[Heterochronia of nerve fibers in man. Diagnostic value: initial results]

A classical physiological observation not usually apparent with methods used for detecting nerve potential in man, heterochronia of the nerve fibres is often found in extraordinary circumstances with considerably higher than normal frequence : mainly in muscular disorders, in particular myotonic dystrophy ; more incidentally in disorders of muscle tone. The authors draw attention to certain sources of error which could lead to wrong diagnosis of heterochronia and emphasize that these are only the initial results of research which needs to be pursued further.