Measurement Of Nerve Cross-sectional Area Research Articles

Detection of Reduced Diameter of the Cochlear Nerve in Long-term Deaf Patients Quantified With Semiautomatic Measurement of Nerve Cross-sectional Area Using 3T MRI Data.

High-resolution parallel transmit T2 sampling perfection with application optimized contrast using different flip angle evolution sequence with improved edge discrimination and semiautomatic determination of nerve cross-sectional area (CSA) can be used to evaluate nerve degeneration in the inner auditory canal (IAC) in long-term deaf patients. In patients with hearing loss, temporal bone MRI is routinely acquired to evaluate the morphology of the nerves within the IAC. Earlier studies have shown that the diameter of the cochlear nerve can be used as prognostic marker for the auditory performance after cochlear implantation in postlingually deaf patients. Eighty-two consecutive MRI scans were analyzed using a semiautomatic tool to measure CSA of cranial nerves in the IAC. Results were correlated with patient history and audiology testing as well as with age and gender. There was a significant reduced CSA of the cochlear nerve in ears with moderate-to-profound hearing loss and deafness compared with ears with normal hearing, but no significant difference in ears with mild-to-moderate hearing loss compared with normal hearing. In detail, normal hearing ears had a CSA of 1.23 ± 0.11 mm2, whereas ears with pantonal hearing loss of more than 40 dB had 1.02 ± 0.05 mm2 (P = 0.026). Maximal CSA of the facial nerve was not different among all groups (average, 1.04 mm2 ± 0.03; linear regression, P = 0.001) and stable with age. However, vestibular nerve CSA decreased significantly with age (average, 1.78 ± 0.05 mm2; linear regression, P = 0.128). In long-term deaf patients, smaller the diameter of cochlear nerve is the more severe the hearing loss is. The new semiautomatic tool can primarily be used to assess nerve diameter and possibly determine ears with nerve degeneration.

Correlation of Ultrasonography and MRI with Electrodiagnostic Studies in Carpal Tunnel Syndrome.

Background: One controversial question in Carpal Tunnel Syndrome (CTS) diagnosis is whether magnetic resonance imaging (MRI) and Ultrasound (US) imaging tools have any relationship with electrodiagnostic (EDX) study. The objective of this study is to determine the possible correlation between MRI and US measurements with EDX parameters. Methods: Both US and MRI of the median nerve were simultaneously performed in 12 confirmed CTS wrists, at two levels of forearm distal fold (proximal) and the hook of the hamate (distal), to measure various anatomic parameters of the nerve. EDX parameters of median motor distal latency (DL) and median sensory proximal latency (PL) were evaluated in milliseconds. Results: Nerve cross-sectional area (CSA), measured by MRI, correlated with sensory PL at distal level (p = 0.015). At proximal level MRI, nerve width and width to height ratio also correlated with motor DL (p = 0.033 and 0.021, respectively). Median nerve CSA proximal to distal ratio correlated with sensory PL (p = 0.028) at MRI. No correlation was found between US and EDX measurements. Conclusions: Median nerve MRI measurement of nerve CSA at hook of the hamate (distal) level or CSA proximal to distal ratio correlated with EDX parameter of sensory PL. On the other hand, nerve MRI width and width to height ratio at distal level correlated with motor DL in EDX. Level of Evidence: Level III (Diagnostic).

Changes in Cross-sectional Area of the Median Nerve and Boston Carpal Tunnel Questionnaire Scores After Carpal Tunnel Release.

