Physical, psychologic, and social function in chronic pain patients after epidural spinal electrical stimulation.

The overall function, pain, and mood disturbance of 54 patients with benign chronic pain were studied as to their response to epidural spinal electrical stimulation (ESES) more than 12 months after the implantation of ESES electrodes. Both responder (n = 23) and nonresponder (n = 31) pain patients demonstrated extensively worse physical and psychosocial function on the Sickness Impact Profile (SIP) and worse self-rated mood disturbance on the Mood Adjective Check List (MACL) than a control population sample. Responders to ESES were insignificantly less impaired in physical functions of daily life than nonresponders, but clearly less inhibited in the social pattern of contact. Self-rated pain sensation differed 36% between responders and nonresponders, and the pain measures of all pain patients correlated with total mood disturbance on the MACL and with its dimensions for depression and fatigue. Social characteristics, sex, diagnoses, comorbidity, and duration of pain did not discriminate. In a supplementary prospective short-term study, pain ratings had improved by 30% 3 weeks after implantations. The night sleep and general psychic balance (SIP category emotional behavior) were then also significantly improved. A shortened SIP version of 8 items optimizing responder-nonresponder differences and 12 items of mood disturbance are suggested to supplement pain ratings for overall assessment of chronic pain patients. A wider usage of ESES is recommended for pain patients who can comply to the regimen, because the surgical technique is now simple and safe.