OBJECTIVE: Myotonia is a key symptom of myotonic dystrophies (DM), and its quantification is challenging. This exploratory study evaluated the utility of tissue Doppler ultrasound (TDU) to assess myotonia in DM.
METHODS: Twelve DM patients (seven type-1 DM [DM1] and five type-2 DM [DM2]) and 20 age-matched healthy subjects were included in this cross-sectional study. After measuring cross-sectional areas of the flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC) muscles in a resting state, muscle contraction/relaxation time, time to peak tissue velocity, peak tissue velocity and velocity gradients of these muscles were measured via TDU while performing forced fist unclenching after fist closure. Additionally, grip strength, Medical Research Council Sum score and patient-reported myotonia severity scores were assessed.
RESULTS: DM1 and DM2 patients had a lower grip strength than healthy subjects (p = .0001/p = .002). Patient-reported myotonia did not differ between DM1 and DM2 patients. DM1 patients revealed FDS and EDC atrophy compared to DM2 patients and healthy subjects (p = .003/p = .004). TDU revealed prolonged muscle contraction and relaxation times in both DM subtypes, with prolonged time to reach FDS peak relaxation velocity and altered peak FDS relaxation velocity only in DM1 patients (p = .03/p = .003). Peak FDS relaxation velocity correlated inversely with C(C)TG repeat numbers in DM patients. Sensitivity of TDU parameters to detect myotonic dystrophy varied between 50% and 75%, with a specificity of 95%.
CONCLUSIONS: Our exploratory study suggests that TDU could serve as a novel tool to quantify myotonia in DM patients, but larger follow-up studies are warranted to validate its diagnostic accuracy.

BACKGROUND: For the study of quantitative and qualitative muscle parameters, ultrasound and bioelectric impedance analysis are reliable, non-invasive, and reproducible. The aim of this study was to test the combined role of those techniques for the diagnosis of sarcopenia in a population of hospitalized older males and females.
METHODS: A total of 70 subjects were recruited, including 10 healthy adults and 60 hospitalized elderly patients with a good level of independence and cooperation, with and without sarcopenia. The rectus femoris cross-sectional area (CSA), thickness, echogenicity, and compressibility were measured with ultrasound echography. The phase angles (PhAs) and skeletal muscle mass were calculated by bioimpedence analysis. The muscle quality index (MQI) was calculated as the product of CSA and PhA.
RESULTS: Muscle compressibility was greater and PhA was lower in sarcopenic when compared with non-sarcopenic subjects. The threshold values for sarcopenia diagnosis in both sexes of CSA, of PhA, and of the MQI were identified. The obtained CSA values showed an AUC of 0.852 for women and 0.867 for men, PhA of 0.792 in women and 0.898 in men, while MQI was 0.900 for women and 0.969 for men.
CONCLUSIONS: The newly calculated cut-off values of CSA, PhA, and MQI predicted the presence of sarcopenia with good sensitivity and specificity values. The use of the MQI proved to be more promising than the separate use of CSA and PhA in both male and female subjects.

BACKGROUND: Sarcopenia is associated with many adverse outcomes in patients with cirrhosis. The tools currently in use for assessing sarcopenia have numerous flaws. We evaluated the utility of portable ultrasonography and a dynamometer for the bedside assessment of sarcopenia and its implications in hospitalized cirrhosis patients.
METHODS: A dynamometer was used to test the hand-grip strength (HGS) and ultrasound was used to measure the thickness of the forearm and quadriceps muscles. HGS value < 27 kg for men and < 16 kg for women was taken as significant according to the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria. The lower normal limit of muscle mass (5th percentile) was determined on 100 matched healthy controls.
RESULTS: According to the EWGSOP2 criteria and HGS values, the prevalence of sarcopenia and probable sarcopenia among 300 cirrhosis patients were 56% and 62.3%, respectively. HGS alone identified sarcopenia in 88.9% of patients, while overestimated it in 6.3% of cases. The prevalence rate of sarcopenic obesity was 11%. Compared to patients without sarcopenia, sarcopenic patients had more complications of cirrhosis such as ascites, variceal bleeding, hepatic encephalopathy, spontaneous bacterial peritonitis, sepsis, hepatorenal syndrome and refractory ascites. In-hospital (p = 0.037), three-month (p < 0.001), and six-month (p < 0.001) mortality rates were all higher among sarcopenic patients. On cox regression survival analysis, overall six-month mortality was significantly higher in sarcopenic patients compared to patients without sarcopenia (hazard ratio, 6.37; 95% confidence interval, 3.15-12.8, p < 0.001).
CONCLUSIONS: Bedside assessment of sarcopenia using a portable ultrasound machine and a dynamometer detects liver cirrhosis patients with high risk of complications and mortality.

