
Department of Neurosurgery, Medical University of South Carolina, Charleston.
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Perot
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Lee
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Hsu
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Hogan
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Cox
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Gross
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D008124:Locomotion; D009069:Movement Disorders / Q000209:etiology* / Q000503:physiopathology; D009420:Nervous System / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D012720:Severity of Illness Index; D013119:Spinal Cord Injuries / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D013997:Time Factors