[Collagen VI related myopathies. When to suspect, how to identify. The contribution of muscle magnetic resonance]. / Miopatías relacionadas a colágeno VI. Cuando sospecharlas, cómo identificarlas. Aporte de la resonancia magnética muscular.

Myopathies secondary to collagen VI mutations (COLVI-M) are the most frequent in the northern hemisphere, affecting the adult and pediatric population. There are no data on its prevalence in Latin America. They are characterized by a great clinical variability, from severe phenotypes, such as Ullrich congenital muscular dystrophy (UCMD), to intermediate and mild ones such as Bethlem myopathy (BM). Its onset is also variable and extends from the neonatal period to adulthood. Given the presence of joint hypermobility, the differential diagnosis should be made with various connective tissue diseases. The classical diagnostic algorithm in many patients has been insufficient to guide the genetic study in an adequate way, and from this the muscular magnetic resonance imaging has emerged as a very useful tool for a better diagnostic approach of this and other muscular pathologies. This ob jective of this review is to study the forms of presentation, clinical characteristics, specific diagnostic study, differential diagnosis and management of one of the most frequent hereditary muscular patho logies, with emphasis on the contribution of muscle magnetic resonance imaging.

Insights from genotype-phenotype correlations by novel SPEG mutations causing centronuclear myopathy.

Centronuclear myopathies (CNM) are a clinically and genetically heterogeneous group of congenital myopathies, defined histologically by increased number of fibres with centrally located nuclei, and type I fibre predominance in muscle biopsy. Myotubular myopathy, the X-linked form of CNM caused by mutations in the phosphoinositide phosphatase MTM1, is histologically characteristic since muscle fibres resemble myotubes. Here we present two unrelated patients with CNM and typical myotubular fibres in the muscle biopsy caused by mutations in striated muscle preferentially expressed protein kinase (SPEG). Next generation sequencing revealed novel biallelic homozygous mutations in SPEG in both cases. Patient 1 showed the c.1627_1628insA (p.Thr544Aspfs*48) mutation and patient 2 the c.9586C>T (p.Arg3196*) mutation. The clinical phenotype was distinctive in the two patients since patient 2 developed a dilated cardiomyopathy with milder myopathy features, while patient 1 showed only myopathic features without cardiac involvement. These findings expand the genotype-phenotype correlations after the initial report. Additionally, we describe whole body muscle MRI of patient 2 and we argue on the different SPEG isoforms in skeletal muscle and heart as the possible explanation leading to variable phenotypes of SPEG mutations.

Are erythropoiesis-stimulating agents beneficial for anemia in chronic heart failure patients? / ¿Son beneficiosos los agentes estimulantes de la eritropoyesis en pacientes anémicos con insuficiencia cardiaca?

Anemia is a common comorbidity among patients with chronic health failure and appears to be associated with increased mortality and morbidity. However, it is unclear whether correcting it with erythropoiesis stimulating agents improves clinical outcomes. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified 11 systematic reviews including 17 trials overall addressing the question of this article. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded the use of erythropoiesis stimulating agents in patients with chronic heart failure and anemia does not decrease mortality, and it is not clear if they decrease the risk of hospitalization or if they improve functional status because the certainty of the evidence is very low. The risk of thromboembolic events probably increases.

Miopatías relacionadas a colágeno VI: cuando sospecharlas, cómo identificarlas: aporte de la resonancia magnética muscular / Collagen VI related myopathies: when to suspect, how to identify: the contribution of muscle magnetic resonance

Resumen: Las miopatías secundarias a mutaciones en el colágeno VI (M-COLVI) son las más frecuentes en el hemisferio norte, afectando población adulta y pediátrica. No existen datos de su prevalencia en Latinoamérica. Se caracterizan por presentar una gran variabilidad clínica, desde fenotipos severos, como la distrofia muscular congénita de Ullrich (DMCU), a intermedios y leves como la Miopatía de Bethlem (MB). Su inicio también es variable y se extiende desde el período de recién nacido hasta la vida adulta. Dada la presencia de hiperlaxitud articular, el diagnóstico diferencial se debe realizar con diversas enfermedades del tejido conectivo. El algoritmo diagnóstico clásico en muchos pacientes ha sido insuficiente para orientar el estudio genético de forma adecuada, y a partir de esto la resonancia magnética muscular ha emergido como una herramienta de gran utilidad para una mejor aproxima ción diagnóstica de ésta y otras patologías musculares. Esta revisión tiene como objetivo examinar las formas de presentación, características clínicas, estudio diagnóstico específico, diagnóstico dife rencial y manejo de una de las patologías musculares herediatarias más frecuentes, con énfasis en el aporte de la resonancia magnética muscular.

