PediaCast 169 * Pseudotumor Cerebri
Today on PediaCast Dr. Mike discusses the condition Pseudotumor Cerebri with special guest Dr. Shawn Aylward, a pediatric neurologist at Nationwide Children's Hospital.
Dr Shawn Aylward
Announcer 1: This is PediaCast.
Announcer 2: Welcome to PediaCast, a pediatric podcast for parents. And now, direct from the campus of Nationwide Children's, here is your host, Dr. Mike!
Dr. Mike Patrick: Hello, everyone, and welcome to another episode of PediaCast. It is Episode 169 for July 7th, 2011 and we are calling this one 'Pseudotumor Cerebri'. Now, I realize it's a big word, but we're going to break it down. Dr. Shawn Aylward is a pediatric neurologist here at Nationwide Children's, he's in the studio, actually, and we're going to talk about that.
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Now I know we've had a whole lineup of interview shows here, and as I mentioned before, we had some that were rescheduled and that's the reason for that, but next week we have a News Parents Can Use episode coming your way, and then a listener question episode will be coming up soon after that. So keep those questions rolling in. We always appreciate hearing from you.
All right, we're going to turn our attention now to our studio guest. Dr. Shawn Aylward is an attending physician in the Division of Pediatric Neurology at Nationwide Children's Hospital and he's an assistant professor of Pediatrics at the Ohio State University College of Medicine.
Dr. Aylward completed his Pediatric Residency and Neurology Fellowship just down the road from us at Cincinnati Children's Hospital Medical Center. His clinical interests include epilepsy and pseudotumor cerebri, which is the topic of our show today.
Welcome to the program, Dr. Aylward.
Shawn Aylward: Thank you. Thank you for having me.
Dr. Mike Patrick: So you just trained in Cincinnati not too long ago, and prior to that you went to medical school at Southern Illinois University School of Medicine. So where's home? Where did you grow up?
Shawn Aylward: I grew up in Central Illinois.
Dr. Mike Patrick: So are you a Fighting Illini fan? Or you don't really follow Big Ten stuff?
Shawn Aylward: Sort of.
Dr. Mike Patrick: Or are you a Buckeye fan now?
Shawn Aylward: Becoming one.
Dr. Mike Patrick: By transplant. It's kind of hard not to get into the Buckeye spirit when you live in Columbus.
Shawn Aylward: Yes, it's very hard.
Dr. Mike Patrick: So you've been here since last Fall or so here in Columbus.
Shawn Aylward: Yes.
Dr. Mike Patrick: How are you finding the community?
Shawn Aylward: I like it. I like it. It's a good community. We're getting accustomed to it.
Dr. Mike Patrick: I had lived here previously, and then we were down in Orlando, and this 4th of July, there's just been so many things that we did. We went to a couple concerts, we went to Red, White and Boom downtown, actually, at Huntington Field, so it wasn't too crazy, and then saw the fireworks in Hilliard as well. There are so many festivals and things going on and you get this impression, well, you lived in Orland before, how can Columbus be exciting? But it is.
In Orlando, there were so many big, mega-theme parks, there weren't these little festival things and concerts. I don't know, it's a whole different feeling. Not to make the people in Orlando who are listening to our show feel bad, but just because you have the big theme parks doesn't mean the rest of us don't have fun when we live somewhere else.
Shawn Aylward: Yes. There's plenty to do in Columbus.
Dr. Mike Patrick: Yeah, there really, really is.
OK, we're going to talk about pseudotumor cerebri. I guess, if you could just start out by defining for our listeners just in basic terms what that is and what that term means.
Shawn Aylward: Well, there's actually two terms for it. 'Pseudotumor cerebri' is the more common one. The other one, 'idiopathic intracarnial hypertension' is the other term that it goes by. What that means, basically, it's a condition in which the patient's spinal fluid, the pressure inside the skull, is higher than it should be, which then causes the symptoms of pseudotumor cerebri.
Dr. Mike Patrick: So pseudotumor, 'pseudo' would be like a tumor.
Shawn Aylward: Yes.
Dr. Mike Patrick: There's not really a tumor there, just acting like one.
Shawn Aylward: No, that goes back to before we had the luxury of CAT scans and MRIs. The patients have similar symptoms to someone that does have a tumor inside of their skull, but obviously in this condition, since it's pseudotumor, there actually is no tumor.
Dr. Mike Patrick: The 'cerebri' part is just cerebrum, brain, inside the skull.
Shawn Aylward: Yes.
Dr. Mike Patrick: And then the other term for it, idiopathic intracranial hypertension, 'idiopathic' means we don't really know why, 'intracranial' inside the skull, and 'hypertension' means too much pressure.
Shawn Aylward: Yes.
Dr. Mike Patrick: That makes sense. So it's too much pressure inside the brain, and we don't know exactly for sure why.
