Cross-sectional Area Values Research Articles

Subjective and Objective Differences in Patients with Unilateral and Bilateral Carpal Tunnel Syndrome and the Role of Obesity in Syndrome Severity.

It remains unclear whether physiologic differences exist in musculoskeletal ultrasound nerve measurements when comparing bilateral and unilateral carpal tunnel syndrome (CTS) patients. Similarly, the influence of body mass index on CTS severity is not well characterized. Unilateral and bilateral CTS patients were seen from October of 2014 to February of 2021. Obese and nonobese CTS patients were compared. Median nerve cross-sectional area (CSA), Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ), and six-item Carpal Tunnel Symptom Score (CTS-6) measures were obtained. Nerve conduction studies recorded distal motor latency (DML) and distal sensory latency (DSL). Statistical analysis used Wilcoxon signed rank testing for paired continuous variables, Mann-Whitney U testing for nonpaired continuous variables, and chi-square testing for continuous variables, with a significance level of P < 0.05. A total of 109 (218 nerves) bilateral and 112 (112 nerves) unilateral CTS patients were reviewed. Bilateral patients had larger median nerve CSAs on their more symptomatic side, when defined by BCTSQ score ( P < 0.0001), CTS-6 score ( P < 0.0001), DML ( P < 0.0001), and DSL ( P < 0.01). Bilateral patients also had higher symptom severity scale ( P < 0.01) and DSL ( P < 0.001) outcomes compared with unilateral patients. Obese patients had higher median nerve CSA ( P < 0.01), prolonged DML, and prolonged DSL ( P < 0.0001) values despite similar CTS severity (BCTSQ and CTS-6). Ultrasound identifies the more symptomatic side in bilateral patients, which correlates with increasing severity (NCS and BCTSQ). Obesity increases median nerve CSA and prolongs nerve conduction studies without influencing CTS severity. This information can be used when considering which diagnostic test to order for CTS.

Evaluation of the degeneration of the multifidus and erector spinae muscles in patients with low back pain and healthy individuals.

Although several studies have been conducted to determine the cause of low back pain (LBP), a sufficient correlation has not been found between research findings and symptoms. Therefore there seems to be a need for studies to explain the relationship between pain and morphological changes in the paraspinal muscles of patients with LBP through comparisons with healthy control subjects. The aim of this study was to examine degeneration in the lumbar musculus multifidus (LMF) and lumbar musculus erector spinae (LES) muscles in patients with chronic LBP with non-radiculopathy lumbar disc herniation (LDH), patients with mechanical LBP, and healthy individuals. The study included 35 patients with mechanical LBP, 38 patients with non-radiculopathy LDH, and a control group of 36 healthy participants. In all patients and the control group, evaluations were made on axial magnetic resonance imaging slices at L3-S1 level of the LMF and LES cross-sectional areas (CSA), total CSA (TCSA = LMF+LES), fat infiltrations and asymmetries. The mean CSA values of the right and left LMF and LES showed significant differences between the groups (p< 0.001, p= 0.002, p= 0.002, p= 0.010, respectively). Fat infiltrations showed a difference between the right-left LMF and left LES groups (p= 0.007, p< 0.001, p= 0.026, respectively). Asymmetry was not observed between the CSA and TCSA of the right and left sides. A correlation was found between fat infiltration in the LMF and mechanical LBP and LDH. However, no significant correlation was determined between LBP and the CSA and TCSA of the LMF and LES. This was thought to be due to an incorrect result of CSA and TCSA in the evaluation of muscle mass. Therefore, for a more accurate evaluation of muscle mass, it can be considered necessary to measure muscle atrophy associated with fat infiltration or functional CSA.

High-resolution ultrasonography for early diagnosis of neural impairment in seropositive leprosy household contacts.

