A 54-year-old male presents with progressive pins and needles | Neurology collections 2020

A 54-year-old male presents with progressive pins and needles 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 a mild bilateral weakness of foot dorsiflexion, both ankle reflexes were absent and
plantar responses were flexor. 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 upper limbs. He had no evidence of a retinopathy and urinalysis was normal.
What is the most likely diagnosis?