scholarly journals Motor terminal latency index in carpal tunnel syndrome

1999 ◽  
Vol 5 (2) ◽  
pp. 262-267
Author(s):  
M. M. Kabiraj ◽  
S. Al Rajeh ◽  
A. R. Al Tahan ◽  
M. Abdulijabbar ◽  
M. Al Bunyan

We determined the motor terminal latency index [MTLI]of the median nerve across the carpal tunnel in 41 upper extremities of 31 patients with carpal tunnel syndrome. Changes in motor nerve conduction velocity [MNCV], motor terminal latency [MTL], sensory action potential and the amplitude of the compound muscle action potential recorded from the abductor pollicis brevis muscle were all suggestive of proximal and distal segment involvement of the nerve across the carpal tunnel. There was no correlation between forearm MNCV and MTL [r = 0.40], although MTLI was correlated with MTL [r = 0.67]but not with MNCV, indicating a disproportionate conduction across the carpal tunnel

2020 ◽  
Vol 65 (1) ◽  
pp. 61-71
Author(s):  
Veysel Alcan ◽  
Hilal Kaya ◽  
Murat Zinnuroğlu ◽  
Gülçin Kaymak Karataş ◽  
Mehmet Rahmi Canal

AbstractConventional electrophysiological (EP) tests may yield ambiguous or false-negative results in some patients with signs and symptoms of carpal tunnel syndrome (CTS). Therefore, researchers tend to investigate new parameters to improve the sensitivity and specificity of EP tests. We aimed to investigate the mean and maximum power of the compound muscle action potential (CMAP) as a novel diagnostic parameter, by evaluating diagnosis and classification performance using the supervised Kohonen self-organizing map (SOM) network models. The CMAPs were analyzed using the fast Fourier transform (FFT). The mean and maximum power parameters were calculated from the power spectrum. A counter-propagation artificial neural network (CPANN), supervised Kohonen network (SKN) and XY-fused network (XYF) were compared to evaluate the classification and diagnostic performance of the parameters using the confusion matrix. The mean and maximum power of the CMAP were significantly lower in patients with CTS than in the normal group (p < 0.05), and the XYF network had the best total performance of classification with 91.4%. This study suggests that the mean and maximum power of the CMAP can be considered as less time-consuming parameters for the diagnosis of CTS without using additional EP tests which can be uncomfortable for the patient due to poor tolerance to electrical stimulation.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuichi Sasaki ◽  
Tohru Terao ◽  
Emiko Saito ◽  
Keiichiro Ohara ◽  
Shotaro Michishita ◽  
...  

Abstract Background Carpal tunnel syndrome is a common peripheral nerve compression disorder. However, there is no established opinion regarding the predictors of symptom improvement after surgery. This study aimed to identify the predictors of surgical outcomes of severe carpal tunnel syndrome patients. Methods In the patients who underwent a carpal tunnel syndrome surgery, we selected the patients who had a preoperative Bland’s classification of grade 5 or 6, and assessed for the changes in Bland’s classification grade before and after surgery. Those who showed improvement from preoperative grades 5–6 to postoperative grades 1–4 comprised the improvement group. In contrast, those who did not show improvement and had postoperative grades 5 or 6 comprised the non-improvement group. In a nerve conduction study, amplitudes of the compound muscle action potential and sensory nerve action potential of the palms were assessed between the improvement and non-improvement groups. Results Among the 60 hands of 46 patients who had a preoperative Bland’s classification of grade 5 or 6, 49 hands of 37 patients comprised the improvement group, and 11 hands of 9 patients comprised the non-improvement group. The amplitudes of the compound muscle action potential and sensory nerve action potential of the palms before surgery were significantly higher in the improvement group. The degree of improvement in Bland’s classification grade was correlated with the degree of clinical symptom improvement. Conclusions Amplitudes of compound muscle action potential and sensory nerve action potential before surgery induced by palmar stimulation can predict improvements in nerve conduction study scores and clinical findings after surgical treatment.


Hand Surgery ◽  
2013 ◽  
Vol 18 (01) ◽  
pp. 49-52 ◽  
Author(s):  
Tomoo Inukai ◽  
Kenzo Uchida ◽  
Chikara Kubota ◽  
Takaharu Takamura ◽  
Hideaki Nakajima ◽  
...  

We examined 57 hands referred with suspected carpal tunnel syndrome (CTS) using the second lumbrical-interossei nerve test (2L-INT) as well as standard test. Sensory nerve conduction velocity (SCV) was detectible in 67% of patients (38/57), the abductor pollicis brevis-compound muscle action potential (APB-CMAP) in 84% (48/57), 2L-CMAP in 96% (55/57) and the first interossei palmares muscle (INT-CMAP) in 100% (57/57). ABP-CMAP was not recorded in patients in whom severe atrophy of the abductor pollicis brevis muscle was evident. As 2L-CMAP is maintained even in the most severe cases of CTS, the 2L-INT method is a valuable test for improving the accuracy of preoperative diagnosis in the electrophysiological diagnosis of CTS.


2016 ◽  
Vol 54 (3) ◽  
pp. 427-431 ◽  
Author(s):  
Hisao Kamiya ◽  
Michio Kimura ◽  
Satoshi Hoshino ◽  
Masahito Kobayashi ◽  
Masahiro Sonoo

Hand Surgery ◽  
2014 ◽  
Vol 19 (02) ◽  
pp. 199-204 ◽  
Author(s):  
Tatsuki Ebata ◽  
Katsumi Imai ◽  
Susumu Tokunaga ◽  
Yuji Takahasi ◽  
Yoshihiro Abe

Thumb opposition does not always represent the function of the median nerve due to variations in thenar muscle innervation. One hundred and thirty hands of 109 idiopathic carpal tunnel syndrome (CTS) patients with an undetectable compound muscle action potential of the abductor pollicis brevis (APB-CMAP) were classified into one of four groups; Type 1 (86.2%) had thenar muscle atrophy and could not perform thumb opposition; Type 2 (10.8%) had thenar muscle atrophy but could perform thumb opposition; Type 3 (2.3%) did not have thenar muscle atrophy and could perform thumb opposition, but needle electromyography of the APB showed neurogenic changes and Type 4 (0.8%) had no thenar muscle atrophy, could perform thumb opposition, and needle electromyography showed no neurogenic changes. Over 10% of severe CTS patients have mild or no muscle atrophy and intact thumb opposition. The purpose of this study was to investigate the variations in thenar muscle innervation in patients with severe CTS.


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