Muscle Magnetic Resonance Imaging Research Articles

Persistent asymptomatic or mild symptomatic hyperCKemia due to mutations in ANO5: the mildest end of the anoctaminopathies spectrum.

The ANO5 gene encodes for anoctamin-5, a chloride channel involved in muscle cell membrane repair. Recessive mutations in ANO5 are associated with muscular diseases termed anoctaminopathies, which are characterized by proximal or distal weakness, or isolated hyperCKemia. We present the largest series of patients with asymptomatic/paucisymptomatic anoctaminopathy reported so far, highlighting their clinical and radiological characteristics. Twenty subjects were recruited retrospectively from the Neuromuscular Disorders Units database of two national reference centers. All had a confirmed genetic diagnosis (mean age of diagnosis was 48years) established between 2015 and 2019. Clinical and complementary data were evaluated through clinical records. None of the patients complained about weakness or showed abnormal muscular balance. Among paucisymptomatic patients, the main complaints or findings were generalized myalgia, exercise intolerance and calf hypertrophy, occasionally associated with calf pain. All patients showed persistent hyperCKemia, ranging from mild-moderate to severe. Muscle biopsy revealed inflammatory changes in three cases. Muscle magnetic resonance imaging revealed typical signs (preferential involvement of adductor and gastrocnemius muscles) in all but one patient. In two cases, abnormal findings were detectable only in STIR sequences (not in T1). Three patients showed radiological progression despite remaining asymptomatic. Twelve different mutations in ANO5 were detected, of which seven are novel. Recessive mutations in ANO5 are a frequent cause of undiagnosed asymptomatic/paucisymptomatic hyperCKemia. Patients with an apparent indolent phenotype may show muscle involvement in complementary tests (muscle biopsy and imaging), which may progress over time. Awareness of anoctaminopathy as the cause of nonspecific muscular complaints or of isolated hyperCKemia is essential to correctly diagnose affected patients.

Whole-body muscle MRI of patients with MATR3-associated distal myopathy reveals a distinct pattern of muscular involvement and highlights the value of whole-body examination

ObjectiveMATR3-associated distal myopathy is a rare distal myopathy predominantly affecting lower legs as well as wrist- and finger extensors. Whilst most distal myopathies are clinically and genetically well characterized, diagnosis often remains challenging. Pattern-based magnetic resonance imaging (MRI) approaches offer valuable additional information. However, a consistent pattern of muscular affection is missing for most distal myopathies. Thus, the aim of the present study was to establish a disease-specific pattern of muscular involvement in MATR3-associated distal myopathy using whole-body MRI.Methods15 patients (25–79 years of age, 7 female) with MATR3-associated distal myopathy were subjected to whole-body MRI. The grade of fatty involution for individual muscles was determined using Fischer-Grading. Results were compared to established MRI-patterns of other distal myopathies.ResultsThere was a predominant affection of the distal lower extremities. Lower legs showed a severe fatty infiltration, prominently affecting gastrocnemius and soleus muscle. In thighs, a preferential involvement of semimembranous and biceps femoris muscle was observed. Severe affection of gluteus minimus muscle as well as axial musculature, mainly affecting the thoracic segments, was seen. A sufficient discrimination to other forms of distal myopathy based solely on MRI-findings of the lower extremities was not possible. However, the inclusion of additional body parts seemed to yield specificity.InterpretationMuscle MRI of patients with MATR3-associated distal myopathy revealed a distinct pattern of muscular involvement. The usage of whole-body muscle MRI provided valuable additional findings as compared to regular MRI of the lower extremities to improve distinction from other disease entities.

Clinical spectrum of BICD2 mutations

Mutations in the BICD2 gene cause autosomal dominant lower extremity-predominant spinal muscular atrophy 2A (SMALED2A), a condition that is associated with a specific pattern of thigh and calf muscle involvement when studied by magnetic resonance imaging (MRI). Patients may present minor clinical sensory impairment, but objective sensory involvement has yet to be demonstrated. We collected clinical data from 11 patients from five different families carrying mutations in BICD2. Genetic diagnosis was achieved using gene panel testing and skin biopsies were taken from two patients to study the epidermal nerve fiber density. In the studied patients, three new pathogenic mutations were detected as well as the already defined pathogenic p.Ser107Leu mutation. The most frequent clinical picture was characterized by lower-limb weakness in combination with foot deformities. One patient manifested clinical and electrophysiological sensory impairment, and the epidermal nerve fiber density study of another patient revealed the existence of a small-fiber neuropathy. Muscle MRI showed a common pattern of fat deposition including selective involvement of gluteus medius and minimus at the pelvic level, the anterior compartment of the thigh and the posterior compartment of the calf, with only mild or no involvement of the intrinsic foot muscles. We report three new pathogenic mutations in the BICD2 gene. Muscle MRI confirms the existence of a selective pattern of thigh and leg muscle involvement in SMALED2A, providing additional information regarding pelvic and foot muscles. Moreover, our results raise the possibility of sensory involvement in the disease.

