Effect of Burst Stimulation Evaluated in Patients Familiar With Spinal Cord Stimulation

Spinal cord stimulation (SCS) is used for treating intractable neuropathic pain. It has been suggested that burst SCS (five pulses at 500 Hz, delivered 40 times per second) suppresses neuropathic pain at least as well as conventional tonic SCS, but without evoking paraesthesia. The efficacy of paraesthesia-free high and low amplitude burst SCS for the treatment of neuropathic pain in patients who are already familiar with tonic SCS was evaluated.

Forty patients receiving conventional (30-120 Hz) tonic SCS for at least six months were included. All patients received high and low amplitude burst SCS, for a two-week period in a double blind randomized crossover design, with a two-week period of tonic stimulation in between. The average visual analogue scale (VAS) scores for pain during the last three days of each stimulation period were evaluated as well as quality of life (QoL) scores, and patient's preferences.

Average VAS score for pain were lower during high (40, p = 0.013) and low amplitude burst stimulation (42, p = 0.053) compared with tonic stimulation (52). QoL scores did not differ significantly. At the individual level 58% of the patients experienced significant additional pain reduction (>30% decrease in VAS for pain) during high and/or low amplitude burst stimulation. Eleven patients preferred tonic stimulation, fifteen high, and fourteen low amplitude burst stimulation.

Burst stimulation is in general more effective than tonic stimulation. Individual patients can highly benefit from burst stimulation; however, the therapeutic range of burst stimulation amplitudes requires individual assessment.