Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy.
OBJECTIVE
Small myelinated (A-delta) and unmyelinated (C) somatic sensory fibers are initially affected and may be the earliest exhibited sign of neuropathy in glucose dysmetabolism. Cutaneous silent period (CSP) is an inhibitory spinal reflex and its afferents consist of A-delta nerve fibers. The aim of this study was to evaluate CSP changes in Type 2 diabetic patients with small fiber neuropathy.


METHODS
Forty-three patients and 41 healthy volunteers were included. CSP latency and duration, as well as CSP latency difference of the upper and lower extremities, were examined.


RESULTS
Nerve conduction studies were within normal limits in both groups. Lower extremity CSP latency was longer (122.1+/-15.5 vs. 96.4+/-6.4 ms; p<0.001), CSP duration was shorter (29.5+/-8.9 vs. 43.1+/-5.0 ms; p<0.001), and latency difference was longer (48.1+/-12.6 vs. 22.7+/-3.7; p<0.001) in patients than controls. The difference was more significant in patients with neuropathic pain. No significant difference existed in upper extremity on CSP evaluation.


CONCLUSIONS
The CSP evaluation together with nerve conduction study, has been demonstrated to be beneficial and performance of latency difference in addition to CSP latency and duration may be a valuable parameter in electrophysiological assessment of diabetic patients with small fiber neuropathy.


CONCLUSIONS
An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information.
Gulhane Military Medical Academy, Department of Neurology, Turkey.
M R
MR
Onal
U H
UH
Ulas
O
O
Oz
V S
VS
Bek
M
M
Yucel
A
A
Taslipinar
Z
Z
Odabasi
D003924:Diabetes Mellitus, Type 2; D003929:Diabetic Neuropathies / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007866:Leg / Q000294:innervation; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009431:Neural Conduction; D009433:Neural Inhibition; D009437:Neuralgia / Q000503:physiopathology; D010525:Peripheral Nerves / Q000503:physiopathology*; D011930:Reaction Time; D012018:Reflex; D012032:Refractory Period, Electrophysiological; D012867:Skin / Q000294:innervation*; D013116:Spinal Cord / Q000503:physiopathology