PT  - JOURNAL ARTICLE
AU  - Helmchen, Christoph
AU  - Machner, Björn
AU  - Gablentz, Janina von der
AU  - Sprenger, Andreas
AU  - Zee, David S.
TI  - Downbeat Nystagmus Is Abolished by Alcohol in Nonalcoholic Wernicke Encephalopathy
AID  - 10.1212/CPJ.0000000000001138
DP  - 2022 Oct 01
TA  - Neurology: Clinical Practice
PG  - e129--e132
VI  - 12
IP  - 5
4099  - http://cp.neurology.org/content/12/5/e129.short
4100  - http://cp.neurology.org/content/12/5/e129.full
AB  - Background and Objectives Lesions of the cerebellar flocculus cause enduring downbeat nystagmus (DBN) with unrelenting oscillopsia. Unlike most patients with DBN, the flocculus is structurally spared in nonalcoholic Wernicke encephalopathy (nWE) with chronic DBN. The objective was to study the effects of alcohol in nWE.Methods We recorded eye movements of a unique patient with nWE under controlled alcohol consumption who said his oscillopsia disappeared with a few drinks of alcohol.Results His DBN was markedly diminished by alcohol (by 77.4%), although he remained alert with normal saccades.Discussion This striking observation may be caused by the differential effect of alcohol on the perihypoglossal complex and the paramedian tract neurons, which control the level of activity in the flocculus, with opposite (inhibition and excitation, respectively) effects. The finding suggests new ideas about the treatment and pathophysiology of DBN with a structurally intact cerebellum.