Follow-up of late-onset Pompe disease patients with muscle magnetic resonance imaging reveals increase in fat replacement in skeletal muscles.

BackgroundLate‐onset Pompe disease (LOPD) is a genetic disorder characterized by progressive degeneration of the skeletal muscles produced by a deficiency of the enzyme acid alpha‐glucosidase. Enzymatic replacement therapy with recombinant human alpha‐glucosidase seems to reduce the progression of the disease; although at the moment, it is not completely clear to what extent. Quantitative muscle magnetic resonance imaging (qMRI) is a good biomarker for the follow‐up of fat replacement in neuromuscular disorders. The aim of this study was to describe the changes observed in fat replacement in skeletal muscles using qMRI in a cohort of LOPD patients followed prospectively.MethodsA total of 36 LOPD patients were seen once every year for 4 years. qMRI, several muscle function tests, spirometry, activities of daily living scales, and quality‐of‐life scales were performed on each visit. Muscle MRI consisted of two‐point Dixon studies of the trunk and thigh muscles. Computer analysis of the images provided the percentage of muscle degenerated and replaced by fat in every muscle (known as fat fraction). Longitudinal analysis of the measures was performed using linear mixed models applying the Greenhouse–Geisser test.ResultsWe detected a statistically significant and continuous increase in mean thigh fat fraction both in treated (+5.8% in 3 years) and in pre‐symptomatic patients (+2.6% in 3years) (Greenhouse–Geisser p < 0.05). As an average, fat fraction increased by 1.9% per year in treated patients, compared with 0.8% in pre‐symptomatic patients. Fat fraction significantly increased in every muscle of the thighs. We observed a significant correlation between changes observed in fat fraction in qMRI and changes observed in the results of the muscle function tests performed. Moreover, we identified that muscle performance and mean thigh fat fraction at baseline visit were independent parameters influencing fat fraction progression over 4 years (analysis of covariance, p < 0.05).ConclusionsOur study identifies that skeletal muscle fat fraction continues to increase in patients with LOPD despite the treatment with enzymatic replacement therapy. These results suggest that the process of muscle degeneration is not stopped by the treatment and could impact muscle function over the years. Hereby, we show that fat fraction along with muscle function tests can be considered a good outcome measures for clinical trials in LOPD patients.

Novel Recessive TNNT1 Congenital Core-Rod Myopathy in French Canadians.

Recessive null variants of the slow skeletal muscle troponin T1 (TNNT1) gene are a rare cause of nemaline myopathy that is fatal in infancy due to respiratory insufficiency. Muscle biopsy shows rods and fiber type disproportion. We report on 4 French Canadians with a novel form of recessive congenital TNNT1 core-rod myopathy. Patients underwent full clinical characterization, lower limb magnetic resonance imaging (MRI), muscle biopsy, and genetic testing. A zebrafish loss-of-function model using morpholinos was created to assess the pathogenicity of the identified variant. Wild-type or mutated human TNNT1 mRNAs were coinjected with morpholinos to assess their abilities to rescue the morphant phenotype. Three adults and 1 child shared a novel missense homozygous variant in the TNNT1 gene (NM_003283.6: c.287T > C; p.Leu96Pro). They developed from childhood very slowly progressive limb-girdle weakness with rigid spine and disabling contractures. They suffered from restrictive lung disease requiring noninvasive mechanical ventilation in 3 patients, as well as recurrent episodes of rhabdomyolysis triggered by infections, which were relieved by dantrolene in 1 patient. Older patients remained ambulatory into their 60s. MRI of the leg muscles showed fibrofatty infiltration predominating in the posterior thigh and the deep posterior leg compartments. Muscle biopsies showed multiminicores and lobulated fibers, rods in half the patients, and no fiber type disproportion. Wild-type TNNT1 mRNA rescued the zebrafish morphants, but mutant transcripts failed to do so. This study expands the phenotypic spectrum of TNNT1 myopathy and provides functional evidence for the pathogenicity of the newly identified missense mutation. ANN NEUROL 2020;87:568-583.

