A case of uncommon withdrawal symptoms after a short period of spinal morphine administration.

A 54-year-old female with chronic failed back surgery syndrome and pain in the back and the right leg was treated by chronic spinal morphine administration by an external pump. After a positive test instillation over a 3-week period the spinal catheter was removed. Within 24 h the patient developed fever, leucocytosis, impaired sense of smell and allodynia and hyperpathia in all 4 limbs. Infection was excluded as a possible cause and a withdrawal after a second test period some weeks later reinitiated the symptoms. The symptoms vanished after restarting the morphine administration. Finally, an internal Medtronic pump was implanted because the patient obtained good pain relief with the test instillation. Good pain relief could be obtained with the daily instillation of 5 mg morphine intrathecally. Fever, leucocytosis, impaired sense of smell, allodynia and hyperpathia in the limbs reappeared a few weeks later. Evaluation showed catheter migration out of the spinal canal.