O ultrassom terapêutico na medula espinhal acelera a regenera？？o do nervo ciático de ratos

objective: to study the effects of low intensity ultrasound irradiation applied on the spinal cord on the regeneration of the rat's sciatic nerve after a controlled crush injury, evaluating the functional results of the sciatic functional index as measured on the video recorded images of the foot sole. methods: eighteen rats were submitted to a controlled crush injury of the right sciatic nerve and divided into two groups according to the treatment: group 1 (n=9), simulated irradiation; group 2 (n=9), effective irradiation. low-intensity ultrasound irradiation was started on the 7th postoperative day and applied daily for 6 weeks. images of the animals′ foot sole were video recorded on a see-through treadmill type walking belt machine at weekly intervals until the 6th week of irradiation and the corresponding sciatic functional index (sfi) was measured with specific software. results: the sfi during the first and last week of treatment was -59.12 and -12.55 in group 1, -53.31 and -1.32 in group 2, indicating a 79% and 97% improvement, respectively, but differences between groups were only significant (p<0.05) during the third week. conclusion: the authors conclude that low intensity therapeutic ultrasound enhances nerve regeneration, with significance during the 3rd week of treatment. level of evidence: level ii, prospective comparative study.