SPINAL-CORD COMPRESSION BY CATHETER GRANULOMAS IN HIGH-DOSE INTRATHECAL MORPHINE THERAPY - CASE-REPORT

OBJECTIVE AND IMPORTANCE: The use of chronic intrathecal morphine for the treatment of intractable, nonmalignant pain is becoming more preva lent. A rare but devastating complication of this therapy is the devel opment of spinal cord compression secondary to the formation of intrat hecal granulomas. CLINICAL PRESENTATION: We report three cases of intr athecal granuloma formation in the thoracic subarachnoid space, associ ated with intrathecal morphine pumps. These three patients were receiv ing high doses of morphine to control their pain (25 mg/d, 28 mg/d, an d 45 mg/d, respectively) when they presented with signs and symptoms o f thoracic spinal cord compression. Myelography and postmyelographic c omputed tomography of the spine revealed masses causing spinal cord co mpression. INTERVENTION: Two patients underwent thoracic laminectomies for resection of these masses, and the other patient had the intrathe cal catheter removed. A pathological examination revealed sterile gran ulomas in the resected masses. CONCLUSION: Intrathecal granulomas are likely to occur with increasing frequency as the use of chronic intrat hecal morphine delivery increases in patients with nonmalignant pain. The cause of intrathecal granulomas is unknown, although it is likely that morphine plays a major role in their formation. We think that tho se patients receiving high doses of morphine are at greater risk for d eveloping this complication.