Leprosy household contacts (HC) represent a high-risk group for the development of the disease. Anti-PGL-I IgM seropositivity also increases the risk of illness. Despite significant advances in leprosy control, it remains a public health problem; and early diagnosis of this peripheral neuropathy represents one of the main goals of leprosy programs. The present study was performed to identify neural impairment in leprosy HC by analyzing differences in high-resolution ultrasonographic (US) measurements of peripheral nerves between leprosy HC and healthy volunteers (HV). Seventy-nine seropositive household contacts (SPHC) and 30 seronegative household contacts (SNHC) underwent dermato-neurological examination and molecular analysis, followed by high-resolution US evaluation of cross-sectional areas (CSAs) of the median, ulnar, common fibular and tibial nerves. In addition, 53 HV underwent similar US measurements. The US evaluation detected neural thickening in 26.5% (13/49) of the SPHC and only in 3.3% (1/30) among the SNHC (p = 0.0038). The CSA values of the common fibular and tibial nerves were significantly higher in SPHC. This group also had significantly greater asymmetry in the common fibular and tibial nerves (proximal to the tunnel). SPHC presented a 10.5-fold higher chance of neural impairment (p = 0.0311). On the contrary, the presence of at least one scar from the BCG vaccine conferred 5.2-fold greater protection against neural involvement detected by US (p = 0.0184). Our findings demonstrated a higher prevalence of neural thickening in SPHC and support the role of high-resolution US in the early diagnosis of leprosy neuropathy. The combination of positive anti-PGL-I serology and absence of a BCG scar can identify individuals with greater chances of developing leprosy neuropathy, who should be referred for US examination, reinforcing the importance of including serological and imaging methods in the epidemiological surveillance of leprosy HC.

Automatic estimation of the cross-sectional area of the waist of the nerve fibre layer at the optic nerve head.

Glaucoma leads to pathological loss of axons in the retinal nerve fibre layer at the optic nerve head (ONH). This study aimed to develop a strategy for the estimation of the cross-sectional area of the axons in the ONH. Furthermore, improving the estimation of the thickness of the nerve fibre layer, as compared to a method previously published by us. In the 3D-OCT image of the ONH, the central limit of the pigment epithelium and the inner limit of the retina, respectively, were identified with deep learning algorithms. The minimal distance was estimated at equidistant angles around the circumference of the ONH. The cross-sectional area was estimated by the computational algorithm. The computational algorithm was applied on 16 non-glaucomatous subjects. The mean cross-sectional area of the waist of the nerve fibre layer in the ONH was 1.97 ± 0.19 mm2 . The mean difference in minimal thickness of the waist of the nerve fibre layer between our previous and the current strategies was estimated as CIμ (0.95) 0 ± 1 μm (d.f. = 15). The developed algorithm demonstrated an undulating cross-sectional area of the nerve fibre layer at the ONH. Compared to studies using radial scans, our algorithm resulted in slightly higher values for cross-sectional area, taking the undulations of the nerve fibre layer at the ONH into account. The new algorithm for estimation of the thickness of the waist of the nerve fibre layer in the ONH yielded estimates of the same order as our previous algorithm.

Study of ultrasound and nerve electromyogram in diagnosis of carpal tunnel syndrome and its severity in the elderly

ABSTRACT Objective: To explore the diagnostic value of ultrasound and nerve electromyography (EMG) in the diagnosis of carpal tunnel syndrome (CTS) and its severity in the elderly. Methods: The data of 140 elderly CTS patients were retrospectively analyzed. The data of 80 patients with other diseases with similar symptoms and high suspicion of CTS during the same period were retrospectively analyzed. Pearson method was used to analyze the correlation between cross-sectional area (CSA) and motor nerve conduction velocity (MCV), distal motor latency (DML), compound muscle action potential (CMAP), sensory conduction velocity (SCV), middle-latency (ML) and sensory nerve action potential (SNAP) levels. The value of CSA, MCV, DML, CMAP, SCV, ML and SNAP in the diagnosis of CTS and its severity was analyzed by receiver operating characteristic (ROC) curve. Results: CSA in mild, moderate and severe groups was positively correlated with DML (P < 0.001) and negatively correlated with CMAP (P < 0.001). The area under the curve (AUC) values of CSA, MCV, DML, CMAP, SCV, ML and SNAP in the diagnosis of normal people and mild CTS were 0.877, 0.787, 0.921, 0.730, 0.860, 0.688 and 0.904. The AUC values of CSA, DML, CMAP, SCV, ML and SNAP in the diagnosis of mild and moderate CTS were 0.863, 0.890, 0.760, 0.848, 0.850 and 0.739, respectively. The AUC values of CSA, MCV, DML and CMAP in the diagnosis of mild and moderate CTS were 0.683, 0.660, 0.870 and 0.693. Conclusion: Ultrasound and nerve EMG are effective in the diagnosis of CTS.

