Carpal tunnel syndrome : Which finger should be tested? An analysis of sensory conduction in digital branches of the median nerve (original) (raw)
Related papers
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.
Rheumatology International, 2004
To compare the sensitivity of different electrodiagnostic tests on the same hand affected by mild carpal tunnel syndrome (CTS), 189 hands with the clinical diagnosis of CTS and 61 hands of healthy persons were evaluated prospectively. On all hands, median sensory studies from digits 1, 2, 3, 4, and the palm-towrist segment from digit 3 and medial motor latency were recorded. Sixty-two hands with delayed motor latency (>4.2 ms) were excluded to ensure that only mild cases were enrolled. Sensory median-radial latency differences from the thumb, median-ulnar latency difference between second and fifth digits, and median-ulnar latency difference from the fourth digit were calculated in each limb. Sensory studies of only one median innervated digit failed to diagnose 15-20% of hands. Conduction velocity at the palm-to-wrist segment was the most sensitive, diagnosing 99% of cases. In comparative tests, median radial sensory latency difference from the first digit was the most sensitive (94%), and median ulnar latency difference from the fourth digit was the least (85%) sensitive. Segmental measurement has the highest diagnostic yield and may be used first in the evaluation of CTS.
International journal of scientific research, 2019
BACKGROUND: Patients with Mild Carpal tunnel syndrome (CTS) may not be picked up by routine nerve conduction methods. So, this study was performed to identify the most sensitive way to detect mild to moderate Carpal tunnel syndrome and to evaluate the sensitivity of different methods for diagnosis of carpal tunnel syndrome. MATERIAL AND METHOD: We included sixty clinically confirmed CTS patients in our study. We recorded the clinical characteristics and laboratory features in a proforma. We also included sixty healthy age and sex-matched asymptomatic individuals as controls in our study. We excluded patients with underlying peripheral neuropathy. We included Median distal motor latency, Median distal sensory latency, Median-versusulnar 2nd Lumbrical-interossei comparison study, Median-versus-ulnar wrist-to-digit four comparison study, Median-versus-Radial thumb sensory study, Median-versus-ulnar motor distal latency difference, and Median-versus-ulnar sensory latency difference tests in our study. RESULTS: Out of sixty patients, female: male ratio was 2.3:1, and the mean age was 44.28±11.41 years. The mean symptom duration was 0.76±0.03 years. Out of 42 females, 38(90.4%) were engaged in daily household activities. In patients group median nerve distal motor latency was 5.024±2.05 ms, whereas sensory latency was 3.53±0.75 ms. We found maximum sensitivity in Median-versus-ulnar wrist-to-digit four comparison study (90.19%). In Median-versus-Radial thumb sensory study sensitivity was 88.23%, followed by Median-versus-ulnar 2nd Lumbrical-interossei comparison study (86.27%). We found lowest sensitivity (72.55%) in Median distal motor latency test. CONCLUSION: Electrophysiological tests including Median-versus-ulnar wrist-to-fourth digit comparison study, and comparative study of Median-versus-ulnar 2nd Lumbrical-interossei should be included to diagnose mild CTS patients with normal Median distal motor latency, and median distal sensory latency tests. KEYWORDS carpal tunnel syndrome, median nerve, electrophysiological tests INTRODUCTION: Carpal tunnel syndrome (CTS) is caused due to entrapment of the median nerve at the wrist, as it passes through the carpal tunnel. Women are more often affected as compared to men, and it usually [1] involves dominant hand first. CTS is clinically characterized by pain and paresthesias over the lateral palm and the lateral 3 fingers. These paresthesias may result in a disturbed night time sleep, and patient usually shakes hands to get rid of them. If symptoms are not present in lateral 3 fingers, it is unlikely to [2] be CTS.
Electrophysiological studies in mild idiopathic carpal tunnel syndrome
… and Motor Control, 1998
Many techniques have been reported to improve the diagnosis of carpal tunnel syndrome (CTS), but there is no agreement on the diagnostic yield of these different methods. We used an electrophysiological protocol including the assessment of the orthodromic sensory conduction velocity of the median nerve along the carpal tunnel, comparison of median and ulnar sensory conduction between the ring finger and wrist, short segment incremental median sensory nerve conduction across the carpal tunnel recording from the III digit ('inching test'), the study of the refractory period of transmission (RPT) and calculation of the distoproximal ratio obtained by dividing the nerve conduction velocity in the median nerve between the third digit and the palm and between the palm and wrist in 41 patients with mild CTS (75 symptomatic hands) and in 45 control subjects. The distoproximal ratio calculation was the most sensitive technique (81%), but was also the least specific. The 'inching test', even though less sensitive, had the advantage of localising focal abnormalities of the median nerve along the carpal tunnel. RPT was abnormal in patients with recent symptoms. Combining the different techniques, an overall sensitivity of 92% was reached, 11% higher than the yield of the single best test suggesting that a multimodal approach could be useful. The best procedure for electrodiagnosis of mild CTS was to combine the median/ulnar comparison test with calculation of the disto-proximal ratio.
