Wernicke's encephalopathy with upbeat nystagmus

抄録

　A 41-year-old man was found to have collapsed in his room. It was discovered that he had no money and had not eaten for approximately one week. Blood tests showed that Vit B₁ (thiamine) was 9 ng/ml. He exhibited upbeat nystagmus (UBN) on the gaze nystagmus and positional nystagmus tests. Electronystagmography (ENG) showed the same findings. This patient was diagnosed as having Wernicke's encephalopathy (WE). WE is chacterized by the triad of oculomotor dysfunction, ataxia and consciousness disorders. Although chronic alcoholism is a well-known cause of WE, reports of this disorder due to nutritional deficiencies associated with dietary intake and inanition are limited. Regarding the incidence of vertical nystagmus, UBN was five times more frequent than downbeat nystagmus. Many patients of WE complain of dizziness associated with oculomotor disorders. Such patients are very likely to require treatment by otorhinolaryngologists in the future.