Sandyk R
Department of Neuroscience at the Institute for Biomedical Engineering and Rehabilitation Services of Touro College, Dix Hills, NY 11746, USA.
Int J Neurosci. 1998 Apr;93(3-4):239-50. doi: 10.3109/00207459808986429.
Visual evoked response (VER) studies have been utilized as supportive information for the diagnosis of multiple sclerosis (MS) and may be useful in objectively monitoring the effects of various therapeutic modalities. Delayed latency of the VER, which reflects slowed impulse transmission in the optic pathways, is the most characteristic abnormality associated with the disease. Brief transcranial applications of AC pulsed electromagnetic fields (EMFs) in the picotesla flux density are efficacious in the symptomatic treatment of MS and may also reestablish impulse transmission in the optic pathways. A 36 year old man developed an attack of right sided optic neuritis at the age of 30. On presentation he had blurring of vision with reduced acuity on the right and fundoscopic examination revealed pallor of the optic disc. A checkerboard pattern reversal VER showed a delayed latency to right eye stimulation (P100 = 132 ms; normal range: 95-115 ms). After he received two successive applications of AC pulsed EMFs of 7.5 picotesla flux density each of 20 minutes duration administered transcranially, there was a dramatic improvement in vision and the VER latency reverted to normal (P100= 107 ms). The rapid improvement in vision coupled with the normalization of the VER latency despite the presence of optic atrophy, which reflects chronic demyelination of the optic nerve, cannot be explained on the basis of partial or full reformation of myelin. It is proposed that in MS synaptic neurotransmitter deficiency is associated with the visual impairment and delayed VER latency following optic neuritis and that the recovery of the VER latency by treatment with pulsed EMFs is related to enhancement of synaptic neurotransmitter functions in the retina and central optic pathways. Recovery of the VER latency in MS patients may have important implications with respect to the treatment of visual impairment and prevention of visual loss. Specifically, repeated pulsed applications of EMFs may maintain impulse transmission in the optic nerve and thus potentially sustain its viability.
视觉诱发电位（VER）研究已被用作支持多发性硬化症（MS）诊断的信息，并且可能有助于客观监测各种治疗方式的效果。VER潜伏期延迟反映了视路中冲动传导减慢，是与该疾病相关的最具特征性的异常。皮特斯拉通量密度的交流电脉冲电磁场（EMF）经颅短暂应用对MS的症状治疗有效，也可能重新建立视路中的冲动传导。一名36岁男性在30岁时发生右侧视神经炎发作。就诊时，他视力模糊，右侧视力下降，眼底检查显示视盘苍白。棋盘格模式翻转VER显示右眼刺激潜伏期延迟（P100 = 132毫秒；正常范围：95 - 115毫秒）。在他接受了两次经颅给予的7.5皮特斯拉通量密度的交流电脉冲EMF，每次持续20分钟后，视力有显著改善，VER潜伏期恢复正常（P100 = 107毫秒）。尽管存在视神经萎缩（反映视神经慢性脱髓鞘），视力快速改善且VER潜伏期恢复正常，这无法基于髓鞘部分或完全重塑来解释。有人提出，在MS中，突触神经递质缺乏与视神经炎后的视力损害和VER潜伏期延迟有关，并且通过脉冲EMF治疗使VER潜伏期恢复与视网膜和中枢视路中突触神经递质功能增强有关。MS患者VER潜伏期的恢复可能对视力损害的治疗和预防视力丧失具有重要意义。具体而言，重复脉冲应用EMF可能维持视神经中的冲动传导，从而潜在地维持其活力。
