Arthritis Pain Processed in Emotion-Linked Brain Area

Mar. 23 --

WEDNESDAY, March 28 (HealthDay News) -- Arthritis pain is processed in areas of the brain that also control emotions and fear, a U.K. study finds.

The study, published in the April issue of the journal Arthritis & Rheumatism, may offer a new target for treating arthritis pain.

The analysis included 12 people with knee osteoarthritis. Using brain imaging scans, researchers at the University of Manchester Rheumatic Diseases Centre monitored the patients' brain activity as they experienced osteoarthritis pain, pain caused by heat application, and no pain.

Both the osteoarthritis and heat-induced pain activated a network of brain structures known as the pain matrix, which contains two parallel systems. The medial pain system processes the emotional aspects of pain, including fear and stress. The lateral system processes the pain's physical location, intensity and duration.

While both osteoarthritis and heat-induced (experimental) pain activated both systems, osteoarthritis pain caused heightened activity in the medial pain system. This suggests that arthritis pain may have more of an emotional impact and stronger association with fear and distress than experimental pain, the researchers said.

They also found that osteoarthritis pain triggered increased activity in the prefrontal cortex and the inferior posterior parietal cortex -- areas of the brain that play an important role in paying attention. The activation of these areas during osteoarthritis pain may be the result of patients' focusing on strategies to cope with their arthritis pain, the researchers said.

"The present study demonstrates the importance of the medial pain system during the experience of arthritis pain and suggests that it is a likely target for both pharmacologic and nonpharmacologic interventions," study lead author Professor A.K.P. Jones said in a prepared statement.

More information

The U.S. Centers for Disease Control and Prevention has more about arthritis.

SOURCE: Arthritis & Rheumatism, news release, March 28, 2007