Adult-onset centronuclear myopathy: evidence against a neurogenic pathology.

A case of sporadic adult-onset centronuclear myopathy is presented. EMG was myopathic and nerve conduction study entirely normal. Single-fiber electromyography showed a normal percentage of potential pairs with abnormal jitter, slightly increased mean jitter value, no blocking and normal fiber density. Somatosensory and motor evoked potentials were within the normal limits. While it is still a subject of debate whether centronuclear myopathy is neuropathic or myopathic in origin, our findings are against peripheral nerve and CNS involvement.