Neuropathy Diabetic Neuropathy 2 — Questions and Answers
Question 1: Which pathophysiological mechanism is central to hyperglycemia-induced nerve damage in diabetes?
- Excess insulin signaling
- Polyol pathway activation and oxidative stress (Correct answer)
- Hypocalcemia-induced demyelination
- Elevated LDL depositing in nerves
Correct answer: Polyol pathway activation and oxidative stress
Excess glucose enters the polyol pathway, depleting NADPH and increasing oxidative stress, which damages axons and Schwann cells.
Question 2: Charcot neuroarthropathy (Charcot foot) is a catastrophic complication of diabetic neuropathy affecting which structure?
- Spinal cord
- Joints and bones of the foot (Correct answer)
- Peripheral blood vessels
- Skin of the foot
Correct answer: Joints and bones of the foot
Charcot neuroarthropathy causes progressive destruction of joints and bones of the foot due to loss of protective sensation.
Question 3: Which test is used to assess large fiber function in diabetic neuropathy screening?
- Pinprick sensation test
- 10-g Semmes-Weinstein monofilament test (Correct answer)
- Warm/cold temperature discrimination
- Nerve biopsy
Correct answer: 10-g Semmes-Weinstein monofilament test
The 10-g Semmes-Weinstein monofilament detects loss of protective sensation by assessing large myelinated fiber function.
Question 4: Which organ is primarily responsible for producing advanced glycation end-products (AGEs) that contribute to diabetic neuropathy?
- Liver
- Throughout the body in hyperglycemic states (Correct answer)
- Pancreas
- Kidney
Correct answer: Throughout the body in hyperglycemic states
AGEs form throughout the body when chronic hyperglycemia causes glucose to bond non-enzymatically to proteins and lipids, damaging nerves.
Question 5: Duloxetine is FDA-approved for painful diabetic neuropathy and works primarily through which mechanism?
- Opioid receptor agonism
- Serotonin-norepinephrine reuptake inhibition (Correct answer)
- GABA-A receptor modulation
- Sodium channel blockade
Correct answer: Serotonin-norepinephrine reuptake inhibition
Duloxetine inhibits reuptake of serotonin and norepinephrine, enhancing descending pain inhibitory pathways.
Question 6: Which skin biopsy finding confirms small fiber neuropathy in diabetes?
- Demyelinated large axons
- Reduced intraepidermal nerve fiber density (IENFD) (Correct answer)
- Amyloid deposits in dermis
- Inflammatory infiltrate around vessels
Correct answer: Reduced intraepidermal nerve fiber density (IENFD)
Skin punch biopsy showing reduced IENFD is the gold standard for diagnosing small fiber neuropathy in diabetic patients.
Neuropathy Diabetic Neuropathy 2
Which pathophysiological mechanism is central to hyperglycemia-induced nerve damage in diabetes?