MRCP-0699
A 59-year-old surgeon presents with a progressive paraesthesia and numbness in both feet, which have deteriorated over the last six months. He has a 10 year history of type 2 diabetes mellitus and had cervical spondylosis, for which he underwent surgery eight years ago. He also confessed to drinking approximately 40 units of alcohol weekly. On examination he had mild bilateral weakness of foot dorsiflexion and both ankle reflexes were absent. There was absent sensation to light touch to mid-shin level with loss of joint position sensation in the toes and absent vibration sensation below the hips. He had a marked sensory ataxia and pseudoathetosis of the upper limbs. He had no evidence of a retinopathy and urinalysis was normal. Which of the following is the most likely diagnosis?