Abstract: Myopathies secondary to collagen VI mutations (COLVI-M) are the most frequent in the northern hemisphere, affecting the adult and pediatric population. There are no data on its prevalence in Latin America. They are characterized by a great clinical variability, from severe phenotypes, such as Ullrich congenital muscular dystrophy (UCMD), to intermediate and mild ones such as Bethlem myopathy (BM). Its onset is also variable and extends from the neonatal period to adulthood. Given the presence of joint hypermobility, the differential diagnosis should be made with various connective tissue diseases. The classical diagnostic algorithm in many patients has been insufficient to guide the genetic study in an adequate way, and from this the muscular magnetic resonance imaging has emerged as a very useful tool for a better diagnostic approach of this and other muscular pathologies. This ob jective of this review is to study the forms of presentation, clinical characteristics, specific diagnostic study, differential diagnosis and management of one of the most frequent hereditary muscular patho logies, with emphasis on the contribution of muscle magnetic resonance imaging.

Resonancia magnética fetal en el estudio prequirúrgico de disrafia espinal / Foetal magnetic resonance imaging in the pre-surgical assessment of spinal dysraphism

Abstract. Spinal dysraphism is an important indication for foetal magnetic resonance imaging (MRI), considering the evaluation of potential candidates for intrauterine surgery. Foetal MRI has proved to be superior to 2D and 3D ultrasound for the posterior fossa, brain stem, corpus callosum, and cortical development abnormalities. The description and level of spinal injury, hydrocephalus, magnitude of cerebellum herniation, and associated injuries, are valuable information, which is useful for the preoperative assessment, as well as for the comparison with postnatal studies.

Resumen. Las disrafias espinales son una indicación importante de resonancia magnética fetal (RMF), considerando la evaluación de posibles candidatos para cirugía intrauterina. La RMF ha demostrado ser superior a la ultrasonografía 3D y 2D para la evaluación de la fosa posterior, el tronco cerebral, el cuerpo calloso, y las anormalidades del desarrollo de la corteza cerebral. La descripción y el nivel del daño espinal, el grado de hidrocefalia, la magnitud de la herniación del cerebelo, y la presencia de lesiones asociadas son variables importantes, útiles para la planificación preoperatoria y la comparación con estudios posnatales.

Variabilidad en la determinación de fracción grasa muscular en resonancia magnética utilizando la técnica de Dixon / Variability in magnetic resonance quantification of muscle fat fraction using Dixon's technique

Abstract. Muscle MRI has emerged as a valuable tool in the diagnosis of neuromuscular-disorders. The Dixon fat-water separation technique allows objective intra-muscular fat quantification. There are few reports concerning measurement standardisation with Dixon technique. The objective of this study was to evaluate the variability in fat quantification using Dixon's technique in a cohort of patients with congenital myopathies, by analysing intra-segment, intra-muscle, and inter-muscle variability of 60 muscles in each patient. Whole body MRI was performed on 31 patients, 23 with congenital myopathies and 8 healthy controls, aged between 10 months and 35 years old, from January 2014 to June 2016. The mean fat-fraction in healthy patients was around 5%, with less than 2% intra-muscle variability. An intra-muscle variability between 3.1-7.8% was estimated in patients with congenital myopathies. It may be concluded that there is high intra- and inter-muscle fat-fraction variability among patients with congenital myopathies, and this is an observation that should be incorporated in the analysis of fat replacement.

Resumen. La resonancia magnética muscular ha emergido como una valiosa herramienta de apoyo diagnóstico en enfermedades neuromusculares. La técnica de Dixon permite objetivar la fracción grasa muscular, pero no existe consenso sobre la estandarización de estas mediciones. El objetivo de este estudio fue evaluar la variabilidad en la determinación de fracción grasa utilizando la técnica de Dixon, estudiando la variabilidad intrasegmentaria, intramuscular e intermuscular en 60 músculos por paciente. Se realizó RM de cuerpo completo a 31 pacientes: 23 con miopatía congénita y 8 controles, entre 10 meses y 35 años de edad, desde enero del 2014 a junio del 2016. En pacientes sanos se estimó una fracción grasa promedio cercana al 5%, con una variabilidad intramuscular inferior al 2%. En pacientes con miopatías congénitas existe una variabilidad entre el 3,1-7,8%. El estudio permite concluir que existe una alta variabilidad intra e intermuscular en pacientes miopáticos, que no se observa en pacientes sanos.