PSYCHONEUROIMMUNOLOGICAL CORRELATES OF PERSISTING SCIATIC PAIN IN PATIENTS WHO UNDERWENT DISKECTOMY

Patients suffering from persisting sciatic pain 8 weeks following disc ectomy were compared with patients displaying low complaints and healt hy, pain-free volunteers regarding their interleukin-6 (IL-6) levels, morning cortisol levels and degree of psychological distress. Whereas serum concentrations of IL-6 were measured by collecting blood samples between 0945 and 2400 h in intervals of 45 min, morning cortisol leve ls were obtained by sampling saliva on five ensuing measurements, begi nning immediately after awakening. In addition, questionnaires aimed a t measuring depressive mood, somatic symptoms, coping and chronic stre ss were filled out by the subjects. The patients with ongoing pain dis played significantly elevated IL-6 levels and an attenuated elevation of cortisol secretion after awakening compared to the two other groups . Patients with persisting pain were also suffering more frequently fr om depressive mood and ongoing work-related strains. In addition, mala daptive coping strategies were favoured by these patients. The present ed data support the hypothesis that the persistence of pain in many of the concerned patients may significantly be related to dysfunctional reciprocal relations between neural, endocrine and immune function. (C ) 1997 Elsevier Science Ireland Ltd.