Diminution of Secondary Injury after Administration of Pharmacologic Agents in Acute Spinal Cord Injury Rat Model -Comparison of Statins, Erythropoietin and Polyethylene Glycol-
Study Design: An experimental animal study.
Objectives: To evaluate and compare the neuroprotective effect of statins, erythropoietin and polyethylene glycol (PEG) after spinal cord injury (SCI).
Summary of Literature Review: There are few comparative studies of pharmacological agents for acute SCI.
Materials and Methods: Forty Sprague Dawley (SD) rats had a spinal cord injury at T9/10 using an Ohio State University (OSU)impactor. The animals were randomized to receive one of the following; simvastatin, erythropoietin, PEG or saline. A behavioral outcome assessment was performed on days 2, 4 and 7, and then every week using the Basso, Bresnahan, and Beattie (BBB) score and subscore.
The animals were sacrificed at the end of 6 weeks and histologic assessment was performed to measure the areas of white and gray matter.
Results: For the animals treated with simvastatin, erythropoietin, PEG and saline, the mean BBB scores at 6 weeks post-injury were 13.2±0.1, 11.7±0.4, 13.3±0.3, and 11.4±0.2, and the BBB subscores were 9.2±1.1, 5.0±1.3, 9.1±1.1, 4.4±1.2, respectively. The BBB scores and BBB subscores were significantly higher in simvastain and PEG-treated animals (p<0.05). The areas of white matter at the lesion epicenter were 0.78±0.05mm2, 0.46±0.04 mm2, 0.68±0.15 mm2, and 0.41±0.04mm2 in the simvastatin, erythropoietin, PEG and saline groups, respectively. The simvastatin and PEG-treated animals showed increased sparing of the white matter at the injury epicenter and at 0.2mm rostral and 0.4mm caudal(p<0.05).
Conclusion: Simvastatin and polyethylene glycol administration showed diminished secondary injury after SCI in rats. In addition, they showed almost the same efficacy. However, erythropoietin did not show neuroprotective effect.