The median palmar cutaneous nerve in normal subjects and CTS (original) (raw)

Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome

1994

The median sensory nerve conduction between ring finger and wrist is a suitable parameter for early detection of carpal tunnel syndrome (CTS), although shorter segments of median nerve have also been proposed for the same goal. In order to assess the relative diagnostic value of the sensory nerve conduction velocity (SNCV) of the third palmar branch versus the SNCV of the second palmar branch, generally performed until now, we studied 62 patients with typical signs and symptoms of CTS. The following parameters were evaluated by surface recording: orthodromic SNCVs in digit-wrist segments for median (index = M2, third = M3 and ring = M4 fingers), ulnar (fourth = U4 finger) and radial (thumb = R1) nerves; SNCVs in palm-wrist segments by surface bipolar stimulation at each metacarpo-phalangeal interspace (second = P2 and third = P3 for the median nerve and fourth = P4 for the ulnar nerve); and distal motor latencies of the median and ulnar nerves. No responses at the wrist were recorded in 22.6% of patients after digital stimulation of M4, whereas the SNCV of P3, the palmar nerve branch arising from digital nerves of the medial side of M3 and the lateral side of M4, was measurable in 93.5% of patients. As significantly expressed (P < 0.001) by the increased ratio of the mean values of P2 and P3 in CTS patients, the SNCV of P3 decreased more frequently and to a greater extent than the SNCV of P2.

Carpal tunnel syndrome : Which finger should be tested? An analysis of sensory conduction in digital branches of the median nerve

Muscle & Nerve, 1990

Each digital branch of the median nerve was stimulated in turn in 34 women (55 hands) with carpal tunnel syndrome (CTS). The amplitude and conduction velocity of the sensory nerve action potential (SNAP) recorded at the wrist, and the threshold for patient perception of the electrical stimu-Ius on the median innervated sides of each digit, were compared with the corresponding values in a group of asymptomatic, age-matched women. Sensory conduction velocity or SNAP amplitude were abnormal in more than 80% of all digital nerves studied apart from those in the index finger. Stimulation of digital nerves in the index finger proved the least sensitive means of detecting the electrophysiological abnormality. We conclude that selective digital nerve stimulation is a sensitive technique in the diagnosis of CTS. If ring electrodes are preferred, our results suggest that the middle rather than the index finger should be used.

Median mixed and sensory nerve conduction studies in carpal tunnel syndrome1

… and Motor Control, 1998

To assess the sensitivities and specificities of velocity differences between median mixed nerve conduction across the wrist (Medmxpw) and (I) median mixed nerve conduction in the forearm (Medmxf) and (II) palm to D2 sensory conduction (MedpD2). Design and Methods: We prospectively studied 67 limbs of patients with clinically definite carpal tunnel syndrome (CTS). Medmxf and Medmxpw were performed by stimulating the median nerve at the elbow and palm respectively and recording at the proximal wrist crease. We also compared conventional median sensory (D2-wrist) and mixed (palm-wrist) tests in all patients. Thirty limbs of asymptomatic subjects served as normal controls and 21 limbs of subjects with other neuropathies served as diseased controls; control data was collected prospectively. Results: The sensitivity of the MedpD2-Medmxpw difference (0.87) was significantly greater than that of the Medmxf-Medmxpw difference (0.61, P Ͻ 0.001). Both tests were similar and highly specific (0.98 and 0.96, respectively). Conclusions: The MedpD2-Medmxpw study is among the most sensitive and specific electrophysiologic tests for CTS.

Median mixed and sensory nerve conduction studies in carpal tunnel syndrome

Electroencephalography and clinical neurophysiology, 1998

To assess the sensitivities and specificities of velocity differences between median mixed nerve conduction across the wrist (Medmxpw) and (I) median mixed nerve conduction in the forearm (Medmxf) and (II) palm to D2 sensory conduction (MedpD2). We prospectively studied 67 limbs of patients with clinically definite carpal tunnel syndrome (CTS). Medmxf and Medmxpw were performed by stimulating the median nerve at the elbow and palm respectively and recording at the proximal wrist crease. We also compared conventional median sensory (D2-wrist) and mixed (palm-wrist) tests in all patients. Thirty limbs of asymptomatic subjects served as normal controls and 21 limbs of subjects with other neuropathies served as diseased controls; control data was collected prospectively. The sensitivity of the MedpD2-Medmxpw difference (0.87) was significantly greater than that of the Medmxf-Medmxpw difference (0.61, P < 0.001). Both tests were similar and highly specific (0.98 and 0.96, respectively...

