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Searching for Answers: What We Know About Acute Flaccid Myelitis
Christina Gurnett, MD, PhD discuses the recent outbreak of acute flaccid myelitis and when a pediatrician should refer to the specialists at St. Louis Children's Hospital for this rare but serious condition.
Featured Speaker:
Christina Gurnett, MD, PhD
Christina Gurnett, MD, PhD Areas of Clinical Interest include Pediatric neurological disorders, epilepsy, neurogenetic disorders, musculoskeletal disorders. Transcription:
Melanie Cole (Host): There’s been a sudden rise in cases of a frightening polio-like condition that can leave children paralyzed or with weakened limbs. Here to tell us about it is Dr. Christina Gurnett. She’s a Washington University Pediatric Neurologist and Neurologist in Chief at St. Louis Children’s Hospital. Dr. Gurnett explain a little bit about acute flaccid myelitis. What is it and why are we seeing it?
Christina Gurnett, MD, PhD (Guest): Yeah so acute flaccid myelitis which I will just call AFM for short, is a disorder that affects the spinal cord. It’s something that’s likely been around for a long time, but it really became much more apparent in 2014 when there was an uptick in the number of these cases. Because it affects the spinal cord, it can cause mostly weakness of the arms or legs, but can also cause facial weakness, problems swallowing, problems with eye movements and in worst cases problems with breathing. It has very sudden onset, so the child can be perfectly normal and within a day have these symptoms come on. And overall, we find that this is something that is very, very rare. Only about one million cases have been reported.
Melanie: Wow. Do we have any idea what’s causing this outbreak and why are only children affected?
Dr. Gurnett: That’s a great question. There has been a lot of interest in identifying the potential cause for this. In the past, before we had good vaccination for polio; we knew that cases that happened in the 30s and 40s were due to polio virus. We do think that these current cases are also likely due to a virus, but there has been a lot of controversy as to whether there is one infection that’s causing it or whether these are multiple different viruses. There is still a lot of research ongoing. We do know that enteroviruses of which polio is one have been the causes in the past. There are some new strains of enterovirus including enterovirus D68 that have been spiking and causing some respiratory illnesses around the same time of these occurrences over the last several years, but not all cases have evidence for that infection. In fact, it’s actually a very small number that do. We also know that other viruses including West Nile Virus and adenovirus can cause similar AFM.
Melanie: Are there any confirmed cases in Missouri?
Dr. Gurnett: You know this is kind of changing on a daily basis. We do report our suspected cases from what I most currently know, we have reported two cases probable, but I don’t know that they have been confirmed.
Melanie: So, you said a child could be fine one day and afflicted the next. How is it identified? Tell us about the clinical presentation and what should parents who are bringing their children to the pediatrician and what should pediatricians be looking for?
Dr. Gurnett: This is a great question. So, there – because there has been so much information in the press, families are very attuned to these symptoms. The arm and leg weakness that we see tends to- or facial weakness, tend to come on very quickly and tend to be very severe. These are kids that often can’t move the limb or can barely move the limb or having trouble feeding themselves, getting their hands to their mouths, droopy eyelids, any kind of problems breathing, or swallowing would definitely want further evaluation.
Melanie: So, what are some of the complications and long-term affects of AFM? What can it do to a child?
Dr. Gurnett: Right, so, the kids that we have been seeing again have pretty severe problems with movement. The cases that I have been involved with have almost all needed rehabilitation for many weeks to many months after these episodes. The complications can include death in severe cases where the respiratory problems have not been addressed. Fortunately, with good ICU care and respiratory support most of these kids will survive and actually very few really need the respiratory support. For the most part, they come in with weakness that is pretty maximal when they come in. As part of our diagnostic evaluation to make the diagnosis certainly we would do a brain and spinal cord MRI scan and would require if these signal changes in the spinal cord mostly in the gray matter particularly the anterior horn cells where we would see signal abnormalities in the spine. The other part of the diagnosis would come from a spinal tap to rule out other types of bacterial infections, but if we see pleocytosis including white blood cells counts above 5 or so, then we would also take that into part of the diagnostic criteria for AFM.
Melanie: Speak about treatment and what are some current issues in medical management that you might try once you assess what’s going on?
Dr. Gurnett: Right, so, when we see kids that have this type of abnormality and once we have excluded the possibility of a severe bacterial infection or a bacterial infection that can be treated with antibiotics; often when we are thinking about inflammation of the spinal cord we look to kind of our classic treatments which are potentially steroids, IVIG, plasma exchange, so there are acute treatments that we certainly try in these cases. Again, because they are so potentially heterogeneous in terms of their etiology or of unknown etiology, we really don’t have good treatment trials to know whether any of these treatments are effective. But we know that related disorders can often respond to these treatments. So, typically, we do offer some treatment for these patients. Otherwise, the treatment really is supportive especially with respiratory support if there is weakness in breathing, but also a lot of physical therapy and bracing to help prevent contractures or other complications from not moving over a long period of time.
