Elderly Type 2 DM patient...

An 86-year-old right-handed gentleman presented with a 2-year H/o gradual onset proximal weakness and pain in both the lower limbs. His symptoms deteriorated gradually to the point where he had become bed-bound. His mobility was restricted significantly by frequent involuntary jerks and weakness in his legs. His medical record was significant for type 2 DM. He was on metformin for diabetes control. Clinical examination demonstrated involuntary, asynchronous, high amplitude myoclonic jerks in both lower limbs, which were stimulus-insensitive and were present at rest. The sensory study showed reduced pinprick sensations in glove and stocking distribution. Other investigations were regular.

MR scan of the whole spine showed multilevel degenerative changes with no neural or cord compression. CSF analysis showed significantly elevated protein at 4.74 g/l. Electrophysiological studies revealed features suggestive of extensive polyradiculoneuropathy with background axonal sensory and motor polyneuropathy, as shown in the figure. The demyelinating changes with evidence of markedly prolonged F wave latencies were localised in the region of the nerve roots. EMG of the thoracic paraspinal muscles showed increased insertional activity, low-amplitude-positive sharp waves and fibrillation potentials.