Quantitative Muscle MRI Protocol as Possible Biomarker in Becker Muscular Dystrophy.

Aim of this study is to compare Quantitative Magnetic Resonance Imaging (qMRI) measures between Becker Muscular Dystrophy (BMD) and Healthy Subjects (HS) and to correlate these parameters with clinical scores. Ten BMD patients (mean age ±standard deviation: 38.7 ± 15.0 years) and ten age-matched HS, were investigated through magnetic resonance imaging (MRI) at thigh and calf levels, including: 1) a standard axial T1-weighted sequence; 2) a volumetric T2-weighted sequence; 3) a multiecho spin-echo sequence; 4) a 2-point Dixon sequence; 5) a Diffusion Tensor Imaging (DTI) sequence. Mean Fat Fraction (FF), T2-relaxation time and Fractional Anisotropy (FA) DTI at thigh and calf levels were significantly higher in BMD patients than in HS (p-values<0.01). FF at thigh and calf levels significantly correlated with North Star Ambulatory Assessment (NSAA) score (p-values<0.01) and6 Minutes Walking Test (6MWT) (p-values<0.01), whereas only calf muscle FF was significantly associated with time to get up from floor (p-value = 0.01). T2 significantly correlated with NSAA score (p-value<0.01), 6MWT (p-value = 0.02) and time to get up from floor (p-value<0.01) only at calf level. Among DTI values, only FA in thigh and calf muscles significantly correlated with NSAA score, 6MWT and 10-m walk (all p-values<0.05); only FA in calf muscles significantly correlated with time to get up from floor (p = 0.01). Muscle FF, T2-relaxometry and DTI, seem to be a promising biomarker to assess BMD disease severity, although further studies are needed to evaluate changes over the time.

Lower limb muscle magnetic resonance imaging in Chinese patients with myotonic dystrophy type 1

ABSTRACTObjectives: Muscle magnetic resonance imaging (MRI) is a reliable noninvasion tool for detecting muscle abnormalities of myopathies. This study aimed to investigate the MRI features of lower limb muscles in Chinese patients with myotonic dystrophy type 1 (DM1) and to evaluate the correlation between clinical factors and muscle MRI.Methods: We retrospectively reviewed the medical records and lower limb muscle MRI in 24 Chinese DM1 patients. Muscular Impairment Rating Scale (MIRS) was used to assess the clinical muscular impairment. Modified Mercuri’s scale was used to assess the degree of fatty infiltration. Spearman rank correlation test was used to analyze the relationship between fatty degeneration score with age, age of onset, disease duration, MIRS grading and creatinine kinase (CK) level.Results: Fatty infiltration was found in 22 of 24 DM1 patients and 8 patients were asymmetrically affected. The medial gastrocnemius was the most affected muscle, followed by soleus and tibialis anterior muscles in lower legs. At thigh level, the anterior compartment was usually the most affected region with the rectus femoris relatively spared. 79.2% of DM1 patients had edema in lower limb muscles. The total mean score of fatty infiltration correlated with MIRS grading, age and disease duration but did not correlate with the age of onset or CK level.Conclusion: Here, we found fatty infiltration present in most Chinese DM1 patients with a selective involvement pattern. There is a correlation between the total mean score of fatty infiltration and MIRS grading, age and disease duration.

