Back pain linked to short-term memory deficits

NEW YORK (Reuters Health) - Patients with chronic back pain have significant impairments in short-term prospective memory compared with people without pain, according to the findings reported in the February/March issue of Psychosomatic Medicine.

Prospective memory is the memory of future intentions, such as picking up groceries or making a doctor's appointment. Prospective memory can be triggered by a time cue, such as remembering an appointment after checking the time of day, or an event cue, seeing a mailbox and remembering that a letter needs to be posted.

Dr. Jonathan Ling, of Keele University, Staffordshire, UK, and colleagues compared the prospective memory of 50 subjects with chronic back pain to the memory of 50 subjects who were pain-free.

The investigators used the Prospective Memory Questionnaire, a self-rating scale that requires users to record the number of times their prospective memory fails in a given period. It measures three aspects of prospective memory: long-term habitual, short-term episodic, and internally cued. In addition, the questionnaire records the use of techniques to aid remembering.

Compared with subjects who were pain-free, those with chronic pain had significantly impaired short-term prospective memory. The deficit was not observed in other areas of prospective memory, the researchers report.

Subjects in the chronic pain group who used the least amount of analgesics each day had less impairment than those in the medium- or high-use categories.

"One explanation for the observation of short-term prospective memory deficits may be related to the link between pain and stress and the impact of this relationship on cognitive function," Ling's team explains. "An alternative explanation may be related to glucocorticoid (steroid) treatment to which our group of patients may have been exposed."

The investigators hope these findings will help guide the care of patients with chronic pain and encourage the development of skills to offset memory problems.

SOURCE: Psychosomatic Medicine, February/March 2007.