Kerry Thoirs

Loss of skeletal muscle mass after stroke: a systematic review.

Loss of muscle mass after stroke has implications for strength and functional ability and may also contribute to impaired glucose metabolism. Therefore, prevention of muscle loss is desirable. Before interventions to prevent loss of muscle can be designed and evaluated, the expected rate, magnitude and timing of muscle loss need to be understood. A systematic search was undertaken to identify all studies that investigated changes in skeletal muscle mass, volume or cross-sectional area in people after stroke. Studies that used either direct measures of muscle size (computer tomography, magnetic resonance imaging or ultrasound) or measures of lean tissue mass (dual X-ray absorptiometry) were included. Fourteen trials were found and the results were pooled for differences in lean tissue mass between the paretic and the nonparetic leg and arm as well as differences in the midthigh cross-sectional area. In individuals at least 6-month post-stroke, there was significantly less lean tissue mass in the paretic compared with the nonparetic lower limb (MD 342.3 g, 95% confidence interval 247.0–437.6 g) and upper limb (MD 239.9 g, 95% confidence interval 181.7–298.2 g), and significantly less midthigh muscle cross-sectional area (MD 15.4 cm2, 95% confidence interval 13.8–16.9 cm2). There were insufficient data to pool with regard to change in muscle mass over time. There is a significant difference in the regional muscle mass in the paretic vs. the nonparetic limb in individuals greater than 6-months poststroke but little is known about how early and how quickly changes in muscle mass occur.

Ultrasonographic Measurements of the Ulnar Nerve at the Elbow : Role of Confounders

Objective. The purpose of this study was to identify factors confounding high‐resolution ultrasonographic measurements of the ulnar nerve to test their influence when discriminating between limbs affected and unaffected by ulnar nerve entrapment (UNE) at the elbow. Methods. High‐resolution ultrasonographic measurements of ulnar nerve dimensions at the elbow were compared between 2 groups of subjects: symptomatic and asymptomatic for UNE. Rank analysis of covariance regression tests were performed to determine whether significant differences existed between the 2 groups. The changing coefficient method (using rank analysis of covariance tests) was used to test for potential confounding effects of age, weight, height, body mass index, sex, limb sidedness, limb handedness, and nerve mobility. These tests were repeated for each measurement while controlling for the identified confounders. Exact 2‐tailed Wilcoxon signed rank tests were performed to test for significant differences between measurements of the diameter of the ulnar nerve with the elbow in full extension and full flexion. Results. Age, weight, body mass index, sex, and elbow position were shown to have confounding influences on high‐resolution ultrasonographic measurements of the ulnar nerve. No confounding effect was apparent for limb sidedness or dominance. Cross‐sectional area and long‐axis diameter measurements demonstrated significant differences between nerves with and without UNE after controlling for confounders. Conclusions. Two cross‐sectional measurements (area and maximum cross‐sectional diameter) of the ulnar nerve, made at the level of the medial epicondyle, were found to be robust discriminators between nerves with and without UNE. In the absence of normative reference values of the ulnar nerve, the contralateral limb may be used as the comparative control.

Ultrasound measures of muscle thickness: intra-examiner reliability and influence of body position

Ultrasound is an inexpensive and practical alternative to gold standard measures of muscle mass. Changes in body position may lead to intra‐muscular fluid shifts that may affect the reliability of ultrasound measures. We assessed test–retest reliability of ultrasound measures of muscle thickness and the effect of position on these measures. Measures of muscle thickness were made from B‐mode ultrasound images in 18 healthy participants. Repeated measurements were made by one examiner from two participant positions; standing and recumbent, from 18 anatomical sites. Results demonstrated high test–retest reliability for measures taken in both participant positions [intra‐class coefficient (ICC) scores 0·65 to 0·94], except for the recumbent posterior lower leg measures (ICC 0·34). Recumbent measures were significantly smaller than those taken with participants standing. Length of time participants spent lying down did not significantly affect measures, indicating that any changes in intra‐muscular fluid related to the time spent recumbent are negligible.

