Falsini B, Porciatti V
Eye Clinic, Catholic University, Rome, Italy.
Electroencephalogr Clin Neurophysiol. 1996 Sep;100(5):428-35.
Steady-state pattern electroretinograms (PERGs) and visual evoked potentials (VEPs) in response to sinusoidal gratings (2 c/deg), sinusoidally counterphased at closely spaced temporal frequencies (TFs) between 4 and 28 Hz, were recorded from 11 patients with unilateral optic neuritis (ON; 11 affected eyes and 10 healthy fellow eyes) and 7 age-matched normal subjects (7 eyes). Amplitude and phase of responses' second harmonics were measured. Responses' apparent latencies were estimated from the rate at which phase lagged with TF. When compared to control values, mean PERG and VEP amplitudes of ON eyes were reduced (by about 0.4 log units) at both low (5-10 Hz) and high (16-20 Hz) TFs. Mean PERG amplitudes of fellow eyes were selectively reduced at low TFs (by about 0.3 log units). Mean PERG apparent latencies of both ON and fellow eyes were delayed (by 15 and 9 ms, respectively). Mean VEP apparent latency of ON eyes was delayed at both low and high TFs (by 24 and 30 ms, respectively), while that of fellow eyes was selectively delayed at high TFs (by 28 ms). The results in ON eyes indicate non-selective abnormalities of PERG and VEP generators responding at both low and high TFs. VEP TF losses may be in part accounted for by corresponding PERG losses. In the fellow eyes of patients, more selective PERG and VEP TF abnormalities may suggest differential impairment of retinal and postretinal subsystems responding better to low and high TFs (i.e. parvo- and magnocellular streams).
从11例单侧视神经炎（ON；11只患眼和10只健侧眼）患者及7名年龄匹配的正常受试者（7只眼）记录了稳态图形视网膜电图（PERG）和视觉诱发电位（VEP），这些反应是针对空间频率为2周/度的正弦光栅，在4至28赫兹的紧密间隔时间频率（TF）下进行正弦反相刺激产生的。测量了反应二次谐波的振幅和相位。根据相位随TF滞后的速率估计反应的表观潜伏期。与对照值相比，患侧眼的平均PERG和VEP振幅在低（5 - 10赫兹）和高（16 - 20赫兹）TF时均降低（约0.4对数单位）。健侧眼的平均PERG振幅在低TF时选择性降低（约0.3对数单位）。患侧眼和健侧眼的平均PERG表观潜伏期均延迟（分别延迟15和9毫秒）。患侧眼的平均VEP表观潜伏期在低TF和高TF时均延迟（分别延迟24和30毫秒），而健侧眼的平均VEP表观潜伏期在高TF时选择性延迟（延迟28毫秒）。患侧眼的结果表明，在低TF和高TF时做出反应的PERG和VEP发生器存在非选择性异常。VEP TF损失可能部分由相应的PERG损失所解释。在患者的健侧眼中，更具选择性的PERG和VEP TF异常可能提示视网膜和视网膜后子系统对低TF和高TF（即小细胞和大细胞通路）反应的差异损伤。