Ultrasound evaluation of vagus nerve cross-sectional area in a community-dwelling elderly Japanese cohort.

Although the vagus nerve (VN) is easily observed by ultrasonography, few studies have evaluated the cross-sectional area (CSA) of the VN in healthy older individuals from East Asia. In this study, we aimed to report reference values for the CSA of the VN in community-dwelling elderly Japanese individuals and to identify any associated medical history and/or lifestyle factors. The present study included 336 participants aged ≥ 70 years from a prospective cohort study conducted in Yahaba, Japan from October 2021 to February 2022. The CSA of the VN was measured bilaterally at the level of the thyroid gland by ultrasonography. Simple linear regression analysis and generalized estimating equation were conducted to identify the associations between clinical and background factors and the CSA of the VN. In our cohort, the median CSA of the VN was 1.3 mm2 (interquartile range [IQR] 1.1-1.6) on the right side and 1.2 mm2 (IQR 1.0-1.4) on the left side. Generalized estimating equation showed that history of head injury (β = 0.19, p < .01), current smoking habit (β = -0.09, p = .03), and BMI (β = 0.02, p < .01) were independently associated with the CSA of the VN. We have reported reference VN CSA values for community-dwelling elderly Japanese individuals. In addition, we showed that the CSA of the VN was positively associated with a history of head injury and BMI and inversely associated with current smoking habit.

Area Deprivation Index Is Not Associated With the Severity of Carpal Tunnel Syndrome.

While living in a socially disadvantaged neighborhood is linked with numerous health outcomes, its effect on patient-reported outcome scores and diagnostic measures in carpal tunnel syndrome (CTS) is not fully understood. This study examines the effect of neighborhood socioeconomic deprivation on CTS severity as measured by the Boston Carpal Tunnel Questionnaire (BCTQ), 6-item Carpal Tunnel Symptoms Scale (CTS-6), and diagnostic testing modalities. This was a retrospective analysis of patients who presented to the hand clinic at a single hospital system with symptoms consistent with CTS. Ultrasound cross-sectional area (CSA) of the median nerve, CTS-6, Symptom Severity Scale (SSS) and Functional Status Scale (FSS) of the BCTQ, and the Area Deprivation Index (ADI) national rank percentile were collected. Patients were grouped into 4 quartiles based on their ADI national percentile. Analyses of variance (ANOVAs) were conducted to test for statistical differences between the 4 quartiles based on the average values of median nerve CSA, CTS-6, SSS, and FSS score. The bottom quartile was compared with the upper 75% of the sample (26th-100th percentile) and to the upper quartile via Student t test. Statistical significance was set at P < .05. Analyses of variance revealed no statistically significant differences between the 4 quartiles for either median nerve CSA, CTS-6, SSS, or FSS. When comparing the bottom quartile with the upper 75% of the sample and the upper quartile, no significant statistical differences were identified. No relationships were found between social deprivation (ADI) and patient-reported outcomes, CTS-6 scores, or median nerve CSA.

Associations between adiponectin and leptin levels and skeletal muscle mass and myosteatosis in older adults: The Shimanami Health Promoting Program study

Identifying plasma molecules associated with skeletal muscle properties can elucidate the pathophysiology of sarcopenia. Because adipocytokines are a promising candidate marker, the current study aimed to clarify the possible associations between adiponectin and leptin levels and mid-thigh muscle cross-sectional area and mean attenuation value, which are indices of muscle mass and fat deposition in muscle, respectively. The current study included 1440 older Japanese adults (mean age 69.3 years). Mid-thigh skeletal muscle cross-sectional area and mean attenuation value were evaluated through computed tomography scan. A low attenuation value showed a greater fat deposition in muscle. Circulating adiponectin and leptin levels were assessed using blood specimens collected during the baseline investigation. Plasma leptin level was inversely correlated with muscle cross-sectional area, but not with attenuation value. The association with cross-sectional area was independent of possible confounding factors including body size (Q1: reference; Q2: β = -0.032, P = 0.033; Q3: β = -0.064, P < 0.001; Q4: β = -0.111, P < 0.001). In contrast, adiponectin level was independently and inversely associated with attenuation value (Q1: reference; Q2: β = -0.044, P = 0.122; Q3: β = -0.080, P = 0.006; Q4: β = -0.159, P < 0.001), but not with cross-sectional area. These associations between adipocytokine levels and muscle properties were independent of abdominal fat area and insulin resistance. There were adiposity- and insulin resistance-independent associations between adipocytokines levels and skeletal muscle mass and fat deposition in muscle, suggesting an involvement of adipocytokines in muscle properties. Geriatr Gerontol Int 2023; 23: 444-449.

