LAUSR

© Author(s) (or their employer(s)) 2021. No commercial reuse. See rights and permissions. Published by BMJ. CASE PRESENTATION A previously independent 64yearold man presented to his local hospital with newonset diplopia and dysarthria while watching television. Over the following days, he developed painless perioral and upper limb sensory disturbance, gait unsteadiness and limb ataxia, most pronounced in the upper limbs. He was initially admitted and treated for a cerebrovascular event, followed by a period of failed rehabilitation. At 6week review, his symptoms had worsened, and he required the assistance of two people to walk short distances. He was then transferred to a regional neurology unit. It was uncertain whether his symptoms had stabilised or progressed over the preceding fortnight. He had no other neurological symptoms, normal bladder and bowel function, and no history of preceding illness. Table 1 provides the background history.