Gulhane Military Medical Academy, Department of Neurology, Turkey.
Clin Neurophysiol. 2010 May;121(5):714-8. doi: 10.1016/j.clinph.2009.12.024. Epub 2010 Feb 6.
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.
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.
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.
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.
An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information.
小髓鞘（A-德尔塔）和无髓鞘（C）躯体感觉纤维最初受到影响，可能是葡萄糖代谢障碍性神经病最早表现出的征象。皮肤静息期（CSP）是一种抑制性脊髓反射，其传入纤维由 A-德尔塔神经纤维组成。本研究旨在评估 2 型糖尿病伴小纤维神经病患者的 CSP 变化。
纳入 43 例患者和 41 名健康志愿者。检查 CSP 潜伏期和持续时间，以及上下肢 CSP 潜伏期差异。
两组神经传导研究均在正常范围内。下肢 CSP 潜伏期较长（122.1±15.5 比 96.4±6.4 ms；p<0.001），CSP 持续时间较短（29.5±8.9 比 43.1±5.0 ms；p<0.001），潜伏期差异较大（48.1±12.6 比 22.7±3.7；p<0.001）患者比对照组。在有神经痛的患者中，这种差异更为显著。CSP 评估在上肢无显著差异。
CSP 评估与神经传导研究相结合，已被证明是有益的，除 CSP 潜伏期和持续时间外，潜伏期差异的测定可能是糖尿病小纤维神经病患者电生理评估的一个有价值的参数。
对于神经传导研究不能提供足够信息的病例，可以考虑进行额外的 CSP 评估。
