Eremeev V S, Semeniutin V B, Tashaev Sh S, Teplov S I
Fiziol Zh SSSR Im I M Sechenova. 1978 Aug;64(8):1145-51.
In acute experiments in cats, separate measurement of impedance of extra and intracranial tissues and skull bones was carried out by passing 30-150 kHz electrical current. Extra and intracranaial tissue impedances are approximately equal and one order less than that of skull bones which excludes electrical current penetration into the cranial cavity directly through the bone. The changes on electroplethysmograms recorded with extra and intracranial electrodes during simultaneous clipping of both common carotids or external and internal jugular veins were compared. In part of experiments jugular veins were clipped before and after switching off extracranial blood flow. Intracranial impedance changes thus achieved are several times greater than extracranial ones and are not registered in extracranial bitemporal electrode location. The only way to register them without intracranial electrode insertion is by use of ocular-occipital lead. Yet in this case the intracranial component makes only about 30% of the registered signal. This value increases significantly with artifical stabilization of extracranial hemodynamics.
在对猫进行的急性实验中，通过施加30 - 150千赫的电流，分别测量颅外组织、颅内组织和颅骨的阻抗。颅外和颅内组织的阻抗大致相等，比颅骨的阻抗小一个数量级，这排除了电流直接通过骨头穿透到颅腔的可能性。比较了在同时夹闭双侧颈总动脉或颈外静脉和颈内静脉时，用颅外和颅内电极记录的电阻抗体积描记图的变化。在部分实验中，在阻断颅外血流前后夹闭颈静脉。由此获得的颅内阻抗变化比颅外阻抗变化大几倍，并且在颅外双颞电极位置未记录到。在不插入颅内电极的情况下记录这些变化的唯一方法是使用眼枕导联。然而，在这种情况下，颅内成分仅占记录信号的约30%。随着颅外血流动力学的人工稳定，该值会显著增加。
