Scarring around cervical epidural stimulating electrode

Scarring around the electrically stimulating electrodes has been of concern since dorsal column stimulation was introduced. This concern resurfaced in the days of cerebellar electrodes and, with the advent of epidural stimulating techniques for the control of pain and spasticity, it again arises as a potential problem. We present a patient who underwent the placement of a C-2-C-4 electrode to treat torticollis; 3 months later, a mild spastic quadriparesis developed and the stimulation became ineffective. At reexploration, dense scar surrounded the electrode and confined the cervical spinal cord. With microdissection techniques, the scar was removed from the dura mater and the dura began to pulsate freely. The quadriparesis reversed. Examination of the scar tissue microscopically showed linearly arrayed fibroblastic nuclei, and we are uncertain whether the exuberant fibroblastic response is a response to electrical stimulation, the materials used in the electrode, or some technical aspects of the operation.