[Correlation between vibratory detection threshold and conduction study of sural nerve in diabetic patients]

Vibratory detection threshold (VDT) was determined on the plantar side of the distal phalanx of the right great toe of 22 diabetic (NIDDM) patients. In addition, a neurological examination and a sural nerve conduction study were performed. Peripheral neuropathy, based on our criteria, was found in 41% of the patients. VDT was abnormally high in 23% of the patients. The combined frequency of the abnormality of the amplitude of the action potential of the sural nerve or the conduction velocity or both was 73%. The nerve conduction study showed the highest sensitivity in detecting the abnormality of the peripheral nerve in this study; this is in agreement with the result shown in the literature. Seven patients showed no response to electrical stimulation of the sural nerve, although VDT was obtained in these patients. Among the 6 patients that underwent the normal sural nerve conduction study, no one showed abnormally high VDT. The determination of VDT seems to be a useful examination for the follow-up study of diabetic neuropathy, although it is less sensitive than the sural nerve conduction study.