Lockard J S, Congdon W C, DuCharme L L
Department of Psychology, University of Washington, Seattle 98195.
Epilepsia. 1990;31 Suppl 2:S20-6. doi: 10.1111/j.1528-1157.1990.tb05844.x.
The feasibility, safety, and preliminary effects of chronic vagal stimulation were studied in an aluminagel monkey model. Pilot studies to perfect the equipment, determine stimulation thresholds, and insure the comfort and safety of the animals preceded this study. Four monkeys were equipped with an indwelling, 2-electrode cuff (titanium bands spaced 7 mm apart; silicone encased; 1.5 cm total length) in contact around the right vagus nerve; avoidance of the cardiac branch was confirmed by electrocardiograms. After postsurgical recovery, the intact and awake animals received constant-current stimulation (5 mA; 83 Hz, 143 Hz, or 50-250 Hz randomly; 0.5-ms pulse width) at the onset of every spontaneous seizure for the duration of the seizure or every 3 h for 40 s if stimulation had not occurred in the preceding hour. Stimulation periods of 2-6 weeks, with differing levels of stimulation, were preceded and followed by at least a 2-week baseline period of no stimulation. During the stimulation periods, the seizure rate decreased to zero in two monkeys and the interseizure intervals became invariable in the remaining two monkeys. These effects carried over temporarily into the poststimulation baseline periods. Vagal stimulation had no consistent effects on seizure severity or EEG interictal spikes. Histological studies of six vagus nerves were unable to separate electrode cuff damage from any direct effects stimulation may have had on the nerves. Although it appears that chronic vagal stimulation is feasible and that epileptogenic processes are influenced, the safety and efficacy of the procedure are still in question.
在铝凝胶猴模型中研究了慢性迷走神经刺激的可行性、安全性和初步效果。在本研究之前，进行了试点研究以完善设备、确定刺激阈值并确保动物的舒适度和安全性。四只猴子在右迷走神经周围安装了一个留置的双电极袖带（钛带间距7毫米；硅胶包裹；总长度1.5厘米）；通过心电图确认避开了心脏分支。术后恢复后，完整清醒的动物在每次自发癫痫发作开始时接受恒流刺激（5毫安；83赫兹、143赫兹或随机50 - 250赫兹；0.5毫秒脉冲宽度），刺激持续癫痫发作的持续时间，或者如果前一小时未发生刺激，则每3小时刺激40秒。在2 - 6周的不同刺激水平的刺激期之前和之后，至少有一个2周的无刺激基线期。在刺激期，两只猴子的癫痫发作率降至零，其余两只猴子的发作间期变得恒定。这些效果在刺激后的基线期暂时持续。迷走神经刺激对癫痫发作严重程度或脑电图发作间期尖峰没有一致的影响。对六条迷走神经的组织学研究无法区分电极袖带损伤与刺激可能对神经产生的任何直接影响。尽管慢性迷走神经刺激似乎是可行的，并且癫痫发生过程受到影响，但该手术的安全性和有效性仍存在疑问。
