氯胺酮抗惊厥作用对脑电图δ频段功率谱的影响

The anticonvulsant action of ketamine onδ-band of quantitative pharmaco-EEG in rabbits

目的观察氯胺酮在治疗士的宁诱发惊厥中的作用以及对定量药物脑电图(QPEEG)δ频段的影响。方法健康家兔50只随机分成生理盐水组(NS组)、氯胺酮1.25mg/kg(K1.25组)、2.5mg/kg(K2.5组)、5.0mg/kg(K5.0组)和苯巴比妥组5.0mg/kg(PB组),耳缘静脉注射士的宁0.25mg/kg(15s内注完)制作惊厥模型,一旦强直惊厥出现,立即静脉注射相应的治疗药物。观察各药对家兔的死亡率、强直持续期的影响,并连续监测脑电图,分析QPEEGδ频段功率谱的变化。结果氯胺酮各剂量组与NS和PB组相比,家兔强直持续期明显缩短(P<0.05,r=0.8696),死亡率为零。脑电图变化与行为学表现同步,NS组在给药后1～5min几乎所有脑区的δ频段脑电功率百分比较基础值显著降低(P<0.01)。PB组在1、2min时δ功率百分比较基础值降低(P<0.01),5min时顶枕区开始恢复。氯胺酮各剂量组在给药后多数观察脑区的δ频段功率百分比与基础值相比变化不大,除顶枕区外其他脑区的功率百分比在给药后1～5min均较NS组和PB组有所提高(P<0.01,P<0.05)。结论氯胺酮抗惊厥的作用主要通过维持额区和颞区脑电δ波频率,减少惊厥时痫性波发放。

Objective To observe the therapeutic action of ketamine and effect on 8-band power of quantitative pharmaco-electroenciphalogram （QPEEG） in strychnine-convulsive rabbits. Methods Convulsion was induced by intravenous strychnine （0. 25 mg/kg） within 15 seconds. Rabbits were randomly divided into NS, K1.25, K2.5, K5.0 and PB groups （ N = 10）. Drugs treatment of groups was administered intravenously once convulsion occurred. Mortality and duration of tonic state were noted. The EEG activity was processed with the power spectral analysis. The percentage of power of eaeh frequency band of QPEEG sample was obtained on different time after drug injection. Results Ketarnine could dose-dependently short the duration of tonic state induced by strychnine（P 〈0. 05, r =0. 8696）, and decrease mortality. The percentage of 8-band power in all brain were decreased （P 〈0.01 ） in groups of NS within 1 -5 minute after therapy. Compare with bases, the percentage of δ-band power decreased within 1 -2 minute in PB group, and started to recovery in parietal and occipital region at 5 minute. After ketamine injection, the percentage of δ-band power had no significant change in almost all areas. Compared with NS and PB groups, the percentages of δ-band power in brain areas except parietal and occipital bone were increased within 1-5 minute in three ketamine groups （P 〈 0. 05, P 〈 0. 01 ）. Conclusion Ketamine has the effect of anti-convulsion and maintain δ band power in forehead and temporal bone to decrease convulsive paroxysm.