Clinical and imaging hallmarks of the MYH7-related myopathy with severe axial involvement.

INTRODUCTION: MYH7 gene mutations are related to a heterogeneous group of skeletal and cardiac myopathies. METHODS: We evaluated clinical and muscle MRI changes in patients with mutations in the rod domain of MYH7, including 1 with mosaicism and 3 with novel missense mutations. RESULTS: Patients presented in childhood with a distal and axial phenotype. Biopsy findings were variable. Half of the cases displaying some type of core pathology, including minicores and eccentric cores. Most patients demonstrated internal bands of infiltration ("inverted-collagen-VI sign") in multiple muscles, particularly the soleus, and prominent atrophy and fatty infiltration of the tongue and the paraspinal, gluteus minimus, sartorius, gracilis, tibialis anterior, and extensor digitorum longus muscles. DISCUSSION: Muscle imaging findings in patients with axial involvement provide significant clues permitting the distinction between MYH7-related myopathies and other axial myopathies such as those related to SEPN1 and LMNA genes. Muscle Nerve 58: 224-234, 2018.

Aumento de transaminasas: una manifestación de distrofia muscular de Duchenne / Transaminases increase: a manifestation of Duchenne's muscular dystrophy

Commonly used in clinical practice, glutamic oxalacetic (GOT) and glutamic piruvic (GPT) transaminases are produced in various body tissues, including striated muscle, so their blood elevation is not due exclusively to liver disease. The objective of this study is to demonstrate the correlation between elevated creatinkinase (CK) and transaminases in patients with diagnosis of Duchenne muscular dystrophy (DMD), the most frequent neuromuscular disease in children. Patients and Method: Assessment in 61 children with diagnosis of DMD of CK, AST and ALT levels, and their correlation. Results: Aill patients had increase of CK ( = 13.363 IU/L), AST ( = 203 lU/L) and ALT ( = 194 IU/L) above normal values. The increase of transaminases related directly with the increase of CK. Conclusion: Patients with DMD have increased transaminases, so it is necessary to include this diagnostic possibility in a child with hypertransaminemia, prior to performing liver biopsy.

Las transaminasas que comúnmente se utilizan en clínica, glutámico oxalacética (GOT) y glutámico pirúvica (GPT) son producidas en varios tejidos del organismo entre los cuales se cuenta el músculo estriado, por lo que la elevación de transaminasas en sangre no es producida exclusivamente por enfermedades hepáticas. Objetivo: Demostrar la correlación entre el alza de la creatinkinasa (CK) y transaminasas en pacientes con el diagnóstico de distrofia muscular de Duchenne (DMD), la enfermedad neuromuscular más frecuente en niños. Pacientes y Método: Evaluación en 61 niños con diagnóstico de DMD de los niveles de CK, GOT y GPT y la relación entre ellos. Resultados: Todos los pacientes presentaron aumento de CK ( = 13.363 IU/L), GOT ( = 203 IU/L) y GPT ( = 194 IU/L) sobre los valores normales. El aumento de transaminasas se relacionó en forma directa con aumento de CK. Conclusiones: Los pacientes con DMD presentan transaminasas aumentadas, por lo que es necesario incluir esta posibilidad diagnóstica en niños con hipertransaminasemia, previo a realizar biopsia hepática.

Rabdomiolisis inducida por ejercicio en adolescentes chilenos / Exercise-induced rhabdomyolysis in Chilean adolescents

Rabdomiolisis es la destrucción de las fibras musculares y se caracteriza clínicamente por dolor, edema y debilidad muscular, orina color rojo-café (mioglobinuria) y la elevación por un corto período de la enzima creatinquinasa en sangre. Entre las múltiples causas de rabdomiolisis está el ejercicio intenso. La rabdomiolisis inducida por el ejercicio está escasamente documentada en la población pediátrica y en general requiere descartar alguna patología metabólica de base. Las complicaciones de la rabdomiolisis pueden ser múltiples y graves: falla renal, arritmias cardíacas, síndrome compartamental, coagulación intravascular diseminada, acidosis láctica, etc. La falla renal es consecuencia de la necrosis tubular aguda secundaria al taponamiento de los túbulos renales por la mioglobina, que puede llegar a ser fatal. Comunicamos nuestra experiencia con tres adolescentes que después de iniciar un programa de entrenamiento físico, desarrollaron intenso dolor y edema muscular constatándose un significativo aumento de la enzima creatinquinasa y edema muscular en la ultrasonografía de los músculos utilizados en el ejercicio. El estudio complementario descartó una patología metabólica de base en todos ellos. El tratamiento oportuno incluyó terapia sintomática e hidratación intravenosa. No se desarrolló insuficiencia renal en ninguno. Frente al incremento no controlado del entrenamiento físico, el diagnóstico oportuno de esta patología permite evitar sus graves consecuencias.