The sensitivity of median versus ulnar palmar mixed nerve study in the early diagnosis of carpal tunnel syndrome

Egyptian Rheumatology and Rehabilitation

Background Electrodiagnostic tests (EDX) are the most frequent and applicable studies in early diagnosis of carpal tunnel syndrome (CTS), but the definitive sensitive and specific tests are still under study. We aimed to evaluate the role of the median versus ulnar palmar mixed nerve study (Mix M-U), and its sensitivity in comparison to other provocative comparison studies, in supporting the early diagnosis of CTS. This cross-sectional study included 142 idiopathic early CTS hands from 100 patients and 71 hands from 50 healthy subjects as a control group. We did routine median motor and sensory studies and 4 comparative tests namely median versus radial sensory study (MVR), Mix M-U, median versus ulnar sensory study (MVU), and median versus ulnar lumbrical-interossei motor study (LU-IN). Results The routine median motor and sensory latency and amplitude showed a statistically significant difference between CTS and control groups as (p< 0.05) and a highly statistically significant...

Segmental study of the median nerve versus comparative tests in the diagnosis of mild carpal tunnel syndrome

Clinical Neurophysiology, 2006

Objective: The aims of this study were to analyze normative data of nerve conduction studies (NCS) by optimal transformations, and compare the utility of electrodiagnostic tests in detecting mild carpal tunnel syndrome (CTS). Methods: In 131 hands of patients with mild CTS and 136 hands of controls, the segmental study of the median nerve between the digit-palm and palm-wrist segments, and the median-to-ulnar and median-to-radial comparative tests were performed. Normal limits were derived by calculating the meanG2 standard deviations of the optimally transformed data of the controls. The specificity, sensitivity, and misclassification rate were calculated to evaluate the utility of each test. Results: All tests had high specificities, ranging from 98.5 to 100%. The distoproximal latency ratio (DPLR) of the median nerve showed the highest sensitivity and the difference between the median and radial sensory latencies (D1MKD1R) the second highest, but there was no statistical difference between them. The difference between the median and ulnar mixed nerve latencies in the palm-to-wrist segment (PMK PU) showed the lowest sensitivity. Misclassification rates of the DPLR, D1MKD1R, and PMKPU were 6.9, 3.8, and 6.1%, respectively. Conclusions: Optimal transformation of NCS data is mandatory to diminish the effect of skewness and enhance the diagnostic accuracy. As compared to the comparative tests, the segmental study of the median nerve is more easily applied and yields higher sensitivity in detecting mild CTS. Significance: With a high diagnostic yield and easy application, the segmental study of the median nerve may routinely be used to evaluate patients with mild CTS.

Prevalence of asymptomatic neurophysiological carpal tunnel syndrome in 130 healthy individuals

Neurology International, 2016

Diagnosis of carpal tunnel syndrome (CTS) is frequently confirmed by performing nerve conduction studies. Previous studies demonstrated that abnormal nerve conduction study (NCS) is suggestive of CTS among asymptomatic individuals. However, previous studies included individuals with risk factors for the syndrome. A NCS was performed on the median and ulnar nerves in 130 healthy individuals. About 15% of individuals in this study demonstrated electrodiagnostic evidence of carpal tunnels syndrome. Four cases have shown signs of isolated median neuropathy with normal median sensory component. Results indicated that the most widely used method for confirming diagnosis of CTS may have up to 15% of false positives. However, most of those showed changes of minimal CTS. Isolated prolongation of the median motor latency should be investigated further as they are usually classified as moderate to severe CTS and may undergo unnecessary surgeries.

Clinical Evaluation and Diagnostic Utilities of Different Nerve Conduction Tests in 100 Patients with Carpal Tunnel Syndrome

Journal of neurosciences in rural practice

The purpose of the study is to determine whether the clinical profile of patients with carpal tunnel syndrome (CTS) has been same over the years with the help of routine and comparative electrodiagnostic tests. A prospective study of 100 patients with suspected CTS was conducted without controls. Three provocative maneuvers were performed. Routine and comparison nerve conduction tests were performed, i.e., second lumbrical interossei motor latency difference (2 LIMLD), digit 4 median-ulnar sensory latency difference (D4MUSLD), palm wrist distal sensory latency difference (PWDSLD), and digit 1 median-radial sensory latency difference (D1MRSLD). Data entry, analysis, and statistical evaluation were done using International Business Machines Corporation Statistical Package for the Social Sciences statistics package (IBM, SPSS). A total of 195 hands of 100 patients met the criteria for CTS. Forty-three percentage of patients were homemakers. Considering the rapidly changing communicatio...