Burst spinal cord stimulation for limb and back pain.

Publication Information

Author(s): De Ridder D, Plazier M, Kamerling N, Menovsky T, Vanneste S.
Journal: World Neurosurg
Volume, issue, pages: 80(5):642-649
Year: 2013
PubMed Link: http://www.ncbi.nlm.nih.gov/pubmed/23321375

Study description

Study design: Randomized double-blind placebo-controlled trial
Study question: Is SCS more successful than placebo in treating neuropathic pain?
Population assessed: Human. Implanted.
Study dates: Jan through Sept 2011
Follow-up intervals: Weekly
Other efforts to reduce bias: Patient self-report VAS and PVAQ. Patients and data evaluator blinded.
Patient protection: IRB; patients given a means to stop stimulation in case of emergency.
Outcome measures: 100 mm VAS, PVAQ (pain vigilance awareness); EEG (n=5 pts)
Primary outcome: Pain relief
Secondary outcomes: VAS pain now, worst & least pain in past week; paresthesia amplitudes to suppress pain scored on VAS; PVAQ
Statistical significance: P < 0.05

Patient selection

Inclusion criteria: Consecutive patients fulfill Belgium SCS eligibility
Exclusion criteria: Psychogenic pain, contraindicating psychiatric morbidity
Psychological evaluation: Yes

Demographic / prognostic factors

Sex (male/female): 4 male; 11 female
Mean patient age in years (+/- SD, range): 54.07 (39 to 68)

Pain location

Back only or predominant: 7
Back and leg(s): 15 (designated as back and limb)

Pain characteristics

Indications (trial/implant)

Failed back surgery syndrome: 13 (including 1 designated as failed neck)
Spinal cord injury: 2 myelopathy

Screening trial

Number patients who underwent trial: 15
Trial electrode type: Lamitrode
Trial electrode manufacturer: St. Jude
Pain control during trial: General anesthesia
Length of hospitalization: Discharged on 2nd postoperative day
Trial duration (days): Minimum 28 days

Stimulation

Paresthesia coverage: Determined with initial tonic stimulation. Limb pain covered in all patients.
Stimulation programming methods: After initial tonic stimulation, patients randomly received burst, tonic, or placebo for a week each. Wash-out assumed to occur when pain returned after stimulation turned off before next type of stimulation turned on.
Parameters: Patient chose best stim intensity. Burst = amplitude below paresthesia threshold; 40-Hz burst mode with 5 spikes at 500 Hz per burst, 1ms and 1ms interspike interval constant current, cumulative charge of 5 spikes balanced during 5 ms interval after the spikes (differentiating burst from intermittent HF stim); placebo stim intensity decreased to zero amplitude.

System implantation

Electrode location(s): 14 thoracic; 1 cervical

Outcomes

Number in study: 15
Number followed: 15
Answer to study question: No effect from order in which type of stimulation was delivered; burst had significantly better impact vs. others on least/worst pain; on EEG, burst led to increased activation of 'dorsal anterior cingulate and right dorsolateral prefrontal cortex' vs. tonic; no significant difference between burst and placebo in terms of paresthesia elicited. SCS leads to increased pain relief vs. placebo.
Data presented disaggregated and summarized?: Yes

Outcomes: pain

Mean pain reduction: Placebo 10.9%; tonic 30.9%; burst 55.0% (significant difference between placebo/tonic and burst)
Pain reduced back: Placebo 18.9%; tonic 51.1%; burst 51.3% (significant difference between placebo and burst)
Pain reduced legs: (Limbs) placebo 11.7%; tonic 30.9%; burst 55.0% (significant difference between placebo and tonic/burst)

Other beneficial outcomes

Change in quality of life: Only burst had significant impact on attention pts gave to pain.

Biological complications

Device complications

Stimulation side effects

Uncomfortable stimulation: None

Cost effectiveness

Faculty and staff

Facility location: New Zealand; Belgium
Facility type: Universities

Data extraction information