Correlation between Ultrasound Findings and Nerve Conduction Studies in Evaluation of Upper Limb Neuropathy

Confirmatory methods such as nerve conduction studies are often performed to support a clinical carpal tunnel syndrome diagnosis and to rule out other upper extremity pathologies. Ultrasonography provides another diagnostic option, especially when nerve conduction studies are discordant with history and physical examination. The authors explored the correlation of ultrasound findings with clinical carpal tunnel syndrome diagnosis in patients with normal nerve conduction study results. A database of 220 patients with carpal tunnel syndrome was analyzed retrospectively to reveal 24 patients (28 hands) with a clinical diagnosis and normal nerve conduction study results. Patient demographics and nerve conduction study and ultrasound findings were compared with those of a control group of patients without carpal tunnel syndrome (42 patients, 52 hands). Median nerve cross-sectional area was recorded; values of 10 mm 2 or greater were considered positive for carpal tunnel. Statistical and correlation analyses were performed between control and carpal tunnel groups comparing key measures of interest. Mean cross-sectional area was significantly increased in patients with carpal tunnel syndrome with normal nerve conduction study results compared with controls. The proportion of carpal tunnel-positive, nerve conduction study-negative patients with cross-sectional area measurements greater than 10 mm 2 was significantly greater than the proportion for control patients. Neither age nor body mass index correlated with cross-sectional area measurements. Nerve conduction study latencies and amplitudes did not correlate with ultrasound abnormalities. Patients diagnosed clinically with carpal tunnel syndrome with normal nerve conduction study results were found to have clinically significant median nerve cross-sectional area on ultrasound (10.1 ±2.1 mm 2 , p < 0.001). Cross-sectional area measurements on ultrasound did not correlate with nerve conduction study measures. These results suggest that ultrasound holds a unique diagnostic utility in the evaluation of carpal tunnel syndrome, especially when nerve conduction studies are negative. Diagnostic, II.

Neuropathy following axillary brachial plexus block: is it the tourniquet?

Neuromuscular ultrasound in the diagnosis of focal neuropathies superimposed on polyneuropathy: A case report

This review aims to remind you of some of the fallibility of electromyography (EMG) and nerve conduction studies, as well as their usefulness. Areas covered will include designing the nerve conduction and EMG study, variables that effect the test including aging and temperature, how extensive a study needs to be, the importance of patient cooperation, interpretation of spontaneous discharges, types of electrical interference, and the importance of looking at the waveforms themselves from nerve conduction studies.

Unusual neurophysiological features in Cockayne's syndrome: a report of two cases as a contribution to diagnosis and classification

This study evaluated the Wisconsin functional sensory and psychomotor test battery for carpal tunnel syndrome (CTS). Subjects were 27 employees recruited from a food processing plant. Both hands of all subjects were examined and categorized by presence or absence of symptoms and nerve conduction study (NCS) findings (Symptom-/NCS-, Symptom+/NCS-, Symptom-/NCS+, and Symptom+/NCS+). Symptom-/NCS- category hands had significantly better performance (15-60%) for most of the functional test battery variables than Symptom+/NCS+ category hands. A significant gap detection threshold difference (32%) was observed between NCS+ and NCS- hands regardless of symptoms, with NCS- having impaired performance. No significant effect of CTS symptoms on performance was observed. Stepwise discriminant analysis was used to select the best variables to differentiate between groups. The ratio of the change in pinch rate with respect to required pinch force differentiated NCS+ from NCS- hands, with a sensitivity of 0.71 and a specificity of 0.68. The same variable had a sensitivity of 0.74 and specificity of 0.83 for distinguishing Symptom-/NCS- hands from all other categories. Pinch rate had a sensitivity of 0.82 and a specificity of 0.81 for separating Symptom+/NCS+ hands from all other categories. Use of both gap detection threshold and the ratio of the change in pinch rate with respect to required pinch force could best differentiate Symptom+/NCS+ from Symptom-/NCS- cases for a sensitivity of 0.91 and specificity of 0.87. Outcomes could not be generalized to a specific work population but demonstrate that the non-invasive test battery may be useful for providing objective measures of deficits associated with CTS symptoms and electrophysiological parameters.

ObjectiveThe frequency and type of neuropathy in vitamin B12 deficiency neurological syndrome (VBDNS) is controversial. This study reports the frequency and type of nerve dysfunction in VBDNS using nerve conduction and sural nerve biopsy and its response to treatment.MethodSixty-six patients with VBDNS diagnosed on the basis of low serum vitamin B12 level and/or megaloblastic bone marrow were subjected to clinical evaluation, hemoglobin, mean corpuscular volume, thyroid function test, HIV serology, and vasculitic profile. Peroneal motor and sural sensory nerve conduction studies were done. Sural nerve biopsy was done in six patients. The patients were treated with cyanocobalamin injection and followed up clinically and with nerve conduction study at 3 and 6 months.ResultsThe median age of the patients was 46 (12–80) years and 11 patients were females. The duration of symptoms was 1–96 (median 7) months. Clinical features of neuropathy were present in 46 (69.7%) patients and nerve conduction was abnormal in 36 (54.5%) patients. On nerve conduction study, 8 (22.2%) patients had axonal, 4 (11.1%) had demyelinating, and 24 (66.7%) had mixed features. Nerve biopsy revealed acute axonal degeneration in early stage and chronic axonopathy with demyelination in the late stages of disease. The nerve conduction parameters improved at 6 months along with clinical recovery.ConclusionNearly 70% patients with VBDNS had evidence of neuropathy which is mainly axonal with some demyelinating features.

