Jacques Devulder

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.

A psychoanalytic investigation to improve the success rate of spinal cord stimulation as a treatment for chronic failed back surgery syndrome.

OBJECTIVE The analysis of patient data concerning psychological structure and functioning produced an instrument to determine whether a neurostimulator ought to be implanted or not. DESIGN A questionnaire containing 24 items was developed by a psychologist and tested in 40 chronic failed back surgery patients for whom a spinal cord stimulation seemed to be the only therapeutic approach. This questionnaire was based upon some crucial psychological themes, on which the patient took a position. A predictive indication factor (I.F.; %) for implantation of the neurostimulator was obtained from the 24 items. Six months after the implantation of the neurostimulator, we correlated the evaluation factor (E.F.; %) with a six-point evaluation scale considering the pain reduction. The aim was to compare the I.F. and E.F. to verify the correlation between them. This comparison was intended to answer the question if psychological variables included in our scale improve the success rate of the therapy. SETTING Data were collected by a psychologist at the Pain Clinic of the University Hospital of Gent, Belgium. RESULTS AND CONCLUSIONS The correlation between the I.F. and the E.F. was calculated for the 40 patients by the Spearman correlation test. A coefficient value of 0.8083 (p = 0.000) was found, indicating the existence of a very close correlation between the predictive I.F. and the E.F. The indication scale appears to be a useful instrument for clinical psychologists to predict the success rate of a spinal cord stimulator in this group of patients.

Nightmares and hallucinations after long term intake of tramadol combined with antidepressants

Tramadol is a weak opioid with effects on adrenergic and serotonergic neurotransmission that is used to treat cancer pain and chronic non malignant pain. This drug was initiated in association with paroxetine and dosulepine hydrochloride in a tetraparetic patient with chronic pain. Fifty-six days after initiation of the treatment the patient presented hallucinations that only stopped after the withdrawal of psycho-active drugs and tramadol. The case report questions the long term use of pain killers combined with psycho-active drugs in chronic non malignant pain, especially if pain is under control.

Infra-red thermographic evaluation of spinal cord electrostimulation in patients with chronic pain after failed back surgery

This study sought to visualize spinal-cord stimulation activity by infra-red thermography in humans suffering from chronic lumbosciatic pain. All the patients had previously undergone neurosurgery for a herniated intervertebral disc. Temperature changes were evaluated in two defined body areas after starting, stopping, maintaining or not starting the stimulation. In one body area, corresponding to the pain location, the patient experienced stimulation paraesthesia, whereas in the non-painful (second) area no stimulation paraesthesia were present. The patients were studied on four consecutive days with a randomly chosen stimulation pattern. Temperature changes in identical and comparable skin areas were measured and statistically analysed. No statistically significant temperature variation was found between the painful and non-painful areas. These findings do not confirm the idea that spinal cord stimulation induces vasodilation in the affected pain area when stimulation is present. Infra-red thermography is not able to differentiate the stimulated from the non-stimulated areas.

Stellate ganglion block alleviates pseudo-obstruction symptoms followed by episodes of hypermetropia: Case report

Background and Objectives. The chronic intestinal pseudo‐obstruction due to visceral myopathy is a disorder resembling bowel obstruction but without mechanical occlusion. Frequently, parenteral nutrition becomes the final palliative treatment. A patient affected with this syndrome for 16 years was suffering causalgic pain provoked by intraveneous perfusion. Stellate ganglion block was requested in the hope of maintaining the perfusion. Methods. Stellate ganglion block not only stopped the pain but unexpectedly, it temporarily relieved the pseudo‐obstruction symptoms. Two radiofrequency coagulations in the stellate ganglion prolonged the beneficial effects on gastrointestinal transit for more than 3 weeks, after which the symptoms returned. Multidisciplinary and multicenter advice was that further destructive treatments not be attempted. Results. Repetitive stellate ganglion blocks with 2 mL of bupivacaine 0.75% restored gastrointestinal function for more than 3 weeks. However, after performance of radiofrequency coagulation, infiltration with bupivacaine was followed by hypermetropia on the right eye of 2 weeks duration. Conclusions. The relationship between stellate ganglion block and gastrointestinal function has not been described. This case report does not provide sufficient information to recommend this technique for pseudo‐obstruction symptoms. Moreover, the result in this case is a fortuitous observation, lacking a clear scientific explanation. Further study may be warranted.

Epidural spinal cord stimulation does not improve microvascular blood flow in neuropathic pain

For many years, spinal cord stimulation (SCS) has been used successfully in various pain syndromes. SCS is also used to treat vascularly-impaired patients since it apparently improves the microcirculation. The exact physiological mechanisms involved are still unclear. There are even some anecdotal reports of a cooling of the legs during SCS. This study investigated the vascular effects of SCS in 15 patients with failed back surgery syndrome, using infrared thermography of the affected foot and capillaroscopy in the nailfold of the big toe. There were no statistically significant differences (Students t test) in temperature (P = 0.923) or red blood cell velocity (P = 0.819 first day and P = 0.218 second day) in the affected foot with or without stimulation. A physiological difference in relation to neuropathic pain might explain the lack of improvement in skin microcir culation with SCS.