Pain in the surgical incision site might contribute to the temporary memory and learning problems that can occur after surgery, according to a new study performed on mice.
Up to 80 percent of surgical patients in the United States have some level of pain after surgery, and several studies have suggested that such pain could cause problems with thinking ability after surgery.
To investigate the possible connection, Massachusetts General Hospital researchers made small incisions on the mice's paws while they were under general anesthesia. The mice were tested one, three and seven days after the procedure to see how sensitive their paws were to discomfort. The animals' paws showed increased sensitivity to pressure at one and three days, but not at seven days.
Compared to mice with no incisions, those with incisions had poorer performance on some learning and memory tests at days three and seven, but not on day 30, according to the study, which was published Nov. 6 in the Journal of Neuroscience.
Thinking problems associated with incision-related pain occurred in middle-aged mice, while young-adult mice showed few signs of such problems, the researchers said.