Tubular aggregate congenital myopathy associated with a neuromuscular block

Various myopathies are described associated with tubular aggregates. Howeve r, in several cases tubular aggregates constitute the main structural featu re allowing to consider myopathy with tubular aggregates as a distinct enti ty. A 50-year-old woman whose parents were consanguinous, presented frequen t falls. She walked only after 18 months of age and did poorly in gymnastic s. The weakness, which has myasthenic feature, involved predominantly the p elvis girdle, The serum creatine kinase was 206 UI/L (normal < 110 UI/L). E lectromyogram showed a myogenic pattern in proximal muscles. Repetitive sti mulation on the trapezius revealed 50 p. cent decrementing response. Muscle biopsy showed numerous tubular aggregates in type II fibers. Anti-acetylch oline receptor (AChR) antibodies were absent. There was no thymoma. The neo stigmine test was negative. Clinical and electrical myasthenic features cha racterize one of the numerous forms of myopathy with tubular aggregates. In our case, the lack of AChR antibodies and the negative response to neostig mine argue in favor of a dysfunction of the AChR. This unusual observation highlights the therapeutic difficulties in this myopathy with neuromuscular block.