早产儿视觉诱发电位特点与临床应用

Characteristics and clinical application of visual evoked potential in premature infants

目的通过分析新生儿视觉诱发电位(visual evoked potential,VEP)波形及潜伏期的发育规律,获得早产儿与足月新生儿的VEP潜伏期参考数据,评价其对早产儿远期预后的意义。方法采用美国Nicolet公司生产的VikingⅣ诱发电位仪,对纠正胎龄近37周的91例早产儿及55例足月儿进行视觉诱发电位检测,同期对91例早产儿进行脑干听觉诱发电位(brainstem auditory evoked potential,BAEP)检测,并对早产儿进行远期追踪。结果 91例早产儿纠正胎龄至近足月时,82例VEP波形已发育成熟,9例未引出或单侧未引出。纠正胎龄近足月早产儿N75、P100、N145潜伏期仍较足月儿长,P均<0.05。随访至纠正胎龄6个月时5例早产儿表现为不同程度的运动、语言发育落后及肌张力异常,其中3例为VEP未正常引出者;纠正胎龄1岁时均发育正常,无明显神经系统后遗症。VEP评价近期早产儿预后的敏感度为60.0%,特异度为93.0%,均高于ABR的40.0%及89.5%。结论早产儿纠正胎龄至近足月时VEP波形已可正常引出,异常者应密切关注其预后。早产儿纠正胎龄接近足月时VEP检测对其预后评价优于ABR。

Objectives To compare premature infants with full term infants in the characteristics of visual evoked potential（VEP） and evaluate its significance of the neurological prognosis of premature infants.Methods Ninety-one premature infants and 55 full term infants were enrolled in the test.Gestational age was calculated from mother＇s last menstrual period,confirmed by ultrasound examination in early pregnancy and clinical assessment.VEP was performed on all infants.Brainstem auditory evoked potential（BAEP） were preformed after the VEP in premature infants.Serial neurological examinations were performed on premature infants throughout the first year after birth.Results The component of VEP of premature infants changed significantly with increasing post conceptional age.The waves of premature infants were performed as full term infants and the latency still remained longer.Nine of 91 premature infants were failed of VEP and three of them were demonstrated abnormalities in muscle tone and dynamic function at sixth month of corrected gestational age but were neurologically normal by 1 year of age.Eleven of 91 premature infants were failed of ABR and 2 of them were demonstrated abnormalities at sixth month of corrected gestational age but were neurologically normal by 1 year of age.The sensitivity and positive predictive power for abnormal neurological develepment were 60.0% and 33.3% and the specificity and negative predictive power were 93.0% and 97.5% respectively,which were higher than that of BAEP.Conclusions The premature infants with corrected gestational age of near term might present normal waves of VEP as term infants do,which suggests close attention to infants with abnormal VEP for unfavorite prognosis.Testing VEP in premature infants with corrected gestational age of near term can be more effective compared to the test of ABR.