vendex and Charcot-Marie-Tooth-Disease

In a randomized clinical trial the efficacy of strength training was studied in patients with myotonic dystrophy (n = 33) and in patients with Charcot-Marie-Tooth disease (n = 29). Measurements were performed at the start and after 8, 16 and 24 weeks of progressive resistance training. Surface electromyography (SEMG) of proximal leg muscles was recorded during isometric knee extension at maximum voluntary contraction (MVC) and at 20, 40, 60 and 80% of MVC. Changes in MVC, maximum electrical activity and torque-EMG ratios (TER) were calculated. Fatigue was studied by determining the changes in endurance and in the decline of the median frequency (Fmed) of the SEMG during a sustained contraction at 80% MVC. These parameters showed no significant changes after the training in either of the diagnostic groups. Only the Charcot-Marie-Tooth training group showed a gradual significant increase in mean MVC over the whole training period (21%). After 24 weeks, the increase in mean RMS was similar (25%), but this was mainly due to a sharp rise during the first 8 weeks of training (20%). The findings indicate that the initial strength increase was due to a neural factor, while the subsequent increase was mainly due to muscle hypertrophy.

Topics: Adult; Case-Control Studies; Charcot-Marie-Tooth Disease; Electromyography; Evoked Potentials; Female; Follow-Up Studies; Humans; Hypertrophy; Isometric Contraction; Leg; Male; Muscle Fatigue; Muscle, Skeletal; Myotonic Dystrophy; Physical Endurance; Stress, Mechanical; Torque; Weight Lifting

Patients with hereditary peripheral neuropathies exhibit characteristic deformities of the hands and feet and have difficulty ambulating. To examine to what extent neuropathic animals recapitulate these deficits, we studied trembler J (TrJ) mice, which model early-onset demyelinating neuropathy.. A cohort of 4-month-old female wild type and neuropathic mice were evaluated for locomotor measurements, neuromuscular function, and skeletal muscle proteolysis and morphometry.. Utilizing the DigiGait imaging system, we identified pronounced alterations in forepaw and hindpaw angles and a decrease in hindpaw area on the treadmill in neuropathic rodents. Torque production by the tibialis anterior (TA) muscle was significantly weakened and was paralleled by a decrease in myofiber cross-sectional area and an increase in muscle tissue proteolysis.. Our findings in TrJ mice reflect the phenotypic presentation of the human neuropathy in which patients exhibit weakness of the TA muscle resulting in foot drop and locomotor abnormalities. Muscle Nerve 57: 664-671, 2018.

Topics: Animals; Charcot-Marie-Tooth Disease; Disease Models, Animal; Female; Gait Analysis; Hereditary Sensory and Motor Neuropathy; Locomotion; Mice; Muscle, Skeletal; Myelin Proteins; Peripheral Nervous System Diseases; Phenotype; Torque

The leading hypothesis was that a relation exists between muscular strength and functional abilities. Therefore a study was undertaken to quantify such a relationship in a population of subjects with different muscular strengths. This population consisted of healthy subjects and subjects with slowly progressive neuromuscular disorders.. The study included 33 patients with myotonic dystrophy, 29 patients with Charcot-Marie-Tooth disease and 20 healthy subjects. Isokinetic and isometric knee torques were measured on an isokinetic dynamometer at various velocities. The following activities were timed: descending and ascending stairs, rising from a chair, rising from supine, walking at natural speed and walking at maximum speed.. The population covered a wide range of the variables: whereas the healthy subjects performed best (i.e. had the highest knee torques and performed the activities most quickly), the myotonic dystrophy group included the subjects with the lowest knee torques. The natural logarithms (In) of isokinetic extension torque at the highest velocity (120 degrees/s) and those of the time taken to perform the described activities showed the highest levels of correlation. It was found that after correction for age and weight, 56% (walking at natural speed) to 73% (descending stairs) of the variance in the In of the time taken could be attributed to the variance in the In of the torques.. A strong relation between quadriceps strength and timed motor performances were demonstrated. The impact of strength reduction on time taken was most obvious in subjects with considerably decreased strength. Therefore, it is feasible to try to influence muscle strength in patients with relevant strength reduction in order to achieve better functional ability.

Topics: Adolescent; Adult; Case-Control Studies; Charcot-Marie-Tooth Disease; Female; Humans; Isometric Contraction; Knee; Linear Models; Male; Middle Aged; Movement Disorders; Multivariate Analysis; Muscle Contraction; Myotonic Dystrophy; Psychomotor Performance; Time Factors; Torque