What it's like to have polio, and how it spreads
Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be The Informed Patient with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Polio can be a disabling and life threatening disease, and it spreads easily from person to person. Many people who are infected don't have visible symptoms, but the virus can infect a person's spinal cord and cause paralysis. And some people deal with something called Post Polio Syndrome later on in their lives. Today I'm speaking about the effects of polio with Dr. Jenny Meyer. She's an assistant professor of neurology at Upstate. Welcome back to "The Informed Patient," Dr. Meyer.
Jenny Meyer, MD: Thanks for having me, Amber. It's really nice to see you guys again.
Host Amber Smith: Polio is back in the news because a case of polio left a person paralyzed in downstate New York and the discovery of polio virus in the New York city wastewater. But the polio virus has been around for centuries. Can you tell us when and how it was discovered or first identified?
Jenny Meyer, MD: So I recently was looking at some literature from the BBC, who did a news article about this, and actually, I did not know this, but apparently polio was even depicted in hieroglyphics in Egypt. There are drawings of humans with deformed limbs walking with canes in hieroglyphics. So apparently it's been around a very, very long time. but I believe it was first identified sometime in the early 1900s. and I believe it was found in the spinal fluid of humans that they had then injected into animals. And then the animals would get a polio like syndrome, and that's how they determined it was an infectious material. But I believe it was after the electron microscope was invented that they actually saw polio, because it's a virus, so it's very small.
Host Amber Smith: It just hasn't been something we've been concerned about in recent years, or recent decades, even, in America, so it's back in the news, all of a sudden. Why is that?
Jenny Meyer, MD: Well, unfortunately, I think it's because of the movement to avoid vaccination in children. In some areas of the world, this remains an endemic illness, specifically Sub-Saharan Africa and in areas of Asia where they don't have adequate medical facilities to keep vaccination materials available for populations. And so, in many areas of the Second and Third World, this is still a virus that is very real and part of life. In the US, we've thankfully been all, mostly, vaccinated for the last 20 to 30 years, since about the 1950s, when the vaccine became mainstream. And therefore, many of us have never seen polio in our daily lives, and therefore, I think we've forgotten about it.
Host Amber Smith: Now from what I understand, a small portion of people with a poliovirus infection will develop serious symptoms, either meningitis where the brain or the spinal cord is infected, or paralysis where their arms or legs become weak or immobile. For meningitis, it's up to five people out of 100. And for paralysis, it might be as many as one out of 200. So it's a fraction of those who are infected with polio who may develop more severe cases, is that right?
Jenny Meyer, MD: That is correct. Most people who experience polio, would have had a GI (gastrointestinal) illness that probably resembled the common stomach bug. So it's one of those viruses that's very contagious because people don't get that sick. So they may not stay home very long. They may not realize they're still contagious and go out into the community and use a public bathroom or go to a restaurant and not adequately wash their hands for 30 seconds under hot water with soap. These are things that we all take for granted, and that's how many of the viruses are spread, you know.
Host Amber Smith: Are there simple tests like we have for COVID that tell whether a person is infected with poliovirus?
Jenny Meyer, MD: I don't know how available the testing has been in the past, because it's been something that we haven't had to do very often. I do know that there are tests. They test stool, and they test blood for the PCR, which is where they look for the DNA of the virus. I know that in my practice, the time that we are looking for polio is usually when someone has an acute paralysis.
Host Amber Smith: But there's nothing over the counter. Someone can't go to the drug store and get a test like they could for COVID?
Jenny Meyer, MD: No, no, it's nothing over the counter, as far as I know.
Host Amber Smith: Now, once poliovirus infects a person, how does it get -- because it's in the GI system, right? -- how does it get into the brain or the spinal cord?
Jenny Meyer, MD: Well, your GI system is highly connected to your bloodstream because that's where all your nutrients come into your body. So the blood-GI barrier is very weak. So the poliovirus can get into the bloodstream, and then it becomes a systemic infection. So it basically goes wherever blood goes. Polio tends to be a neurotropic virus, which means it likes nerves. So it goes into the blood-brain barrier and tries to penetrate that and enter the spinal cord and motor neurons, which are the nerves that control your muscles.
