Introduction Implantable pulse generators (IPGs) are available with constant voltage and constant current designs. Differences in constant voltage and constant current stimulation pulses¹ can be represented graphically (Fig. 1). Constant voltage pulses have current amplitudes that peak and then fall in response to tissue properties that include impedance. In contrast, constant current pulses have current amplitudes that are unchanged throughout the duration of the pulse. Because constant voltage systems adjust their current to accommodate changing impedance, their total charge (current amplitude × pulse width) can be reduced, requiring adjustments in voltage or pulse width in response. Constant current systems provide a steady charge and generally require fewer adjustments than constant voltage systems as the impedance varies.² Methods A 59-year-old male with post-laminectomy syndrome was implanted with a spinal cord stimulation system consisting of a constant voltage IPG and dual quadrapolar leads. After its battery depleted, the IPG was replaced with a constant current design using a lead extension to make it compatible with the patient's existing leads (Fig 2). The patient's stimulation programming and electrode polarities were adjusted slightly after surgery (Fig. 3). Retrospectively, the patient answered questions about pain relief, functionality, and stimulation sensations provided by the two IPGs. Results The patient reported improved pain relief and functioning with the constant current device. He also described his stimulation sensations as more soothing and comfortable (Fig. 4). Conclusion The patient's report of improved stimulation quality with the constant current IPG may be related to the pulse shape and consistent charge provided by the device. Further inquiry is needed to confirm the relationship between stimulation sensation and constant current and constant voltage systems.