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Given the recent technological advent of muscle ultrasound (US), classification of various myopathic conditions could be possible, especially by mathematical analysis of muscular fine structure called texture analysis. We prospectively enrolled patients with three neuromuscular conditions and their lower leg US images were quantitatively analyzed by texture analysis and machine learning methodology in the following subjects : Inclusion body myositis (IBM) [N=11] ; myotonic dystrophy type 1 (DM1) [N=19] ; polymyositis/dermatomyositis (PM-DM) [N=21]. Although three-group analysis achieved up to 58.8% accuracy, two-group analysis of IBM plus PM-DM versus DM1 showed 78.4% accuracy. Despite the small number of subjects, texture analysis of muscle US followed by machine learning might be expected to be useful in identifying myopathic conditions. J. Med. Invest. 66 : 237-240, August, 2019.

Muscle sonography may show high densities in various myopathic conditions. Further classification among myopathic conditions could be possible by texture analysis, which analyzes relationships between the neighboring pixel densities. The following groups of subjects were assessed: (1) 19 patients with myotonic dystrophy type 1 (MD1), (2) 11 patients with inflammatory myopathy (IM), and (3) 16 normal control. A LOGIQe ultrasonography and an 11-MHz linear probe were used to obtain muscle images of medial gastrocnemius. Texture parameters were obtained by MaZda software. Linear Discriminant Analysis (LDA) was performed for texture-based classification. The mean echodensities of MD1 and IM were higher than those of the control, which yielded high areas under curve (AUC) >0.95. However, MD1 and IM were poorly discriminated by any of the histogram-related parameters (AUC

Summary A case of myopathy in a male Irish Terrier is described in which the clinical symptoms were muscular atrophy, stiffness in walking and difficulty in swallowing. Myotonic sounds were detected electromyographically. Serum levels of CPK, aldolase, SGOT, SGPT and acid phosphatase were raised, particularly those for CPK, but there was no correlation between CPK levels and the clinical condition. Dosage with vitamin E resulted in a fall in CPK but no clinical improvement. No clear morphological or histochemical alterations indicating a neurogenic component in the disease were found. Biochemical findings revealed that the respiration characteristics of the mitochondria isolated from the m. triceps brachii were abnormal. The mitochondria had a normal oxidative phosphorylation but lacked respiratory control (so-called loosely-coupled mitochondria). The findings are discussed in relation to similar myopathic conditions in other animals and in man. Zusammenfassung Myopathie mit metabolischem Defekt der isolierten Mitochondrien bei einem Irish Terrier Bei einem mannlichen Irish Terrier wird eine Myopathie mit folgenden klinischen Symptomen beschrieben: Muskelatrophie, steifer Gang, Schluckbeschwerden. Elektromyographisch wurde auditiv eine Myotonie festgestellt. Im Serum waren die Aktivitaten der folgenden Enzyme erhoht: CPK (besonders stark), Aldolase, GOT, GPT, saure Phosphatase. Zwischen dem CPK-Spiegel und dem klinischen Bild konnte keine Korrelation gefunden werden. Vitamin-E-Medikation reduzierte die CPK, ohne den klinischen Zustand zu verbessern. Die morphologischen und histochemischen Befunde ergaben keinen Hinweis auf das Vorliegen einer nervosen Storung. Biochemisch wiesen isolierte Mitochondrien vom M. triceps brachii respiratorische Abnormitaten auf. Die Mitochondrien waren hinsichtlich der oxidativen Phosphorylierung normal, es fehlte jedoch die respiratorische Kontrolle („loosely coupled” mitochondria). Die Befunde werden unter Berucksichtigung ahnlicher Myopathien bei anderen Tieren und beim Menschen diskutiert. Resume Myopathie avec degradation metabolique des mitochondries isolees chez un terrier irlandais (Irish Terrier) On a decrit les symptomes cliniques suivants chez un terrier irlandais atteint de myopathie: atrophie musculaire, demarche raide et troubles de la deglutition. On a decouvre des phenomenes myotonique par electromyographie. On a relee une elevation de l'activite chez les enzymes seriques suivantes: CPK (particulierment eleve), aldolase, GOT, GPT, phosphatase acide. On n'a pas trouve de correlation entre le taux CPK et l'image clinique. L'administration de vitamine E abaissa CPK sans ameliorer l etat clinique. Les resultats morphologiques et histochimiques n'ont pas montre la presence de troubles nerveux. Les mitochondries isolees dans le muscle triceps brachial presenterent biochimiquement des anomalies respiratoires. Les mitochondries etaient normales en ce qui concerne la phosphorylation oxydative, il manquait toutefois les controles respiratoires („looselycoupled” mitochondries). On discute les resultats en relation avec des myopathies semblables chez l'homme et chez d'autres animaux. Resumen Miopatia con defecto metabolico de las mitocondrias aisladas en un terrier irlandes En un terrier irlandes macho se describe una miopatia con los sintomas clinicos siguientes: atrofia muscular, marcha envarada y dificultad en la deglucion. Los tonos musculares se detectaron electromiograficamente. En el suero sanguineo estaban aumentados los fermentos que se enumeran: CPK (en extremo), aldolasa, GOT, GPT, fosfatasa acida. No se pudo establecer ninguna correlacion entre el nivel de CPK y la condicion clinica. La medicacion a base de vitamina E reducia la CPK sin que mejorase el cuadro clinico. Los hallazgos morfologicos e histoquimicos no revelaron ningun indicio en cuanto a la presencia de una componente neurogena. Las mitocondrias aisladas del musculo triceps braquial manifestaban bioquimicamente anormalidades respiratorias. Las mitocondrias eran normales con respecto a la fosforilizacion oxidativa, aunque faltaba el control respiratorio (mitocondria „con engarce flojo”). Los hallazgos se discuten en relacion con miopatias similares en otras especies animales y en el hombre.

