Iannaccone Alessandro, McCluney Richard A, Brewer Vickie R, Spiegel Peter H, Taylor June S, Kerr Natalie C, Pivnick Enikö K
Department of Ophthalmology, University of Tennessee, Memphis 38163, USA.
Doc Ophthalmol. 2002 Jul;105(1):63-81. doi: 10.1023/a:1015719803719.
The purposes of this investigation were to determine: (a) if visual evoked potential (VEP) abnormalities could be identified in children with neurofibromatosis type 1 (NF1) with no evidence of optic pathway or brain neoplasias on MRI; and (b) if VEP abnormalities could be explained by the presence of hyperintense T2-weighted foci on MRI testing, known as unidentified bright objects (UBOs). To answer these questions, VEPs were recorded from 16 children with NF1 and compared to 13 normal subjects in the same age range tested with the same protocol. Pattern-reversal VEPs were recorded at four stimulus sizes both monocularly and binocularly, the latter to hemi-field stimuli. Flash VEPs were recorded in dark- and light-adapted conditions. VEP measurements and MRI readings for UBOs were conducted in a masked fashion. Ten of the 16 children with NF1 had abnormal VEPs to at least one of the four types of stimuli. Abnormalities included delayed responses (n=6), absent flash VEP P2 component (n=3), or both (n= 1). Abnormalities of the P2 component of the dark-adapted flash VEP were the most common finding (n=7), although no single testing strategy was able to identify all children with abnormal VEPs. UBOs were present in all children, demonstrating that their presence does not fully account for VEP abnormalities in children with NF1. This study also demonstrates that VEP abnormalities are present also in the absence of neoplasias of the optic pathways or of the brain. Our results are suggestive of a primary abnormality of visual processing in children with NF1.
(a) 在1型神经纤维瘤病（NF1）患儿中，磁共振成像（MRI）未显示视路或脑肿瘤迹象时，是否能识别出视觉诱发电位（VEP）异常；(b) VEP异常是否可由MRI检查中T2加权高信号灶（即不明亮物体，UBO）的存在来解释。为回答这些问题，对16名NF1患儿进行了VEP记录，并与13名同年龄范围、采用相同方案检测的正常受试者进行比较。分别以单眼和双眼记录了四种刺激大小下的图形翻转VEP，双眼记录时采用半视野刺激。在暗适应和明适应条件下记录闪光VEP。对VEP测量和UBO的MRI读数采用盲法进行。16名NF1患儿中有10名对至少一种类型的刺激存在VEP异常。异常包括反应延迟（n = 6）、闪光VEP的P2成分缺失（n = 3）或两者皆有（n = 1）。暗适应闪光VEP的P2成分异常是最常见的发现（n = 7），尽管没有单一的检测策略能够识别出所有VEP异常的患儿。所有患儿均存在UBO，这表明其存在并不能完全解释NF1患儿的VEP异常。本研究还表明，在没有视路或脑肿瘤的情况下也存在VEP异常。我们的结果提示NF1患儿存在视觉处理的原发性异常。
