Search

Of 185 patients with myopathy, 22 showed abnormal muscle mitochondria. In 12 of the 22 patients, all of whom had ocular myopathy or the ophthalmoplegia-plus syndrome, muscle biopsies contained 5%-25% "ragged red" fibers. In 4 patients with a facioscapulohumeral distribution of weakness, ragged red fibers were less numerous (3%-8%). In both groups, routine histology showed almost normal muscle. The remaining 6 patients were clinically heterogeneous, all without ptosis or ophthalmoplegia. The biopsies of three of these patients showed severely affected muscle. It is possible that mitochondrial changes in these muscles were nonspecific. Electromyography indicated or suggested a myogenic lesion in 21 of the 22 patients; in 10, the serum creatine kinase was increased.

This review, based on a personal series of 49 cases and on published data, deals with 2 groups of ocular myopathies: ocular myopathies with mitochondrial abnormalities (red ragged fibres, giant mitochondria with paracrystalline inclusions). Three subgroups are described: pure ocular myopathies (14 cases), ophthalmoplegia "plus" or Kearns-Sayre syndrome (10 cases). In one autopsied case spongiform encephalopathy was present; oculopharyngeal muscular dystrophies (11 cases). These forms are very different from the previous ones: late onset, almost constant autosomal dominant inheritance, dysphagia, rare ophthalmoplegia, rimmed vacuoles on muscle biopsy (8 cases). The most typical ultrastructural change is the presence of intranuclear tubular filaments. In 2 autopsied cases the central nervous system was entirely normal.