Paddle lead trial in the case of a prior fusion

Scenario

A 49-year-old woman is referred for placement of a spinal cord stimulator from a physiatrist who sees many patients with persisting back pain and failed back surgery syndrome in general. Although this physician does place trial leads in some patients, he typically is comfortable only with fairly straightforward placements and does not do any permanent placements or implantable pulse generator (IPG) replacements. In this patient, there had been three previous surgeries. Initially, approximately 8 years before, she had a microdiscectomy, somewhat successfully at L5-S1 on the left. Unfortunately, she developed further problems within a year, back and leg pain with degenerative changes at L45 as well, and this led to a fusion from L4-S1. The patient did reasonably well for several years, although she began having more back pain and some bilateral leg symptoms 3 years ago when she was involved in a major motor vehicle accident, wherein she subsequently had a significant burst fracture and instability at T11, requiring fusion from T8 extending down to and including the L4-S1 fusion. Although this stabilized her spine and the construct appeared reasonable by all imaging since then, she remained compromised with worsening low back pain and bilateral leg pains, left worse than right.

The patient came to the visit with an magnetic resonance imaging (MRI) scan that was about 19 months old and several sets of thoracic and lumbar X-rays, clearly showing the extensive hardware construct. She had had multiple trigger-point injections, use of a TENS unit, and several series of physical therapy visits to strengthen her core. She was overweight with a body mass index of 30. She had been out of work since the car accident and was receiving disability payments. Her original job had been as a store manager for a large-chain department store. The burst fracture and subsequent injury appeared to have left her with only modest neurological deficits, and she had been fortunate in that regard. She had some initial bladder dysfunction, which had recovered, and she felt burning and dysesthetic changes in her lower extremities which came and went over periods of minutes or hours at times. She had no clear weakness focally on examination except related to effort to some degree, giving 5 or 5-/5 at all muscle groups, although she did endorse having some balance problems after the accident which had somewhat recovered after physical therapy (PT).

She now felt that she could not enjoy any activities without significant lower lumbar back pain which increased with activity from a baseline 7–8 of 10 to 9–10/10 and could only walk or stand for about 10 minutes at a time because of pain developing more in her legs and her back as well. She did not uniformly get relief with sitting and often had to go into her bedroom and lie down for an hour or more to get any change back to baseline. Medications at this juncture included gabapentin 2400 mg/day, ibuprofen 800–1600/day, hydrocodone 20 mg/day, although it had not changed in over 2 years, and methocarbamol 750 mg bid.

• Variation : Only had bladder dysfunction and numbness in lower extremities -- Spinal cord stimulation (SCS) is not going to be of significant benefit for these neurological sequelae. It would be best to tell the patient this in a direct way. Sometimes patients who have been referred for SCS from their long-term pain management physicians have a harder time believing this response and may doubt whether or not the surgeon has understood their circumstances.

• Variation : Only symptoms of weakness in lower extremities and some higher thoracic back pain -- The higher level back pain is much more likely related to the soft tissues that had been disrupted with the accident and weakness from cord injury in the accident as well. Neither of these symptoms is likely to benefit significantly from SCS.