Predictive value of nerve conduction measurements at the carpal tunnel

Abstract

We compared the predictive values of three measurements of sensory conduction of the median nerve at the carpal tunnel (maximum latency difference [MLD], 8-cm latency [S8], and 14-cm latency [S14]) in 2334 hands of industrial workers, workers' compensation patients, and students. The MLD was determined by the centimetric technique. The MLD was the most sensitive and efficient measurement for predicting carpal tunnel syndrome (CTS). An MLD > or = 0.40 ms correctly identified 86.3% of 753 hands with CTS. The MLD correlated best with CTS and with the primary diagnostic category (CAT). MLD was the second factor selected in stepwise regression analysis for CAT (numbness was first and S8 was third). The MLD was the most important factor for predicting persistent or de novo CTS in a 5-year follow-up of 630 hands. Thus, the MLD was the most reliable nerve conduction study measurement for predicting current or future CTS in these subjects' hands.

Different case definitions to describe the prevalence of occupational carpal tunnel syndrome in meat industry workers

“…These asymptomatic workers have mean SCV-WP values lower than Kimura's healthy people (however within the normal interval) ( Table 2) and the hypothesis could be that they represent a group of preclinical cases of CTS, although the few prospective studies report that most people with abnormal median NCSs do not develop symptoms of CTS [35,42]. Compared with the symptomatic workers with the same occupational exposure, they could also form a sort of subgroup that is more resistant to industrial biomechanical exposure (Isolani et al manuscript submitted).…”

“…Moreover, a high prevalence of median mononeuropathy was reported in asymptomatic subjects, and (other) paresthesias suggestive of CTS were reported in individuals without electrodiagnostic signs of CTS [14,21,23,35].…”

Levels of agreement of nerve conduction studies and symptoms in workers at risk of carpal tunnel syndrome

“…Among the traditional NCS parameters, we recorded discordance rates with respect to symptoms ranging from 19% for WSL to 51% for MCV-WP in the nondominant hand (and from 40% to 50%, respectively, in the dominant hand). Although most studies of occupational CTS consider only sensory parameters (Nathan et al 1993;Bingham et al 1996;Werner et al 1997;Homan et al 1999), motor NCS parameters have also been proposed as a sensitive test for CTS (Waltors and Murray 2001;Chang et al 2002). Nathan et al concluded that maximum latency difference determined by the centimetric technique described by Kimura (1979) was the most sensitive and the most reliable sensory test to confirm a clinical diagnosis of CTS, while sensory 8-cm latency could be recommended as a sensitive substitute (Nathan et al 1993).…”

The Diagnostic Value of Ultrasonography in Korean Carpal Tunnel Syndrome Patients

“…The sensitivity and specificity of EDT for diagnosis of CTS has been estimated to be 80-90% and 82-85%, respectively. 10,13,15,25) Eventually, approximately 10 to 15% of subjects are the "milder" cases of CTS, those with clinical symptom of CTS but normal NCS results. Koyuncuoglu et al 13) found that such "milder" cases of CTS were significantly higher median nerve CSA than healthy control subjects.…”