Melanie: Can it be prevented or is there a way to proactively look to see who might be at risk?
Dr. Gurnett: We are still obviously trying to figure out who is most at risk. We certainly do know that children – and we don’t understand why it predominantly affected children, but the average age has been 4. So, we know that those are the high-risk age groups, but we really don’t know other profiles that put at more of a heightened alert. If you ask these cases almost all of them will have had some recent illness, but often those are mild colds and other viral symptoms that they have had in the preceding week or weeks. As far as prevention, we do hope that people will use common sense in terms of hand washing. We know that this illness is not actually transmissible, but the predisposing prior infection potentially could be prevented with good hygiene, handwashing, although again, these viruses often tend to be lots of places, but we definitely recommend good hygiene. Because some of these cases can be due to preventable illnesses including polio. We do recommend that people maintain and be up to date on their vaccines.
Melanie: That’s a very important point. So, Dr. Gurnett wrap it up for us. What would you like other providers to know about this mysterious rise in AFM and when they should refer to the specialists at St. Louis Children’s Hospital?
Dr. Gurnett: Right, so the good news is that although this is a very serious disorder, it’s relatively rare. We have only seen across the country over the last five years about 400-500 cases. Certainly, if a child comes in with any of these suspicious concerns, we would want to see them early so that we could do these diagnostic tests and hopefully have a better chance of identifying any potential virus that is triggering this type of episode. And then certainly, being at a referral center like St. Louis Children’s Hospital we have lots of additional care and support that we can provide these very sick kids, not only acutely, but also in rehabilitating them and getting them back to their normal life.
Melanie: Thank you so much Dr. Gurnett for joining us today and for sharing for other providers what’s going on with this disease. Because it has been mysterious, and the CDC has printed material about it. Thank you so much for coming on and clearing it up for us. A physician can refer a patient by calling Children’s Direct Physician Access Line at 1-800-678-HELP, that’s 1-800-678-4357. You’re listening to Radio Rounds with St. Louis Children’s Hospital. For more information on resources available at St. Louis Children’s Hospital, you can go to www.stlouischildrens.org, that’s www.stlouischildrens.org. This is Melanie Cole. Thanks so much for listening.
Melanie Cole (Host): There’s been a sudden rise in cases of a frightening polio-like condition that can leave children paralyzed or with weakened limbs. Here to tell us about it is Dr. Christina Gurnett. She’s a Washington University Pediatric Neurologist and Neurologist in Chief at St. Louis Children’s Hospital. Dr. Gurnett explain a little bit about acute flaccid myelitis. What is it and why are we seeing it?
Christina Gurnett, MD, PhD (Guest): Yeah so acute flaccid myelitis which I will just call AFM for short, is a disorder that affects the spinal cord. It’s something that’s likely been around for a long time, but it really became much more apparent in 2014 when there was an uptick in the number of these cases. Because it affects the spinal cord, it can cause mostly weakness of the arms or legs, but can also cause facial weakness, problems swallowing, problems with eye movements and in worst cases problems with breathing. It has very sudden onset, so the child can be perfectly normal and within a day have these symptoms come on. And overall, we find that this is something that is very, very rare. Only about one million cases have been reported.
Melanie: Wow. Do we have any idea what’s causing this outbreak and why are only children affected?
Dr. Gurnett: That’s a great question. There has been a lot of interest in identifying the potential cause for this. In the past, before we had good vaccination for polio; we knew that cases that happened in the 30s and 40s were due to polio virus. We do think that these current cases are also likely due to a virus, but there has been a lot of controversy as to whether there is one infection that’s causing it or whether these are multiple different viruses. There is still a lot of research ongoing. We do know that enteroviruses of which polio is one have been the causes in the past. There are some new strains of enterovirus including enterovirus D68 that have been spiking and causing some respiratory illnesses around the same time of these occurrences over the last several years, but not all cases have evidence for that infection. In fact, it’s actually a very small number that do. We also know that other viruses including West Nile Virus and adenovirus can cause similar AFM.
Melanie: Are there any confirmed cases in Missouri?
Dr. Gurnett: You know this is kind of changing on a daily basis. We do report our suspected cases from what I most currently know, we have reported two cases probable, but I don’t know that they have been confirmed.
