Acute myopathy of intensive care in a child after heart transplantation

Abstract

Purpose: Acute myopathy of intensive care has been described infrequently in children and never after organ transplantation. We report a case of acute myopathy of intensive care in a child after heart transplantation.Clinical features: An 11-yr-old girl, with no previous medical history, developed acute cardiomyopathy leading to cardiac shock. Family history revealed four cases of unidentified myopathy and/or cardiomyopathy. Preoperatively, while muscle biopsy was near normal, myocardial biopsy revealed non specific mitochondrial disorders. A few days after heart transplantation, she developed acute hypotonia and flaccid quadriplegia, consistent with the diagnosis of acute myopathy of intensive care. Nerve conduction studies were normal, electromyography showed myopathic changes and a new muscle biopsy from quadriceps femoris showed severe loss of myosin filaments and ATPase activity in type 2 fibres. A large laboratory screening failed to demonstrate a metabolic disease or a known myopathy. Muscle strength recovered progressively in three weeks allowing home discharge. A few months later, she was free of symptoms and muscle biopsy showed full histopathological recovery.Conclusion: Acute myopathy of intensive care can occur in children after heart transplantation. It should be suspected in the presence of muscle weakness and difficulty in weaning from ventilatory support. Electromyography confirmed a myogenic process and muscle biopsy allowed diagnosis. Full clinical and histopathological recovery usually occur within three weeks.Objectif : La myopathie aiguë de réanimation a été rarement décrite en pédiatrie, et jamais après transplantation d'organe chez l'enfant. Nous rapportons un cas pédiatrique de myopathie aiguë de réanimation après transplantation cardiaque.Éléments cliniques : Une enfant de 11 ans, sans antécédent, est hospitalisée pour choc cardiogénique sur cardiomyopathie aiguë. Dans sa fratrie, on note l'existence de myopathies et de cardiomyopathies non déterminées. La biopsie musculaire préopératoire est normale et la biopsie myocardique montre des anomalies mitochondriales non spécifiques. Quelques jours après une transplantation cardiaque, elle présente une hypotonie globale avec tétraplégie flasque. Une myopathie aiguë de réanimation, évoquée devant des vitesses de conduction nerveuses normales et un tracé électromyographique montrant une atteinte musculaire, est confirmée par une biopsie musculaire montrant une perte des fibres de myosine par dépolymérisation, avec perte de l'activité ATPasique dans les fibres de type 2. La recherche élargie d'une myopathie chronique ou d'une maladie métabolique est négative. En quelques semaines, l'enfant a progressivement récupéré sa force musculaire. Une biopsie musculaire, réalisée à distance, montre une architecture musculaire et une activité enzymatique normales.Conclusion : Une myopathie aiguë de réanimation peut se développer chez le transplanté pédiatrique, puisque des facteurs favorisants sont utilisés pour l'immunosuppression. Elle doit être évoquée ...

Intensive care unit acquired weakness in children: Critical illness polyneuropathy and myopathy

“…In some cases, it was very early in the onset of critical illness. [56] In the only prospective study done so far, weakness was clinically noticed after a wide range of duration of illness (4-26 days) and 86% of these children were mechanically ventilated for > 5 days. [17]…”

“…Recent data suggest that CIP and CIM co-exist; a condition that has been termed critical illness polyneuropathy and myopathy (CIPNM). [34] Data regarding ICUAW in children is restricted to small case series and reports[5678910111213141516] and only one prospective study has been reported so far in the pediatric age group. [17]…”

Neuromuscular Disorders in Critically Ill Patients: Review and Update

“…[3][4][5] While Bolton and colleagues were studying CIP, there were also reports of single cases [10][11][12][13][14] and eventually series [15][16][17][18][19][20][21] of adult and pediatric 10 patients who developed acute myopathy during treatment of status asthmaticus. Later, a similar acute myopathy was noted to follow organ transplantation [22][23][24][25][26][27] and to occur in association with many other critical illness states in children as well as adults. [28][29][30][31][32][33][34][35] Terminology was highly variable initially, but eventually the name critical illness myopathy (CIM) was accepted.…”