Clinical neurophysiology

Background and purpose: Nerve conduction study (NCS) and ultrasonography (US) are used to support the diagnosis of carpal tunnel syndrome (CTS). The ability of the Semmes-Weinstein monofilament test (SWMT), a sensibility threshold test, to detect CTS, and its relationship to clinical severity, NCS, and US, remain controversial. We conducted this study to address this controversy. Method: Thirty-three patients presenting with typical symptoms and signs of CTS and 20 normal subjects were enrolled. SWMT on the index finger, NCS, and US of the cross-sectional area of the median nerve at the pisiform level (PCSA) were performed. Receiver operating characteristic (ROC) curves of SWMT, variables of NCS, and PCSA were plotted to analyze their discriminative utilities. The diagnostic agreement for CTS among SWMT, NCS, and PCSA were analyzed by kappa statistics. Sensitivities, specificities, positive predictive values (PPV), negative predictive values (NPV), and accuracies, as well as the correlation coefficients among SWMT, NCS measures, and PCSA, were calculated. Results: The areas under the ROC curve (AUC) for SWMT and PCSA were 0.852 and 0.71, respectively. AUCs for three NCS variables ranged from 0.822 to 0.902. All these variables were discriminative for CTS and were not significantly different in their discriminative power. SWMT yielded sensitivity, specificity, PPV, NPV, and accuracy of 82%, 70%, 82%, 70%, and 77%, respectively. There is significant agreement in detection of CTS using SWMT and NCS (kappa=0.575, p＜0.001). The kappas between SWMT and PCSA, as well as NCS and PCSA, were 0.305 and 0.427, respectively (p=0.025 and 0.002). SWMT significantly correlates with not only clinical stage, but also NCS measures and PCSA (r ranged from 0.381 to 0.581, p＜0.01). Conclusion: SWMT shows discriminative power similar to NCS and US for detection of CTS. SWMT also has a moderate correlation with clinical stage, NCS measures, and PCSA on US. As a painless, convenient, and inexpensive modality, SWMT may have the ability to diagnose CTS, but further research is needed.

ObjectiveTo determine the optimal stimulation and recording site for infrapatellar branch of saphenous nerve (IPBSN) conduction studies by a cadaveric study, and to confirm that obtained location is practically applicable to healthy adults.MethodsTwelve lower limbs from six cadavers were studied. We defined the optimal stimulation site as the point IPBSN exits the sartorius muscle and the distance or ratio were measured on the X- and Y-axis based on the line connecting the medial and lateral poles of the patella. We defined the optimal recording site as the point where the terminal branch met the line connecting inferior pole of patella and tibial tuberosity, and measured the distance from the inferior pole. Also, nerve conduction studies were performed with obtained location in healthy adults.ResultsIn optimal stimulation site, the mean value of X-coordinate was 55.50±6.10 mm, and the ratio of the Y-coordinate to the thigh length was 25.53%±5.40%. The optimal recording site was located 15.92±1.83 mm below the inferior pole of patella. In our sensory nerve conduction studies through this location, mean peak latency was 4.11±0.30 ms and mean amplitude was 4.16±1.49 µV.ConclusionThe optimal stimulation site was located 5.0–6.0 cm medial to medial pole of the patella and 25% of thigh length proximal to the X-axis. The optimal recording site was located 1.5–2.0 cm below inferior pole of patella. We have also confirmed that this location is clinically applicable.

ObjectiveTo elucidate the ultrasound (US) features of peripheral nerves including nerve roots in patients with different types of Charcot-Marie-Tooth disease (CMT), and the association between US findings, clinical features and...

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy, caused by the compression of the median nerve in the carpal tunnel over the wrist. The purpose of this study is to demonstrate how different wrist positions change median nerve image and their corresponding results of nerve conduction study (NCS). In this study, we investigated 40 normal wrists and 32 wrists with CTS. In both groups, subjects were randomly assigned to wear a splint, and the wrist was placed at 0, 15, 30 and 45 degrees of extension. Ultrasonography was performed before splinting, immediately after splinting and repeated again 2, 4 and 6 hours later. Ultrasonographic examination evaluated the flattening ratio and cross-sectional area of the median nerve at carpal tunnel. NCS was performed before splinting and repeated again 2, 4 and 6 hours later. The motor and sensory components of nerve conduction over median nerve were tested. The results showed that the neutral position was associated with the lowest median nerve compression over time. All the extended wrist positions were associated with significant median nerve flattening at the proximal carpal tunnel level. But there were no significant electrophysiological differences between different wrist positions. The proper wrist position is a very important factor in preventing median nerve compression, and the ultrasonographic finding is more sensitive for earlier detection concerning median nerve compression.

