Teaching NeuroImages: Hypertrophic polyneuropathy.

A 75-year-old man previously diagnosed with multiple sclerosis presented with a 20-year history of therapy-resistant progressive upper and lower limb weakness and sensory deficits. Examination found hand interossei muscle wasting, thickened radius and ulna nerves, and reduced distal lower limb strength. Neurophysiology revealed a sensorimotor polyneuropathy with demyelinating features. MRI showed hypertrophic nerves and nerve roots in the lumbosacral plexus (figure). Charcot-Marie Tooth disease (CMT) and chronic inflammatory demyelinating polyneuropathy (CIDP) are the leading causes of hypertrophic polyneuropathy. Other causes include leprosy, neurofibromatosis and amyloid deposition. In this case, genetic screening was negative for CMT, suggesting probable CIDP.