A case of diabetic polyneuropathy complicated with entrapment neuropathy of the bilateral ulnar nerves due to osteoarthrosis at the elbow

We report a 61-year-old man with diabetic polyneuropathy and bilateral ulnar nerve palsy due to osteoarthrosis in the elbow. He was diagnosed as having non-insulin dependent diabetes mellitus (DM) at 40 years of age. At 56 years of age, he developed muscle atrophy and weakness predominantly in the distal parts of his upper limbs. A neurological examination showed him to have severe atrophy and weakness in the muscles innervated by the ulnar nerve bilaterally. He also had paresthesia on the distal parts of all four limbs. Superficial and deep sensory deficits were observed in the lower limbs. A motor nerve conduction study showed a marked reduction in the motor conduction velocity as well as in the amplitude of the action potentials of both ulnar nerves. Roentgenograms of the elbow joints and grooves for the ulnar nerve revealed marked osteophyte formation bilaterally. The bilateral ulnar nerve palsy was thus considered to be due to the entrapment of the nerve by the osteophyte. Since several studies have suggested the existence of a relationship between DM and osteoarthropathy, it is important to check for the possible presence of osteoarthrosis in cases of diabetic neuropathy complicated with entrapment neuropathy.