Host Amber Smith: So once it's in the spinal cord or the nervous system, are there symptoms that would tell a person that they've got a problem?
Jenny Meyer, MD: It's actually painless, from what I understand from people who've had it. However, it does cause weakness, and it can cause some mild headache because there is some irritation of the lining of the the nervous system called the meninges, so meningitis. But the limbs, people don't experience painful limbs. It's more of just a slowly progressive weakness that can develop, or they can develop mild headache, a little bit of neck stiffness, symptoms that you might experience with flu. So you might not think that much about it. Any of us who've had the flu can say, "you know, I feel like I don't want to get off the couch. I feel like I got hit by a truck," that kind of body ache. Fever would be something that may or may not develop. And it's usually over a course of a few days, days to a week, this paralysis would occur or these symptoms would occur, and in the extreme case, cause paralysis.
Host Amber Smith: So is the body's immune system working to fight the poliovirus, even after it has invaded, if it does invade the nervous system, or is it inevitable that the person's going to develop paralysis?
Jenny Meyer, MD: The immune system kicks in as soon as it hits the bloodstream. Thankfully in your blood, you have immune cells that float around, and when they encounter these foreign viral particles. If they've seen them before, they can recognize them and start fighting right away. So if you've been vaccinated, it's very unlikely you would develop neurologic symptoms from it because your immune system is already in tune to "this is a foreign protein. It's not supposed to be here. Let me activate and get started on fighting this off." However, if you haven't been vaccinated, your immune system may not know what that protein is, and it may take longer for it to develop the mechanisms to start fighting off the infection, which is why people who are unvaccinated are more vulnerable to these severe side effects.
And certainly before the vaccine existed, that is why those, you quoted those numbers earlier about the statistics of the neurologic symptoms. Because if you didn't have immunity, some people's immune systems are better than others and may not recognize right away that the protein is foreign. By the time it kicks in, it's already spread to the nervous system, which is where it likes to live, and causes damage to those nervous tissues. And unfortunately, nervous tissues are one of the few tissues in the body that don't heal very well, which is why the Post Polio Syndrome and some of the after effects of having polio -- which is actually different than Post Polio Syndrome -- but people can develop permanent neurologic side effects from just having the virus in the first place. And that could last their whole lives.
Host Amber Smith: Some older adults who had polio as young children may develop muscle weakness and joint pain and fatigue decades later. How do you go about determining if that's caused by Post Polio Syndrome, or something else?
Jenny Meyer, MD: So Post Polio Syndrome is essentially a disease that you have to rule out other causes. It's very scary because usually these are people who had polio as a child, recovered over the course of a year or two years, maybe has some permanent deficit to begin with, but for the most part feels back to normal. I'll put that in, like, air quotes "back to normal," because they've recovered to the point where they're now living some sort of normal life, whether that's working or, doing a sporting activity or something that makes them feel like they're at baseline. Then, sometime in their 40s, 50s, they might notice things are just slowing down, and it's very gradual. They just feel more tired. They have less energy. Things just seem a little harder. Walking up stairs takes a little longer. Maybe they feel a little unbalanced, and they have to hold onto the railing. Gradually over the course of a couple of years, people notice some changes in their abilities, and usually it takes some time for them to find their doctor to ask about these, because most of my patients will say "I'm old," in air quotes, and that's why they feel this way.
Once they arrive to the doctor, the doctor would certainly interview them about their prior history. And once you've determined that they've had polio in the past, even if they weren't very sick from it, it is sometimes a clue that this is something that could have happened to them. Unfortunately it's a diagnosis where you have to rule out other things. So they often undergo MRIs, nerve conduction studies, electromyography. Sometimes they do physical therapy. And after everything they've done, if nothing seems like it's getting better and we can't find the cause, this is the diagnosis that we give them.
