THE CUTANEOUS WITHDRAWAL REFLEX IN HUMAN NEONATES - SENSITIZATION, RECEPTIVE-FIELDS, AND THE EFFECTS OF CONTRALATERAL STIMULATION
THE CUTANEOUS WITHDRAWAL REFLEX IN HUMAN NEONATES - SENSITIZATION, RECEPTIVE-FIELDS, AND THE EFFECTS OF CONTRALATERAL STIMULATION
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DOI：
10.1016/0304-3959(94)90154-6
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发表时间：
1994-01-01
期刊：
影响因子：
7.4
通讯作者：
FITZGERALD, M
中科院分区：
文献类型：
--
作者：
ANDREWS, K;FITZGERALD, M
皮肤退缩反射的阈值，引起校准冯弗雷头发应用到脚和腿，已被用来研究脊髓感觉处理的发展在一组50个前：足月和足月婴儿，从27.5至42.5周postconceptional年龄（PCA）。收集了关于初始阈值、重复无害刺激的影响、撤回反射的感受野和对侧刺激的影响的数据集（108）。如先前报告（Fitzgerald等人，1988年，1989年），PCA与初始阈值之间存在相关性。29周时的平均阈值为0.237 g（标准误0.042），而41周时的平均阈值为0.980 g（S.E.M.）。0.134）。在长达35周的PCA婴儿中，用von Frey毛发反复刺激导致反射阈值或“敏化”显著降低。此后，阈值降低不显著，并观察到习惯化。从27.5周PCA开始，可以从整个肢体直到大腿顶部和臀部引起撤回反射。PCA低于30周时，该感受野内的阈值是均匀的，但30周后，观察到阈值的梯度从脚底向膝盖逐渐增加。维持刺激对侧肢体的应用显着抑制撤回反射反应同侧冯弗雷毛发刺激，在所有年龄段。这些结果说明了人类脊髓内感觉处理的出生后变化。低阈值在一个大的感受野和敏感的重复刺激表明缺乏一些，但不是所有的，抑制连接;在早产儿，因为对侧抑制是在出生时建立良好。
The threshold of a cutaneous withdrawal reflex, elicited by calibrated von Frey hairs applied to the foot and leg, has been used to study the development of spinal sensory processing in a group of 50 pre:term and full-term infants ranging from 27.5 to 42.5 weeks postconceptional age (PCA). Data sets (108) were collected on initial threshold, the effects of repeated innocuous stimuli, the receptive field of the withdrawal reflex, and the effect of a contralateral stimulus. As reported previously (Fitzgerald et al. 1988, 1989), there was a correlation between PCA and initial threshold. The mean threshold at 29 weeks was 0.237 g (S.E.M. 0.042), whereas the mean threshold at 41 weeks was 0.980 g (S.E.M. 0.134). Repeated stimulation with von Frey hairs led to a significant lowering of threshold or ''sensitization'' of the reflex in infants of up to 35 weeks PCA. Thereafter, the decrease in threshold was not significant, and habituation was observed. From 27.5 weeks PCA, it was possible to elicit the withdrawal reflex from the whole limb as far up as the top of the thigh and buttock. Below 30 weeks PCA, the thresholds within this receptive field were uniform, but after 30 weeks a gradient of thresholds was observed increasing progressively from the sole of the foot towards the knee. The application of a maintained stimulus to the contralateral limb significantly inhibited withdrawal reflex responses to ipsilateral von Frey hair stimulation, across all age bands. These results illustrate postnatal changes in sensory processing within the human spinal cord. Low thresholds over a large receptive field and sensitization on repeated stimulation suggest a lack of some, but not all, inhibitory connections;in the preterm neonate since contralateral inhibition is well established at birth.