Study On Evaluation Of Brachial Plexus Nerve Injury,Classification And Severity By Magnetic Resonance Neurography Combined With Neuroelectrophysiological Examination Technique

Objective:The first,to assess the value of neuroelectrophysiological detection technique and MR neuroimaging(MRN)in the diagnosis of brachial plexus injury;The second,to discuss the pathological type to the brachial plexus injury on MRN according to the electrophysiologic and pathologic type criteria of brachial plexus injury;The last,to explore the correlation between MRI performance and the severity of nerve injury,to provide assistance for the development and prognosis of brachial plexus injury treatment.Materials and Methods:Collected MRI brachial plexus examination in our hospital from 2014.1 to 2016.12,and reviewed a total of 70 cases who accepted the neuroelectrophysiological examination.The clinical data of all cases were complete,and the clinical diagnosis of brachial plexus injury was clear.MR neurological examination included:3D-CISS sequential scan,3D-STIR SPACE sequential flat scan plus enhanced scan.The original image obtained by the scan was transmitted to the workstation,and various post-processing techniques were applied to comprehensively display the pre-and postganglionic nerves of the brachial plexus.Electrophysiological examinations include:NCV and EMG.Both electrophy-siological examination and MRN were carried out independently.MRN was analyzed by single-blind methods(without clinical data)by senior doctors of our department;Meanwhile,the electrophysiological examination were performed without knowledge of MRI findings.The paired chi-square examination was used to examine the differences in the diagnostic sensitivity of MRI,electrophysiology,and a combination examination of the both for all patients.Grouped according to electrophysiological typing criteria,using independent sample t examination and ordinary chi-square examination to perform a differential analysis on both groups'MRI performance.Spearman rank correlation analysis was performed between the patient's MRI performance and the severity of brachial plexus injury.Results:In 70 patients with brachial plexus injury,20 patients were pre-ganglionic injury and 54 patients were post-ganglionic injury.MRI diagnosed 14 patients with positive pre-ganglionic injury and 6 patients with negative pre-ganglionic injury.The diagnostic coincidence rate was 70%.There were 42 patients with positive post-ganglionic injury and 12 patients with negative post-ganglionic injury.The diagnostic coincidence rate was 77.78%.Electrophysiological diagnosis of 12 patients with positive pre-ganglionic injury,8 patients with negative pre-ganglionic injury.The diagnostic coincidence rate was 60%;diagnosis of 37 patients with positive post-ganglionic injury,17 patients with negative post-ganglionic injury.The diagnostic coincidence rate was 68.52%.After the combination examination between both,the diagnostic coincidence rate was increased to 85%and 90.74%,respectively.In the pre-ganglionic injury,the paired chi-square examination was performed on MRI,electrophysiology,and combination examination between the both,all obtained P>0.05.There was no significant difference in sensitivity difference.In the post-ganglionic injury,P>0.05 between MRI and electrophysiology and P<0.05 when MRI and electrophysiology compared with the combined examination.When diagnosed the post-ganglionic injury,it shows that the sensitivity of the combination examination is obviously different from that of any single examination.According to the criteria of electrophysiological classification,they were divided into three groups:72 nerves in the demyelination group(group A),128 nerves in the axon Wallerian degeneration group(group B)and 17 nerves in the demyelination and axonal degeneration group(the number of this group was less,not included in the statistics).In the high signal manifestations of MRI enhanced scans;there were 28 nerves in group A and 18 nerves in group B.In the low signal manifestations of MRI enhanced scans;there were 16 nerves in group A and 58 nerves in group B.In high-signal manifestations,the number of high signal manifestations in the two groups were analyzed using Chi-square test,and the difference was statistically significant(P<0.05).The tube diameter width,signal intensity and involvement length of branch nerve were analyzed by two groups of independent samples t-test,and there only had significant difference in signal intensity(P<0.05).In the low-signal manifestations,the difference of the cases of low signal manifestations and increased signal of adjacent soft tissue between the two groups were analyzed using Chi-square test,and they both had significant difference(P<0.05).In addition,the difference of the increased signal of innervated muscle of injured nerve between the two groups was analyzed using Chi-square test,and the difference was statistically significant(P<0.05).The three MRI parameters in the high-signal manifestations of enhanced MRI,and the low-signal involvement length were analyzed by Spearman rank correlation analysis with the severity of injury,respectively.There was a positive correlation between the tube diameter width in the high-signal manifestations and the severity of injury,as well as a positive correlation between the low-signal involvement length and the severity of injury(r>0,P<0.05).Conclusion:In the diagnosis of postganglionic injury of brachial plexus,the combination of electrophysiology and MRI significantly improves the diagnostic sensitivity and reduces the missed diagnosis rate compared to either single examination.The combined examination also improves the coincidence rate of preganglionic injury diagnosis.The combination of these two methods has great application value in the diagnosis of brachial plexus injury.The high-signal manifestations of enhanced MRI often suggest the possibility of demyelination.The low-signal manifestations of enhanced MRI and increased signal in adjacent soft tissue often suggest the possibility of axonal degeneration.In addition,the increased signal of innervated muscle of injured nerve is the key to distinguish demyelination from axonal degeneration.The thicker the diameter of the tube in the high-signal manifestations of enhanced MRI or the longer the involvement length in the low-signal manifestations of enhanced MRI,the higher the severity of nerve injury.Preganglionic or postganglionic root avulsion or severe axonal degeneration may indicate the possibility of complete injury.