Rhabdomyolysis implies injury to the muscle fibers. The hallmark clinical manifestations are pain, oedema, muscle weakness and dark urine (myoglobinuria). There is an increase, for a short time, of the muscle enzyme creatine kinase in blood. Exercise induced rhabdomyolysis is one of various causes of rhabdomyolysis but has been rarely documented in the pediatric population. In general it is always important to exclude an underlying metabolic pathology. Complications of rhabdomyolysis can be many and severe: renal failure, cardiac arrhythmias, compartment syndrome, disseminated intravascular coagulation, lactic acidosis, etc.. Renal failure is the consequence of the acute tubular necrosis secondary to the obstruction of the renal tubules by myoglobin, which can become fatal. We report our experience with three adolescents that after starting a program of physical training, developed intense pain and muscle oedema at the ultrasound scan of the muscles involved in the exercise. Complementary studies excluded an underlying metabolic disease in all of them. The opportune treatment included symptomatic treatment and endovenous hydratation. Fortunately, none of them developed renal failure.

[Clinical, electrophysiological and molecular study of 26 chilean patients with spinal muscular atrophy]. / Atrofia muscular espinal: caracterización clínica, electrofisiológica y molecular de 26 pacientes.

BACKGROUND: Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder affecting the anterior horn cells of the spinal cord resulting in muscle weakness and atrophy, linked to the homozygous disruption of the survival motor neuron 1 (SMN1) gene. It is the leading genetic cause of infant death. It has been classified into three types based on the severity of symptoms. Type I SMA is the most severe form with death within the first 2 years of life. Type II and III SMA patients show intermediate and mild forms of the disorder. AIM: To describe the clinical and electrophysiological findings of 26 Chilean patients with SMA with molecular confirmation. PATIENTS AND METHODS: Retrospective multicenter analysis of patients with SMA assessed between 2003 and 2010. The diagnosis was suspected on clinical and electrophysiological criteria. Since 2006 molecular genetics confirmation was implemented in one of our centers. RESULTS: Twenty-six patients between 2 months and 18 years of age at presentation were analyzed; 15 (58%) were males. SMA I, II and III clinical criteria were observed in 4 (15.4 %), 11 (42.3%) and 11 (42.3%)patients, respectively. All had proximal muscle weakness and atrophy. Electromyography showed features of acute denervation or re-innervation with normal motor and sensory nerve conduction. Nine patients required a muscle biopsy. The genetic confirmation of the disease by PCR technique followed by restriction fragment length polymorphism method disclosed the SMN1 gene deletion in all 26 cases. All patients died secondary to respiratory failure, between eight and 14 months of life. CONCLUSIONS: An adequate clinical and molecular diagnosis of spinal muscular atrophy will help for a better management of these patients.

Atrofia muscular espinal: Caracterización clínica, electrofisiológica y molecular de 26 pacientes / Clinical, electrophysiological and molecular study of 26 chilean patients with spinal muscular atrophy

Background: Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder affecting the anterior horn cells of the spinal cord resulting in muscle weakness and atrophy, linked to the homozygous disruption of the survival motor neuron 1 (SMN1) gene. It is the leading genetic cause of infant death. It has been classified into three types based on the severity of symptoms. Type I SMA is the most severe form with death within the first 2 years of life. Type II and III SMA patients show intermediate and mild forms of the disorder. Aim: To describe the clinical and electrophysiological findings of 26 Chilean patients with SMA with molecular confirmation. Patients and Methods: Retrospective multicenter analysis of patients with SMA assessed between 2003 and 2010. The diagnosis was suspected on clinical and electrophysiological criteria. Since 2006 molecular genetics confirmation was implemented in one of our centers. Results: Twenty-six patients between 2 months and 18 years of age at presentation were analyzed; 15 (58 percent) were males. SMA I, II and III clinical criteria were observed in 4 (15.4 percent), 11 (42.3 percent) and 11 (42.3 percent)patients, respectively. All had proximal muscle weakness and atrophy. Electromyography showed features of acute denervation or re-innervation with normal motor and sensory nerve conduction. Nine patients required a muscle biopsy. The genetic confirmation of the disease by PCR technique followed by restriction fragment length polymorphism method disclosed the SMN1 gene deletion in all 26 cases. All patients died secondary to respiratory failure, between eight and 14 months of life. Conclusions: An adequate clinical and molecular diagnosis of spinal muscular atrophy will help for a better management of these patients.

Nueva clasificación de cefalea / New clasification of migraine

La cefalea es un síntoma de consulta frecuente. En niños la cefalea vascular (migraña) es la más común. Al no existir un marcador biológico para el diagnóstico de cefalea, la existencia de una clasificación con criterios exactos cobra gran relevancia para el diagnóstico, estudio y tratamiento. En 1988, la Sociedad Internacional de la Cefalea (IHS, sigla de International Headache Society) publicó un sistema de clasificación basado en el consenso de expertos que representó un progreso importante en la definición de criterios diagnósticos comunes. Su uso permitió reconocer algunas falencias lo que llevó a una nueva clasificación por la IHS en el año 2003. El objetivo de este artículo es difundir esta nueva clasificación, compararla con la clasificación del IHS del año 1988 y destacar las nuevas categorías incluidas en esta clasificación.