抗信号识别颗粒抗体阳性的皮肌炎/临床无肌病性皮肌炎患者临床特点分析

Objective To investigate the clinical features of anti-signal recognition particle (SRP) antibody-positive patients with dermatomyositis/clinically amyopathic dermatomyositis (DM/CADM) . Methods Clinical data were collected from 90 patients with DM/CADM, who were hospitalized at the Department of Dermatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from June 2015 to July 2017. Immunoblotting assay was performed to determine the serum level of anti-SRP antibody in these patients. Statistical analysis was carried out using t test and Chi-square test. Results Of the 90 patients with DM/CADM, 11 (12.2%) were positive for serum anti-SRP antibody, including 6 with DM and 5 with CADM. Among 82 adult patients with DM/CADM, the prevalence of malignant tumors was significantly higher in the patients with anti-SRP antibody than in those without (7/9 vs. 31.5%[23/73], χ2 = 7.394, P = 0.006) . The 11 patients with anti-SRP antibody had typical DM skin lesions, and their cutaneous dermatomyositis disease area and severity index (CDASI) was 18.1 ± 2.9. The prevalence of angel wings sign (aliform erythema on the trunk) was significantly higher in the patients with anti-SRP antibody than in those without (7/11 vs. 29.9%[20/67], Fisher′s exact test, P = 0.028) . The positive rate of antinuclear antibody was significantly higher in the patients with anti-SRP antibody than in those without (4/8 vs. 16.7%[13/78], χ2 = 6.053, P = 0.014) . Magnetic resonance imaging of muscles of both thighs of the 10 patients with anti-SRP antibody (6 with DM and 4 with CADM) showed the presence of abnormal signals in the thigh muscle group in 8, swelling of the muscle group in 2, subcutaneous edema in 2, myofascial swelling in 1, and no abnormities in 2. No interstitial lung disease or myocardial involvement was observed in the patients with anti-SRP antibody. Conclusions The anti-SRP antibody-positive patients with DM/CADM showed a high prevalence of angel wings sign , and a high risk of malignant tumors. Early detection of the anti-SRP antibody in patients with DM/CADM is helpful to predict the occurrence of malignant tumors. Key words: Dermatomyositis; Polymyositis; Signal recognition particle; Skin manifestations

Value of muscle magnetic resonance imaging in the differential diagnosis of muscular dystrophies related to the dystrophin-glycoprotein complex

BackgroundDystrophin-glycoprotein complex (DGC)-related muscular dystrophies may present similar clinical and pathological features as well as undetectable mutations thus being sometimes difficult to distinguish. We investigated the value of muscle magnetic resonance imaging (MRI) in the differential diagnosis of DGC-related muscular dystrophies and reported the largest series of Chinese patients with sarcoglycanopathies studied by muscle MRI.ResultsFifty-five patients with DGC-related muscular dystrophies, including 22 with confirmed sarcoglycanopathies, 11 with limb-girdle muscular dystrophy 2I (LGMD2I, FKRP-associated dystroglycanopathy), and 22 with dystrophinopathies underwent extensive clinical evaluation, muscle biopsies, genetic analysis, and muscle MRI examinations. Hierarchical clustering of patients according to the clinical characteristics showed that patients did not cluster according to the genotypes. No statistically significant differences were observed between sarcoglycanopathies and LGMD2I in terms of thigh muscle involvement. The concentric fatty infiltration pattern was observed not only in different sarcoglycanopathies (14/22) but also in LGMD2I (9/11). The trefoil with single fruit sign was observed in most patients with dystrophinopathies (21/22), and a few patients with sarcoglycanopathies (4/22) or LGMD2I (2/11). Hierarchical clustering showed that most patients with sarcoglycanopathies or LGMD2I can be distinguished from dystrophinopathies based on the concentric fatty infiltration pattern and trefoil with single fruit sign at the thigh level on muscle MRI.ConclusionsMuscle MRI at the thigh level potentially allows distinction of sarcoglycanopathies or FKRP-associated dystroglycanopathy from dystrophinopathies.

Tracking muscle wasting and disease activity in facioscapulohumeral muscular dystrophy by qualitative longitudinal imaging.

BackgroundFacioscapulohumeral muscular dystrophy (FSHD) is one of the most frequent late‐onset muscular dystrophies, characterized by progressive fatty replacement and degeneration involving single muscles in an asynchronous manner. With clinical trials at the horizon in this disease, the knowledge of its natural history is of paramount importance to understand the impact of new therapies. The aim of this study was to assess disease progression in FSHD using qualitative muscle magnetic resonance imaging, with a focus on the evolution of hyperintense lesions identified on short‐tau inversion recovery (STIR+) sequences, hypothesized to be markers of active muscle injury.MethodsOne hundred genetically confirmed consecutive FSHD patients underwent lower limb muscle magnetic resonance imaging at baseline and after 365 ± 60 days in this prospective longitudinal study. T1 weighted (T1w) and STIR sequences were used to assess fatty replacement using a semiquantitative visual score and muscle oedema. The baseline and follow‐up scans of each patient were also evaluated by unblinded direct comparison to detect the changes not captured by the scoring system.ResultsForty‐nine patients showed progression on T1w sequences after 1 year, and 30 patients showed at least one new STIR+ lesion. Increased fat deposition at follow‐up was observed in 13.9% STIR+ and in only 0.21% STIR‐ muscles at baseline (P < 0.001). Overall, 89.9% of the muscles that showed increased fatty replacement were STIR+ at baseline and 7.8% were STIR+ at 12 months. A higher number of STIR+ muscles at baseline was associated with radiological worsening (odds ratio 1.17, 95% confidence interval 1.06–1.30, P = 0.003).ConclusionsOur study confirms that STIR+ lesions represent prognostic biomarkers in FSHD and contributes to delineate its radiological natural history, providing useful information for clinical trial design. Given the peculiar muscle‐by‐muscle involvement in FSHD, MRI represents an invaluable tool to explore the modalities and rate of disease progression.

