Pediatric pain practitioners often face unique challenges in the placement of neuromodulation devices, spinal cord stimulators in particular. Concomitant medical conditions, that at times may be difficult to diagnose, can frequently affect placement techniques in this population. We present a unique case of a 16-year-old female with Klippel-Trenaunay-Weber syndrome resulting in significant arteriovenous (AV) malformations, scoliosis, abnormal bone growth and chronic pain in the right lower extremity.
The patient underwent multiple embolizations over several years to the right lower extremity due to her extensive AV malformations. Despite this, she eventually necessitated an above-knee-amputation. Consequently, she developed significant neuropathic pain in the distal portion of her stump. After surgical revision and exhaustion of medication management, she underwent a spinal cord stimulator trial.
Initially, dual 8-contact trial leads were successfully placed with intraoperative confirmation of coverage. Pain relief was noted to be significant but transient due to coverage migration toward the unaffected limb. As a result, permanent dual 8-contact percutaneous leads were placed off midline towards the affected side. Unfortunately, despite the off midline placement, coverage again migrated postoperatively toward the unaffected limb.
Further investigations performed at that time revealed that in addition to her scoliosis, she developed subtle yet progressive spinal rotation. (Figures 1. and 2.)
The implant was subsequently revised with placement of a secured paddle lead via laminotomy to the extreme right lateral position (Figure 3.) Immediately postoperatively, she noticed a significant improvement in her symptoms reporting a greater than 50% reduction in her pain with increased function and prosthetic tolerance. Unfortunately due to disease progression, her symptoms are currently incompletely covered by the SCS. Patient satisfaction improved at follow-up with re-education about proper device use, and reprogramming however, she is currently awaiting additional sclerotherapy of her recurrent AVMs.
Although not completely studied, placement of spinal cord stimulators have shown significant benefit in patients with neuropathic limb pain. For this reason, it is our belief that neuromodulation can be an invaluable treatment option in the management of chronic neuropathic limb pain for select pediatric patients. These patients however, may present challenges and considerations during lead placement not usually encountered in their adult counterparts.
With respect to the spine, rapid growth or co-morbid conditions seen in the pediatric population can cause significant variations in anatomy. This can range from obvious scoliosis to subtler and often confounding, difficult to delineate variations in rotational anatomy. We propose that in the subset of pediatric populations with abnormal spinal anatomy, obtaining recent dedicated imaging prior to the stimulator trial and eventual placement of permanent leads.
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