Trisciuzzi Maria Teresa S, Riccardi Riccardo, Piccardi Marco, Iarossi Giancarlo, Buzzonetti Luca, Dickmann Anna, Colosimo Cesare, Ruggiero Antonio, Di Rocco Concezio, Falsini Benedetto
Institute of Ophthalmology, Catholic University, Lgo F. Vito 1, 00168 Rome, Italy.
Clin Neurophysiol. 2004 Jan;115(1):217-26. doi: 10.1016/s1388-2457(03)00282-7.
To evaluate a fast technique of visual evoked potentials (VEPs) recording, in response to steady-state luminance stimuli (SS-LVEPs), for functional assessment and follow-up of childhood optic gliomas (OGs).
Eighteen OG patients (age range: 3.5-18 years), with different degrees of optic pathway damage severity, were examined. Sixteen age-matched normal subjects served as controls. Ten of the 18 OG patients were re-tested 1-3 months after the first examination. SS-LVEPs were elicited by a sinusoidally-modulated flickering (8 Hz) uniform field, generated by a light emitting diode (LED)-array and presented monocularly in a mini-ganzfeld. Amplitude and phase of the Fourier-analyzed response fundamental (1F) and second harmonic (2F) were measured. The full VEP protocol had a median duration of 6 min (range: 4-12).
When compared to normal control values, median 1F and 2F SS-LVEP amplitudes of OG patients were reduced (P<0.01), with a borderline increase in 2F phase lag (P<0.05). In 11 OG patients with asymmetric optic pathway damage in between-eye comparisons, median 1F amplitude losses were greater (P<0.01) in fellow eyes with more severe damage. No significant interocular difference was observed in control subjects. Median test-retest changes of 1F and 2F component were <20% and 30 degrees for amplitude and phase, respectively. In individual OG patients, 1F and 2F amplitudes were positively correlated (P<0.01) with visual acuity. 1F amplitude losses were correlated (P=0.01) with the severity of optic disc atrophy. Considering both 1F and 2F abnormalities, diagnostic sensitivity of SS-LVEP in detecting OG-induced optic pathways damage was 83.3%.
The present findings support the use of this technique, as an alternative to pattern VEPs, for functional assessment and follow-up of OG in uncooperative children.
评估一种用于儿童视神经胶质瘤（OG）功能评估及随访的视觉诱发电位（VEP）快速记录技术，该技术针对稳态亮度刺激（SS-LVEP）。
对18例不同程度视神经通路损伤严重程度的OG患者（年龄范围：3.5 - 18岁）进行检查。16例年龄匹配的正常受试者作为对照。18例OG患者中有10例在首次检查后1 - 3个月进行了重新测试。SS-LVEP由发光二极管（LED）阵列产生的正弦调制闪烁（8Hz）均匀场诱发，单眼呈现于小型全视野刺激器中。测量经傅里叶分析的反应基波（1F）和二次谐波（2F）的振幅和相位。完整的VEP检查方案中位持续时间为6分钟（范围：4 - 12分钟）。
与正常对照值相比，OG患者的1F和2F SS-LVEP中位振幅降低（P<0.01），2F相位滞后有临界性增加（P<0.05）。在11例两眼间视神经通路损伤不对称性的OG患者中，损伤更严重侧眼的1F振幅损失中位数更大（P<0.01）。在对照受试者中未观察到显著的两眼间差异。1F和2F成分的重测变化中位数，振幅<20%，相位<30度。在个体OG患者中，1F和2F振幅与视力呈正相关（P<0.01）。1F振幅损失与视盘萎缩严重程度相关（P = 0.01）。综合考虑1F和2F异常情况，SS-LVEP检测OG所致视神经通路损伤的诊断敏感性为83.3%。
本研究结果支持将该技术作为图形VEP的替代方法，用于不合作儿童OG的功能评估及随访。
