[Central-core myopathy. A clinical and morphological study on the diagnostic specificity of central muscle fiber...

Predominance of type I fibres and loss of oxidative enzyme activity, such as DPNH-dehydrogenase, in the centre of muscle fibres, an alteration called "central core", are considered characteristic findings in central core myopathy. Similar findings in various peripheral neurogenic disorders motivated the authors to check the diagnostic specificity of central cores. Among 1200 muscular biopsies performed for various neuromuscular diseases, 13 biopsies with central cores were found. Only 2 or 3 of them were central core myopathies, while clinical and electromyographic findings served to classify the remaining 10 cases as peripheral neurogenic disorders (anterior horn cells, anterior nerve roots, plexus, peripheral nerves). The results support the observation that central cores are not a specific finding in central core myopathy; identical alterations are caused by various peripheral neurogenic disorders. Clinical, electromyographic and morphologic findings must be considered for the purpose of diagnostic classification. It is not yet known whether central core myopathy really is of myogenic origin or whether it is caused by a peripheral neurogenic disorder. The authors therefore prefer the term "central core disease" to "central core myopathy". Their findings support the neurogenic hypothesis.