Neonatal rhabdomyolysis as a presentation of muscular dystrophy

Rhabdomyolysis in a neonate due to very long chain acyl CoA dehydrogenase deficiency

Very long chain acyl CoA dehydrogenase deficiency (VLCADD) is an inborn error in long chain fatty acid oxidation with significant variability in the severity and timing of its clinical presentation. Neonatal presentations of VLCADD have included hypoglycemia and cardiomyopathy while rhabdomyolysis is usually a later onset complication. We describe a neonate with VLCADD presenting with rhabdomyolysis prior to the return of an abnormal newborn screen. This report suggests that evaluating for rhabdomyolysis, in addition to a cardiac and hepatic work-up, is an important part of the initial evaluation of an infant with an abnormal newborn screen suggesting a diagnosis of VLCADD.

Lethal peracute rhabdomyolysis associated with stress and general anesthesia in three dystrophin-deficient cats

Three cats affected with dystrophin deficiency and hypertrophic muscular dystrophy developed peracute rhabdomyolysis with a fatal outcome. Two cats were anesthetized with isoflurane for routine procedures and did not recover properly from the anesthetic procedure. One cat was manually restrained for an echographic examination and started staggering after a short struggle; its condition worsened, and it died. Blood chemistry findings included severe hyperkalemia, hyperphosphatemia, hypocalcemia, massive increases in creatine kinase, aspartate aminotransferase, and alanine aminotransferase concentrations, and high ion gap metabolic acidosis. Light microscopic evaluation of skeletal muscle revealed severe acute rhabdomyolysis with marked extensive necrosis of large groups of fibers and endomysial edema. These lesions were observed in many skeletal muscles but particularly in the masseter and supraspinatus muscles and in the diaphragm. Typical changes associated with dystrophin deficiency in cats were also noted. Histochemical analysis revealed that the dystrophin deficiency was associated with a decrease in the percentage of type 1 myofibers in all three cats. This change was marked in the 20-month-old cat and milder in the younger cats (6.5 and 8.5 months of age). Percentages of type 2A fibers were markedly decreased and percentages of type 2X fibers were markedly increased in the younger cats. Rhabdomyolysis has been reported in dystrophinopathic humans but not in other animal models of dystrophin deficiency. An increased sensitivity of the dystrophin-deficient sarcolemmal membrane to volatile anesthetic agents, stress, or intense muscular activity is suspected.

Duchenne muscular dystrophy associated with fetal pleural effusion and polyhydramnios

A case of fetal pleural effusion in a fetus affected with Duchenne muscular dystrophy (DMD) is reported. This case is discussed in the context of the previous observation of frequent stillbirths among male fetuses in DMD families.

Congenital muscular dystrophy presenting with respiratory failure

Respiratory failure is an unusual initial manifestation of congenital muscular dystrophy. The authors describe a case of congenital muscular dystrophy in a patient presenting with rhabdomyolysis at birth. Despite an initially poor prognosis, aggressive respiratory therapy during the neonatal period permitted normal subsequent development. The muscular dystrophy predominantly involved the respiratory muscles.

Fatal rhabdomyolysis complicating general anaesthesia in a child with Becker muscular dystrophy

A 6-yr-old boy who presented with brown urine due to myoglobinuria and who was otherwise virtually asymptomatic was diagnosed as having Becker muscular dystrophy on the basis of a greatly elevated creatine kinase, muscle biopsy, dystrophin analysis, and a deletion of exons 3-7 in the dystrophin gene. Fifteen months later, during a general anaesthetic for dental treatment, he had a cardiac arrest associated with acute rhabdomyolysis, hyperkalaemia and hypocalcaemia. He died 4 days later. This case is reported to highlight this rare but potentially fatal complication of anaesthesia in muscular dystrophy, and to discuss possible ways of preventing such a catastrophe.