Two years ago I was diagnosed with CRPS. Nothing I’ve tried helps with the pain. I’m giving some thought to trying one of those spinal stimulators. What’s the success rate of these units?

You may be referring to the treatment called epidural spinal cord stimulation (SCS). Programmable electrodes can be placed inside the cervical or thoracic spine. The goal is to stimulate the spinal cord directly and prevent pain signals from reaching the brain. Patients with complex regional pain syndrome (CRPS) are often good candidates for this type of treatment.

However, there are some problems with this treatment. Hardware failure is common and reported in up to half of all patients using the SCS device. The delicate nature of the device combined with the stress of movement in the spine can create problems.

In a recent study, doctors in the Department of Neurosurgery at Northwestern University (Chicago) reviewed hardware problems for 289 patients. There was an overall 33.5 percent rate of complications such as infection, breakage, or migration of the unit.

In almost half the cases, revision surgery to repair the problem was unsucessful. Hardware engineers are hard at work to find a way to implant a sturdy, effective pain control unit that will allow normal movement.