Diabetic peripheral neuropathy

What it is

In diabetes patients, glove and stocking peripheral and autonomic neuropathy occur as a result of osmotic damage to Schwann cells.

How it presents

Paresthesia and numbness in both feet, with decreased sensation on microfilament testing, do not by themselves name the cause. Those same findings are set as a question whose options are Charcot-Marie-Tooth disease, diabetic peripheral neuropathy, hyperthyroidism, tarsal tunnel syndrome and vitamin B12 deficiency, with no answer marked, and they come alongside a hemoglobin A1c of 5.8%, a hemoglobin of 10.4 g/dL where normal is 12.0-16.0, a mean corpuscular volume of 102 where normal is 81-99, and a proton pump inhibitor taken for the past 2 years. Claw toe and hammer toe may suggest underlying diabetic neuropathy. Hammer toe is dorsal flexion at the DIP joint, dorsal flexion at the MTP joint, and plantar flexion at the PIP joint; claw toe is dorsal flexion at the MTP joint with plantar flexion at the PIP and DIP joints, where DIP is distal interphalangeal, MTP is metatarsophalangeal, and PIP is proximal interphalangeal. The autonomic form reaches the bladder: diabetic neuropathy is listed among the causes of detrusor overactivity behind urge incontinence, and among the causes of chronic urinary retention behind overflow incontinence with its continuous dribbling and incomplete emptying.

Gathered as the features of the diabetic foot, the peripheral neuropathy gives loss of ankle jerk and vibration sense, accidental injury with tissue damage, and Charcot joints, that is neuropathic arthropathy. Beside it run large vessel arterial disease and small vessel arterial disease, and an autonomic neuropathy with reduced sweating and dry, cracked skin, and then infection. All of those contribute to ulcer formation, which is why the foot is examined as one thing and not as a nerve alone. The autonomic signs named elsewhere are gastroparesis and ED, on a stocking-glove sensory loss.