The effects of dorsal column stimulation on measures of clinical and experimental pain in man.

Despite the extensive use of dorsal column stimulation (DCS) for the control of various chronic pain conditions, most clinicians report only modest success rates. Surprisingly, there has been little placebo-controlled investigation of its efficacy for altering either clinical or experimental pain perception. The current study compared the effects of DCS to placebo stimulation on clinical pain perception, perceived intensity of painful heat stimuli and visual stimuli, and the discrimination of small changes in noxious heat intensity and in light intensity. We found that DCS, but not placebo stimulation, significantly altered ratings of spontaneous clinical pain as well as those of painful cutaneous heat. In addition, heat discrimination thresholds were increased by DCS, but not placebo. On the other hand, DCS had no effect on ratings of visual stimulus intensity nor on visual discrimination, suggesting that the DCS modulation of pain perception was not due to a general change in attention. These data indicate that DCS significantly alters pain transmission in humans. Nevertheless, the relatively small reduction in clinical pain (less than 30%) must be weighed against the invasive nature of electrode implantation.

Combined stereotactic and peripheral surgical approach for spasmodic torticollis.

Thalamotomy with or without pallidotomy and peripheral denervation, if necessary, was performed in 14 cases of spasmodic torticollis or other late dystonias. Of 4 bilateral procedures, 2 had a good result, in 1 there was little change and in another the patient remained with a pseudobulbar syndrome, the only complication in this group. 1 patient only required peripheral denervation with a good result. Of the 9 patients who underwent unilateral thalamotomy, with or without pallidotomy, the result was excellent in 6 and good in 2 others, but in 4 of these 8 patients peripheral denervation was also performed.