Cordotomy for Refractory Cancer Pain

Radiologist performs a spinal tap to inject a contrast drug into the spinal fluid. A 20G spinal needle guided by real-time CT scan to the C1-C2 level opposite to participant's pain. A radiofrequency electrode inserted through the spinal needle into the spinal cord, to the anatomic location of the spinothalamic tract. Once ideal position of the electrode is confirmed, 1 or 2 radiofrequency ablations performed at 70C-80C for 60 seconds. The procedure will take 1-2 hours.

Pain and symptom questionnaire completed at baseline, by phone during first week of study, and once each month by phone during 6 month follow up.

Sharpness detection determined using 8, 10, 16, 20, 32, 64, and 128g weighted needle devices. Each stimulus applied for about 1 second in ascending order. Participants asked to rate each stimulus as producing the sensation of touch, pressure, sharp, or pain. The sharpness detection threshold defined as the mean force of the stimuli deemed ''sharp'' or ''painful'' from 3 trials separated by an average interval of 30 to 90 seconds.

Thermal ramps will applied using a 3.6 x 3.6 cm Peltier thermode (Medoc Inc.) from a baseline temperature set at 32C. Skin heated at a rate of 0.30C/s, and participants asked to signal when the stimulus is perceived as first becoming warmer and then painfully hot.