Diagnostic value of simplified median nerve inching in mild carpal tunnel syndrome
Objective To investigate the diagnostic value of simplified median nerve inching in carpal tunnel syndrome(CTS)with normal or mild abnormal conventional electromyography.Methods A median nerve inching test was conducted on 50 healthy subjects.Firstly,four stimulation points for the median nerve movement and sensation at the wrist from the proximal to the distal end were identified.The distance between the two stimulation points was determined to be 2 cm.Through statistical calculation,the normal range of the maximum latent period generated by the distance between the two points was obtained.Then,this normal value was used to determine whether there was a conduction time delay in 50 CTS patients with normal or mild abnormalities in conventional electromyography.The results of two simplified methods for detecting median nerve inching and median nerve ulnar nerve sensory wave peak time difference were compared to determine whether there was a difference between the two methods in examining CTS.Results The conduction time of the wrist segment movement of the median nerve in normal individuals from the proximal to distal segments of the wrist was(0.32±0.21),(0.51±0.19),and(0.41±0.23)ms,respectively.The upper limit of the normal nerve conduction value at a distance of 2 cm was established as 1 ms for the second segment with the longest duration,and exceeding 1 ms was considered abnormal.The conduction time of the reverse sensory nerve conduction in the wrist segment of the median nerve was(0.21±0.21),(0.39±0.19),and(0.54±0.23)ms,respectively,from the proximal to distal segments of the wrist.The upper limit of the normal value of the median nerve sensory conduction at a distance of 2 cm was established as 1 ms,with a distance exceeding 1 ms being considered abnormal.There was a statistically significant difference between the results of median nerve displacement and median nerve ulnar nerve sensory wave peak time difference(x2=13,P=0.002).Conclusion The simplified median nerve inching is a simple and reliable method for early diagnosis of CTS,and can become the standard for diagnosing CTS.
Carpal tunnel syndromeElectrophysiologySimplified median nerve inching testDistance motor latency
NETL
NSTL
万方数据
