In the cases reported the only constant finding has been that diabetes mellitus has been present for a long period of time. Nerve damage, with involvement of the peripheral nerves, of the nerve roots, or of the posterior columns, has been the most consistent pathological finding. It is manifested by sensory, vibratory, and reflex changes. Benefit from the use of ACTH seems to be present. It has probably resulted in lessening of the leg pain and healing of pathological fractures.