Sensitivities of conventional and new electrophysiological techniques in carpal tunnel syndrome and their relationship to body mass indexReport as inadecuate

Sensitivities of conventional and new electrophysiological techniques in carpal tunnel syndrome and their relationship to body mass index - Download this document for free, or read online. Document in PDF available to download.

Journal of Brachial Plexus and Peripheral Nerve Injury

, 4:12

First Online: 31 July 2009Received: 23 December 2008Accepted: 31 July 2009


The purpose of this study is to evaluate prospectively the sensitivities of conventional and new electrophysiological techniques and to investigate their relationship with the body mass index BMI in a population of patients suspected of having carpal tunnel syndrome CTS.

In this study, 165 hands of 92 consecutive patients 81 female, 11 male with clinical diagnosis of CTS were compared to reference population of 60 hands of 30 healthy subjects 26 female and 4 male. Extensive sensory and motor nerve conduction studies NCSs were performed in the diagnosis of subtle CTS patients. Also, the patients were divided into subgroups and sensitivities were determined according to BMI.

The mean BMI was found to be significantly higher in the CTS than in the control group p < 0.001. The sensitivity of the median sensory nerve latency mSDL and median motor distal latency mMDL were 75.8% and 68.5%, respectively. The most sensitive parameters of sensory and motor NCSs were the difference between median and ulnar sensory distal latencies to the fourth digit D4M-D4U, 77% and the median motor terminal latency index mTLI, 70.3%, while the median-to-ulnar sensory action potential amplitude ratio 27% and the median-thenar to ulnar-hypothenar motor action potential amplitude ratio 15% were least sensitive tests. Sensory tests were more sensitive than motor NCSs. Combining mSDL with D4M-D4U, and mMDL with mTLI allowed for the detection of abnormalities in 150 91% and 132 80% hands, respectively. Measurements of all NCSs parameters were abnormal in obese than in non-obese patients when compared to the BMI.

The newer nerve conduction techniques and combining different NCSs tests are more sensitive than single conventional NCS test for the diagnosis of suspected CTS. Meanwhile, CTS is associated with increasing BMI.

AbbreviationsCTScarpal tunnel syndrome

BMIbody mass index

NCSsnerve conduction studies

mSNAPamedian sensory nerve action potential amplitude

mSDLmedian sensory distal latency

mSNCVsensory nerve conduction velocity

D4M-D4Udifference between the median and ulnar sensory distal latency to the fourth digit

D2M-D5Udifference between sensory median distal latency to second digit and ulnar distal latency to the fifth digit

D2M-U5 SNAPa ratiomedian-to-ulnar SNAP amplitude ratio

mMDLmedian motor distal latency

mMNCVmedian motor nerve conduction velocity

mCMAPamedian compound muscle action potential amplitude

mTLImedian terminal latency index

M-U LDthe median-thenar to ulnar-hypothenar motor latency differences

M-U CMAPa ratiothe median-thenar to ulnar-hypothenar motor CMAPa ratio.

Download fulltext PDF

Author: Recep Aygül - Hızır Ulvi - Dilcan Kotan - Mutlu Kuyucu - Recep Demir


Related documents