Kogure Y, Fujii H, Higashi S, Hashimoto M, Yamamoto S
Department of Neurosurgery, Kanazawa University, Japan.
No Shinkei Geka. 1988 Dec;16(13):1439-43.
The present study was designed to induce plateau waves by electrical stimulation of the brain stem and examine the changes in EEG during the plateau waves. Experiments were carried out on 10 adult mongrel dogs which were slightly anesthetized, immobilized and artificially respired. Electroencephalogram (EEG), intracranial pressure (ICP), systemic blood pressure (SBP) and cerebral perfusion pressure were simultaneously recorded on the electromagnetic tape after transorbital puncture of the intracavernous internal carotid artery. EEGs were recorded from cortical electrodes, and were analyzed by a frequency analysis. At the stage of increased ICP, the mesencephalic reticular formation was stimulated. Stimulation parameters, i.e., intensity, duration and frequency, were 0.1 mA, 1 msec and 40 - 50 Hz, respectively. The total duration of each period was 5 seconds. Spontaneous plateau waves occurred in 2 dogs associated with subarachnoid hemorrhage, subdural hematoma and intraventricular hemorrhage. Plateau waves were induced by electrical stimulation in the mesencephalic reticular formation in one of two dogs with spontaneous plateau waves. Twenty-one repetitions of electrical stimulation induced ten plateau waves. Two plateau waves were induced during slow EEG associated with desynchronization of EEG. Eight plateau waves were induced during fast EEG activity with no changes in EEG before and after the stimulation. In addition, plateau waves occurred immediately after short duration (5 seconds) of electrical stimulation. It seems that CBV increases during plateau waves are due to rapidly occurring neurogenic vasodilatation of cerebral vessels, later augmented by increases in cerebral metabolism. In conclusion, plateau waves are produced in a rigid condition within the cranial cavity by stimulation of the brainstem reticular formation which influences cortical activation and cerebral vasodilatation.
本研究旨在通过电刺激脑干诱发平台波，并观察平台波期间脑电图（EEG）的变化。实验在10只成年杂种犬身上进行，这些犬轻度麻醉、制动并进行人工呼吸。经海绵窦内颈动脉眶上穿刺后，将脑电图（EEG）、颅内压（ICP）、全身血压（SBP）和脑灌注压同时记录在电磁带上。EEG由皮质电极记录，并通过频率分析进行分析。在ICP升高阶段，刺激中脑网状结构。刺激参数，即强度、持续时间和频率，分别为0.1 mA、1毫秒和40 - 50赫兹。每个周期的总持续时间为5秒。2只犬出现自发性平台波，与蛛网膜下腔出血、硬膜下血肿和脑室内出血有关。在2只有自发性平台波的犬中，有1只通过电刺激中脑网状结构诱发了平台波。21次电刺激诱发了10次平台波。在与EEG去同步化相关的慢EEG期间诱发了2次平台波。在快EEG活动期间诱发了8次平台波，刺激前后EEG无变化。此外，在短时间（5秒）电刺激后立即出现平台波。似乎平台波期间脑血容量（CBV）的增加是由于脑血管迅速发生神经源性血管扩张，随后因脑代谢增加而增强。总之，通过刺激脑干网状结构在颅腔内的刚性条件下产生平台波，这会影响皮质激活和脑血管扩张。