We hypothesized that postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores and ultrasound (US) measurements of the median nerve cross-sectional area (CSA) at the distal wrist crease are significantly decreased at 2-week, 6-week, and ≥ 6 months follow-up appointments, compared with baseline values. This study was a retrospective chart review of patients who presented to a single hand clinic with evidence of carpal tunnel syndrome over a 6-year period (2014-2020). Patients received baseline US measurements of the median nerve CSA as well as completion of the BCTQ, and for the patients who underwent carpal tunnel release (CTR), postoperative US measurements and questionnaire scores were obtained at 2 weeks, 6 weeks, or ≥ 6 months postoperatively. This study included 224 separate wrists. Median Nerve CSA measurements were 13.2 ± 4.5 mm2 at baseline, 11.9 ± 3.6 mm2 at 2 weeks postoperatively, 11.6 ± 4.5 mm2 at 6 weeks postoperatively, and 11.7 ± 4.3 mm2 at 6 months or more (P = .002). The BCTQ Symptom Severity Scale scores were 3.14 ± 0.76 at baseline, 1.76 ± 0.63 at 2 weeks, 1.68 ± 0.70 at 6 weeks, and 1.41 ± 0.64 at 6 months or longer (P < .001). The BCTQ Functional Status Scale scores were 2.56 ± 0.89 at baseline, 2.03 ± .1.0 at 2 weeks, 1.65 ± 0.77 at 6 weeks, and 1.36 ± 0.61 at 6 months or longer (P < .001). These findings demonstrated a sustained decrease in median nerve CSA and patient-reported outcomes following CTR at 2 weeks, 6 weeks, and between 6 and 12 months.

P 83 Nerve ultrasound cross-sectional area reference values in children from 2 to 17 years and their correlation with demographic and anthropometric data

Question: High-resolution ultrasound (HRUS) is of growing importance in the routine workup of disorders of the peripheral nervous system. However, reference values for children and adolescents are not available in most ultrasound laboratories. The correlation of cross-sectional area (CSA) values with demographic and anthropometric data has been analysed in adults, the exact influence of anthropometric data on nerve ultrasound reference values in children and adolescents is discussed in the literature (1,2). The present prospective observational study analyses the influence of height, weight, age, gender, and the volume of the hands on CSA values in nerve HRUS in healthy children and adolescents from 2 – 17 years. Methods: CSA were measured in 30 healthy children and adolescents from 2 – 17 years in the median, ulnar and radial nerves in the upper extremity and in the tibial, peroneal and sural nerve in the lower extremity at different nerve sites. Height, weight, age, handedness and gender were recorded, the volume of the hands was measured using the water displacement method. The intra-nerve CSA variability and the side-to-side difference ratio of the intra-nerve CSA variability (SSDIVA) for the median, ulnar and tibial nerves was calculated. Normal distribution of the data was tested using the Shapiro-Wilk test. Spearman’s rho and Pearson's correlation coefficient was calculated for CSA, intra-nerve CSA variability, SSDIVA and age, weight, gender, hand volume. Multiple linear regression analysis with backward exclusion was used to calculate the best model predicting CSA. Model selection was based on the Akaike information criterion (AIC). Results: Nerve CSA values were consistently lower than those reported for adults and increased in all measured nerve sites with increasing age, height and weight (see Figure 1 for the ulnar nerve and age groups). This increase had a tendency to levell off at an age of 14 – 17 years. The highest correlation coefficients and best-fitting model predicting CSA were found for the variable “weight”. Correlation coefficients were higher in a linear than in logarithmic model (Figure 2). Hand volume showed a positive correlation with age, weight and nerve CSA. Conclusions: Normal values for CSA in high-resolution nerve ultrasound should be adapted for children and adolescents. Demographic data such as height, weight and age can be considered to stratify and adjust normal values to the individual child's development. Corresponding with the findings of Druzhinin (1) and in contrast to the results of Schubert (2) our data suggest that weight, and not age, has the maximum influence on nerve CSA measurements.

Normative Values for the Sonographic Measurement of the Pediatric Median and Ulnar Nerves

Ultrasound investigation of peripheral nerves, long used in the adult population, has been shown to be of value in diagnosing a variety of peripheral nerve abnormalities. More recently, nerve sonography has also been shown to be of use in pediatrics. However, normative values for nerve size in children have been lacking. As such, the goal of this research was to establish normative data for cross sectional area (CSA) measurements of the median and ulnar nerves in children. The median and ulnar nerves of 48 children ranging in age from 2 years to 17 years were imaged by ultrasound. CSA measurements were made at 2 separate sites for each nerve and measured independently by 6 pediatric radiologists. Reliability of ultrasound measurements between the radiologists was assessed by calculating intraclass correlation coefficients. Linear mixed-effects modeling was performed to develop prediction models for nerve cross sectional area for each nerve segment; 95% prediction values were generated from these models to approximate normal ranges. Agreement in nerve cross-sectional area measurements among the 6 radiologists for all nerve segments was good (ICC 0.82, 95% CI 0.78 to 0.85). CSA for both the median and ulnar nerves is larger in older children. However, statistical models to predict CSA using height perform better rather than those using a child's age. The range of normal nerve segment CSA using these prediction models based on child height are reported. Median and ulnar nerve CSA can be reliably measured with ultrasound. Normal reference values for ulnar and median nerve CSA correlate with patient age but may be more optimally determined based on a child's height.