It's primarily a motor disease. They don't often have much pain. Although I will say that the joint aches and pains are often something that people will complain about with this, because if your muscles are weaker, they don't support your joints as well. So your tendons undergo more stress, and things just don't feel quite as easy as before. The other thing that many patients with postal syndrome complain about is fatigue, which is a very hard thing to measure. I mean, my tired level versus your tired level on any given day might fluctuate. There's not really good scales to measure the subjective experience of being tired. But patients constantly tell me that if they could take one thing away, it would be their tiredness because it doesn't seem to matter how much they sleep. They just feel tired. And I think that's actually muscle fatigue that they feel. Their muscles don't want to move. They can't move them as easily. And everything is more effortful, so that overall experience of needing more energy to just do the most basic things is what they're expressing.
Host Amber Smith: So, this being a motor disease, what do you do to treat it? You mentioned the fatigue. Is there a medication that will give people a little more energy back?
Jenny Meyer, MD: Unfortunately, no. There's been many research studies in the past, trying to determine what we can do for these people. And there are two theories of why this disease happens, which I can get into a little later. But to specifically answer your question, the main area of treatment right now is supportive care, which means teaching people exercises to help them use their joints and limbs in a way that's safe so that they don't injure them further; helping people maintain their energy levels by taking time, whether that means stopping their job, whether that means taking breaks between activities so that they can have the energy to do what they want to do; providing equipment for them so that they can actually do the types of jobs or activities that they want to do, whether that's power mobility devices, handicapped stickers for their cars, canes, walkers. Orthotics are often used to help support, specifically like weak ankles or weak knees. Those types of things are really the areas that we use right now to manage Post Polio Syndrome.
So it's better to never get the disease, than to get the disease.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with Upstate Medical University neurologist, Dr. Jenny Meyer about how the poliovirus affects the nervous system. So If you're an adult who had polio as a child, are there things you can do to prevent the development of Post Polio Syndrome?
Jenny Meyer, MD: This is another area of research. We don't really know why the disease recurs, or why it comes out in late aging. There's two different academic theories of why this is happening. One is that it's a decompensation of damaged neurons over time, due to aging, which certainly no one has control over how fast they age. Their body is aging at the same rate as everyone else. And whether you started out perfect, or you started out with some damaged neurons really depends on whether you got polio in the first place. As opposed to the other theory, which is that it's an immune response, and that it may be some type of autoimmune disease where polio gets reactivated and causes further damage, which is a target of some research studies to use medications for autoimmune diseases to try to suppress the immune system, to prevent the reactivation of polio.
Unfortunately, the research studies that I know about have not well elucidated these two theories. And so they remain theories at this time. And the treatments have not followed that because they have not elucidated the true cause.
Host Amber Smith: What are the late effects of this? If someone is determined to have it, what's likely to happen?
Jenny Meyer, MD: So usually they'll experience weakness in a new limb. So many people after polio may have one limb or maybe two limbs that were weaker to start with because they didn't 100 percent recover from polio. But it's really defined as weakness in a new limb. And there's actually specific criteria that we use in medical research for Post Polio Syndrome. It's part of the March of Dimes. It's called the March of Dimes criteria. And that is a definition saying that you don't have any other found cause for your weakness, it's involving a new limb that wasn't involved originally in your polio, and that it is a gradual onset of weakness over time. And those basically three main criteria are the foreground of designing who meets that.
Going forward from that, the rate of decline is variable. So some patients who maintain a low impact frequent exercise program can often maintain their strength, despite having Post Polio Syndrome in those weak limbs. But it's really key to work with a therapist that knows about Post Polio Syndrome because certainly you wouldn't want to do, like, a marathon level training if you've had polio in the past, because you don't want to create any additional damage to the muscle tissue. Because those neurons are already struggling. And those muscles are dependent on those struggling neurons. So we want to make sure that we maintain what we have as long as we can, and we support the joints that are involved so that they don'y deteriorate further. Because another big thing is rotator cuff tears, knee injuries, falls. These are things that certainly greatly impact someone's quality of life and their longevity. Hip fractures, for example, we know in the elderly can cause a major cause of mortality. So the big thing is preventing the injuries that can occur because of the weakness.
