A Research On The Relationship Between Degree Of Amyotrophy Resulted From Denervation And Clinical Recoverable Time

Objective:This research is to find out the relationship between degree of amyotrophy, myofibrosis and time of denervation, look for a certain examination of safety, no trauma and high reliability, and provide an evidence for the determination on limited time of clinical neural restoration in the later period.Motheds:44 patients and specimens of their Biceps were taken in, divided into 6 groups in terms of denervated time, including 0-3m(10 cases),3-6m(18),6-12m(8), 1-2y(8),>2y(8). In the the control group, there were 8 normal cases. We carried on examinations(EMG, type-B ultrasonography, MRI) on the patients'Biceps, and evaluated reliability of these estimations at amyotrophic degree, regarding the pathological examination as gold standard.Result:As the denervated time prolongs, muscles involves in decrease of muscular sectional area and hyperplasia of fatty connective tissue. EMG shows that peak value of pathological fibrillation wave and positive sharp wave decrease and time interval of the waves extend, which are obvious in the cases(>2y). B ultrasonography shows that in the cases(>2y), there are lots of high-level echo spots and some residual normal spots, sectional area drops to 24% of normality. MRI (T1W1, T2W1, IR-FSE) shows that there is also a certain residual muscular tissue resulted from 3 years denervation and sectional area is 27% of normality, which is similar with the pathological examination.Conclusion:EMG could show pathological fibrillation wave and positive sharp wave in denervated muscles, as denervation time prolongs, peak value and time interval of waves would decrease. B ultrasonography and MRI would show hyperplasia of connective tissue and decrease of muscular sectional area(which drop to 24% and 27% of control group). The pathological examination shows lost of muscular cytoplasm, decrease of sectional area and hyperplasia of collagen fibers. Analysing results of pathological examination, we found that decrease of sectional area and ratio of muscular/collagen fibers is obvious within the latest 2 years after denervation, which is considered a key period of amyotrophy and myof ibrosis, then amyotrophy and myofibrosis slow down and sectional area in case(>2y) is 36% of control group. Considering the results of pathological examination, EMG, B ultrasonography and MRI, the latest 2 years after denervation is a key period of carrying on neural restoration and preventing from amyotrophy and myofibrosis, but there is an evidence for carrying on neural restoration later than 2 years after denervation.