Mercuri E, Braddick O, Atkinson J, Cowan F, Anker S, Andrew R, Wattam-Bell J, Rutherford M, Counsell S, Dubowitz L
Visual Development Unit, University College London, UK.
Neuropediatrics. 1998 Aug;29(4):169-74. doi: 10.1055/s-2007-973556.
The onset and maturation of visual cortical mechanisms can be recorded by using steady-state visual evoked potentials. The aim of this study was to evaluate and compare orientation-reversal (OR) and phase-reversal (PH) VEP as indicators of the maturation of cortical function in a population of fullterm infants with brain lesions on neonatal MRI. Forty-six infants with brain lesions on neonatal MRI were tested on both PH and OR VEP at 8 reversals/second at the age of 5 months and, if the responses were not significant, at a lower temporal frequency (4 reversals/second). Children whose VEPs were not significant at 5 months were tested longitudinally at 6, 9, 12 and 18 months. The results showed that 23 of the 46 infants (50%) did not show significant responses at 5 months and that while in 7 of the 23 (14% of the whole cohort) the responses became significant between 5 and 12 months, in the other 16 infants (34%) the VEP responses were persistently abnormal. Children with focal lesions, such as focal infarction or haemorrhages, tended to show normal or only mildly delayed VEP while more generalised lesions, such as the ones seen in infants with hypoxic-ischaemic encephalopathy grade 2 and 3, tended to be associated with abnormal VEP responses. The involvement of the optic radiations and occipital cortex was not always associated with abnormal VEP responses but the concomitant involvement of the basal ganglia was always associated with abnormal VEP. We were also able to demonstrate that VEP can be also used as a prognostic indicator: while normal OR VEP are reliably associated with a normal visual and neurodevelopmental outcome, abnormal 4 OR or 8 PH at 5 months are consistently associated with abnormal outcome.
视觉皮层机制的起始和成熟可以通过使用稳态视觉诱发电位来记录。本研究的目的是评估和比较方向反转（OR）和相位反转（PH）视觉诱发电位，作为新生儿MRI显示有脑损伤的足月儿群体中皮层功能成熟的指标。对46例新生儿MRI显示有脑损伤的婴儿在5个月大时进行了每秒8次反转的PH和OR视觉诱发电位测试，如果反应不明显，则在较低的时间频率（每秒4次反转）下进行测试。5个月时视觉诱发电位不明显的儿童在6、9、12和18个月时进行纵向测试。结果显示，46例婴儿中有23例（50%）在5个月时未显示出明显反应，在这23例中的7例（占整个队列的14%）中，反应在5至12个月之间变得明显，而在其他16例婴儿（34%）中，视觉诱发电位反应持续异常。有局灶性病变（如局灶性梗死或出血）的儿童倾向于表现出正常或仅轻度延迟的视觉诱发电位，而更广泛的病变（如在2级和3级缺氧缺血性脑病婴儿中所见的病变）则倾向于与异常的视觉诱发电位反应相关。视辐射和枕叶皮层的受累并不总是与异常的视觉诱发电位反应相关，但基底神经节的同时受累总是与异常的视觉诱发电位相关。我们还能够证明视觉诱发电位也可以用作预后指标：虽然正常的OR视觉诱发电位与正常的视觉和神经发育结果可靠相关，但5个月时异常的4次OR或8次PH始终与异常结果相关。
