Impaired neuropsychological performance in chronic nonmalignant pain patients receiving long-term oral opioid therapy

The study investigated neuropsyhcological performance in chronic nonmaligna nt pain patients receiving long-term oral opioid therapy. Forty patients tr eated solely with regular and stable closes of an oral opioid were compared with 40 healthy volunteers. The patients received daily opioid doses of 15 -300 mg of oral morphine (median: 60 mg) or equianalgesic doses of other op ioids. The neuropsychological tests consisted of continous reaction time (C RT), which measured vigilance/attention; finger tapping test (FTT), which m easured psychomotor speed; and paced auditory serial addition task (PASAT), which measured working memory Three months after the study had been carrie d out, 14 of the controls were retested in order to determine the reliabili ty of the three tests. The patients performed statistically significantly p oorer than the controls in all the tests. Significantly positive correlatio ns were Sound between the PASAT and pain visual analogue scales (VAS). In t he retesting of 14 controls, if war found that the tests showed high reliab ility. Vigilance/attention, psychomotor speed, and working memory were sign ificantly impaired in chronic nonmalignant pain patients The present study cannot determine which factors influenced the test results, but pain itself seemed to have an arousal effect on working memory. (C) U.S. Cancer, Pain Relief Committee, 2000.