POPDC3 Gene Variants Associate with a New Form of Limb Girdle Muscular Dystrophy.

The Popeye domain containing 3 (POPDC3) gene encodes a membrane protein involved in cyclic adenosine monophosphate (cAMP) signaling. Besides gastric cancer, no disease association has been described. We describe a new muscular dystrophy associated with this gene. We screened 1,500 patients with unclassified limb girdle weakness or hyperCKemia for pathogenic POPDC3 variants. Five patients carrying POPDC3 variants were examined by muscle magnetic resonance imaging (MRI), muscle biopsy, and cardiac examination. We performed functional analyses in a zebrafish popdc3 knockdown model and heterologous expression of the mutant proteins in Xenopus laevis oocytes to measure TREK-1 current. We identified homozygous POPDC3 missense variants (p.Leu155His, p.Leu217Phe, and p.Arg261Gln) in 5 patients from 3 ethnically distinct families. Variants affected highly conserved residues in the Popeye (p.Leu155 and p.Leu217) and carboxy-terminal (p.Arg261) domains. The variants were almost absent from control populations. Probands' muscle biopsies were dystrophic, and serum creatine kinase levels were 1,050 to 9,200U/l. Muscle weakness was proximal with adulthood onset in most patients and affected lower earlier than upper limbs. Muscle MRI revealed fat replacement of paraspinal and proximal leg muscles; cardiac investigations were unremarkable. Knockdown of popdc3 in zebrafish, using 2 different splice-site blocking morpholinos, resulted in larvae with tail curling and dystrophic muscle features. All 3 mutants cloned in Xenopus oocytes caused an aberrant modulation of the mechano-gated potassium channel, TREK-1. Our findings point to an important role of POPDC3 for skeletal muscle function and suggest that pathogenic variants in POPDC3 are responsible for a novel type of autosomal recessive limb girdle muscular dystrophy. ANN NEUROL 2019;86:832-843.

Palbociclib in combination with simvastatin induce severe rhabdomyolysis: a case report

BackgroundPalbociclib is a selective well-tolerated antineoplastic drug used in the treatment of advanced HER2-negative, estrogen-receptor positive breast cancer that has shown significant improvement in progression-free survival. We present a patient that developed severe rhabdomyolysis with tetra-affection and loss of gait after initiating the first cycle of Palbociclib concomitantly with Simvastatin 40 mg treatment.Case presentationA 71-year-old woman with metastatic breast cancer developed tetraparesis and near fatal rhabdomyolysis after initiation of first cycle Palbociclib. For 10 years prior to this treatment, the patient had been treated with Simvastatin without myalgia or other neuromuscular complaints prior to the first cycle of Palbociclib. The patient was admitted at the neurology department, where Palbociclib and Simvastatin were discontinued. The patient was aggressively hydrated and treated with intravenous immunoglobulin therapy with slowly remission and finally regaining independent gait function. Evaluation showed a negative myositis antibody work-up. Muscle magnetic resonance imaging showed edema in multiple foci, but skeletal muscle biopsy did not show necrosis. Post discharge genetic analysis showed single heterozygosity for nucleotide polymorphism rs4149056.ConclusionWe present a patient who developed severe rhabdomyolysis induced by a combination of Palbociclib and Simvastatin treatment. Rhabdomyolysis was most likely induced by toxic plasma concentrations of Simvastatin due to Palbociclibs inhibition of the CYP3A4 enzyme in combination with a decreased hepatic uptake of Simvastatin due to single nucleotide polymorphism rs4149056. The study underscores that combining Simvastatin and Palbociclib should be done cautiously and genetic testing of the rs4149056 SNP is warranted. If present, Simvastatin should be discontinued or replaced with a lesser myopathic statin in regard to patients risk of cardiovascular events.