The 4-point Heckmatt grading scale can easily be used to analyze muscle ultrasound images. The scale is used in an expanding set of muscles and neuromuscular disorders. This prompted the need for evaluation of the measurement properties of the scale in its current form. In this retrospective observational study we included muscle ultrasound images from patients who were undergoing an ultrasound exam for either clinical or research purposes. The primary outcome of this study was to investigate and improve the measurement properties of the Heckmatt scale using Rasch analysis. We investigated whether observers consistently used the 4 response categories. Data was available of 30.967 muscle ultrasound images from 1783 patients and 43 different individual muscles. In 8 of the 43 muscles, observers had difficulty to discriminate between the response categories, especially in bulbar muscles. After rescoring to a 3-point scale, the response categories were consistently used in all 43 muscles. In conclusion, a 3-point Heckmatt grading scale leads to improved accurate scoring compared to the original 4-point Heckmatt grading scale. Using the 3-point Heckmatt grading scale will not only simplify the use of the scale but also enhance its application in clinical practice and research purposes.

OBJECTIVE: The most adequate amount of protein that should be administered to critically ill patients is still debated and diverging findings are recently accumulating. We hypothesized that the effect of protein administration might depend on the amount of muscle mass.
METHODS: A secondary analysis of a single-centre prospective observational study of body composition in critically ill patients. Mechanically-ventilated subjects with an expected intensive care unit (ICU) stay >72 h were enrolled. Within 24 h from ICU admission, bioimpedance-derived muscle mass (BIA MM) and rectus femoris cross-sectional area (RF CSA) were measured. The amount of proteins and calories administered on the 7th ICU day was recorded.
RESULTS: We enrolled 94 subjects (65 males, actual body weight 72.9 ± 14.4 Kg, BMI 26.0 ± 4.8 kg/m2). Actual body weight was only weakly related to BIA MM (R = 0.478, p < 0.001) and not related to RF CSA (R = 0.114, p = 0.276). A higher protein intake was associated with a reduced mortality in the highest quartile of BIA MM (OR 0.68 [0.46; 0.99] per each 10 g of proteins administered) and in the third (OR 0.74 [0.57; 0.98]) and highest quartile of RF CSA (OR 0.68 [0.48; 0.96]).
CONCLUSIONS: A higher protein intake was associated with lower ICU mortality only in patients admitted with a higher muscle mass, as either assessed by BIA or muscle ultrasound.

Muscle ultrasound has been shown to be a valid and safe imaging modality to assess muscle wasting in critically ill patients in the intensive care unit (ICU). This typically involves manual delineation to measure the rectus femoris cross-sectional area (RFCSA), which is a subjective, time-consuming, and laborious task that requires significant expertise. We aimed to develop and evaluate an AI tool that performs automated recognition and measurement of RFCSA to support non-expert operators in measurement of the RFCSA using muscle ultrasound. Twenty patients were recruited between Feb 2023 and July 2023 and were randomized sequentially to operators using AI (n = 10) or non-AI (n = 10). Muscle loss during ICU stay was similar for both methods: 26 ± 15% for AI and 23 ± 11% for the non-AI, respectively (p = 0.13). In total 59 ultrasound examinations were carried out (30 without AI and 29 with AI). When assisted by our AI tool, the operators showed less variability between measurements with higher intraclass correlation coefficients (ICCs 0.999 95% CI 0.998-0.999 vs. 0.982 95% CI 0.962-0.993) and lower Bland Altman limits of agreement (± 1.9% vs. ± 6.6%) compared to not using the AI tool. The time spent on scans reduced significantly from a median of 19.6 min (IQR 16.9-21.7) to 9.4 min (IQR 7.2-11.7) compared to when using the AI tool (p < 0.001). AI-assisted muscle ultrasound removes the need for manual tracing, increases reproducibility and saves time. This system may aid monitoring muscle size in ICU patients assisting rehabilitation programmes.

Frailty and sarcopenia are well-recognized factors related to worse outcomes in patients with cirrhosis, including liver transplant (LT) candidates. Implications of pre-LT functional and muscle deterioration also affect post-LT outcomes. Patients with cirrhosis and acute-on-chronic liver failure (ACLF) have a lower survival rate, both before and after LT. There is a need to better identify those patients with ACLF who would benefit from LT. This review aims to present the available data about frailty and sarcopenia in patients with ACLF in the LT setting. An exhaustive review of the published literature was conducted. Data regarding frailty and sarcopenia in LT candidates with ACLF are scarce and heterogeneous. Studies evaluating frailty and sarcopenia in critically ill patients outside the liver literature are also presented in this review to enrich the knowledge of this field in expansion. Frailty and sarcopenia seem to contribute to worse outcomes in LT candidates with ACLF, both before and after LT. Sarcopenia evaluation may be the most prudent approach for those very sick patients. Skeletal muscle index assessed by computed tomography is recommended to evaluate sarcopenia. The role of muscle ultrasound and bioelectrical impedance analysis is to be determined. Frailty and sarcopenia are crucial factors to consider on a case-by-case basis in LT candidates with ACLF to improve patient outcomes.

