Down-beat nystagmus is often observed in dizzy patients with a central lesion focus; however, up-beat nystagmus has rarely been noted. A 57-year-old man who com-plained of dizziness was diagnosed as having Wernicke encephalopathy on the basis of neurological findings, an MRI and the past history given at first visit to Aichi Medical University. Up-beat nystagmus was observed under an infrared camera and recorded by electronystagmography (ENG). An eye-tracking test for optokinetic nystagmus showed saccades and ataxia. Vitamin B1 50 mg per day was administered immediately. Although symptoms such as cerebellar ataxia had improved by the third day after administration and were almost absent by the 19th day, saccades and ataxia, recorded by ENG, and up-beating nystagmus remained for more than 4 months.