Muscle Magnetic Resonance Imaging versus Clinical Function in Duchenne Muscular Dystrophy

Muscle Magnetic Resonance Imaging versus Clinical Function in Duchenne Muscular Dystrophy

P.318MRI evaluation of skeletal muscle in the deltaE50-MD dog model of Duchenne muscular dystrophy

There is currently no cure for the fatal X-linked disorder Duchenne muscular dystrophy (DMD) and clinically-applicable translational trials continue to rely heavily on use of animal models. The Royal Veterinary College has a unique colony of dystrophin deficient dogs: the deltaE50-MD dog model. Magnetic Resonance Imaging (MRI) is a valuable non-invasive technique for monitoring the progression of the disease in human DMD patients. The aim was to determine if the deltaE50-MD dog has a skeletal muscle MRI phenotype that resembles that of DMD boys and to determine MRI differences of skeletal muscles in dystrophic and wildtype dogs. MRI was conducted in 15 deltaE50-MD dogs and 10 age-matched littermate wildtype male dogs under general anaesthetic, every 12 weeks from 3 months to 18 months of age. Up to 7 pelvic limb muscles and 4 lumbar muscles were assessed bilaterally in each dog. Four MRI biomarkers assessed were muscle volume normalised to femur length, T2 map signal intensity (SI), T1w to post gadolinium T1w SI ratio and muscle heterogeneity. The mean was calculated for each pair of muscles for all MRI biomarkers. Mixed model analyses (SPSS) were used to examine differences between groups at different ages. Muscle volumes were significantly smaller (p<0.001) in affected dogs when compared to wildtype dogs in all examined muscles, apart from the cranial sartorius. T2 map SI (p<0.001) and muscle heterogeneity (p<0.05) were significantly higher in affected dogs when compared to wildtype dogs. Affected dogs had significantly increased post gadolinium T1w SI in all muscles (p<0.05), apart from the cranial sartorius muscle, when compared to wildtype dogs. The most useful MRI biomarkers found in this study were muscle volume normalised to femur length and T2 map SI. Both of these biomarkers were able to show differences between groups and track changes longitudinally. These MRI biomarkers will be useful to determine efficacy of therapeutic clinical trials in the colony.

European muscle MRI study in limb girdle muscular dystrophy type R1/2A (LGMDR1/LGMD2A).

Limb girdle muscular dystrophy type R1/2A (LGMDR1/LGMD2A) is a progressive myopathy caused by deficiency of calpain 3, a calcium-dependent cysteine protease of skeletal muscle, and it represents the most frequent type of LGMD worldwide. In the last few years, muscle magnetic resonance imaging (MRI) has been proposed as a tool for identifying patterns of muscular involvement in genetic disorders and as a biomarker of disease progression in muscle diseases. In this study, 57 molecularly confirmed LGMDR1 patients from a European cohort (age range 7-78years) underwent muscle MRI and a global evaluation of functional status (Gardner-Medwin and Walton score and ability to raise the arms). We confirmed a specific pattern of fatty substitution involving predominantly the hip adductors and hamstrings in lower limbs. Spine extensors were more severely affected than spine rotators, in agreement with higher incidence of lordosis than scoliosis in LGMDR1. Hierarchical clustering of lower limb MRI scores showed that involvement of anterior thigh muscles discriminates between classes of disease progression. Severity of muscle fatty substitution was significantly correlated with CAPN3 mutations: in particular, patients with no or one "null" alleles showed a milder involvement, compared to patients with two null alleles (i.e., predicting absence of calpain-3 protein). Expectedly, fat infiltration scores strongly correlated with functional measures. The "pseudocollagen" sign (central areas of sparing in some muscle) was associated with longer and more severe disease course. We conclude that skeletal muscle MRI represents a useful tool in the diagnostic workup and clinical management of LGMDR1.

Quantitative evaluation of age-related changes to pelvic floor muscles in magnetic resonance images from 369 patients.