Defining Normal Reference Range For The Cross Sectional Area Of The Median Nerve At The Wrist And Forearm Using High-Resolution Ultrasonography In Asymptomatic Pakistani Adults.

Carpal tunnel syndrome (CTS) can be diagnosed easily on ultrasonography (USG); which is a cheap, non-invasive and readily available modality. However, there is wide normal variation in the normal values of cross-sectional area (CSA) of median nerve among different populations; therefore, its necessary to establish a normal range of variability in median nerve dimensions in different populations. A total of 500 asymptomatic patients i.e., 1000 median nerves were evaluated at the distal wrist crease and mid-forearm by 3 expert radiologists independently. All patients having a positive nerve conduction study or history of carpal tunnel syndrome and wrist trauma were excluded. Ultrasound was performed with a 7.5-15 MHz high-frequency linear probe. SPSS v 20 was used to analyze data. The study population had a mean age of 31.40±10.11 years with a female-to-male ratio of 1.36:1. Mean BMI was 22.15±4.34 Kg/m2 . The mean cross section area of the median nerve at the right wrist was calculated to be 6.8±1.96 mm2 and the left wrist was 6.6±1.96 mm2 . The mean median nerve cross-section area at the right mid-forearm was 5.3±1.46 mm2 and the left mid-forearm was 5.2±1.50 mm2 . A decrease in mean median nerve cross-section areas was noted by moving from wrist to forearm. Similarly, males showed higher median nerve CSA than females. Mean median nerve cross-section area was found to be different from Western countries. This warrants the utilization of the data of the Pakistani population to establish our own normal reference range for median nerve cross-sectional area to avoid misdiagnoses.

A Bayesian network model to predict neoplastic risk for patients with gallbladder polyps larger than 10 mm based on preoperative ultrasound features.

Polyp size of 10 mm is insufficient to discriminate neoplastic and non-neoplastic risk in patients with gallbladder polyps (GPs). The aim of the study is to develop a Bayesian network (BN) prediction model to identify neoplastic polyps and create more precise criteria for surgical indications in patients with GPs lager than 10 mm based on preoperative ultrasound features. A BN prediction model was established and validated based on the independent risk variables using data from 759 patients with GPs who underwent cholecystectomy from January 2015 to August 2022 at 11 tertiary hospitals in China. The area under receiver operating characteristic curves (AUCs) were used to evaluate the predictive ability of the BN model and current guidelines, and Delong test was used to compare the AUCs. The mean values of polyp cross-sectional area (CSA), long, and short diameter of neoplastic polyps were higher than those of non-neoplastic polyps (P < 0.0001). Independent neoplastic risk factors for GPs included single polyp, polyp CSA ≥ 85 mm 2, fundus with broad base, and medium echogenicity. The accuracy of the BN model established based on the above independent variables was 81.88% and 82.35% in the training and testing sets, respectively. Delong test also showed that the AUCs of the BN model was better than that of JSHBPS, ESGAR, US-reported, and CCBS in training and testing sets, respectively (P < 0.05). A Bayesian network model was accurate and practical for predicting neoplastic risk in patients with gallbladder polyps larger than 10 mm based on preoperative ultrasound features.

Duration of Back Pain Symptoms and Its Relationship to Paralumbar Muscle Volume.

