PT  - JOURNAL ARTICLE
AU  - M Dieterich
AU  - A Straube
AU  - T Brandt
AU  - W Paulus
AU  - U Büttner
TI  - The effects of baclofen and cholinergic drugs on upbeat and downbeat nystagmus.
AID  - 10.1136/jnnp.54.7.627
DP  - 1991 Jul 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 627--632
VI  - 54
IP  - 7
4099  - http://jnnp.bmj.com/content/54/7/627.short
4100  - http://jnnp.bmj.com/content/54/7/627.full
SO  - J Neurol Neurosurg Psychiatry1991 Jul 01; 54
AB  - The GABAergic drug baclofen and the cholinergic drug physostigmine were administered to patients with upbeat and downbeat nystagmus. Baclofen (orally, 5 mg three times daily) reduced nystagmus slow phase velocity and distressing oscillopsia by 25-75% in four out of five patients (two upbeat nystagmus; two downbeat nystagmus). Physostigmine (1 mg single intravenous injection) increased nystagmus in five additional patients with downbeat (1) or positional downbeat nystagmus (4) for a duration of 15-20 minutes. The different interactions of baclofen and physostigmine on neurotransmission subserving vertical vestibulo-ocular reflex could account for these effects. The response to baclofen appears to be a GABA-B-ergic effect with augmentation of the physiological inhibitory influence of the vestibulo-cerebellum on the vestibular nuclei. Similarly baclofen has an inhibitory effect on the velocity storage mechanism. Cholinergic action may cause the increment of nystagmus by physostigmine.