Pryds O, Greisen G, Trojaborg W
Department of Neonatology, State University Hospital of Copenhagen, Denmark.
Electroencephalogr Clin Neurophysiol. 1988 Jul-Aug;71(4):257-65. doi: 10.1016/0168-5597(88)90025-1.
Flash evoked cortical potentials (VEPs) were studied in 33 preterm infants with gestational ages from 27 to 33 weeks. During the first 12 h after birth a visual response was evoked in all infants. Better estimates of the VEP latency and amplitude were obtained by using the values of 3 VEPs recorded at 30 sec intervals. The VEP latency decreased during the first hours of life, which was accounted for by an increase in core temperature; the latency decreased 6 msec/degrees C increase. Changes in amplitude were less influenced by changes in temperature. Both VEP latency and amplitude were inversely related to gestational age, but there was no association between head circumference and latency. The flash intensity could be reduced from 155 cd to 39 cd without any effect on VEP latency or amplitude. Similarly, a variation of background illumination below 200 lux did not cause VEP changes. The VEP was not affected by development of minor subependymal haemorrhages but it was severely attenuated during a short episode of hypoxia. It is suggested that when taking core temperature into account the VEP can be used to determine changes in the cerebral function in preterm infants.
对33名孕周在27至33周的早产儿进行了闪光诱发皮层电位（VEP）研究。在出生后的前12小时内，所有婴儿均诱发了视觉反应。通过使用每隔30秒记录的3次VEP值，可以更好地估计VEP潜伏期和波幅。VEP潜伏期在出生后的最初几个小时内缩短，这是由核心温度升高所致；潜伏期每升高1摄氏度缩短6毫秒。波幅变化受温度变化的影响较小。VEP潜伏期和波幅均与孕周呈负相关，但头围与潜伏期之间无关联。闪光强度可从155坎德拉降至39坎德拉，而对VEP潜伏期或波幅无任何影响。同样，背景光照强度在200勒克斯以下的变化也不会引起VEP改变。VEP不受轻微室管膜下出血发展的影响，但在短暂的缺氧发作期间会严重衰减。建议在考虑核心温度的情况下，VEP可用于确定早产儿脑功能的变化。
