Reversible Late Thoracic Myelopathy and Neurostimulation Tolerance Caused by Fibrous Scar Tissue Formation Around the Spinal Cord Stimulation Electrode.

Objective: Spinal cord stimulation has now been used for four decades and has become an established treatment for neuropathic pain. Spinal cord compression by formation of excessive fibrous tissue at the level of an epidural neurostimulation electrode is a rare, delayed, but serious complication of neuromodulation for chronic neuropathic pain that may appear at various timings after the initial surgery, but is usually preceded by progressive tolerance and fading of the pain-relieving effect of the neurostimulation.
Methods: We report one patient treated by neuromodulation with percutaneous lead between 1998 and 2001, then by a larger surgical lead since 2001. He started presenting with clinical signs of spinal cord compression, along with progressive fading of the antalgic effect of the stimulation five years later, finally leading to surgery in 2013.
Results: The microsurgical removal of fibrous tissue under the electrode allowed both the decompression of the spinal cord and the return of efficient pain control, while leaving the electrode at the same place.
Conclusion: Careful surgical removal of the fibrous tissue can be performed to allow decompression of the spinal cord and may help to obtain a more efficient pain management. As large surgical electrodes could be specifically associated with compressive scar tissue formation, they should therefore be considered as a second line of treatment after percutaneous leads.
(© 2015 International Neuromodulation Society.)