Investigation of the Effect of Cervical Radiculopathy on Peripheral Nerves of the Upper Extremity With High-Resolution Ultrasonography.

Prospective, cross-sectional observational study. We aimed to investigate the effects of chronic cervical radiculopathy (CR) on the cross-sectional area (CSA) values of the cervical nerve roots (CNRs), median, ulnar, and radial nerves with high-resolution ultrasonography. Symptomatic nerve roots are wider than asymptomatic nerve roots due to the presence of edema. Peripheral nerves have also been shown to develop edema, fibrosis, and changes distal to the affected nerve as a result of mechanical compression. In addition according to "double-crush syndrome" hypothesis, the peripheral nerves are more sensitive to pressure, and a proximal nerve lesion makes the distal segment of the nerve more susceptible to anatomic deterioration by causing interruption in the axoplasmic conduction due to compression. Forty patients with chronic CR were included to the study. Both affected CNRs and the contralateral nerve roots (control group) were evaluated with high-resolution ultrasonography. Ulnar and median nerve CSA measurements were performed at four measurement points and radial nerve measurements at a single measurement point. CSA measurements were statistically significantly higher at the CNR of the affected side compared to the unaffected side. There was no statistically significant difference when affected and unaffected sides were compared in terms of measurements performed from median, ulnar, and radial nerves at all measurement points. The results of the present study indicate that the changes in the CNR caused by CR do not have any effect on the peripheral nerves. We did not find any affection in peripheral nerve CSA that might have been suggestive of double-crush syndrome in CR. 2.

Carpal tunnel syndrome in patients with and without diabetes mellitus in Upper Egypt: The impact of electrophysiological and ultrasonographical studies

BackgroundCarpal tunnel syndrome (CTS) is the most common entrapment neuropathy in the upper extremity. Nerve conduction studies (NCS) is the most valid way of diagnosing CTS in combination of these clinical symptoms together with positive signs by physical examination. Ultrasonography is a useful non-invasive diagnostic method for CTS and there is considerable correlation between the electrophysiological tests and the measurements of cross-sectional area (CSA) by ultrasonography. Many studies have shown that the carpal tunnel syndrome seems to occur more frequently in patients with diabetes mellitus and might be associated with the duration of diabetes mellitus, microvascular complications and degree of glycemic control. Although diabetes mellitus is a risk factor for CTS, reports about median nerve CSA measurements between CTS patients with and without DM are scant. This prospective study aimed to evaluate whether or not ultrasonographic findings of the median nerve is different between DM and non-DM-CTS patients. To correlate the diagnostic results in both DM and non-DM-CTS patients. Patients and methodsThirty six non-diabetic patients and twenty five diabetic patients with CTS were assessed. All patients were subjected to thorough history taking, full clinical examination, electrophysiological assessment of wrists and gray scale ultrasonography (US). ResultsHigh mean cross sectional area of median nerve (CSA) on ultrasonographical studies was detected with non-significant difference between both groups. Additionally, a non-significant difference for flattening ratio was found between two groups. Moreover, there was a highly significant positive correlation between electro diagnostic and ultrasonographic results in diabetic patients. ConclusionThe CSA of median nerve is larger in CTS hands in both DM and non-DM patients. Mean electro-diagnostic parameters were not significant predictors of CTS in patients with diabetes. The combination of electrophysiological and ultrasonography provides diagnostic effective tools across the entire spectrum of CTS in diabetic and non-diabetic patients. Nevertheless, screening for DM in patients with CTS is not recommended.