OBJECTIVE: Sarcopenia and myosteatosis are common in patients with cirrhosis. The study aimed to evaluate efficacy of ultrasound to monitor muscle status during branched-chain amino acid (BCAA) supplementation and/or muscle exercise interventional approaches.
METHODS: A randomized controlled study, included 220 liver cirrhosis patients with Child- Pugh B and C, randomized into a control group (55 patients) received only the standard care, and interventional groups (165 patients) equally distributed into three subgroups, in addition to standard care, they received BCAA, programmed exercise, or BCAA and programmed exercise. At baseline and after 28 days, all participants were subjected to ultrasound-measured quadriceps muscle thickness and echo-intensity, muscle strength using handgrip, performance using short physical performance battery (SPPB), Model for End-Stage Liver Disease (MELD) score and nutritional assessment using 7- point Subjective Global Assessment Score (SGA) and laboratory assessment.
RESULTS: All interventional groups showed a significant improvement in the ultrasound detected quadriceps muscle thickness (p = 0.001) and echo intensity, in addition to muscle strength, muscle performance, and SGA. Hematological parameters (hemoglobin and platelet count), biochemical parameters (ALT, AST, bilirubin, creatinine, urea and INR) and MELD score were also improved in the interventional groups. In Child-Pugh B patients BCAA combined with exercise showed an add-on effect.
CONCLUSIONS: BCAA supplements, programed muscle exercise and both are useful interventional methods in improving muscle quality and quantity in cirrhosis patients, which can be monitored by ultrasound. The best results can be achieved by combined intervention in Child-Pugh B, while in Child-Pugh C single intervention may lead to an acceptable improvement. The trial was registered retrospectively in the Clinical Trials Registry (registration number NCT06088550).

Steroid myopathy is a non-inflammatory toxic myopathy that primarily affects the proximal muscles of the lower limbs. Due to its non-specific symptoms, it is often overshadowed by patients\' underlying conditions. Prolonged or high-dosage use of glucocorticoids leads to a gradual decline in muscle mass. There are no tools available to identify the course of steroid myopathy before the patient displays substantial clinical symptoms. In this study, we investigated individuals with nephrotic syndrome receiving prednisone who underwent muscle ultrasound to obtain cross-sectional and longitudinal pictures of three major proximal muscles in the lower limbs: the vastus lateralis, tibialis anterior, and medial gastrocnemius muscles. Our findings revealed that grip strength was impaired in the prednisolone group, creatine kinase levels were reduced within the normal range; echo intensity of the vastus lateralis and medial gastrocnemius muscles was enhanced, the pennation angle was reduced, and the tibialis anterior muscle exhibited increased echo intensity and decreased thickness. The total dose of prednisone and the total duration of treatment impacted the degree of muscle damage. Our findings indicate that muscle ultrasound effectively monitors muscle structure changes in steroid myopathy. Combining clinical symptoms, serum creatine kinase levels, and grip strength improves the accuracy of muscle injury evaluation.

BACKGROUND: Frailty is a geriatric syndrome that is characterized by increased vulnerability to intrinsic and extrinsic stressors due to decreased biologic reserves. Muscle ultrasound (US) is a valid and reliable method for assessing muscle quantity in older adults. The study aims to examine the relationship between frailty definitions and US-derived muscle parameters.
METHODS: We conducted a cross-sectional study with type 2 diabetes mellitus outpatients in a tertiary hospital, and all participants underwent a comprehensive geriatric assessment. For frailty assessment, the Fried Frailty Phenotype (FFP), the Clinical Frailty Scale (CFS), and the Edmonton Frailty Scale (EFS) were performed. Muscle US measurements included Gastrocnemius Medialis (GM) muscle thickness, GM fascicle length, GM pennation angle, Rectus Femoris (RF) muscle thickness, Rectus Femoris cross-sectional area (RFCSA), Rectus Abdominis (RA) muscle thickness, External Oblique (EO) muscle thickness, Internal Oblique (IO) muscle thickness, and Transverse Abdominis (TA) muscle thickness.
RESULTS: In all, 373 participants were included in the study. The median age of participants was 72.7 ± 5.9 years, and 64.6% of them were female. According to the FFP, 18.2% of the participants were living with frailty, 56% of them were pre-frail; 57.4% of them were living with frailty according to the CFS; 25.2% of them were living with frailty, and 20.6% of them were pre-frail according to the EFS. The FFP, CFS, and EFS scores were related to muscle thickness of GM, RF, and RA, fascicle length of GM, and pennation angle of GM and RFCSA. Particularly, GM pennation angle, RF muscle thickness, and RFCSA were associated with an increased risk of frailty. Besides muscle thickness of GM, RF, and RA, fascicle length of GM, pennation angle of GM, and RFCSA were significant for predicting the presence of frailty.
CONCLUSIONS: US-derived regional muscle measurements are associated with frailty definitions (in both physical, cumulative deficit, and multidimensional models) in a diabetic geriatric population.