Reliability of real-time ultrasound for measuring skeletal muscle size in human limbs in vivo: a systematic review:

Objective: To systematically review evidence for the reliability of real-time brightness-mode ultrasound for assessing skeletal muscle size in human limbs in vivo and to establish in which populations and anatomical sites the reliability had been tested. Data sources: Articles were retrieved via electronic database searching and expert contact. Study selection: Studies reporting reliability indices of test–retest measures of real-time brightness-mode ultrasound measures of skeletal muscle size within human limbs were included. Data extraction: Articles were assessed for methodological quality by two reviewers, decisions were made by consensus. Participant characteristics, measurement protocol, ultrasound protocol, type of reliability measured and statistical methods were extracted by one reviewer. Data synthesis: Twenty-four articles were included, involving 605 participants. Studies were of low to moderate methodological quality. Most studies were conducted within the healthy population. Only one study demonstrated poor reliability at one site only, and only when the participants were measured in the supine position. Conclusion: There is a moderate amount of low-level evidence that real-time brightness-mode ultrasound has good reliability for measuring muscle size across a number of limb sites in healthy populations. There is limited evidence for the reliability of ultrasound measures of muscle size in clinical populations.

Ultrasound Is a Reliable Measure of Muscle Thickness in Acute Stroke Patients, for Some, but Not All Anatomical Sites: A Study of the Intra-Rater Reliability of Muscle Thickness Measures in Acute Stroke Patients

This prospective, blinded study investigates the test retest reliability of measures of muscle thickness made by one sonographer across two cohort groups (n = 29) of people hospitalised with acute stroke. Reliability was assessed in cohort one (n = 14) for measurements made bilaterally at the anterior and posterior upper arms, the anterior and posterior thighs (total of eight measurements) and in cohort two (n = 15), for measurements made bilaterally at the lateral forearms, the anterior abdominal wall and the anterior and lower legs (total of eight measurements). Reliability estimates varied between measurement sites; intraclass correlation coefficients (ICCs) ranged from -0.26 (lateral forearm, paretic side) to 0.95 (anterior thigh, nonparetic side), percent mean differences ranged from 0.42% (posterior upper arm, nonparetic side) to 14.68% (anterior lower limb, nonparetic side) and method error ranged from 1.08 (abdomen, nonparetic side) to 9.69 mm (posterior lower limb, nonparetic side). Only four measurement sites (anterior upper arm, posterior upper arm, abdomen and anterior thigh) were within the acceptable ranges (ICC 0.60 to 1.00, mean percent difference range 0%-5% and method error range 0-5 mm) and considered reliable to use for measures of muscle thickness in people hospitalised with acute stroke.

The diagnostic validity of musculoskeletal ultrasound in lateral epicondylalgia: a systematic review

BackgroundUltrasound is considered a reliable, widely available, non-invasive and inexpensive imaging technique for assessing soft tissue involvement in Lateral epicondylalgia. Despite the number of diagnostic studies for Lateral Epicondylalgia, there is no consensus in the current literature on the best abnormal ultrasound findings that confirm lateral epicondylalgia.MethodsEligible studies identified by searching electronic databases, scanning reference lists of articles and chapters on ultrasound in reference books, and consultation of experts in sonography. Three reviewers (VCDIII, KP, KW) independently searched the databases using the agreed search strategy, and independently conducted all stages of article selection. Two reviewers (VCDIII, KP) then screened titles and abstracts to remove obvious irrelevance. Potentially relevant full text publications which met the inclusion criteria were reviewed by the primary investigator (VCDIII) and another reviewer (CGS).ResultsAmong the 15 included diagnostic studies in this review, seven were Level II diagnostic accuracy studies for chronic lateral epicondylalgia based on the National Health and Medical Research Council Hierarchy of Evidence. Based from the pooled sensitivity of abnormal ultrasound findings with homogenous results (p > 0.05), the hypoechogenicity of the common extensor origin has the best combination of diagnostic sensitivity and specificity. It is moderately sensitive [Sensitivity: 0.64 (0.56-0.72)] and highly specific [Specificity: 0.82 (0.72-0.90)] in determining elbows with lateral epicondylalgia. Additionally, bone changes on the lateral epicondyle [Sensitivity: 0.56 (0.50-0.62)] were moderately sensitive to chronic LE. Conversely, neovascularity [Specificity: 1.00 (0.97-1.00)], calcifications [Specificity: 0.97 (0.94-0.99)] and cortical irregularities [Specificity: 0.96 (0.88-0.99)] have strong specificity for chronic lateral epicondylalgia. There is insufficient evidence supporting the use of Power Doppler Ultrasonogrophy, Real-time Sonoelastography and sonographic probe-induced tenderness in diagnosing LE.ConclusionsThe use of Gray-scale Ultrasonography is recommended in objectively diagnosing lateral epicondylalgia. The presence of hypoechogenicity and bone changes indicates presence of a stressed common extensor origin-lateral epicondyle complex in elbows with lateral epicondylalgia. In addition to diagnosis, detection of these abnormal ultrasound findings allows localization of pathologies to tendon or bone that would assist in designing an appropriate treatment suited to patient’s condition.

