Effect of Intravenous Diazepam and Thiopental on Voluntary Saccades and Pursuit Eye Movements

Abstract

The effects of diazepam and thiopental on voluntary saccades and pursuit eye movements were tested in 9 volunteers, with an interval of at least 2 weeks between tests. One, 4 and 8 h after intravenous injection of diazepam (0.3 mg/kg) or thiopental (6.0 mg/kg), voluntary saccades and pursuit eye movements were tested and blood samples taken for analysis of drug concentration. As compared to results of tests without drugs, a significant reduction both of saccadic peak velocity and gain of pursuit eye movements was found 1 h after injection of either drug, but not after 4 and 8 h. The amplitude of saccades elicited with the 60 degrees stimulus was significantly reduced 1 h after injection of diazepam. Latency of saccades increased significantly up to 4 h after injection of either drug. No significant correlation was found between peak velocity of saccades and blood concentration of either thiopental or diazepam 1 h after administration. The present results confirm that in man saccades and pursuit eye movements are reduced by benzodiazepines and barbiturates, but provide no support for the previously described efficacy of saccades in monitoring the effect of benzodiazepines. It is hypothesized that diazepam and thiopental also induce reduction of voluntary saccades and pursuit eye movements via a general sedation of the central nervous system (CNS), besides having specific effects on CNS structures important to the performance of voluntary eye movements.

Effects of low‐dose isoflurane on saccadic eye movement generation

“…Similarly, Padoan et al [11] showed an increase in saccadic latency following the intravenous delivery of 6.0 mg.kg ¹1 of thiopentone. Although the experiments reported here were not double-blinded, as it was not possible to disguise the metallic taste of isoflurane, in the case of the countermanded protocol there appears to be no placebo effect, and this is also likely to be true with respect to simple latency.…”

The Effect of Apomorphine, MK-212 (6-chloro-2-[1-piperazinyl]-pyrazine) and Placebo on Smooth Pursuit Gain and Corrective Saccades in Normal Subjects

“…This pattern of results raises the possibility that the reduc tion in slow-target-gain after apomorphine was second ary to sedation. A number of compounds with sedat ing effects have been found to reduce smooth pursuit gain, including barbiturates (Padoan et al 1992), ben zodiazepines (Rothenberg and Selkoe 1981;Bittencourt et al 1983;Padoan et al 1992), alcohol (Baloh et al 1979;Barnes et al 1984;Tedeschi et al 1984;Stapleton et al 1986), nitrous oxide (Magnusson et al 1989), and metha done (Rothenberg et al 1980). However, in an acute study of the effects of chlorpromazine on eye move ments, Holzman et al (1975) found no effect on eye tracking in the presence of a large soporifIc effect.…”

The effect of oral ethanol consumption on eye movements in healthy volunteers

“…Smooth-pursuit gain reduction is known to appear in various other conditions, including barbiturate and [28,30] diazepam administration [28], inattention [5] and schizophrenia [24] and is also seen rather unspecifically in other neurological and psychiatric disorders [22]. Control of smooth-pursuit eye movements involves parts of the pontine nuclei, vestibulo-cerebellum, cerebellar vermis, extrastriate visual cortex, frontal eye fields, and parietal lobe [13,22].…”

“…Alcohol consumption leads to prolonged oculomotor reaction times in response to visual stimuli, but it has also been suggested to induce disturbances in basic and complex visual and ocular motor functions [2,28]. Measurement of eye movements by the infrared reflection technique is a reliable method for assessing dysfunctions of the visuomotor system [23][24][25].…”