This study aimed to establish and validate a quantitative evaluation method for pelvic floor muscles using magnetic resonance images (MRI) and to examine the morphological change of pelvic floor muscles with aging. Data from 369 consecutive patients (163 men, 206 women; median age 58 years; range 17-92 years) who underwent coronal T2-weighted pelvic MRI at Osaka General Hospital between January 2016 and December 2016 were retrospectively examined. MRI of the levator ani muscle was evaluated. The MRI image blinded the patient information and was evaluated by a radiology specialist with 22 years of experience. In coronal T2-weighted MRI of the pelvis, the levator ani muscle was evaluated using the slice; it showed the most upward and downward convexity. We measured the thickness of the levator ani muscle, and the distance at the most convex part from a straight line connecting the origin and insertion of the levator ani muscle on both the left and right sides. Upward and downward convexity was recorded in positive and negative values, respectively. The levator ani muscle was able to be evaluated quantitatively in all cases. Both men and women showed thinning (men: mean 3.316 mm, r = -0.388, P < 0.0001; women: mean 3.947 mm, r = -0.359, P < 0.0001) and concavity (men: mean 1.412 mm, r = -0.362, P < 0.0001; women: mean 4.979 mm, r = -0.630, P < 0.0001) of the levator ani muscle with aging. A quantitative evaluation method for pelvic floor muscles using MRI was established. Aging was associated with morphological changes in the pelvic floor muscles in both men and women. Geriatr Gerontol Int 2019; 19: 834-837.

MON-LB074 Ultrasonography May Reliably Assess Muscle Architecture in Patients with Cushing's Syndrome in Remission: Comparison with Gold-Standard Muscle MRI

Myopathy is a frequent feature in patients with Cushing’s syndrome (CS), long-term after eucortisolism is achieved. Muscle magnetic resonance imaging (MRI) is the gold standard technique to assess muscle architecture but cannot be performed in daily clinical practice. Ultrasonography (US) may be a useful and cost-effective tool to evaluate muscle impairment in the clinical setting. Utility of US to evaluate the impairment of muscle structure in “cured” CS patients is not established. The aim of our study was to assess the correlation between US- and MRI-measured parameters of muscle architecture. We included 21 female patients [mean (±SD) age, 50±12 years; mean (±SD) BMI, 26.7±3.8] and 21 age- and BMI-matched healthy women. Mean (±SD) duration of remission was 132±87 months. We obtained transverse ultrasound images of the rectus femoris and assessed muscle intensity at both the midpoint (QmitR) and the distal third (QtercR), between the anterior inferior iliac spine and the proximal end of the patella. We scored muscle intensity using the Heckmatt’s rating scale and classified our findings as follows: 1-normal, 2-mildy increased muscle echoes with normal bone reflection, 3-moderately increased muscle echoes with reduced bone, 4-severely increased muscle echoes with absent bone reflection. We found that mean US intensity score of the rectus femoris at midpoint (QmitR) was increased in patients vs. the control group (p<0.001), suggesting more impaired architecture in the former, likely due to fibrosis/fatty infiltration. We also measured the degree of fatty infiltration of the thigh muscles using magnetic resonance imaging (MRI) and ultrashort multiecho T2-weighted and 3-point Dixon sequences in the anterior, posterior, and anterior+posterior muscle compartments. T2 signal intensity was classified as “high” (corresponding to fat), “medium” (muscle) or “low” (macromolecules-muscle). Of note, mean muscle fat fraction (%) in the posterior compartment, as determined by 3-point Dixon, was increased in patients vs. the control group (20±6% vs. 17±3%; p=0.018), indicating greater muscle fatty infiltration in the former. When US and MRI findings were compared, higher QtercR was associated with greater mean muscle fat fraction in the anterior (ρ=0.697, p=0.003), in posterior (ρ=0.600, p=0.014), and anterior+posterior compartment (ρ=0.702, p=0.002) in patients. QmitR was associated with greater mean muscle fat fraction in the anterior (ρ=0.510, p=0.043) and anterior+posterior compartment (ρ=0.500, p=0.049). No correlations were found between muscle US and MRI in controls. We conclude that US parameters of muscle architecture are correlated with muscle MRI measurements in “cured” CS patients. US may be a useful technique to identify, in a clinical setting, those CS patients showing residual myopathy. This work was supported by ISCIII FIS PI14/0194 and PI17/00749 and FEDER funds. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Muscle MRI findings in herpes zoster‐associated brachial plexopathy

AbstractA 70‐year‐old woman presented at our hospital with difficulty in raising the left arm. Two months previously, she developed vesicular rash and pain in the left shoulder and was diagnosed with herpes zoster. Muscle magnetic resonance imaging (MRI) revealed increased diffusion‐weighted image (DWI) signal intensity in the left supraspinatus, infraspinatus, and subscapularis muscles. After steroid therapy, her muscle strength showed complete clinical recovery and a follow‐up MRI showed a remarkable reduction in DWI hyperintensity in the left shoulder girdle muscles. Muscle MRI findings could be useful to diagnose lesions and evaluate progression in cases presenting focal weakness associated with herpes zoster.

