Case report

A 50-year-old man gave a 6-year history of muscle wasting and weakness of both legs. He had noticed marked muscle loss across his chest and back and ‘spasms’ of his legs at night, often induced by coughing or sneezing. There were no sensory symptoms or problems with sphincters, speech or swallowing.

On examination, there was muscle wasting in both legs and in the pectoral muscles, but no fasciculations. There was increased tone in all four limbs, with several beats of clonus in the legs. His strength was normal when examined on the couch, although he was adamant that he was not as strong as he used to be. Reflexes were brisk bilaterally in all four limbs and both plantars were upgoing. Sensations to fine touch and to joint-position sense were normal; vibration sense …