Chapter 11, Problem 5CCS

Nursing Student with Neuropathic Pain

Tamara Costa broke her right tibia and has undergone two separate surgeries to repair it. Although the bone has healed, she suffers increasing pain around the incision sites. The painful area covers the lateral surface of her right leg. She can't stand wearing anything over it or even having a sheet touch it. Her diagnosis is postsurgical neuropathic pain. Pain medication has not helped.

Tamara is a second-year nursing student and has done some reading to try to understand her problem and perhaps find a solution. She has found an article that says neuropathic pain may be caused by a decreased threshold for action potential generation in pain-detecting neurons. However, she has forgotten some of her physiology and needs some help in understanding what she is reading. She has logged into the “Ask a Nurse" chat line–and she got you!

5. You’ve found a copy of the same article, and see that it identifies other ways pain inhibition could decrease. Explain each of them:

a. A decrease in the number of receptors for the inhibitory neurotransmitter GABA.

b. A local decrease in the amount of Cl^-outside the cell. (Hint: GABA opens Cl^–channels, allowing Cl^– influx into the postsynaptic cell.)