Extensive sonographic ulnar nerve enlargement above the medial epicondyle is a characteristic sign in Hansen's neuropathy.

ObjectiveEarlier studies have shown sonographic enlargement of the ulnar nerve in patients with Hansen’s neuropathy. The present study was performed to determine whether sonography or electrophysiological studies can detect the specific site of ulnar nerve pathology in leprosy.MethodsEighteen patients (thirty arms) with Hansen’s disease and an ulnar neuropathy of whom 66% had borderline tuberculoid (BT), 27% lepromatous leprosy (LL) and 7% mid-borderline (BB) leprosy were included in the study. Cross-sectional area (CSA) of ulnar nerve was measured every two centimeters from wrist to medial epicondyle and from there to axilla. All patients underwent standard motor and sensory nerve conduction studies of the ulnar nerve. Thirty age and sex matched controls underwent similar ulnar nerve CSA measurements and conduction studies.ResultsUlnar nerve was clinically palpable in 19 of the 30 arms of patients. Motor and sensory nerve conduction studies of the ulnar nerve showed a reduced compound motor action potential and sensory nerve action potential amplitude in all patients. Motor Conduction Velocity (MCV) in patients were slower in comparison to controls, especially at the elbow and upper arm, but unable to exactly locate the site of the lesion. In comparison to controls the ulnar nerveCSA was larger in the whole arm in patients and quite specific the maximum enlargement was seen between nulnar sulcus and axilla, peaking at four centimeters above the sulcus.ConclusionsA unique sonographic pattern of nerve enlargement is noted in patients with ulnar neuropathy due to Hansen’s disease, while this was not the case for the technique used until now, the electrodiagnostic testing. The enlargement starts at ulnar sulcus and is maximum four centimeters above the medial epicondyle and starts reducing further along the tract. This characteristic finding can help especially in diagnosing pure neuritic type of Hansen’s disease, in which skin lesions are absent, and alsoto differentiate leprosy from other neuropathies in which nerve enlargement can occur.

Peripheral nerve ultrasound in pediatric Charcot-Marie-Tooth disease type 1A

To investigate differences in nerve cross-sectional area (CSA) as measured by peripheral nerve ultrasound in children with Charcot-Marie-Tooth disease type 1A (CMT1A) compared to healthy controls. This was a cross-sectional, matched, case-control study. CSA of the median, ulnar, tibial, and sural nerves was measured by peripheral nerve ultrasound. The mean difference in CSA between children with CMT1A and controls at each nerve site was determined. The relationship between nerve CSA and age/body metrics, and between nerve CSA and neurologic disability in CMT1A, was also evaluated. Twenty-nine children with CMT1A and 29 age- and sex-matched controls were enrolled. Nerve CSA was significantly increased in children with CMT1A compared to controls (1.9- to 3.5-fold increase, p < 0.001). The increase in nerve CSA with age was disproportionately greater in those with CMT1A. Nerve CSA showed a strong positive linear correlation with age, height, and weight in both the CMT1A and control groups. Disease severity correlated with both nerve CSA and age. Children with CMT1A have significantly increased nerve CSA compared to controls, and the increase in nerve CSA with age is disproportionately greater in CMT1A, suggesting ongoing nerve hypertrophy throughout childhood. Nerve CSA correlates with neurologic disability. These findings demonstrate the utility of peripheral nerve ultrasound as a diagnostic tool in pediatric neuropathies, and as an outcome measure in natural history studies and clinical trials in CMT1A. This study provides Class IV evidence that measurement of nerve CSA by peripheral nerve ultrasound accurately identifies patients with CMT1A.

