Polio Survivors “Shake It Like That”
Question: I had polio that left me severely paralyzed in all 4 limbs, my back, head, neck and chest and have been wheelchair dependent ever since. My problem is this: After I’m out of bed for a bit I start shaking. I’m not cold, just shaking - head, neck, shoulders – when I'm sitting in my wheelchair. I can stop it but it starts for no reason and is increasing. My hands shake when I use them, but I interpret this as maybe age + polio weakness. But could this be the onset of Parkinson’s?
Dr. Bruno’s Response: There are two broad categories of tremor.
“Resting tremor" (shaking when your muscles are at rest) as in Parkinson's disease and “action tremor" (shaking when your muscles are being used). The cause of an average polio survivor’s tremor - and possibly yours - may be easy to explain by using your own interpretation: "age + polio weakness".
I think there are two possibilities for your shaking.
The first and most likely is an “action tremor” caused by “age + polio weakness”, stressing muscles whose few remaining overworked, aging, poliovirus-damaged motor neurons can’t sustain firing to continuously and smoothly activate muscles, for example when using your hands and sitting upright in your wheelchair.
The loss of smooth, continuous motor neuron firing leads to the muscles turning on and off, causing shaking. Resting your hands and lying down stops the shaking as it allows the motor neurons to metabolically recover and fire smoothly again.
The second possibility, which is rare, is a condition called "enhanced physiological tremor." EPT, also an "action tremor”, occurs when brain motor neurons fire intermittently when you use your muscles, thereby causing tremor. The tremor is said to be "enhanced" because shaking occurs even when you haven't overworked your muscles. EPT also stops when you rest, for example when lying down in bed.
The simplest treatment for a post polio "motor neuron tremor" is to monitor your activities and decrease or eliminate circumstances that cause you to stress your muscles – and your motor neurons – and trigger a tremor. EPT also decreases with a reduction in muscle activity but may require medication for there to be a significant reduction in tremor that improves your ability to function. Neurologists specializing in movement disorders should be able to make the EPT diagnosis but only if they are aware of the possibility of an underlying “age + polio weakness” tremor.