Melanie: So, you said a child could be fine one day and afflicted the next. How is it identified? Tell us about the clinical presentation and what should parents who are bringing their children to the pediatrician and what should pediatricians be looking for?
Dr. Gurnett: This is a great question. So, there – because there has been so much information in the press, families are very attuned to these symptoms. The arm and leg weakness that we see tends to- or facial weakness, tend to come on very quickly and tend to be very severe. These are kids that often can’t move the limb or can barely move the limb or having trouble feeding themselves, getting their hands to their mouths, droopy eyelids, any kind of problems breathing, or swallowing would definitely want further evaluation.
Melanie: So, what are some of the complications and long-term affects of AFM? What can it do to a child?
Dr. Gurnett: Right, so, the kids that we have been seeing again have pretty severe problems with movement. The cases that I have been involved with have almost all needed rehabilitation for many weeks to many months after these episodes. The complications can include death in severe cases where the respiratory problems have not been addressed. Fortunately, with good ICU care and respiratory support most of these kids will survive and actually very few really need the respiratory support. For the most part, they come in with weakness that is pretty maximal when they come in. As part of our diagnostic evaluation to make the diagnosis certainly we would do a brain and spinal cord MRI scan and would require if these signal changes in the spinal cord mostly in the gray matter particularly the anterior horn cells where we would see signal abnormalities in the spine. The other part of the diagnosis would come from a spinal tap to rule out other types of bacterial infections, but if we see pleocytosis including white blood cells counts above 5 or so, then we would also take that into part of the diagnostic criteria for AFM.
Melanie: Speak about treatment and what are some current issues in medical management that you might try once you assess what’s going on?
Dr. Gurnett: Right, so, when we see kids that have this type of abnormality and once we have excluded the possibility of a severe bacterial infection or a bacterial infection that can be treated with antibiotics; often when we are thinking about inflammation of the spinal cord we look to kind of our classic treatments which are potentially steroids, IVIG, plasma exchange, so there are acute treatments that we certainly try in these cases. Again, because they are so potentially heterogeneous in terms of their etiology or of unknown etiology, we really don’t have good treatment trials to know whether any of these treatments are effective. But we know that related disorders can often respond to these treatments. So, typically, we do offer some treatment for these patients. Otherwise, the treatment really is supportive especially with respiratory support if there is weakness in breathing, but also a lot of physical therapy and bracing to help prevent contractures or other complications from not moving over a long period of time.
Melanie: Can it be prevented or is there a way to proactively look to see who might be at risk?
Dr. Gurnett: We are still obviously trying to figure out who is most at risk. We certainly do know that children – and we don’t understand why it predominantly affected children, but the average age has been 4. So, we know that those are the high-risk age groups, but we really don’t know other profiles that put at more of a heightened alert. If you ask these cases almost all of them will have had some recent illness, but often those are mild colds and other viral symptoms that they have had in the preceding week or weeks. As far as prevention, we do hope that people will use common sense in terms of hand washing. We know that this illness is not actually transmissible, but the predisposing prior infection potentially could be prevented with good hygiene, handwashing, although again, these viruses often tend to be lots of places, but we definitely recommend good hygiene. Because some of these cases can be due to preventable illnesses including polio. We do recommend that people maintain and be up to date on their vaccines.
Melanie: That’s a very important point. So, Dr. Gurnett wrap it up for us. What would you like other providers to know about this mysterious rise in AFM and when they should refer to the specialists at St. Louis Children’s Hospital?
Dr. Gurnett: Right, so the good news is that although this is a very serious disorder, it’s relatively rare. We have only seen across the country over the last five years about 400-500 cases. Certainly, if a child comes in with any of these suspicious concerns, we would want to see them early so that we could do these diagnostic tests and hopefully have a better chance of identifying any potential virus that is triggering this type of episode. And then certainly, being at a referral center like St. Louis Children’s Hospital we have lots of additional care and support that we can provide these very sick kids, not only acutely, but also in rehabilitating them and getting them back to their normal life.
Melanie: Thank you so much Dr. Gurnett for joining us today and for sharing for other providers what’s going on with this disease. Because it has been mysterious, and the CDC has printed material about it. Thank you so much for coming on and clearing it up for us. A physician can refer a patient by calling Children’s Direct Physician Access Line at 1-800-678-HELP, that’s 1-800-678-4357. You’re listening to Radio Rounds with St. Louis Children’s Hospital. For more information on resources available at St. Louis Children’s Hospital, you can go to www.stlouischildrens.org, that’s www.stlouischildrens.org. This is Melanie Cole. Thanks so much for listening.