Abstract：
OBJECTIVE: The purpose of this study was to evaluate the applicability of visual evoked potentials (VEP) for intraoperative visual pathway monitoring in epilepsy surgery of the posterior hemispheric quadrant (PHQ) and to correlate it with post-operative visual field status.
METHODS: VEP monitoring was performed in 16 patients (12 females, 7 children). Flash-induced VEP were recorded with strip electrodes from the banks of the calcarine cortex. Latency and amplitude of the first component of VEP (V1-lat, V1-amp) were monitored. Evaluation of the visual field was performed pre- and post-operatively in all patients.
RESULTS: All procedures were successfully completed without adverse events. In 10 patients the strip covered both the inferior and superior calcarine banks, while only one bank was sampled in 6 cases (inferior in 4, superior in 2). Considering one of the two calcarine banks, at the end of the resection VEP had disappeared in 4 patients, whereas a decrease >33.3% in 4 and <20% of V1-amp was recorded in 5 and in 4 cases respectively. The percentage of V1-amp reduction was significantly higher for the patients who experienced a post-operative visual field reduction (p < 0.001). Post-operative visual field deficits were found in patients presenting a reduction >33.3% of V1-amp.
CONCLUSIONS: VEP monitoring is possible and safe in epilepsy surgery under general anesthesia.
CONCLUSIONS: Intraoperative recording of VEP from the banks of the calcarine cortex allows monitoring the integrity of post-geniculate visual pathways during PHQ resections for epilepsy and it is pivotal to prevent disabling visual field defects, including hemianopia and inferior quadrantanopia.
METHODS: VEP monitoring was performed in 16 patients (12 females, 7 children). Flash-induced VEP were recorded with strip electrodes from the banks of the calcarine cortex. Latency and amplitude of the first component of VEP (V1-lat, V1-amp) were monitored. Evaluation of the visual field was performed pre- and post-operatively in all patients.
RESULTS: All procedures were successfully completed without adverse events. In 10 patients the strip covered both the inferior and superior calcarine banks, while only one bank was sampled in 6 cases (inferior in 4, superior in 2). Considering one of the two calcarine banks, at the end of the resection VEP had disappeared in 4 patients, whereas a decrease >33.3% in 4 and <20% of V1-amp was recorded in 5 and in 4 cases respectively. The percentage of V1-amp reduction was significantly higher for the patients who experienced a post-operative visual field reduction (p < 0.001). Post-operative visual field deficits were found in patients presenting a reduction >33.3% of V1-amp.
CONCLUSIONS: VEP monitoring is possible and safe in epilepsy surgery under general anesthesia.
CONCLUSIONS: Intraoperative recording of VEP from the banks of the calcarine cortex allows monitoring the integrity of post-geniculate visual pathways during PHQ resections for epilepsy and it is pivotal to prevent disabling visual field defects, including hemianopia and inferior quadrantanopia.
摘要：
目的：本研究的目的是评估视觉诱发电位（VEP）在后半球象限（PHQ）癫痫手术中用于术中视觉通路监测的适用性，并将其与术后视野状态相关联。
方法：对16例患者进行了VEP监测（12例女性，7个孩子）。用条状电极从calcarine皮层的银行记录闪光诱导的VEP。VEP的第一分量(V1-lat,V1-amp）进行了监测。在所有患者术前和术后进行视野评估。
结果：所有手术均顺利完成，无不良事件。在10例患者中，条带覆盖了下壁和上壁。而只有一家银行在6例中被抽样(差4例，优2例)。考虑到两个calcarine银行之一，在切除结束时，4例患者的VEP消失，而在5例和4例中，分别记录了4例V1-amp的下降>33.3％和<20％。对于经历了术后视野减少的患者，V1-amp减少的百分比显着升高（p<0.001）。在V1-amp减少>33.3％的患者中发现了术后视野缺损。
结论：VEP监测在全身麻醉下的癫痫手术中是可行且安全的。
结论：术中记录钙卡林皮质的VEP可以在癫痫的PHQ切除过程中监测膝后视觉通路的完整性，这对于防止致残视野缺陷至关重要，包括半弱视和下弱视。
方法：对16例患者进行了VEP监测（12例女性，7个孩子）。用条状电极从calcarine皮层的银行记录闪光诱导的VEP。VEP的第一分量(V1-lat,V1-amp）进行了监测。在所有患者术前和术后进行视野评估。
结果：所有手术均顺利完成，无不良事件。在10例患者中，条带覆盖了下壁和上壁。而只有一家银行在6例中被抽样(差4例，优2例)。考虑到两个calcarine银行之一，在切除结束时，4例患者的VEP消失，而在5例和4例中，分别记录了4例V1-amp的下降>33.3％和<20％。对于经历了术后视野减少的患者，V1-amp减少的百分比显着升高（p<0.001）。在V1-amp减少>33.3％的患者中发现了术后视野缺损。
结论：VEP监测在全身麻醉下的癫痫手术中是可行且安全的。
结论：术中记录钙卡林皮质的VEP可以在癫痫的PHQ切除过程中监测膝后视觉通路的完整性，这对于防止致残视野缺陷至关重要，包括半弱视和下弱视。