Shawn Aylward: Yes.
Dr. Mike Patrick: How common is this condition?
Shawn Aylward: Well, if you look at the literature, it's more widely reported for the adult population. The classic patient is listed as a middle-aged obese female is the more common patient demographic that we find. In the general population, it's reported around 0.9 per 100,000 patients.
If you focus just on pediatrics, the incidence isn't as well-recorded. Our own observations in our clinic, we see kind of two peaks.
We see a pre-pubertal peak usually around age three to five. Those are usually equally affected between male and female, and usually weight is not an issue. The other peak we see is the post-pubertal patient, which usually is going to be more common with the adult demographic, so usually more common in females. It's usually about four to one female to male ratio, and those patients' weight usually is an issue.
Dr. Mike Patrick: Just our last episode we talked to Dr. Katie Koranyi, she's an infectious disease specialist here, about hand-foot-mouth disease, so we covered something really common. This is something that, in the general population, we're talking about one in 100,000 people, and child-bearing women who are obese are the biggest population affected, and yet we're talking about it here on a pediatric podcast.
But it's something we do see. I know when I work in the emergency department here, we do see kids who come in with it, and of course we have a big referral base. But it's something still that parents, I think, should be aware of out there, and it's kind of an interesting thing, too.
What about associations with other things? You can say, well, it just happens on its own, but medications or health problems that can sort of go along with pseudotumor cerebri?
Shawn Aylward: There are some medical conditions that we do see that our patients with pseudotumor do have, again, obesity being the most common. It's usually a recent weight gain within the last six to 12 months that we see.
Other conditions that we see it with, thyroid problems, we can see it with pregnancy. Polycystic ovarian syndrome is another common one. Again, that usually is more of a weight issue that's associated with that. Kidney transplants, sometimes we'll see it with it. Those are the main medical conditions.
In terms of medications, the cyclines, so tetracycline, metacycline, a lot of the common medications for acne that are given. Growth hormone, Synthroid, the thyroid medications, as well as steroids are the most common medications that we see that cause it.
Dr. Mike Patrick: So we have this condition where you have kids who, like a tumor, they have increased pressure inside of their brain. Even though the exact causes is not known, are these some ideas or thoughts about what could be happening here?
Shawn Aylward: Yeah. The kind of thought is that there's a decreased reabsorption of the spinal fluid. Everyone produces and reabsorbs the spinal fluid day in and day out, and the thought is that that balance is off, more so because of the reabsorption. But the exact cause is not really clear.
Dr. Mike Patrick: Sure. So the cerebral spinal fluid or CSF, and we do have some listeners out there who are in the medical field, doctors and nurses and residents and such, for the parents out there who may not really be familiar with that, what exactly is cerebral spinal fluid?
Shawn Aylward: It's a fluid that your body makes that surrounds your brain and your spinal cord. It delivers nutrients. It also acts as a protective effect, kind of cushions the brain and the spinal cord, and helps in that nature.
Dr. Mike Patrick: So we've got this fluid in the brain and it's a shock absorber, helps with nutrition of cells, and it's being produced at a certain rate, and then in its normal cycle as it gets made, but then it gets absorbed into the bloodstream, so the problem seems to be more, we think, with the absorption of it. You're making it but it's not getting absorbed, so you're making too much of it. You have too much spinal fluid, and that's why we get the increase?
Shawn Aylward: It's not that you're making too much. It's just that you're making too much compared to how much you're absorbing.
Dr. Mike Patrick: Right. So you're making the right amount but it's not getting absorbed properly, so that results in an excess which causes the increased pressure.
Shawn Aylward: Yes.
Dr. Mike Patrick: Is there a genetic predisposition to this?
Shawn Aylward: There's thoughts of that, but it's not really clear, because not every obese patient gets pseudotumor. It's not really clear.
Dr. Mike Patrick: You don't necessarily see it running in families.
Shawn Aylward: Exactly.
Dr. Mike Patrick: So we have an increased amount of cerebral spinal fluid, and that causes pressure inside the skull. What signs and symptoms, then, does that lead to? How do we see it in terms of the clinical picture?
Shawn Aylward: In terms of symptoms that the patient will describe, the most common scenario that we see is a new onset of a daily pulsatile type of frontal headache. The patient will usually say that it's worse when they're lying down or in the morning. Certain maneuvers that will increase the intracranial pressure in general such as coughing, the Valsalva maneuver, which is bearing down like you're going to have a bowel movement, or even just bending over can worsen the headache.
Some patients describe a tinnitus type of symptom. They describe a whooshing or a ringing sound in one or both ears. Some people will describe what we call a 'transient visual obscuration' which means that they have very brief periods where they lose their vision. Some patients will also describe visual loss or even that their vision is not what it should be, blurry vision, double vision, things of that nature.
