Subclinical diabetic neuropathy with normal conventional electrophysiological study.
BACKGROUND
For early detection and prevention of diabetic neuropathy, it is important to identify subclinical diabetic neuropathy. Routine nerve conduction study often fails to detect early stage of neuropathy.


OBJECTIVE
The purpose of this study is to evaluate the clinical usefulness of electrophysiological indexes in detecting early diabetic neuropathy with no objective clinical or electrophysiological abnormalities.


METHODS
Nerve conduction study of upper/lower limbs was investigated in 31 subclinical diabetic neuropathy patients with normal nerve conduction studies(group I), 38 clinical diabetic neuropathy patients with normal nerve conduction studies(group II) and 31 normal controls. Residual latency (RL), terminal latency index (TLI) and modified F ratio (MFR) were calculated and compared among groups.


RESULTS
Compared with controls, MFR of lower limbs and TLI of both upper/lower limbs were significantly decreased in both group I and II (p<0.05). RL was increased in both groups, but the difference was not statistically significant. Comparing the indexes between group I and II, there was no significant difference.


CONCLUSIONS
RL, TLI and MFR, which reflect distal conduction slowing, may be useful indexes to identify subclinical diabetic neuropathy. The results also suggest that electrophysiological changes that are obscured in routine nerve conduction study are present before the clinical manifestation.
Bae
Jong Seok
JS
Dept. of Neurology, Inje University College of Medicine Busan, Seoul, Korea(O).
Kim
Byoung Joon
BJ
D000328:Adult; D000704:Analysis of Variance; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D004558:Electric Stimulation; D004594:Electrophysiology / Q000379:methods*; D005121:Extremities / Q000294:innervation / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology* / Q000528:radiation effects; D011930:Reaction Time / Q000502:physiology* / Q000528:radiation effects; D012016:Reference Values; D012189:Retrospective Studies; D013979:Tibial Nerve / Q000503:physiopathology; D014459:Ulnar Nerve / Q000503:physiopathology