Host Amber Smith: You mentioned the March of Dimes. Can you tell us a little about that organization?
Jenny Meyer, MD: From what I know, the March of Dimes was founded during FDR's presidency. And it was a nonprofit group that was created to raise money to support mothers and children. Their main goal at that time was to support vaccination for polio because it was at that time endemic. And there was a significant amount of disability associated with having a child that had had polio. And also, there was a big push for the public health to support vaccination. So I believe that the name March of Dimes came about because there was a campaign where they asked people to donate 10 cents, or a dime, toward polio research. Just as you might see a bucket in your barbershop raising money for St. Jude (Children's Research Hospital,) this was how they raised money for polio research. The March of Dimes criteria is a criteria created because of the funding from the March of Dimes used for research for polio, and that's where the name comes from.
Host Amber Smith: So beyond maybe being a little more susceptible to injury, does Post Polio Syndrome put a person at higher risk for other medical conditions?
Jenny Meyer, MD: As far as I know, no. I might be proven wrong if they determine that it's an autoimmune disease, which may later on impact their immune system's ability to fight off other viruses. But I think as of right now, we haven't elucidated that fact yet that it necessarily increases your risk of heart disease, GI illnesses, other infections. I think at this point it does increase your risk of orthopedic injuries. It certainly increases your risk of disability from being unable to maintain your activities of daily living -- brushing your teeth, toileting, showering. These are things that most people don't think about as challenging, but if you can't lift your leg up more than two inches, getting over that tub rail is pretty hard.
Host Amber Smith: So we talked about how it's just a small fraction of people who are infected with polio that develop paralysis or meningitis. If a person had a mild case as a child, or maybe they even had it without knowing it, are they still at risk for developing Post Polio Syndrome?
Jenny Meyer, MD: Yes, they are. Anybody can develop Post Polio Syndrome, even if their polio was mild. Unfortunately, because of the fact that this is a lesser known illness now, because of the fact that we have almost essentially eradicated it in the US, I would say many providers are probably unaware of this possibility. And certainly it's only been in my experience, people who lived prior to vaccinations. So my post polio population is largely in their 70s or grew up in a country where there were no vaccinations available, if they're under that age.
Host Amber Smith: So that means maybe we should pay really good attention to the polio threat that is emerging today. What can people do now to protect themselves from possibly becoming exposed to this polio virus that's been recently detected?
Jenny Meyer, MD: First of all, I would say, talk to your doctor. Certainly if you are not sure about your vaccination status, whether or not you were vaccinated, asking them to check you for titers to see if you have the immunoglobulin against polio. And if your vaccination status has waned, getting a booster would certainly be the first step. Areas where I would say probably require more attention would be pregnant women, because certainly if you're carrying a new person, you want to make sure that you're giving them those immune globulins through your milk when they're first born so they can be protected, because they're not going to be able to wash their hands or deal with the spread from other humans. Certainly I would say if you live in an area where you are very closely affiliated, so college students, military personnel, anywhere where you're going to be living very close quarters with other people and using shared bathrooms, I would say checking your vaccination status and getting boosted is a reasonable place to start.
And then children, if the children have been unvaccinated because of whatever reason, certainly you can always change your mind as a parent. If you made a decision when your child was young and said, "you know, I didn't want to get my kid vaccinated, but now that I realize this is something that maybe is a real threat again," you know, you can change your mind, and your pediatrician will understand.
Host Amber Smith: Well, Dr. Myer, thank you so much for making time for this interview.
Jenny Meyer, MD: Thank you guys for having me. It's been a pleasure.
Host Amber Smith: My guest has been Dr. Jenny Meyer. She's an assistant professor of neurology at Upstate. "The Informed Patient" is a podcast covering health, science and medicine brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at Upstate.edu/informed. This is your host, Amber Smith, thanking you for listening.