Reflecting on the causes of BR's pain

BR had the SCS controller adjusted yesterday, with a few new programs added. We are still experimenting, trying to find a program that isn't too irritating, yet masks some of the pain.

I asked the technician how BR compared to other patients she's worked with. "Everybody's different. You just have to play around with it." We now have 12 programs with 20 power levels each. That's 240 combinations to "play around with". The vast majority of these create more discomfort for BR than the relief they provide.

She recommended a technique for setting the power level:

1. Slowly increase the power until the sensation is noticeable


2. If the sensation is uncomfortable, back the power down a notch or two

This would be fine except for the fact that BR is experiencing "sensation echoes." An unpleasant sensation will replay in his head for up to a minute or more after the stimulus has been removed. This turns the recommended technique into a form of torture that could get someone a court date at The Hague.

I'm still wondering if a cervical placement of the stimulator leads wouldn't have been more effective. Evidence is mounting that progressive MS is a result of damage to the nerve axon, which gets exposed after the myelin sheath is stripped away during the initial MS attacks. Like a metal wire without insulation and exposed to the elements, the wire eventually starts to corrode. Signals get weaker and degrade as the corrosion gets worse. Eventually the signals don't get through at all.

I found this video from the Mayo Clinic on YouTube. It talks about a couple of enzymes that may be responsible for the axon damage in people with progressive MS.



In the telecommunications world, there is an effect called electrical signal reflection.

Signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber, some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end. This happens because imperfections in the cable cause impedance mismatches and non-linear changes in the cable characteristics.

Could it be that the pain signals we are trying to mask are actually impulses that started in the brain and were reflected back at the point of axon damage? This might explain a couple things.

• Stress and anxiety increase BR's pain levels. Research has shown that accompanying anxiety, "Almost invariably there are physical disturbances -- palpitations, tremulousness, sweating, diarrhea, etc. -- due principally to overactivity of the autonomic, particularly the sympathetic, nervous system, and to increased output of catecholamines by the adrenal medulla." In theory, when this increased activity hits the damage, it reflects back to the brain as a pain signal.


• The sensation echo could be caused by two or more damaged axons along a single neural pathway. The signal bounces back and forth between the points of damage, losing strength over time.

Of course, I'm not a doctor. My training is in engineering and computer science. But still, my instincts tell me that if the stimulator leads were placed in the cervical spine between the brain and the axon damage, we might have a better chance of scrambling the pain signal with fewer sensation echoes.