 Richard L. Bruno
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Richard L. Bruno is chairperson of the International Post-Polio Task Force and director of The Post-Polio Institute at Englewood Hospital and Medical Center. Please e-mail questions directly to him at ppsforum@newmobility.com.
Note: This column is for information purposes only and is not intended as a substitute for professional medical advice.
Q: I had polio with weakness in my left leg. I recovered and carried on a normal life until the early 1990s when I started to have fatigue, heart palpitations, skipped beats and low blood pressure, especially after I eat. Should my doctor be considering any tie-in with polio?
A: Oh, yes! Fifty years ago polio pioneer David Bodin discovered that every polio survivor had some poliovirus damage to neurons in the brain stem, the so-called "bulb" of the brain. When brain stem damage was severe, the diagnosis was "bulbar" polio--whose best known symbol, the iron lung, was needed when brain stem breathing-control neurons stopped working. But the most common symptom of "bulbar" polio was trouble swallowing, not trouble breathing. Some "bulbar" polio patients also had severe difficulty controlling their blood pressure and heart rate.
The damaged brain stem neurons that are responsible for these symptoms control the vagus nerve, which carries commands from the brain stem to activate muscles in your throat, esophagus, stomach and intestines. It also controls your heart rate. But the vagus nerve is a two-way street, since it "listens" to activity in the gut and sends that information back up to brain stem neurons.
Vagus damage that disrupts the normal functioning of the gut may explain our Post-Polio Survey findings that swallowing difficulty, diarrhea, colitis, ulcers and constipation are as much as six times more common in polio survivors than in nondisabled individuals. And the symptoms you describe may result from poliovirus damage to the vagus as well as to brain stem blood pressure and heart rate control neurons.
We have a growing number of post-polio patients who feel exhausted after a meal. When their stomachs fill with food, the vagus is apparently overstimulated and triggers a drop in blood pressure, causing feelings of fatigue and sometimes palpitations. Polio survivors have also been reporting another problem: food sticking in the upper esophagus. We think this is due to the vagus not stimulating esophagus muscles to move the food downward. When food gets stuck, irritation triggers a painful esophagus muscle spasm that also stimulates the vagus nerve, causing blood pressure to drop and the heart to race or to slow.
Although blood pressure drops, our patients don't faint, a finding consistent with our 1995 Post-Polio Survey discovery that polio survivors do not faint any more frequently than nondisabled folk. However, the survey did find that those who had fainted only once in their lifetimes reported significantly more daily fatigue than those who had never fainted. This suggests that damage to brain stem blood pressure control and vagus neurons may be coupled with poliovirus damage to bulbar "brain activating system" neurons, those which our laboratory research suggests are responsible for post-polio brain fatigue.
The relationship between fatigue, brain stem damage and low blood pressure links polio survivors to another bunch of very tired folk: those with chronic fatigue syndrome. About one quarter of CFS patients have fatigue that is associated with low blood pressure or increased heart rate. Some CFS patients report fatigue when a hot shower or hot room causes blood pressure to drop, as do about one third of polio survivors. Other CFS patients have blue feet, just like our patients' "polio feet," suggesting that blood pooling in the legs contributes to low blood pressure.
Polio survivors should have a doctor take their blood pressure and heart rate lying, sitting and--if possible--standing. Anyone having fatigue associated with a drop in blood pressure or a slowed or racing heart needs to see a cardiologist who treats low blood pressure. Compression stockings--which push blood back toward the heart--and medications that increase the fluid in your blood or stop blood from pooling in the legs, can be helpful. If fatigue follows eating, try consuming frequent, small, higher protein meals--they can prevent the stomach from getting too full and stimulating the vagus.
Polio survivors having trouble swallowing should see an ear, nose and throat doctor. Eating smaller bites of softer foods and washing down each bite can prevent food from sticking in the esophagus. For those who still have a sticking problem, a low dose of the muscle relaxant Klonopin taken 30 minutes before eating can prevent muscle spasms and help food slide down.
I'd appreciate hearing from polio survivors who are having any these symptoms.
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