Abstract
Introduction
Currently, the recovery of neurological functions after spinal cord injury (SCI) still relies on the host's neural plasticity and compensatory mechanisms. Unfortunately, many of these patients are permanently paralyzed. The objective of this study is to analyze the efficacy of hyperbaric therapy (HT) on the motor recovery process and define the best protocol of treatment.
Materials and Methods
Experimental study with 48 Wistar that was performed following the University standards advocated by the Ethics Committee. The SCI was simulated by performing a laminectomy at the T8–T10 level using a surgical microscope (DF Vasconcelos, RJ, Brazil) and subsequent SCI by a falling object weighing 5 g, controlled by the IMPACTOR equipment (MASCIS Impactor, New Jersey, United States). The drop height was 12.5 mm (mild) (n = 8) or 25 mm (moderate) (n = 8) as they were the models most used in the literature. Motor recovery was assessed by the scale of Basso, Beattie, and Bresnahan (BBB) on days 1, 3, 7, 14, 21, and 28 postoperative (PO). The first phase of the study was the comparison between the two models of SCI. In the second step, 32 rats were subjected to SCI, and were divided into five protocols using HT with a hyperbaric oxygen chamber held at a pressure of 2.5 atmospheres for 1 hour: Control (SCI only), 12H (SCI 12 hours PO in a single session), 12H7D (SCI 12 hours and PO once daily for 7 days), 30 MIN (SCI 30 minutes PO in a single session), 30MIN7D (SCI 30 minutes and PO once daily for 7 days). The comparison between the scores of the BBB test was performed using the one way ANOVA + Tukey HSD. Significance was p < 0.05.
Results
By comparing the curves of motor recovery between rats with mild and moderate SCI, the average BBB in mild SCI was higher than in the moderate group only on days 3 and 7 PO. There was no statistically significant difference between the models in relation to the final motor outcome. The HBT group had a BBB significantly higher than the control group (p = 0.001) on days 1, 3, 14, and 28 PO. The best HT protocol was the 30MIN7D p = 0.03 when compared with control on day 28.
Conclusion
There is no difference in the final outcome after 28 days PO between the light and moderate SCI in rats. Using HT accelerates motor recovery and improves motor outcome of rats. The best HT protocol is 30 minutes and after PO daily for 7 days.