1/25. pregnancy with cytochrome oxidase-deficient mitochondrial myopathy.BACKGROUND: Cytochrome oxidase-deficient mitochondrial myopathies represent a heterogeneous group of muscle disorders. Physical stress can cause life-threatening risks related to rhabdomyolysis or respiratory compromise. CASE: A 21-year-old primigravida with cytochrome C oxidase-deficient mitochondrial myopathy who presented for obstetric care at 8 weeks' gestation complained of muscle fatigue and spasm after exertion. The increased metabolic demands of pregnancy led to worsening pain, muscle fatigue, and ultimately complete immobility. CONCLUSION: Cytochrome oxidase-deficient mitochondrial myopathies are rare but serious complications of pregnancy.- - - - - - - - - - ranking = 1keywords = myopathies (Clic here for more details about this article) |
2/25. General anaesthesia in a man with mitochondrial myopathy undergoing eye surgery.mitochondrial myopathies are rare complex multisystem disorders, which can present several potential anaesthetic problems. A 49-year-old man with mitochondrial myopathy was anaesthetized successfully for cataract extraction using propofol and alfentanil infusions. Vecuronium sensitivity was apparent, with a prolonged duration of action, despite dosage reduction.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
3/25. postpartum hemorrhage and emergency hysterectomy in a patient with mitochondrial myopathy: a case report.mitochondrial myopathies are a rare biochemical group of disorders of the mitochondrial respiratory chain. We report the first case in the literature of a pregnant woman with mitochondrial myopathy who, after cesarean section, had a severe and massive postpartum hemorrhage that required emergency supracervical hysterectomy. We discuss the case and review the literature.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
4/25. Mitochondrial myopathy (complex I deficiency) associated with chronic intestinal pseudo-obstruction.We report a patient presenting with severe muscular impairment and chronic intestinal pseudo-obstruction (CIP) at the age of eight months. Due to the aggravated symptoms, assisted ventilation, an ileostomy and total parenteral nutrition were required. Later on, the patient developed a locked-in syndrome (Leigh's subacute necrotising encephalomyelopathy) and finally died due to recurrent pneumonia and chronic renal failure. The assessment of muscle biopsies revealed a moderate single-fibre type II atrophy, a variation of muscle fibre calibre with focal fatty degeneration and a decreased reactivity of cytochrome-c oxidase. Although ragged red fibres had not been found, mitochondrial enzyme activities were markedly decreased with the lowest residual activity detected for NADH:Q1 oxidoreductase and NADH:O2 oxidoreductase (complex I deficiency), thereby confirming the diagnosis of mitochondrial myopathy. A molecular genetic analysis could not identify known mutations of mitochondrial dna. Gastrointestinal full-thickness biopsies revealed myenteric hypoganglionosis of the colon and stomach and hyperplasia of the submucosal plexus of the ileum. Some of the intestinal smooth muscle cells displayed bulbous protrusions filled with lateralised mitochondria. mitochondrial myopathies are known to be associated with a variety of clinical syndromes including CIP. However, in contrast to previous reports in which CIP has been attributed to visceral intestinal myopathies, the present case is characterised by neuronal intestinal malformations. Therefore, a mitochondrial myopathy associated with CIP requires a subtle assessment of both the intestinal smooth muscle and the enteric nervous system to identify the underlying pathology.- - - - - - - - - - ranking = 1keywords = myopathies (Clic here for more details about this article) |
5/25. A case of mitochondrial myopathy and cleft palate.OBJECTIVE: To present a child born with both mitochondrial myopathy and cleft palate, outlining medical complications of this dual diagnosis-the first reported case in English literature. methods: A preterm Caucasian boy presented to the cleft palate clinic at birth for evaluation of a secondary cleft palate. Multiple anomalies were also identified, including rib fusions, ventricular septal dyskinesis, and mild hypotonia. Initial chromosome studies were unremarkable. RESULTS: After a multidisciplinary preoperative clearance at 11 months old, the infant underwent palatoplasty and muscle biopsy for evaluation of hypotonia. Upon extubation, he became apneic and unresponsive to anticholinesterase reversals. He was reintubated. The next morning, he was extubated uneventfully and was discharged home on postoperative day 2 (POD2). On POD7, he returned with signs of bronchitis, thereby prompting immediate reevaluation and treatment by his primary pediatrician. On POD13, he presented to an outlying emergency department with cyanosis and poor respiratory drive. Before intubation, he received a depolarizing muscle relaxation; cardiac arrest ensued and resuscitation was unsuccessful. pathology from the muscle biopsy and postmortem examination ultimately supported mitochondrial myopathy with dilated cardiomyopathy. CONCLUSION: mitochondrial myopathies are rare disorders suspected in patients demonstrating developmental delays, hypotonia, cardiomyopathy, conduction system defects, or genetic mutations. In these patients, postoperative complications can be lethal, especially when compounded (e.g., anesthetic drug reactions, respiratory compromise, surgical stress, and postoperative infections). General discussion and specific recommendations are provided.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
