Postural changes in spinal cord stimulation perceptual thresholds.

Introduction. Spinal cord stimulation voltage thresholds have been observed to change with body position, but previously have not been characterized in detail. Design. Prospective case series. Methods. We have obtained voltage measurements at the threshold of perception in three body postures for patients with percutaneous dorsal epidural leads. Results. In our sample of 42 patients, we observed a significant (p = 0.000) increase in voltage requirements when moving from supine to sitting or standing positions. This increase can be represented as a linear slope (1.25) across a range of baseline voltage amplitudes. Ninety-five percent of patients experienced an increase, primarily between 11 and 25%. Conclusions. These observations have implications for the design, implantation, and clinical application of spinal cord stimulators. 1998 Blackwell Science, Inc.