To validate the diagnostic accuracy of a previously described short sonographic protocol to identify chronic inflammatory neuropathy (CIN), including chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis Sumner syndrome, and multifocal motor neuropathy (MMN), and to determine the added value of nerve ultrasound to detect treatment-responsive patients compared to nerve conduction studies (NCS) in a prospective multicenter study. We included 100 consecutive patients clinically suspected of CIN in 3 centers. The study protocol consisted of neurologic examination, laboratory tests, NCS, and nerve ultrasound. We validated a short sonographic protocol (median nerve at forearm, upper arm, and C5 nerve root) and determined its diagnostic accuracy using the European Federation of Neurological Societies/Peripheral Nerve Society criteria of CIDP/MMN (reference standard). In addition, to determine the added value of nerve ultrasound in detecting treatment-responsive patients, we used previously published diagnostic criteria based on clinical, NCS, and sonographic findings and treatment response (alternative reference standard). Sensitivity and specificity of the sonographic protocol for CIN according to the reference standard were 87.4% and 67.3%, respectively. Sensitivity and specificity of this protocol according to the alternative reference standard were 84.6% and 72.8%, respectively, and of NCS 76.1% and 93.4%. With addition of nerve ultrasound, 44 diagnoses of CIN were established compared to 33 diagnoses with NCS alone. A short sonographic protocol shows high diagnostic accuracy for detecting CIN. Nerve ultrasound is able to detect up to 25% more patients who respond to treatment. This multicenter study provides Class IV evidence that nerve ultrasound improves diagnosis of CIN.

Foot complications are a well known factor which contribute to the morbidity of diabetes and increases the chance of amputation. A total of 126 consecutive diabetic patients were evaluated by diabetic foot screening. Forty-one patients showed an impaired protective sense when tested with Semmes-Weinstein monofilament 5.07 (10 g), and 92% of them showed peripheral polyneuropathy in nerve conduction study (NCS). The mean vibration score of the Rydel-Seiffer graduated tuning fork in patients with peripheral polyneuropathy in nerve conduction (NCV) study was 5.38+/-2.0, which was significantly different from that of patients without polyneuropathy in NCS. Among the deformities identified on examination, callus, corn, and hallux valgus were the greatest. While checking the ankle/ brachial index (ABI), we also evaluated the integrity of vasculature in the lower extremities. After extensive evaluation, we classified the patients into eight groups (category 0,1,2,3,4A,4B,5,6). The result of this study suggested that the Semmes-Weinstein monofilament test, Rydel-Seiffer graduated tuning fork test, and checking the ankle/brachial index were simple techniques for evaluating pathologic change in the diabetic foot by office screening, and that this screening based on treatment-oriented classification helps to reduce pedal complications in a diabetic population.

Background Ongoing research aims to correlate ultrasound (US) findings with nerve conduction studies (NCS) results for the diagnosis of Guillain–Barré syndrome (GBS). NCS is currently the gold standard for confirming GBS diagnosis. This study aimed to compare nerve cross-sectional area (CSA) between GBS patients and controls and among different GBS subtypes, determine the correlation between CSA and NCS parameters, and identify a potential CSA cut-off value for early GBS screening. This study included 41 patients with GBS and 35 matched controls. Participants underwent comprehensive history taking, physical examination, NCS, and US measurement of CSA of peripheral nerves in upper and lower limbs. Receiver operating characteristic (ROC) analysis was performed to assess the ability of US CSA measurements to discriminate between GBS cases and controls. Results GBS patients had larger US nerve CSA than controls. No significant variations in CSA existed among different GBS electrophysiological subtypes. ROC curve analysis showed that median nerve CSAs at mid-forearm, pronator quadratus, and pronator teres were highly accurate for diagnosing GBS, with an area under the curve (AUC) of 1. Ulnar and posterior tibial nerve CSA were less precise. No substantial correlation existed between CSA and NCS parameters in the same nerve, although some association with clinical rating scales was present. Conclusions This study suggests nerve US may complement NCS in early GBS diagnosis, proposing CSA cut-off values for median, ulnar, and posterior tibial nerves. Further larger studies with standardized US protocols are needed to validate the reproducibility and diagnostic utility of these cut-offs. Trial registration The study was prospectively registered on 17 September 2019 on the ClinicalTrials.gov website, and the registration number is NCT04092140, https://classic.clinicaltrials.gov/ct2/show/NCT04092140