6/25. Relationship of primary mitochondrial respiratory chain dysfunction to fiber type abnormalities in skeletal muscle.Variation in the size and relative proportion of type 1 and type 2 muscle fibers can occur in a number of conditions, including structural myopathies, neuropathies, and various syndromes. In most cases, the pathogenesis of such fiber type changes is unknown and the etiology is heterogeneous. Skeletal muscle mitochondrial respiratory chain analysis was performed in 10 children aged 3 weeks to 5 years with abnormalities in muscle fiber type, size, and proportion. Five children were classified as having definite, four as probable, and one as possible mitochondrial disease. Type 1 fiber predominance was the most common histological finding (six of 10). On light microscopy, four cases had subtle concomitants of a mitochondriopathy, including mildly increased glycogen, lipid, and/or succinate dehydrogenase staining, and one case had more prominent evidence of underlying mitochondrial disease with marked subsarcolemmal staining. Most cases (nine of 10) had abnormal mitochondrial morphology on electron microscopy. All were found to have mitochondrial electron transport chain (ETC) abnormalities and met diagnostic criteria for mitochondrial disease. We did not ascertain any patients who had isolated fiber type abnormalities and normal respiratory chain analysis during the period of study. We conclude that mitochondrial ETC disorders may represent an etiology of at least a subset of muscle fiber type abnormalities. To establish an etiologic diagnosis and to determine the frequency of such changes in mitochondrial disease, we suggest analysis of ETC function in individuals with fiber type changes in skeletal muscle, even in the absence of light histological features suggestive of mitochondrial disorders.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
7/25. Two full-term pregnancies in a patient with mitochondrial myopathy and chronic ventilatory insufficiency.mitochondrial myopathies are a group of diseases characterized by metabolic defects at the mitochondrial respiratory chain level which result in impaired oxidative phosphorylation and ATP synthesis. As with other neuromuscular diseases, respiratory muscles can be affected and ventilatory failure may occur. There have been isolated case reports of pregnant patients with ventilatory failure due to neuromuscular diseases such as polio and spinal muscular atrophy. We describe the case of a 34-year-old patient with mitochondrial myopathy and ventilatory failure requiring non-invasive ventilation who carried two pregnancies to term with no complications. We have not found a similar case in the literature.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
8/25. An unusual case of muscular limb-girdle dystrophy and mitochondrial myopathy.Limb-girdle muscular weakness and wasting could be caused by different diseases (inflammatory and hereditary myopathies, muscular dystrophies and neurogenic atrophies). Among these, Limb-Girdle Muscular Dystrophy (LGMD) is an heterogeneous group of pathologies that have progressive proximal limbs and girdle weakness, with some dystrophic features by the muscle biopsy. We studied a case of LGMD in an adult man with a typical histological and histochemical profile, associated to a mitochondrial deficit characterized by presence of ragged-red fibers, a histochemical Cytochrome Oxidase deficiency and abnormal mitochondria by ultrastructure.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
9/25. Supranuclear eye movement dysfunction in mitochondrial myopathy with tRNA(LEU) mutation.A patient with multiple neurological deficits and biopsy-proven mitochondrial myopathy with mutation of tRNA(LEU) at nucleotide 3243 was referred for eye movement evaluation. He had restricted range of voluntary motions in all directions and full range of eye movements on passive rotation of head while fixating a visual target. Eye movement recordings revealed decreased horizontal and vertical saccadic velocities and markedly decreased smooth pursuit gain in both directions. The vestibulo-ocular reflex showed gain abnormalities with many saccadic intrusions on the smooth reflex response. His brother, with similar mutation, was clinically asymptomatic. However, his eye movement recordings revealed slow horizontal saccadic velocities leftward and normal saccadic velocities rightward in both eyes as well as in upward and downward direction. Smooth pursuit and vestibulo-ocular reflexes were within normal limits. Although eye movement abnormalities are seen commonly in mitochondrial myopathies, the exact mechanism is not known. Our cases suggest supranuclear dysfunction as one of the mechanisms for ophthalmoparesis.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
10/25. Late-onset mitochondrial myopathy.In the majority of patients with mitochondrial encephalomyopathies, signs and symptoms appear in the first three decades of life. Here we report on a group of 9 older patients (> 69 years old) with late-onset skeletal myopathy characterized by focal accumulations of deleted mitochondrial DNAs (mtDNAs) and altered muscle energy status, suggestive of a primary mitochondrial disease. The clinical phenotype was somewhat variable. However, all patients shared a common feature of insidious moderate proximal muscle weakness; some also showed fatigability and axial muscle weakness. in situ hybridization analysis demonstrated accumulations of messenger RNAs transcribed from deleted mtDNAs in a relatively large number of muscle fibers in the patient group. These fiber segments appeared as ragged red with the modified Gomori trichrome stain and hyperreactive with a modified succinate dehydrogenase stain. Most were negative for cytochrome c oxidase activity. On transverse sections their mean frequency was 0.69% (trichrome) and 1.97% (succinate dehydrogenase) significantly above control levels. Multiple mtDNA deletions were demonstrated by the polymerase chain reaction in both the patients and an age-matched control group, but not in younger control subjects. phosphorus 13 magnetic resonance spectroscopy of resting muscle showed a decreased phosphocreatine-inorganic phosphate ratio in the patient group. The myopathy in this group of patients appears to result from mitochondrial dysfunction related to the clonal expansion of different mtDNA deletions in individual fiber segments. While the origin of the mtDNA mutations is not clear, the phenotype seems to represent an exaggerated form of what is observed in the normal aging process.- - - - - - - - - - ranking = 0.5keywords = myopathies (Clic here for more details about this article) |
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