Reference values for nerve ultrasonography in the upper extremity

The aims of this study were to identify factors affecting the measurement of nerve cross-sectional area (CSA) and to establish normal reference values for nerve ultrasonography of the upper extremity. Ninety-seven age-matched, healthy individuals were enrolled. Ultrasonographic tests were performed by tracing nerves from the axilla to the distal arm. CSA was measured at the following locations: median nerve (carpal tunnel inlet, forearm, antecubital fossa, midhumerus); ulnar nerve (wrist, 2 cm proximal to the wrist, forearm, cubital tunnel outlet and inlet, midhumerus); radial nerve (spiral groove, antecubital fossa); and musculocutaneous nerve (proximal humerus). The CSA reference values differed between the measured points along the path of each nerve. Nerve CSA correlated significantly with weight, body mass index, height, and gender; however, the CSA ratio (distal/proximal) did not correlate with demographic factors. The normal reference values may be helpful in diagnosis of pathologies involving these nerves.

Reasons for using swelling ratio in sonographic diagnosis of carpal tunnel syndrome and a reliable method for its calculation

The aim of this study was to investigate factors affecting median nerve cross-sectional area (CSA) and determine a dependable swelling ratio (SR) calculation method. Using ultrasonography, median nerve CSAs were measured at the tunnel inlet, midtunnel, and outlet, and at 4 cm and 12 cm proximal to the wrist. We used CSAmax as the largest of the tunnel measurements and calculated swelling ratios (SRs) by using the CSAmax. Sonographic measurements were correlated with electrophysiologic findings. We evaluated the effects of gender, weight, and height on median nerve thickness. We studied 95 wrists of 55 CTS patients and 48 wrists of 27 volunteers. Gender, weight, and height had effects on certain median nerve CSA measurements. CSAmax, SRmax4, and SRmax12 had superior correlations with electrophysiologic findings. The correlation between 4-cm and 12-cm median nerve CSAs was statistically significant (r = 0.879 and P < 0,001). We have developed a reliable SR method considering factors affecting median nerve CSA.

Diagnostic value of ultrasonography and magnetic resonance imaging in ulnar neuropathy at the elbow.

Aim. To evaluate the diagnostic value of ultrasonography and magnetic resonance imaging (MRI) in patients with ulnar neuropathy at the elbow (UNE). Methods. We prospectively performed electrodiagnostic, ultrasonographic, and MRI studies in UNE patients and healthy controls. Three cross-sectional area (CSA) measurements of the ulnar nerve at multiple levels along the arm and maximum CSA(-max) were recorded. Results. The ulnar nerve CSA measurements were different between the UNE severity grades (P < 0.05). CSA-max had the greatest sensitivity (93%) and specificity (68%). Moreover, CSA-max ≥10 mm2 defined the severe UNE cases (sensitivity/specificity: 82%/72%). In MRI, ulnar nerve hyperintensity had the greatest sensitivity (90%) and specificity (80%). Conclusion. Ultrasonography using CSA-max is sensitive and specific in UNE diagnosis and discriminating the severe UNE cases. Furthermore, MRI particularly targeting at increased signal of the ulnar nerve can be a useful diagnostic test of UNE.

Reproducibility of Sonographic Measurements of the Median Nerve

The purpose of this study was to evaluate the reproducibility of median nerve cross-sectional area (CSA) measurements using the indirect method (ellipsoid formula) and the direct or tracing method. The median nerve CSA was measured in 22 wrists of patients with carpal tunnel syndrome by means of high-frequency sonography. Measurements were made at the level of the pisiform bone by a standardized sonographic examination protocol. Two observers with different levels of experience performed the measurements, independently and blinded. An analysis of reliability was carried out, and the concordance between the methods was determined with parametric statistical tests. The results point to good reproducibility of the median nerve CSA measurements obtained by both methods, whether performed by an experienced observer or by an inexperienced observer after a short learning period. The results suggest sonography for median nerve CSA measurements is reproducible by either the direct or indirect method when a standardized sonographic examination protocol is used.

US and MR imaging of peripheral nerves in leprosy.

To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Fifty-eight nerves with abnormal clinical features or electromyograms were examined in 23 leprosy patients by means of gray-scale US, Doppler US and MR imaging. Image analysis included: measurement of nerve cross-sectional area; assessment of nerve structure and MR signal intensities; identification of nerve compression within osteofibrous tunnels; detection of endoneural color flow signals and Gd-DTPA enhancement. Correlations were made with clinical findings and a control group of 20 subjects. Fourteen nerves in active reversal reaction were followed up after therapy. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started.