Electrophysiological Study of the Hepatic Coma

Abstract

The changes in the brain wave and the evoked muscular discharge of a rabbit after a common bile duct ligation were examined and the following results were obtained.
The arousal reaction following a common bile duct ligation, at first, was found to be facilitatory, and then inhibitory, while the evoked muscular discharge of the fore and hind limbs, which was noticed simultaneously, also showed a similar process. The recruiting response likewise was at first facilitatory, and, then, inhibitory. Inhibition, however, seemed to appear earlier than the recruiting response.
The inter-action between arousal reaction and recruiting response was also examined, and it was found that the excitation of the arousal reaction grew strong at first, but became weakened again. Then, in case of lesion of ventralis anterior (VA), the arousal reaction, recruiting response and spike and wave, as compared with that in the case of normal rabbits, all indicated a strong facilitatory influence.
On the other hand, the spontaneous brain wave and spontaneous muscular discharge were seen to have the following relationship that, at first,5-6 c/s wave were mostly observed, when a muscular discharge was found, but, with a lapse of time. the frequency decreased, and, in the case of 3-4 c/s wave, the muscular discharge also was inhibited. It seemed that 4-5 c/s wave appeared first, followed by the appearance of triphasic wave, while, when it did appear, it was believed to be under inhibition.
In the case of 4-5 c/s wave, on the other hand, the muscular discharge was found at times when it ceased to appear simultaneously in the cerebral cortex and hippocampus. Again, it was difficult to notice a triphasic wave in the case of the lesion of VA.
In the liver function test, involving the icterus index, the total bilirubin and serum transaminase, the findings of an obstructive jaundice were observed.
In the light of these results mentioned above, it was assumed that the disturbance of consciousness seen in liver diseases is invited by the inhibition of the activity of the brain stem reticular formation, while such extrapyramidal symptoms as flapping tremors are produced due to the excitation of such extrapyramidal system as hippocampus.