Nedelec Bernadette, Hou Quanzhi, Sohbi Ismahen, Choinière Manon, Beauregard Gilles, Dykes Robert W
McGill University, Faculty of Medicine, School of Physical and Occupational Therapy, 3654 Promenade Sir William Osler, Montréal, Que., Canada H3G 1Y5.
Burns. 2005 Nov;31(7):817-30. doi: 10.1016/j.burns.2005.06.007.
This study compared the neural structures found in grafted skin of burn survivors with neural structures found in site-matched normal skin and correlated these structures with psychophysical measures of sensation.
Fifteen skin-grafted male burn survivors (47.7+/-10.4 years old) with deep partial- or full-thickness thermal burn injuries covering an average of 11+/-5.6% of their total body surface and with normal skin at a matching, unburned, contralateral site were recruited into this study. Threshold determinations and magnitude estimations for touch, cold, warmth and heat-pain were performed at sites with grafted and normal skin, using Semmes-Weinstein monofilaments and the Medoc TSA 2001 thermal stimulator. Skin biopsies from both the grafted and normal sites were stained with antibodies for protein gene product 9.5 (PGP) and neurofilament 200 kDa. Nerve fibers in the epidermis and nerve fibers or bundles of nerve fibers in the superficial and deep dermis as well as innervated blood vessels, hair follicles and sweat glands were counted.
On average, the data were collected 43.1+/-10.4 months after grafting. When thresholds on grafted skin were compared to thresholds on normal skin, they showed elevated sensory thresholds [touch (p<0.003), cold (p<0.031), warmth (p<0.009)]. Magnitude estimates of touch, cold and warmth differed on the two sides with sensations elicited from grafts being smaller than those from normal skin. Heat-pain thresholds and heat-pain magnitude estimations were not statistically different on the two sites. By comparison to the normal side, and consistent with the attenuated sensory functions of the grafts, counts of neural structures showed a reduction in innervation density; PGP-immunoreactive nerve fibers/bundles were reduced in grafted epidermis (p<0.026) and superficial dermis (p<0.001). The numbers of sweat glands (p<0.006) and hair follicles (p<0.001) were also reduced. The number of innervated blood vessels did not differ significantly on the two sides. There were significant correlations between sensory thresholds and the neuroanatomical variables: thresholds of cold and touch were correlated with the number of sweat glands in both grafted and normal skin (r2=0.56 and 0.50, respectively; p<0.001), while warmth thresholds were significantly correlated with the number of innervated blood vessels in grafted skin (r2=0.62, p<0.001). Encapsulated mechanoreceptors were not encountered in this study of hairy skin.
Touch, cold and warmth thresholds and magnitude estimations do not return to normal levels after skin grafting in burn survivors. The elevation of thresholds and reduction of sensory intensity is accompanied by a general decrease in the density of nerve terminals. The lack, or numerical reduction, of sweat glands and innervated blood vessels was also indicative of diminished sensation on grafted skin.
本研究比较了烧伤幸存者移植皮肤中的神经结构与部位匹配的正常皮肤中的神经结构，并将这些结构与感觉的心理物理学测量结果相关联。
招募了15名接受皮肤移植的男性烧伤幸存者（年龄47.7±10.4岁），他们均为深度部分或全层热烧伤，平均烧伤面积占全身表面积的11±5.6%，且在未烧伤的对侧有匹配的正常皮肤。使用Semmes-Weinstein单丝和Medoc TSA 2001热刺激器，在移植皮肤和正常皮肤部位进行触觉、冷觉、温觉和热痛的阈值测定及强度估计。对移植部位和正常部位的皮肤活检组织用蛋白质基因产物9.5（PGP）和200 kDa神经丝抗体进行染色。计数表皮中的神经纤维以及浅、深真皮中的神经纤维或神经纤维束，以及有神经支配的血管、毛囊和汗腺。
平均而言，在移植后43.1±10.4个月收集数据。将移植皮肤的阈值与正常皮肤的阈值进行比较时，发现移植皮肤的感觉阈值升高[触觉（p<0.003）、冷觉（p<0.031）、温觉（p<0.009）]。两侧触觉、冷觉和温觉的强度估计不同，移植皮肤引起的感觉小于正常皮肤。两个部位的热痛阈值和热痛强度估计无统计学差异。与正常侧相比，与移植皮肤感觉功能减弱一致，神经结构计数显示神经支配密度降低；移植表皮（p<0.026）和浅真皮（p<0.001）中PGP免疫反应性神经纤维/束减少。汗腺（p<0.006）和毛囊（p<0.001）的数量也减少。两侧有神经支配的血管数量无显著差异。感觉阈值与神经解剖学变量之间存在显著相关性：冷觉和触觉阈值与移植皮肤和正常皮肤中的汗腺数量相关（r2分别为0.56和0.50；p<0.001），而温觉阈值与移植皮肤中有神经支配的血管数量显著相关（r2=0.62，p<0.001）。在本项有毛皮肤研究中未发现被囊化的机械感受器。
烧伤幸存者皮肤移植后，触觉、冷觉和温觉阈值及强度估计未恢复到正常水平。阈值升高和感觉强度降低伴随着神经末梢密度的普遍下降。汗腺和有神经支配的血管数量的缺乏或减少也表明移植皮肤的感觉减弱。
