The Influence of Tobacco Smoking, Nicotine, CO and CO₂ on Vestibular Nystagmus

Abstract

The influence of some components of the tobacco smoke on the vestibulo-ocular reflex arc was studied. In accordance with a previous report it was shown that tobacco smoking provoked an obvious increase of the vestibular nystagmus frequency while the speed of the slow components remained unchanged. The injection of nicotine intravenously gave a similar change in the nystagmus pattern as was obtained after smoking. An increase in the carboxy-hemoglobin content by smoking a nicotine-free cigarette did not change the vestibular nystagmus pattern. An elevation of the arterial carbon dioxide tension affected the vestibular nystagmus only slightly, and in an opposite way compared to smoking. The results indicate that nicotine is the main component in the tobacco smoke responsible for the changes in the nystagmus pattern observed after smoking. There is evidence that the effects observed are due to changes in neuronal transmission of the vestibulo-ocular reflex arc.