Changes in fat mass in stroke survivors. A systematic review

Background Stroke survivors have less muscle mass in their paretic limbs compared with nonparetic limbs, which may or may not be accompanied by changes in regional and/or whole body fat mass. Aim To examine the current evidence regarding differences in regional fat mass between paretic and nonparetic limbs and changes in whole body fat mass over time in stroke survivors. Methods A systematic search of relevant databases. Studies measuring whole body or regional fat mass using dual-energy X-ray absorpiometry, computed tomography, or magnetic resonance imaging were included. Results Eleven trials were identified. Fat mass differences between paretic and nonparetic limbs and change in fat mass over time were not consistent. Meta-analyses were conducted using dual-energy X-ray absorpiometry-derived data from 10 trials (n = 324). There were no differences in fat mass between paretic and nonparetic legs (pooled mean difference 31.4 g, 95% confidence interval −33.9 to 96.6, P = 0.35), and slightly greater fat mass in the paretic arms compared with nonparetic arms (pooled mean difference 84.0 g, 95% confidence interval 30.7 to 137.3, P = 0.002). Whole body fat mass did not increase significantly between one-month and six-months poststroke (pooled mean difference 282.3 g, 95% confidence interval −824.4 to 1389, P = 0.62), but there was an increase between six- and 12 months poststroke (pooled mean difference 1935 g, 95% confidence interval 1031 to 2839, P < 0.001). Conclusions There were inconsistent findings regarding changes in fat mass after stroke. Large, well-designed studies are required to further investigate the impact of body composition changes on the health of stroke survivors.

Ultrasound measurements of the liver: an intra and inter-rater reliability study

Introduction: Ultrasound is an easy and inexpensive method to rapidly assess the size of the adult liver. The literature addressing reliability of liver measurements using ultrasound is poorly reported and inadequate. In this study, intra and inter‐rater reliability of multiple measurements of the right lobe, left lobe and entire adult liver were assessed.

Ultrasonography, lateral cephalometry and 3D imaging of the human masseter muscle

PURPOSE To develop prediction equations to assist the clinician to derive cephalometric norms from the non-invasive investigations of ultrasonography (US) and 3D imaging. SETTING AND SAMPLE POPULATION Adult volunteers from University of Adelaide participated in the study. METHODS Eleven volunteers (eight women, three men; age range 22-30 years) were recruited for US and standard lateral radiographs measurements along with 3D facial imaging using a structured light technique. The three examinations were performed to assess the vertical and transverse dimensions of the face along with superficial masseter muscle dimensions. In total, 31 variables were statistically analysed for relationship among the three imaging modalities. RESULTS Pearsons correlation coefficients showed highly significant correlations between lateral cephalometric (Co-Go to R3-R4) and US (volume--thickness) variables (r = 0.92, p < 0.0001; r = 0.95, p < 0.0001, respectively). Strong correlations were also observed with Co-Go and masseter muscle area derived from US r = 0.81 (p = 0.01). Similarly, strong correlations were seen between gonion-menton (Go-me) and facial width from 3D imaging (r = 0.83, p = 0.003). A high statistical significance (p > 0.0001) for curvilinear measurements compared with linear counterparts was revealed with the paired t-test. Factor analyses provided meaningful interrelationships for predictive equations generated for lateral cephalometric variables from 3D image coordinates. CONCLUSIONS This preliminary investigation suggests that useful clinical information for treatment planning and follow-up can be gathered without repeated exposure to ionizing radiation. For more robust predictive equations, a larger sample would be required to validate such a model.

Methods of Determining the Size of the Adult Liver Using 2D Ultrasound A Systematic Review of Articles Reporting Liver Measurement Techniques

Sonography is an effective, noninvasive, safe, and inexpensive technique for measurement of the liver. Measurements of the liver using 2D ultrasound aid in diagnosing and tracking liver disease and in surgical planning. Multiple studies have developed techniques to measure the adult liver using 2D ultrasound. The aim of this systematic literature review was to determine whether a correctly developed, reliable, and reproducible technique for measuring the liver using 2D ultrasound has been reported. Analysis of studies meeting the inclusion criteria showed that none of these studies has been rigorously undertaken in terms of sample size justification, validity, reliability, and/or statistical analysis.