Korean J Anesthesiol.  1980 Dec;13(4):325-332.

Positional Nystagmus Caused by Ketamine in Rabbits

• Choe H

Abstract

Rabbits injected with ketamine, 2-8mg/kg, i.v. were subjected to positional manipulation. Rotation of the head to a unilateral direction (from the neutral to the right or left) and returning towards the neutral produced nystagmic responses in the bilateral eyeballs. The patterns of the nystagmus observed by ketamine were compared with those by alcohol(1-2 gm /kg). The following results were obtained. 1) Intravenous injection of ketamine did not cause spontaneous nystagmus when the animal was left in the neutral position. 2) Following the ketamine injection, positional manipulation such as lateral rotation of the head elicited nystagmus in the bilateral eyeballs. The directions of the nystagmus appeared to be specific to the direction of the rotation. 3) Returning of the head from the laterally rotated position to the neutral also caused nystagmus with specific directions. 4) The patterns of the positional nystagmus caused by ketamine were quite similar to those of "positional nystagmus" caused by alcohol; nystagmic patterns were almost identical between the animals injected with ketamine and alcohol when the direction of the head rotation was the same. 5) Destruction or removal of the bilateral vestibular systems abolished the nystagmic responses to the positional manipulation. These experimental results indicate that the ketamine does elicit positional nystagmus as alcohol, which has been known as a unique agent causing positional nystagmus in man and animals, and the vestibular system is basically related to the genesis of the positional nystagmus caused by ketamine.

MeSH Terms

Animals
Head
Injections, Intravenous
Ketamine*
Nystagmus, Physiologic*
Rabbits*
Ketamine