AbstractThe authors describe a case of myopathy characterized physically by limb weakness, eyelid ptosis, voluntary and reflex paralysis of vertical movements of gaze, and loss of deep tendon reflexes; and morphologically by the abnormal presence of centrally located nuclei in muscle fibers and type 1 fiber hypotrophy. The establishment in this case study of two particular findings–the probably nuclear or supranuclear ophthalmoplegia and the apparently impaired nuclear migration from the center of the muscle fiber toward its periphery–supports the hypothesis of a neuromuscular disorder whose level of severity depends on the degree of difficulty in the nuclear migration itself. This would be linked to a reduction in central nervous system influe