Paralumbar muscle volume has been indicated as an important factor for patients reporting back pain. Our goal was to determine if there is a statistically significant relationship between the duration of patients' back pain symptoms (>12 weeks or ≤12 weeks) and paralumbar muscle volume. In this retrospective cohort study, paralumbar muscles on axial T2-weighted lumbar magnetic resonance images were outlined using ImageJ to determine the paralumbar cross-sectional area (PL-CSA) and lumbar indentation value (LIV) at the center of disc spaces from L1 to L5. The Goutallier classification was determined by the primary author. Quantile regression was performed to compare the PL-CSA, PL-CSA normalized by body mass index, and LIV between the 2 cohorts. Cohort A consisted of patients reporting symptoms ≤12 weeks, and cohort B included patients with symptoms >12 weeks. Negative binomial regression was used to compare Goutallier class. A total of 551 patients operated on by a single surgeon with lumbar magnetic resonance imaging within the past 12 months and recorded duration of symptoms were included. Cohort A consisted of 229 patients (41.6%), and cohort B included 322 patients (58.4%). Statistical significance was not found at any lumbar level for PL-CSA, PL-CSA normalized by body mass index, Goutallier class, and LIV. Our results suggest that duration of symptoms may not be an accurate indicator for lumbar muscle volume. These novel findings are clinically valuable because lumbar muscle volume has been shown to be a marker for recovery. With this information, patients previously believed to be inoperable because of long-standing symptoms can be reevaluated.

Bioimpedance phase angle is independently associated with myosteatosis: The Shizuoka study

Phase angle (PhA) calculated from the resistance and reactance measured using a bioimpedance device was suggested to represent the degree of fat deposition in muscle (myosteatosis), though no direct evidence is available. We aimed to clarify the possible association between PhA and skeletal muscle myosteatosis in community-dwelling middle-aged to older adults. Participants consisted of 424 Japanese (aged ≥50 years). Leg PhA and skeletal muscle mass index (SMI) were obtained by bioelectrical impedance analysis. The mean attenuation values and cross-sectional area of the mid-thigh skeletal muscle were calculated from computed tomography images and considered as indexes of myosteatosis and skeletal muscle mass, respectively. Leg PhA was positively associated with SMI, and cross-sectional area and mean attenuation value at mid-thigh. Multiple regression analysis adjusted for possible covariates identified leg PhA (β=0.214) and SMI (β=0.260) as independent factors of mid-thigh muscle cross-sectional area (P<0.001), while leg PhA (β=0.349, P<0.001) but not SMI (P=0.645) was associated with mean attenuation value. Similar results were observed in the analysis in the older (≥65 years) subpopulation. The combination of low SMI and low leg PhA showed stepwise association with cross-sectional area, while only individuals with low leg PhA had lower mean attenuated value. Leg PhA was independently associated with mean attenuated value of the mid-thigh skeletal muscle, suggesting that the assessment of PhA in combination with SMI could provide additional information for the evaluation of muscle properties.

Comparative Study of Different Entry Spots on Postoperative Gluteus Medius Muscle Cross-Sectional Area in Patients With Intertrochanteric Fractures Nailing.

