Nerve Conduction Studies In Diagnosis Research Articles

The Sensitivity and Specificity of Nerve Conduction Studies for Diagnosis of Carpal Tunnel Syndrome: A Systematic Review.

Background: The utility of nerve conduction studies (NCS) for diagnosis of carpal tunnel syndrome (CTS) has continued to be a subject of debate. Proponents of NCS assume a high sensitivity and specificity; however, many are unaware of the actual literature on this topic and the cutoff values commonly used for diagnosis. The purpose of this systematic review of the literature is to report the sensitivity and specificity of NCS for diagnosis of CTS in various studies. Methods: A literature review of PubMed and EMBASE databases was performed for all articles on NCS for diagnosis of CTS. The outcome of interest was the sensitivity and/or specificity of the NCS distal motor latency (DML) or distal sensory latency (DSL) cutoff value used to diagnose CTS in each study. Results: A total of 3066 total articles were screened and 21 were included in the review after assessment by two independent reviewers. The mean cut-off value for DSL was 3.37 ms (range 2.8-4 ms) and the mean cutoff value for DML was 4.28 ms (range 3.8-4.6 ms). Weighted mean DSL sensitivity was 73.4% and weighted mean DSL specificity was 93.6%. Weighted mean DML sensitivity was 56.2% and weighted mean DML specificity was 95.8%. Conclusions: There is significant variation in the cutoff values used for both DSL and DML. The wide range of cut-off values makes it difficult to interpret the literature, and there is a lack of high-quality studies with control groups using a priori cut-off values for diagnosis.

Utility of nerve conduction studies for diagnosis of injury to the medial branch of the superficial radial nerve.

IntroductionThe clinical utility of nerve conduction study (NCS) for the distal medial branch of the superficial radial nerve (SRN) has not yet been clarified. Therefore, we investigated the clinical utility of NCS in patients with suspected SRN injury and compared the results with those in healthy control subjects.MethodsBilateral NCS of the medial branch of the SRN was performed in two patients with suspected injury of the medial branch of the SRN, and in 20 healthy control subjects. A surface recording electrode was placed at the medial side of the metacarpophalangeal joint of the thumb. The SRN was then stimulated at a location 12 cm proximal from the recording electrode.ResultsThe mean sensory nerve action potential in the two patients was significantly lower than that of the controls (6.75 ± 0.92 vs. 23.8 ± 8.2 μV, P < 0.05). The side-to-side differences in sensory nerve action potential in the two patients were significantly higher than in the controls (55 ± 7.1 vs. 11 ± 7.8%, P < 0.05).ConclusionsNCS may be useful for diagnosing injury of the medial branch of the SRN.

Efficiency of Michigan Neuropathy Screening Instrument and Nerve Conduction Studies for Diagnosis of Diabetic Distal Symmetric Polyneuropathy

Abstract Background and Aims: Little data regarding distal symmetric polyneuropathy (DSP) prevalence in Romania is available. The aim of the present study was to assess the prevalence of DSP in our cohort, to characterize it depending on glycemic control, and also to find an easy-to-apply method for DSP screening which could be used in Romania. Material and Methods: We performed a cross-sectional study enrolling 51 patients followed in the Diabetes, Nutrition and Metabolic Diseases Clinic, Clinical County Hospital of Craiova, Romania. A complete evaluation protocol consisting in clinical examination and Michigan Neuropathy Screening Instrument (MNSI), together with nerve conduction studies were applied for evaluation. Results: Among the type 2 diabetic patients investigated, 72.54% had DSP. Three-quarters of them had poor glycemic control (HbA1c ≥7%). Mean HbA1c level was 9.17%. Poor glycemic control led to a more severe DSP form as proven by nerve conduction studies and clinical examination. Allodynia and motor deficit were predominantly found with HbA1c ≥7%. Mean MNSI score for the group was 2.55, strongly correlated with nerve conduction studies. Conclusion: MNSI is a simple and validated diagnostic tool for DSP with a strong correlation to electrophysiological parameters. Therefore, its daily implementation in clinical practice could help identify and follow patients at risk for DSP.

Accuracy of somatosensory evoked potentials in diagnosis of mild idiopathic carpal tunnel syndrome

Objective Concerning prevalence of carpal tunnel syndrome (CTS) and the difficulties with electromyography (EMG) and nerve conduction studies (NCS), this study was designed to evaluate the power of somatosensory evoked potential (SSEP) in CTS diagnosis among Iranian patients. Patients and methods SSEP was performed on 100 asymptomatic hands of 50 healthy participants (40 female, age range 38–59 years) and on 61 hands of 46 patients (39 female, age range 34–58 years). Mean difference between N 20 latency of the middle finger and the wrist (median nerve innervation) as well as N 20 latency of the third finger and the fifth finger (ulnar nerve innervation) were measured. Using receiver operating characteristic (ROC) curve analysis, the upper limits of these variables were defined as 6.0 and 1.5 ms, respectively. Higher amounts in either of these variables were considered as positive SSEP for diagnosis of CTS. Measures of accuracy for SSEP were measured getting clinical diagnosis by two separate neurologists as the reference standard. In the patients’ group who underwent both techniques of SSEP and EMG–NCS, kappa statistic as the agreement coefficient between two procedures was calculated. Results Sensitivity, specificity, and likelihood ratios for positive and negative results of SSEP in diagnosis of CTS were 70.4%, 91.0%, 7.83 and 0.32, respectively. Sensitivity of EMG–NCS in diagnosis of CTS was measured as 81.9%. Measure of agreement between two procedures (kappa) was calculated as 0.42. Conclusion This study showed that positive results of SSEP might have a role in diagnosis of CTS. However, larger studies to demonstrate diagnostic power of SSEP in comparison with EMG–NCS seem necessary.

Carpal Tunnel Syndrome

To the Editor.— I read with considerable interest the article by Hoffman (233:983-984, 1975). The point he makes about sensory nerve conduction studies in diagnosis is a good one. In the case cited, however, it seems to me from the history that the diagnosis is, if not clear-cut, certainly extremely suggestive of a carpal tunnel syndrome, and one wonders why it was not suspected before a number of fairly elaborate and expensive tests were done. In the practice of hand surgery, we see a large number of persons with symptoms similar to this. It has been our practice to carefully inject the carpal tunnel with a cortisone preparation and lidocaine with a No. 27, 1-cm needle. At the same time, a cock-up splint to put the hand in the position of function is made for night use. These steps serve as both a diagnostic and a therapeutic maneuver since relief

Carpal tunnel syndrome. Importance of sensory nerve conduction studies in diagnosis.

CARPAL tunnel syndrome (median neuropathy at the wrist) is the commonest type of peripheral nerve entrapment syndrome in the upper limb. Electrophysiologic studies have been employed in the diagnosis of this syndrome for almost two decades. Still, however, a large number of these conditions will go undiagnosed unless the physician is aware of the importance of obtaining sensory nerve conduction determinations in suspected individuals. The following case report exemplifies this point. Report of a Case A 33-year-old right-handed physiotherapist was examined at University Hospitals because of a three-year complaint of episodic paresthesias and numbness in her right hand, extending to the shoulder. Symptoms were particularly bothersome at night, frequently awakening her; for the last three months, she had been unable to sleep through a single night. For the past month, she had mild tingling in her left hand and forearm. She denied neck or upper extremity injury. She had not