Discographic pain report. Influence of psychological factors

The possibility of a relationship between discographic pain responses and Minnesota Multiphasic Personality inventory scores was investigated.

To determine if patients with elevated Minnesota Multiphasic Personality Inventory scale scores were more likely to report pain on the injection of a nondisrupted disc than were patients without such high scores.

In general, injection into disrupted discs provokes pain, whereas injection into nondisrupted discs does not. However, discordant results are sometimes obtained and create a more difficult diagnostic challenge.

The primary study group was composed of 72 patients who underwent computed tomography/discography at the three lowest lumbar levels for diagnostic purposes and completed the Minnesota Multiphasic Personality Inventory.

The mean scores on the Minnesota Multiphasic Personality Inventory hypochondriasis and hysteria scales were significantly greater for patients reporting reproduction of clinical pain than for patients not reporting pain on injection of a nondisrupted disc (hypochondriasis: 77.2 vs. 68.6, P < 0.01; hysteria: 74.5 vs. 68.3, P < 0.05). The scores on the depression scale followed a similar trend (68.6 vs. 63.6, P < 0.15). Multivariate analysis, adjusting the means for possible confounding effects of age, symptom duration, and sex, did not alter the results.

Discographic pain reports are not only related to anatomic abnormalities, but are influenced by personality as assessed by the Minnesota Multiphasic Personality Inventory. Patients with elevated scores on the hypochondriasis, hysteria, and depression scales may tend to overreport pain during discographic injection. Among such patients, even those with a concordant computed tomography/discographic image, selection of therapeutic modalities should be made with caution.