Introduction In a preliminary study of cephalo-medullary (CM) nailing in patients with femoral intertrochanteric fractures, the authors of this study found a 25% to 30% decrease in muscle strength, especially abduction force, during the postoperative follow-up period. This decline was partially attributed to the entry point for the nail insertion causing damage to the gluteus medius tendon at the junction of the greater trochanter after reaming. Therefore, we assumed that changing the position of nail insertion to a "bald spot (BS)" could mitigate postoperative functional impairment. Automated computed tomography (CT) imaging of skeletal muscle cross-sectional area (CSA) and adipose tissue ratio (ATR) can show pathological changes on the operated side compared with the non-operated side. In this study, the authors quantified the difference in postoperative CSA and ATR of the gluteus medius muscle after bald spot nailing versus nail insertion through the conventional tip of the greater trochanter. It was hypothesized that bald spot nailing could avoid significant injury to the gluteus medius muscle. Materials and methods Patients with femoral intertrochanteric fractures were grouped according to the site of cephalo-medullary nailing: greater trochanteric tip (TIP) in 27 patients (8 men and 19 women, mean age 84.9±5.1 years) and BSin 16 patients (3 men and 13 women, mean age 86.9±6.2 years). The CSA and ATR of the gluteus medius muscles were assessed in three slices (A, B, and C from proximal to distal). Each slice was manually traced and automatically calculated based on its contour. Adipose tissue (-100 to -50 in Hounsfield units) in the designated area was distinguished by a bimodal image histogram resulting from the distribution of CT numbers of adipose tissue and muscle. The body mass index (BMI) was used to correct the CSA in each patient. Results In the TIP group, the mean CSA values (mm2) from the non-operated/operated sides were as follows: slice A, 2180.2 ± 616.5/1976.3 ± 421.2; slice B, 2112.3 ± 535.7/1857.7 ± 386.7; and slice C: 1671.8 ± 460.0/1404.1 ± 404.3 (p<0.01 in slices A, B, and C). In the BS group, slice A was 2044.1 ± 473.0/2016.9 ± 388.4; slice B was 2073.2 ± 540.7/1848.3 ± 411.1; and slice C was 1659.1 ± 477.2/1468.5 ± 341.7 (p=0.34 in slice A, and p<0.05 in slices B and C, respectively). The mean CSA values (mm2) of the non-operated minus operated side between the TIP/BS groups were as follows: slice A, 241.3 ± 424.3/-11.8 ± 285.6; slice B, 290.3 ± 313.0/211.8 ± 333.2; and slice C, 276.4 ± 270.4/162.8 ± 319.3 (p < 0.05 in slice A, 0.45, 0.24 in slices B, C, respectively). The mean adjusted CSA per BMI values (mm2) of the non-operated minus the operated side between the TIP/BS groups were slice A, 10.6 ± 19.7/-0.4 ± 14.8; slice B, 13.3 ± 15.0/10.1 ± 16.3; and slice C, 13.1 ± 13.4/ 8.7 ± 15.3 (p < 0.05 in slice A and 0.54 and 0.36 in slices B and C, respectively). Conclusion Nail insertion at the bald spot resulted in a significantly smaller decrease in the CSA of the gluteus medius muscle compared with the conventional tip entry. In addition, an examination of BMI-adjusted CSA showed that CSA was maintained in some image slices. These results suggest that nailing from the BS of the greater trochanter can reduce damage to the gluteus medius muscle and highlight the importance of imaging beyond the usual assessment of skeletal changes.

Image analysis can reliably quantify median nerve echogenicity and texture changes in patients with carpal tunnel syndrome

ObjectiveTo study the ability of image analysis measures to quantify echotexture changes of median nerve in order to provide a complementary diagnostic tool in CTS. MethodsImage analysis measures (gray level co-occurrence matrix (GLCM), brightness, hypoechoic area percentage using max entropy and mean threshold) were calculated in normalized images of 39 (19 younger and 20 older than 65y) healthy controls and 95 CTS patients (37 younger and 58 older than 65y). ResultsImage analysis measures were equivalent or superior (older patients) to subjective visual analysis. In younger patients, GLCM measures showed equivalent diagnostic accuracy with cross sectional area (CSA) (Area Under Curve (AUC for inverse different moment = 0.97). In older patients all image analysis measures showed similar diagnostic accuracy to CSA (AUC for brightness = 0.88). Moreover, they had abnormal values in many older patients with normal CSA values. ConclusionsImage analysis reliably quantifies median nerve echotexture alterations in CTS and offers similar diagnostic accuracy to CSA measurement. SignificanceImage analysis may offer added value to existing measures in the evaluation of CTS, especially in older patients. Its clinical implementation would require incorporation of mathematically simple software code for online nerve image analysis in ultrasound machines.

Ultrasound-based Neuropathy Diagnosis in COVID-19 Patients in Post-intensive Care Rehabilitation Settings: A Retrospective Observational Study

ObjectivesUsing ultrasound (US) scanning to examine the correlation between increase of common fibular nerve's (CFN) cross sectional area (CSA) and functional impairment of foot dorsiflexor muscles as an early sign of peripheral neuropathy. DesignRetrospective observational study. SettingIn-patient rehabilitation unit between November 2020 and July 2021. ParticipantsTwenty-six inpatients who underwent prolonged hospitalization in intensive care units (ICUs) and were diagnosed with critical illness myopathy and polyneuropathy after SARS-COV-2 infection (N=26). Physical examination and US scanning of the CFN and EMG/ENG were carried out on each patient. InterventionsNot applicable. Main Outcome Measure(s)CFN's CSA at the peroneal head. ResultsWe verified a significant increase in the CSA of the CFN measured at the peroneal head in more than 90% of the nerves tested. A cut off value of CFN's CSA of 0.20 cm was used to identify pathologic nerves. No correlations with other variables (body mass index, ICU days) were found. ConclusionUS scanning of the CFN appears to be an early and specific test in the evaluation of CPN's abnormalities in post COVID-19 patients. US scanning is a reproducible, cost effective, safe, and easily administered bedside tool to diagnose a loss of motor function when abnormalities in peripheral nerves are present.

