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

Abstract

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.

Relationship of Age, Body Mass Index, Wrist and Waist Circumferences to Carpal Tunnel Syndrome Severity

“…Majority of the subject group were females (85.6%) but no significant difference was identified when the relationship of CTS severity and gender was investigated. Compatible with the distribution of our subjects, generally in the studies 12 , 13) CTS is seen more frequently in the female gender. In some studies it has been reported that the female gender is an independent risk factor.…”

The Usefulness of Terminal Latency Index of Median Nerve and F-Wave Difference Between Median and Ulnar Nerves in Assessing the Severity of Carpal Tunnel Syndrome

“…Carpal tunnel syndrome is the most common entrapment neuropathy, with a 10% lifetime risk in the general population (American Academy of Neurology, 1993aNeurology, , 1993bAygul et al, 2009;Duncan et al, 1987;Jablecki et al, 1993;Katz et al, 1998;Padua et al, 1997;Spitzer, 1996;Wilson and Sumner, 1995;You et al, 1999). Carpal tunnel syndrome results from compression of the median nerve during passage through the carpal tunnel under the transverse carpal ligament.…”

“…The classification is based on the clinical observations and scientific investigations that nerve entrapment of CTS affects earlier sensory nerve than motor nerve (American Academy of Neurology, 1993aNeurology, , 1993bAygul et al, 2009;Heybeli et al, 2002;Jablecki et al, 1993;Katz et al, 1998;Levine et al, 1993;Padua et al, 1997;Spitzer, 1996;You et al, 1999). Mild CTS is indicated when the patient complains of the typical symptoms of CTS and shows Tinel sign or positive Phalene maneuver (inclusion of the aforementioned American Academy of Neurology practice parameters criteria 1 and 4), but the sensory and motor function tests of the affected hand are normal (exclusion of criteria 2 and 3).…”

“…The TLI of median nerve and the F-diff M-U are well-known calculated electrophysiological parameters used to diagnose the early stage of CTS, although its sensitivity and specificity is variable according to investigations (Aygul et al, 2009;Cevik et al, 2012;Simovic and Weinberg, 1997;Uzar et al, 2011). The TLI of median nerve and the F-diff M-U are well-known calculated electrophysiological parameters used to diagnose the early stage of CTS, although its sensitivity and specificity is variable according to investigations (Aygul et al, 2009;Cevik et al, 2012;Simovic and Weinberg, 1997;Uzar et al, 2011).…”

Value of F-wave inversion in diagnosis of carpal tunnel syndrome and it's relation with anthropometric measurements

“…Diabetes mellitus (DM), thyroid disease, connective tissue disease, amyloidosis, acromegaly, and pregnancy are other risk factors that can influence CTS development [5]. CTS is more prevalent in women than men [6,7] and female gender is reported as an independent risk factor [5]. Its incidence has been reported as 136 and 506 per 100,000 people in men and women, respectively [8].…”