Pulsus alternans is a rare hemodynamic condition characterized by beat-to-beat variability in systolic pressure. It is attributed to variations in stroke volume with alternate cardiac cycles and is typically seen in patients with advanced myopathic conditions. Left ventricular pulsus alternans is rare, and right ventricular pulsus alternans is even less common. There are only a few reports of biventricular pulsus alternans. We report the case of a 62-year-old female with a recent anterior wall myocardial infarction who had biventricular pulsus alternans at the time of cardiac catheterization.

Limb contractures are a common impairment in neuromuscular diseases. They contribute to increased disability from decreased motor performance, mobility limitations, reduced functional range of motion, loss of function for activities of daily living, and increased pain. The pathogenesis of contractures is multifactorial. Myopathic conditions are associated with more severe limb contractures compared with neuropathic disorders. Although the evidence supporting the efficacy of multiple interventions to improve range of motion in neuromuscular diseases in a sustained manner is lacking, there are generally accepted principles with regard to splinting, bracing, stretching, and surgery that help minimize the impact or disability from contractures.

The identification of the gene responsible for Becker and Duchenne muscular dystrophy and the characterization of the corresponding biochemical defect, dystrophin, has dramatically changed the management of patient and families with these disorders. The majority of patients with a muscle disease are now recognized to have some form of dystrophinopathy, and the correct identification of these patients is critical not only for patient care, but for family genetic counseling. The clinician must now be familiar with an array of molecular diagnostic procedures and their correct implementation and interpretation. The range of clinical disorders caused by dystrophin abnormalities has expanded to include a large range of myopathic conditions, including the presentation of cardiomyopathy. Radically new therapeutic strategies for Duchenne muscular dystrophy are being tried, and many provide hope that treatment may soon be available.

We evaluated six boys who had developed isolated masseter muscle spasm following intravenous succinylcholine. All were receiving halothane by inhalation.l In vitro muscle contracture tests utilizing halothane and caffeine were performed. Four of the six boys had contracture response similar to those of malignant hyperthermia susceptible patients. Rigidity following succinylcholine should prompt the clinician to consider malignant hyperthermia but has been associated with other myopathic conditions as discussed.