Change in the content of titin and nebulin and their phosphorylation level in the quadriceps femoris muscle in chronic alcoholic myopathy

Objective : to assess the structural and functional state of skeletal muscles in the hip, as well as changes in the content of the sarcomere cytoskeleton proteins titin and nebulin and their phosphorylation level in patients with chronic alcohol intoxication. Patients and methods . Thirteen patients (4 men and 9 women; mean age, 38.9±9.9 years) with chronic alcohol intoxication were examined. The average duration of regular consumption of alcoholic beverages was 7.6±3.7 years. The mean amount of alcohol consumed per week was 48.2±13.1 units. A control group included 10 healthy volunteers matched for age and sex. A neurological examination was performed according to the generally accepted scheme. Laboratory tests involved blood biochemical analysis estimating the levels of liver enzymes, creatine phosphokinase (CPK), and insulin-like growth factor-1 (IGF-1). All the patients underwent hip magnetic resonance imaging (MRI), followed by assessment of the degree of muscle tissue damage and by determination of the volume of anterior and posterior thigh muscles. The content of titin and nebulin and their phosphorylation level were determined in the muscle tissue samples obtained by an open biopsy from the lateral head of the quadriceps femoris muscle. Results and discussion . Four (30.8%) patients were found to have proximal leg muscle weakness; the degree of paresis was the same in the anterior and posterior thigh muscles. There was a significant increase in the plasma level of liver enzymes; the CPK level remained within the reference values; there was a tendency towards lower IGF-1 levels. Analysis of MRI data showed that 7 (53.8%) patients had fatty degeneration in the thigh muscles. Quantitative evaluation ascertained a significant symmetrical decrease in the volume of anterior thigh muscles and a tendency towards a symmetrical reduction in that in the posterior thigh muscle compared to the control. Analysis of the content of titin and nebulin in the lateral head of the quadriceps femoris muscle revealed a significant decrease in the percentage of nebulin (81.1%; p < 0.01) and intact titin-1 (T1) isoforms (83.6%; p < 0.01). The percentage of proteolytic titin-2 (T2) fragments in the muscle of patients did not differ significantly from that in the control group. Estimating the phosphorylation level of the structural muscle proteins showed no significant differences when compared to the control. Conclusion . Anterior and posterior thigh muscle weakness should be considered as the main clinical manifestation of chronic alcoholic myopathy (CAM) in the absence of biochemical and neurophysiological markers of the disease. Lower extremity muscle MRI that can reveal a lower muscle volume concurrent with fatty degeneration is a non-invasive informative diagnostic technique for CAM. The pathogenesis of skeletal muscle atrophy in chronic alcohol intoxication involves the sarcomere structural proteins titin and nebulin, which regulate the interaction of the major contractile proteins actin and myosin, and whole muscle contraction.

Altered myogenesis and premature senescence underlie human TRIM32-related myopathy

TRIM32 is a E3 ubiquitin -ligase containing RING, B-box, coiled-coil and six C-terminal NHL domains. Mutations involving NHL and coiled-coil domains result in a pure myopathy (LGMD2H/STM) while the only described mutation in the B-box domain is associated with a multisystemic disorder without myopathy (Bardet-Biedl syndrome type11), suggesting that these domains are involved in distinct processes. Knock-out (T32KO) and knock-in mice carrying the c.1465G > A (p.D489N) involving the NHL domain (T32KI) show alterations in muscle regrowth after atrophy and satellite cells senescence. Here, we present phenotypical description and functional characterization of mutations in the RING, coiled-coil and NHL domains of TRIM32 causing a muscle dystrophy. Reduced levels of TRIM32 protein was observed in all patient muscle studied, regardless of the type of mutation (missense, single amino acid deletion, and frameshift) or the mutated domain. The affected patients presented with variable phenotypes but predominantly proximal weakness. Two patients had symptoms of both muscular dystrophy and Bardet-Biedl syndrome. The muscle magnetic resonance imaging (MRI) pattern is highly variable among patients and families. Primary myoblast culture from these patients demonstrated common findings consistent with reduced proliferation and differentiation, diminished satellite cell pool, accelerated senescence of muscle, and signs of autophagy activation.