Perineurial calcification.

A study of the occurrence of extracellular deposits of calcium in the perineurium of the human sural nerve demonstrated that there is a higher incidence in abnormal nerves than in normal material and that, of the conditions examined, nerves from cases of diabetic neuropathy showed the greatest incidence of calcification. It seems likely that the process of calcification is similar to that operating in other tissues, with deposition on matrix vesicles or lipid droplets, probably derived from the perineurial cells. The increased incidence in diabetic neuropathy is presumably related to metabolic abnormality consequent upon the diabetic state.