Silent peripheral neuropathy determined by high-resolution ultrasound among contacts of patients with Hansen's disease.

Hansen's disease (HD) primarily infects peripheral nerves, with patients without HD being free of peripheral nerve damage. Household contacts (HHCs) of patients with HD are at a 5-10 times higher risk of HD than the general population. Neural thickening is one of the three cardinal signs that define a case of HD according to WHO guidelines, exclusively considering palpation examination that is subjective and may not detect the condition in the earliest cases even when performed by well-trained professionals. High-resolution ultrasound (HRUS) can evaluate most peripheral nerves, a validated technique with good reproducibility allowing detailed and accurate examination. This study aimed to use the peripheral nerve HRUS test according to the HD protocol as a diagnostic method for neuropathy comparing HHCs with healthy volunteers (HVs) and patients with HD. In municipalities from 14 different areas of Brazil we selected at random 83 HHC of MB-patients to be submitted to peripheral nerve ultrasound and compared to 49 HVs and 176 HD-patients. Household contacts assessed by HRUS showed higher median and mean absolute peripheral nerve cross-sectional area (CSA) values and greater asymmetries (ΔCSA) compared to HVs at the same points. Median and mean absolute peripheral nerve CSA values were higher in patients with HD compared to HCCs at almost all points, while ΔCSA values were equal at all points. Mean ± SD focality (ΔTpT) values for HHCs and patients with HD, respectively, were 2.7 ± 2.2/2.6 ± 2.2 for the median nerve, 2.9 ± 2.7/3.3 ± 2.9 for the common fibular nerve (p > 0.05), and 1.3 ± 1.3/2.2 ± 3.9 for the ulnar nerve (p < 0.0001). Considering HRUS findings for HHCs, asymmetric multiple mononeuropathy signs (thickening or asymmetry) in at least 20% of the nerves evaluated could already indicates evidence of HD neuropathy. Thus, if more nerve points are assessed in HHCs (14 instead of 10), the contacts become more like patients with HD according to nerve thickening determined by HRUS, which should be a cutting-edge tool for an early diagnosis of leprosy cases.

Muscle architecture and muscle fibre type composition in the forelimb of two African mole-rat species, Bathyergus suillus and Heterocephalus glaber.

The scratch-digging Cape dune mole-rat (Bathyergus suillus), and the chisel-toothed digging naked mole-rat (Heterocephalus glaber) are African mole-rats that differ in their digging strategy. The aim of this study was to determine if these behavioural differences are reflected in the muscle architecture and fibre-type composition of the forelimb muscles. Muscle architecture parameters of 39 forelimb muscles in both species were compared. Furthermore, muscle fibre type composition of 21 forelimb muscles were analysed using multiple staining protocols. In B. suillus, muscles involved with the power stroke of digging (limb retractors and scapula elevators), showed higher muscle mass percentage, force output and shortening capacity compared to those in H. glaber. Additionally, significantly higher percentages of glycolytic fibres were observed in the scapular elevators and digital flexors of B. suillus compared to H. glaber, suggesting that the forelimb muscles involved in digging in B. suillus provide fast, powerful motions for effective burrowing. In contrast, the m. sternohyoideus a head and neck flexor, had significantly more oxidative fibres in H. glaber compared to B. suillus. In addition, significantly greater physiological cross-sectional areaand fascicle length values were seen in the neck flexor, m. sternocleidomastoideus, in H. glaber compared to B. suillus, which indicates a possible adaptation for chisel-tooth digging. While functional demands may play a significant role in muscle morphology, the phylogenetic differences between the two species may play an additional role which needs further study.