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...
Ring finger testing in carpal tunnel syndrome: A comparative study of diagnostic utility
Muscle & Nerve, 1989
Because digit 4 (D4) has dual innervation, median and ulnar sensory latencies can be determined over identical distances. To determine if D4 testing is more sensitive than other commonly used techniques to diagnose carpal tunnel syndrome (CTS), we examined 42 hands with clinical evidence of carpal tunnel syndrome and 43 control hands. D4 latency was significantly longer than controls more often than digit 2 (02) in patients with CTS. Comparing median to ulnar latencies from 0 4 was the most sensitive method to make the diagnosis of CTS. In mild CTS, a characteristic double peak potential was seen in recordings from the median nerve after stimulating D4. This potential provided immediate visual confirmation of the diagnosis of CTS. Comparing 0 4 latency along median and ulnar nerves is useful for detecting mild CTS and should be used whenever there are clinical signs and symptoms of CTS but electrodiagnostic studies are normal or borderline.
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.
Electrodiagnostic evaluation of carpal tunnel syndrome
Muscle & Nerve, 2011
Carpal tunnel syndrome (CTS) is the most common nerve entrapment. Electrodiagnostic (EDX) studies are a valid and reliable means of confirming the diagnosis. This monograph addresses the various EDX techniques used to evaluate the median nerve at the wrist. It also demonstrates the limitations of EDX studies with a focus on the sensitivity and specificity of EDX testing for CTS. The need to use reference values for populations such as diabetics and active workers, where normative values differ from conventional cutoffs used to confirm suspected CTS, is presented. The value of needle electromyography (EMG) is examined. 44: 597-607, 2011 Carpal tunnel syndrome (CTS) is a clinical syn-Abbreviations: AANEM, American Association of Neuromuscular and Electrodiagnostic Medicine; AAOS, American Academy of Orthopedic Surgeons; APB, abductor pollicis brevis; CMAP, compound muscle action potential; CSI, combined summary index; CTS, carpal tunnel syndrome; EDX, electrodiagnostic; EMG, electromyography; inching, median sensory short segment stimulation across the wrist; MGA, Martin-Gruber anastomosis; MMW, median mononeuropathy at the wrist; NAP, nerve action potential; NCS, nerve conduction studies; palmdiff, median-ulnar mixed nerve palm latency difference from palm to wrist; ringdiff, median-ulnar sensory latency difference to the ring finger; SNAP, sensory nerve action potential; thumbdiff, median-radial latency difference to the thumb
Muscle & Nerve, 1993
The sensitivity and specificity of nerve conduction studies (NCS'sJ and electromyography (EMG) for the diagnosis of carpal tunnel syndrome CTS) were evaluated by a critical review of the literature. With a search of the medical literature in English through May 1991, 165 articles were identified and reviewed on the basis of six criteria of scientific methodology. The findings of 11 articles that met all six criteria and the results of 48 additional studies that met four or five criteria are presented. We concluded that median sensory and motor NCS's are valid and reproducible clinical laboratory studies that confirm a clinical diagnosis of CTS with a high degree of sensitivity and specificity. Clinical practice recommendations are made based on a comparison of the sensitivities of the several different median nerve conduction study (NCS) techniques.
Ring finger sensorial conduction studies in grading carpal tunnel syndrome: Part II
Journal of Back and Musculoskeletal Rehabilitation, 2018
BACKGROUND: Comparing the distal sensory latencies of median and ulnar nerve over wrist-to-ring finger (RF) segment is a sensitive conduction parameter in the diagnosis of carpal tunnel syndrome (CTS). However to the best of our knowledge, there is not any research questioning whether the RF studies are useful in grading the CTS or not. OBJECTIVES: To determine whether the hands with moderate degree CTS and elicitable median nerve sensory responses over second finger and unelicitable responses over RF represent a more severe electrophysiological grade than the hands with elicitable responses over both fingers. MATERIAL AND METHODS: In patients with clinical diagnosis with CTS, obtained values on sensory and motor nerve conduction studies of median and ulnar nerves were compared between median nerve-to-RF sensorial responders (group 1) and nonresponders (group 2). RESULTS: Seventy-four recordings belong to 59 patients with moderate degree CTS were included. There were 55 hands in group 1, and 19 in group 2. Mean sensory onset latency of median nerve over second finger was longer (4.17 ± 0.53 msec versus 3.47 ± 0.46 msec; p < 0.001), sensory conduction velocity was slower (34.1 ± 5.5 m/sec versus 40.1 ± 5.3 m/sec; p < 0.001), SNAP amplitude was smaller (7.0 ± 3.3 µV versus 13.7 ± 6.7 µV; p < 0.001), and distal motor latency was longer (5.75 ± 0.96 msec versus 4.76 ± 0.42 msec; p < 0.001) in group 2 than in group 1. CONCLUSION: Median nerve-to-RF sensorial nonresponders have a more progressed compressive neuropathy, and represent a more severe electrophysiological grade than the responders.