Patient selection for the treatment of chronic intractable pain requires a closer examination of criteria. In most cases, a psychological evaluation is indicated to examine factors such as patient expectations, psychosomatic components of the pain, and secondary gain motivation.

Selection guidelines for patients include:

• Patient experiences inadequate pain relief and/or intolerable side effects from systemic opioid therapy
• Patient has objective evidence of pathology
• Patient obtains psychological clearance
• Patient has no untreated substance abuse
• Patient has sufficient body size to accept the bulk and weight of the pump
• Clear therapy goals and realistic expectations have been established
• No contraindications to surgery or the therapy exist
• Patient has a favorable response to the screening test