Sonographic peripheral nerve cross-sectional area in adults, excluding median and ulnar nerves: A systematic review and meta-analysis.

Although electromyography remains the "gold standard" for assessing and diagnosing peripheral nerve disorders, ultrasound has emerged as a useful adjunct, providing valuable anatomic information. The objective of this study was to conduct a systematic review and meta-analysis evaluating the normative sonographic values for adult peripheral nerve cross-sectional area (CSA). Medline and Cochrane Library databases were systematically searched for healthy adult peripheral nerve CSA, excluding the median and ulnar nerves. Data were meta-analyzed, using a random-effects model, to calculate the mean nerve CSA and its 95% confidence interval (CI) for each nerve at a specific anatomical location (= group). Thirty groups were identified and meta-analyzed, which comprised 16 from the upper extremity and 15 from the lower extremity. The tibial nerve (n=2916 nerves) was reported most commonly, followed by the common fibular nerve (n=2580 nerves) and the radial nerve (n=2326 nerves). Means and 95% confidence interval (CIs) of nerve CSA for the largest number of combined nerves were: radial nerve assessed at the spiral groove (n=1810; mean,5.14 mm2 ; 95% CI,4.33 to 5.96); common fibular nerve assessed at the fibular head (n=1460; mean,10.18 mm2 ; 95% CI,8.91 to 11.45); and common fibular nerve assessed at the popliteal fossa (n=1120; mean,12.90 mm2 ; 95% CI,9.12 to 16.68). Publication bias was suspected, but its influence on the results was minimal. Two hundred thirty mean CSAs from 15 857 adult nerves are included in the meta-analysis. These are further categorized into 30 groups, based on anatomical location, providing a comprehensive reference for the clinician and researcher investigating adult peripheral nerve anatomy.

Sonographic reference values of nerve size in children: A systematic review and meta-analysis.

Nerve ultrasound is useful in the diagnosis and follow-up of peripheral nerve disorders in children. The aim of this study was to explore and analyze the current literature on nerve cross-sectional area (CSA) in healthy children, with the goal of presenting reference values and discussing their implications. We performed a systematic review and meta-analysis of studies that reported ultrasound measurements of the upper or lower limb nerves in healthy children through a search of Web of Science, PubMed, Embase, and Scopus. Sixteen studies with measurements of 10 nerves covering a total of 5149 nerves measured in 823 healthy children (445 boys and 378 girls) were included. Mean nerve CSA increased with age in the median nerve at the middle and lower third of the upper arm, mid-forearm, and distal wrist crease, the ulnar nerve at the middle third of the upper arm and elbow, the radial nerve at the spiral groove, and the tibial nerve at the popliteal fossa. Growth charts for nerve CSA for different age groups were developed. This meta-analysis provides robust reference values for nerve CSA at different sites in children, and this can inform clinical practice and assist in identifying nerve enlargement. Moreover, it identifies the strength and quality of the current published data. We recommend future studies divide their samples into smaller age subgroups and standardize the anatomic site of measurement.

Cross-sectional area and echo intensity values of peripheral nerves: Ultrasonographic and cadaveric correlation.

Ultrasonography allows high-resolution visualisation of the peripheral nerves for quantitative and qualitative analyses. We report cross-sectional area values (quantitative measure) and echo intensity values (qualitative measure) for 46 peripheral nerve sites in upper and lower extremities in cadaveric specimens. To determine cross-sectional area values and echo intensity values of peripheral nerves of upper and lower extremities at 46 nerve sites. Nerve measurements were obtained using electronic callipers and ultrasonography for linear dimension and cross-sectional area measurements, respectively, in six cadaveric specimens for 46 peripheral nerve sites. Ultrasound images were further analysed to estimate echo intensity percentage values for 46 nerves. We present normal cross-sectional area values of various nerves of upper and lower extremities with their respective echo intensity values. Calculated cross-sectional area values from linear dimensions did not match the measured cross-sectional area values via trace method. Cross-sectional area values (quantitative measure) and echo intensity values (qualitative measure) for 46 peripheral nerve sites in upper and lower extremities in cadaveric specimens are presented. The estimation of cross-sectional area via linear measurement is not a good approximation of the cross-sectional area (cross-sectional area measured by trace method on ultrasound image).