Significance of Upbeat Nystagmus in Smokers

So, yes, smoking can cause upbeat nystagmus. I think the most important thing is to see if it's only present without fixation in the dark, or if it's present with fixation. Slow velocity nystagmus without fixation probably just reflects nystagmus in dark in normal individuals. Another scenario however is to have upbeat spontaneous nystagmus that is present both with fixation and without fixation as well as being associated with other ocular motor findings e.g. lateropulsion of saccades; impairment of vertical canals on vHIT or any abnormality in the neurological exam. So isolated, mild, upbeat, nystagmus, with fixation removed probably, I wouldn't worry that much, because it might occur in normal individuals. But upbeat nystagmus with fixation, particularly when associated with other ocular motor findings should be seen as a significant finding.

Presenter

Dr. João Lemos

Dr. João Lemos, Neurologist and Neuro-Ophthalmologist, has worked in the field of oculomotor testing in neurological patients for 15 years, both as a clinician and researcher. He is based at Coimbra University Hospital Centre, Coimbra, Portugal. Dr. Lemos is the Director of the Neurology of Vision and Balance Unit in the hospital's Neurology Department, which sees around 1500 neuro-ophthalmological and neuro-otological patients annually.