1/7. HyperCKemia as the only sign of McArdle's disease in a child.An asymptomatic 13-year-old boy, who never complained of exercise intolerance or myalgia, was found to have markedly elevated serum creatine kinase (CK) levels during a routine check-up. General physical and neurologic examinations were normal. Surprisingly, histochemical and biochemical analysis of muscle showed myophosphorylase deficiency and genetic analysis showed that the patient was homozygous for the most common mutation encountered in McArdle's disease (R49X). This case illustrates the fuzzy correlation between molecular defect and clinical phenotype in patients with McArdle's disease, and suggests that a thorough study of the muscle biopsy is important in patients with idiopathic hyperCKemia for correct diagnosis and careful follow-up.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
2/7. rhabdomyolysis triggered by an asthmatic attack in a patient with McArdle disease.We describe a patient with McArdle disease who developed rhabdomyolysis triggered by a bronchial asthmatic attack. A 64-year-old man had chronic pulmonary emphysema with asthma, and an asthmatic attack led to severe rhabdomyolysis that required continuous hemodiafiltration. After 2 years, a physical examination revealed atrophy of the extremities compared with previous examinations, especially of the intercostal muscles. During that time, he suffered two severe bronchial asthmatic attacks. His serum level of creatinine kinase remained between 4,000 and 7,000 IU/l when he did not suffer from asthmatic attacks and rhabdomyolysis had abated. Therefore, we suspected that his recent muscle atrophy was caused by asthmatic attacks, and discussed the possibility of his respiratory muscle weakness due to McArdle disease in relation to his severe bronchial asthmatic attacks as well as chronic obstructive pulmonary disease.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
3/7. A 1-year-old infant with McArdle disease associated with hyper-creatine kinase-emia during febrile episodes.A 14-month-old girl was hospitalized due to repeated hyper-creatine kinase (CK)-emia during pyrexia. Mild hypotonia was observed, but other physical and neurological findings were unremarkable. The serum CK level was normal at rest or normothermia. Open muscle biopsy was performed on the rectus femoris, and showed glycogen storage and complete lack of phosphorylase activity histochemically and biochemically, establishing the diagnosis of McArdle disease. The diagnosis of McArdle disease in early infancy is uncommon. Until this study there have been no reports of clinical symptoms or muscle biopsy findings for McArdle disease in early childhood. This disease must be considered when transient hyper-CKemia is observed in infants, even if glycogen storage is unremarkable as compared with adult cases.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
4/7. McArdle's disease diagnosed following statin-induced myositis.We describe the case of a 69-year-old man with a history of muscular symptoms dating back to his childhood; McArdle's disease (glycogen-storage disease V) was diagnosed following an episode of myositis in which a statin and physical exertion appear to have been precipitating factors. This case demonstrates that the ischaemic lactate-ammonia test still has a place in screening patients with symptoms suggestive of McArdle's disease and emphasizes the importance of carrying out glycogen phosphorylase histochemistry on the skeletal muscle biopsy to confirm the diagnosis. In patients who develop a raised plasma creatine kinase level or muscular symptoms during lipid-lowering therapy, the clinician should be alert to the possibility of an underlying myopathy.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
5/7. Neuromuscular disorders in clinical practice: case studies.Neuromuscular disorders represent a large group of highly varied and interesting clinical disorders, many of which have major general medical manifestations. These disorders can be diagnosed largely based on the patient's history and physical examination with a little help from modern technology. Despite the outdated belief that neurologic conditions are diagnosed but rarely treatable, all cases discussed herein represent disorders for which there are extensive options and opportunities for meaningful management. These 16 brief case overviews challenge and refresh diagnostic skills and provide the framework for selected comments regarding management options.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
6/7. Novel mutation in the PYGM gene resulting in McArdle disease.BACKGROUND: McArdle disease is a common metabolic disorder characterized by marked exercise intolerance, premature fatigue during exertion, myalgia, and cramps. Despite the wide knowledge of the molecular basis of McArdle disease, few studies have used a physiological approach or explored the possibility of improving the exercise capacity of these patients. OBJECTIVES: To describe 3 unrelated patients with McArdle disease with a novel mutation in the PYGM gene and to assess the physical capacity in 1 of them. DESIGN: Using molecular genetic approaches, we identified the underlying molecular defect in 3 patients with McArdle disease. Physical performance was evaluated in 1 patient by means of an exercise tolerance test on a bicycle ergometer. SETTING: Two university hospitals. Exercise physiology studies were performed in a university department. patients The 3 patients showed common features of McArdle disease. They were definitively diagnosed by histochemistry, biochemistry, or molecular genetic analysis. RESULTS: All of the 3 patients were genetic compounds for the common Arg50Stop mutation and a novel c.13_14delCT mutation in the PYGM gene. The peak oxygen uptake (VO(2peak)) of the patient who performed the exercise test was only 20.2 mL x kg(-1) x min(-1). CONCLUSIONS: Together with the novel mutation, there is a markedly decreased exercise capacity in a patient with McArdle disease, which could account for the profound alteration in the capacity for performing normal activities of daily living in this subpopulation.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
7/7. A new variant of late-onset myophosphorylase deficiency.McArdle disease classically presents in childhood or adolescence. Rarely does it become symptomatic for the first time in late adulthood, with the onset of progressive muscle wasting and weakness. Our patient is unusual in that despite a life of physical vigor, she developed immobilizing cramps, stiffness, and muscle swelling abruptly at age 60. She had no previous symptoms of muscle disease. The diagnosis was indicated by the ischemic forearm test, which produced muscle contracture and no rise in venous lactate levels, and confirmed by histochemical, electrophoretic, and biochemical studies that showed complete absence of myophosphorylase. This case defines a new variant of the late-onset type and raises important questions about compensatory mechanisms, inheritance patterns, and etiological factors in myophosphorylase deficiency.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |