A comparison of electrophysiological tests for the early diagnosis of diabetic neuropathy.
Clinical criteria and several electrophysiological parameters for detecting nerve damage were compared in 99 patients with diabetes mellitus type 1 and type 2. Abnormal results were found in sural/radial amplitude ratio (51%), minimal F-wave latency of the tibial nerve (36.4%), sensory conduction velocity of the sural nerve (29.8%), and sural sensory nerve action potential amplitude (29.3%) when pooling data from all patients and comparing them to age- and height-matched normal control subjects. Analysis of all the parameters revealed large differences between the diabetes mellitus type 1 and type 2 groups, suggesting that the type of diabetes must be taken into account when comparing the sensitivity of nerve conduction tests. In diabetes mellitus type 1, the sural/radial ratio had the clearest correlation with course of illness and was the first parameter to show a significant reduction. We conclude that the simple ratio between sural and radial amplitudes is a very sensitive parameter and abnormalities in this ratio provide the means for earliest detection of neuropathy in diabetes mellitus type 1.
Pastore
C
C
S. de Neurofisiología Clínica (EMG), Hospital Universitario de San Juan, Ctra. Alicante-Valencia s/n, 03550 San Juan, Alicante, Spain. cpastore@san.gva.es
Izura
V
V
Geijo-Barrientos
E
E
Dominguez
J R
JR
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003929:Diabetic Neuropathies / Q000175:diagnosis* / Q000503:physiopathology; D004568:Electrodiagnosis; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D011826:Radial Nerve / Q000503:physiopathology; D013497:Sural Nerve / Q000503:physiopathology; D013979:Tibial Nerve / Q000503:physiopathology