126. A 60-year-old man with a 15-year history of diabetes mellitus type 2 complains of deep burning pain and sensitivity to touch over his hands and fingers. Nerve conduction studies show slow transmission of impulses and diminished muscle stretch reflexes in both ankles and knees. Sensations to vibrations and light touch are also markedly diminished. Laboratory analysis of CSF shows no biochemical abnormalities. Which of the following is the most likely type of peripheral nerve disease in this patient?
Answer : B Distal polyneuropathy
Peripheral neuropathy is a process that affects the function of one or more peripheral nerves.
Diabetic neuropathy is the most common neuropathy in the United States. Other common causes include alcoholism, renal failure, neurotoxic drugs, autoimmune diseases, monoclonal gammopathy, and HIV infection.
The pathologic findings are limited to axonal degeneration or segmental demyelination, or a combination of both. Diabetes affects both the sensory and the motor portions of the peripheral nervous system and most often presents as distal polyneuropathy.
Autonomic neuropathy and mononeuropathy are less common. The pathogenesis of these disorders is not fully understood, but they may be related to metabolic disturbances or to disease of small blood vessels.
Peripheral sensory or sensorimotor neuropathy typically presents
with cramps or deep burning pain, cutaneous hyperesthesia, or insensitivity to changes of temperature.