ABSTRACT
This pilot study compares the effect on walking speed, in eight subjects with neuromuscular conditions, of wearing Ligaflex ankle-foot orthoses (AFO), Leafspring orthoses and shoes or with shoes alone. Range of motion, muscle strength and sensation were tested in the lower leg. Subjects underwent a standardized timed 10-m walking test five times in each of the orthoses and shoes as a measure of gait efficiency. A self-administered questionnaire was used to seek the subjects' perceptions of their functional difficulties and their opinions about the relative comfort and stability of these orthoses. Subjects had reduced ranges and strength of dorsiflexion and eversion. Some had proprioceptive deficiencies. Mean walking speed was 0.99 m/s (Leafspring) and 1.1 m/s (Ligaflex or shoes) compared to about 1.3 m/s for a normal population. Repeated measures ANOVA revealed that subjects were significantly slower in Leafspring compared to Ligaflex or to shoes. Questionnaire results rated the Leafspring as least comfortable and the Ligaflex most stable. Providing stability may be more important than assisting foot clearance when weakness is restricted to distal muscles. Further research is required to evaluate the comfort and effectiveness of orthoses to compensate for ankle instability in people with neuromuscular conditions.
Subject(s)
Braces , Gait Disorders, Neurologic/rehabilitation , Materials Testing , Neuromuscular Diseases/rehabilitation , Adolescent , Adult , Female , Gait Disorders, Neurologic/physiopathology , Humans , Leg/physiopathology , Male , Middle Aged , Muscle Strength/physiology , Neuromuscular Diseases/physiopathology , Pilot Projects , Prosthesis Design , Range of Motion, Articular/physiology , Surveys and QuestionnairesABSTRACT
Central core disease is a congenital myopathy with muscle weakness defined pathologically by the presence of extensive areas in muscle fibres that are devoid of oxidative enzyme activity. The gene responsible has been shown to be the ryanodine receptor 1 on chromosome 19q13 and mutations have now been identified in several patients. Some cases with the morphological defect remain molecularly undefined, particularly those studied before molecular studies were available. We have studied three families with congenital onset, each with a dominantly inherited mutation in a C-terminal exon of the ryanodine receptor 1. They illustrate the spectrum of pathology that can be observed in patients with the myopathic features of central core disease. We show that extensive fibrosis and fat may be present, type 1 fibre uniformity may occur in the absence of cores; cores may be central or peripheral, single or multiple; and that an appearance of multiple focal minicores might cause a diagnostic pathological dilemma. In addition, we show the value of immunocytochemistry in identifying cores, in particular the use of antibodies to desmin and gamma-filamin.
Subject(s)
Myopathy, Central Core/pathology , Adult , Biopsy , Child , Child, Preschool , Contractile Proteins/metabolism , Female , Filamins , Genetic Linkage , Hematoxylin , Humans , Immunohistochemistry , Infant , Male , Microfilament Proteins/metabolism , Microscopy, Electron , Mutation , Myopathy, Central Core/metabolism , Myopathy, Central Core/physiopathology , NADH Tetrazolium Reductase/metabolism , Pedigree , Ryanodine Receptor Calcium Release Channel/genetics , alpha-Crystallin B Chain/metabolismABSTRACT
Duchenne muscular dystrophy (DMD) causes a progressive impairment of muscle function leading to hypercapnic respiratory failure. Most studies of respiratory function in DMD have been cross-sectional rather than longitudinal, and these data have not been related to survival. We retrospectively studied 58 patients with DMD with at least 2 yr of follow-up spirometry and known vital status. Spirometry was abnormal at entry: median FEV(1) 1.60 L (range 0.4 to 2.6 L), FVC 1.65 L (range 0.45 to 2.75 L), FVC 64% predicted (range 29 to 97%). Individual rates of change of vital capacity varied, with a median annual change of -0.18 L (range 0.04 to -0.74 L), -8.0% predicted FVC (range 2 to -39%). During the study 37 patients died; the median age of death, calculated by Kaplan-Meier analysis, was 21.5 yr (range 15 to 28.5 yr). The age when vital capacity fell below 1 L was a strong marker of subsequent mortality (5-yr survival 8%). The maximal vital capacity recorded and its rate of decline (however expressed) predicted survival time. Repeated spirometric measurement provides a simple and relatively powerful means of assessing disease progression in these patients and should be considered when planning treatment trials.
Subject(s)
Muscular Dystrophy, Duchenne/physiopathology , Spirometry , Adolescent , Child , Disease Progression , Electromyography , Forced Expiratory Volume , Humans , Male , Muscular Dystrophy, Duchenne/complications , Muscular Dystrophy, Duchenne/mortality , Prognosis , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/etiology , Respiratory Muscles/physiopathology , Retrospective Studies , Survival Rate , Vital CapacityABSTRACT
A patient-blind study into the effect of a 10-week cessation of long-term vitamin B6 supplementation on B6 status and performance in McArdle's disease is reported. Muscle performance was assessed both subjectively and objectively by an ischaemic fatiguing protocol of the adductor pollicis muscle. Nine weeks after withdrawal of supplementation, vitamin B6 status had changed from adequacy to inadequacy and the force loss during the ischaemic fatiguing protocol had increased at all frequencies studied. The patient reported decreased exercise tolerance after 7 weeks and by the tenth week was experiencing an increase in muscle cramps. Vitamin B6 status and muscle performance may be linked in McArdle's disease and there is potential for enhancement of performance by B6 supplementation.
