Wednesday, March 14, 2012

Effects of Diabetes on the Nervous System

Although it is generally known for its metabolic effects, diabetes is a disease that also has effects on the peripheral nervous system in approximately 50 percent of patients, affecting its function. The degeneration of function in both the somatosensory and autonomic peripheral nervous systems that occurs during diabetes is called diabetic neuropathy. The predominant clinical symptoms are decreases in sensation in the feet and legs, hands, and arms, as well as decreases in muscle reflexes. The effects begin at the extremities, usually appearing first in the feet and legs several years after the onset of diabetes and progressing to the hands and arms in the later stages of the disease. Aneurological examination would show that electrical signals are not being propagated down the axons of affected neurons. Although there are many underlying causes for this deficit, the hyperglycemia characteristic of diabetes causes alterations in electrolyte balance that deplete the Na+/K+ -ATPase pump and interfere with axonal transport. Both mechanisms interfere with normal neuronal function.