In terms of what the physician will see, in terms of a neurologic exam, it's usually normal, with the exception being that sometimes we can see some cranial nerve issues, so the eye doesn't move as well as it should or as fully.
The eye doctor, the ophthalmologist, when they look, they can see swelling of the actual optic nerve, which is a nerve in the back of the eye that allows you to see. They can also sometimes see visual acuity differences, so maybe they need to have glasses or have their glasses changed. They can even see evidence of visual loss.
Dr. Mike Patrick: Great. Now, that said of symptoms, then, the headaches, the visual disturbances, are there other things, then, obviously that parents need to be aware of? It sounds like something a lot of kids could have as an issue, maybe not to the extreme where you're seeing flashes of light or you're losing vision, but certainly having frequent headaches, there are other things that can do that, so as doctors, we talk about the differential diagnoses of that set of signs and symptoms, what other things would we be worried about?
Shawn Aylward: Yes. Unfortunately, all those symptoms are very common for multiple different diseases. Pseudotumor cerebri is actually what we refer to as a diagnosis of exclusion, meaning we have to rule out all the other issues first, one we've already touched on being a mass or tumor inside the skull, which is probably the one that we worry about the most.
But other conditions that we see that have similar symptoms, infections, meningitis, encephalitis. Lime disease will cause similar symptoms. Trauma, so someone gets hit in the head, they can have similar symptoms. Actually, the headache syndrome sometimes have very similar stuff; migraines, tension headaches, medication-overuse headaches will have some of the similar symptoms.
Hydrocephalus, which is when you're producing too much of the spinal fluid so you have extreme excesses of the spinal fluid, can cause it. Sinus venous thrombosis, which is a blood clot in the venous system in the skull, can cause similar symptoms.
And then just more specific with the actual swelling of the optic nerve. There is a term called 'drusen' which is when you have calcium deposition in and around the optic nerve that can cause that. Some people are born with abnormal optic nerves that can look like swelling but actually are not. Optic neuritis, which is an inflammation of the optic nerve, or even optic nerve ischemia can look very similar.
Dr. Mike Patrick: How does the workup proceed, then, in terms of differentiating pseudotumor cerebri with those other things?
Shawn Aylward: Well, the initial workup usually is that they see an eye doctor. They do a dilated exam, look at the optic nerve, see is it swelling, is it not swelling.
They also do tests to look at the visual acuity, to look at the visual fields to see if there's any vision loss. They can also do an ultrasound of the eye, which will help with the drusen, the calcium deposition, it will help with that. It can also show subtle swelling of the optic nerve as well.
Then, typically the patient is referred for imaging of the head, usually a CAT scan initially, but sometimes they actually get the MRI first, which, there's no right or wrong for which one's done first, and that rules out the main concern of a mass inside the skull. If all of that comes back normal, then the patient typically undergoes a lumbar puncture.
Dr. Mike Patrick: Before we get to that, with the imaging, if they went straight to MRI, do you still need a CAT scan?
Shawn Aylward: No.
Dr. Mike Patrick: So MRI would be sort of definitive, just it's a better picture, basically.
Shawn Aylward: Yes, it's a better picture. A lot of times, the patients obtain the CAT scan first because it's obviously quicker.
Dr. Mike Patrick: Yeah, it's easier to schedule.
Shawn Aylward: It's more readily available.
Dr. Mike Patrick: Right.
Shawn Aylward: Yes, exactly.
Dr. Mike Patrick: So the lumbar puncture then, tell us about that.
Shawn Aylward: Basically, we unfortunately have to stick a needle into the patient's back. We have to get it into the spinal fluid that's based around the spinal cord, and what we do there is we look at the opening pressure so we actually can measure the pressure of that fluid to see, is it high, is it normal, or where does it fall. We also will then take some of the spinal fluid and send it to the lab to rule out an infectious process that's going on.
Dr. Mike Patrick: Let's say you're a parent and you don't have access to a major children's hospital right down in the next suburb over, let's say, so you're kind of far away from one. It's easy enough to send someone to an ophthalmologist and have them look at the eyes. Your local hospital probably can do a CT and an MRI.
Even though pediatricians do lumbar punctures, especially in babies, from a technical standpoint, getting an opening pressure and doing it right, it's not necessarily an easy thing to do, is it?
Shawn Aylward: It's not. It does take some training.
Dr. Mike Patrick: If it's not something that you're used to doing.
Shawn Aylward: Yes.
Dr. Mike Patrick: So what do you recommend, if a physician out there has a patient and they're worried that this could be going on, what do they do?
Shawn Aylward: Well, they can refer to Nationwide Children's would be one option, or a local children's hospital, some place that is capable of checking the opening pressure, because that really is the definitive diagnosis for this condition.
Dr. Mike Patrick: So they could call the children's hospital that's closest to them, or Nationwide Children's, and talk to a neurologist who's on-call, and then kind of arrange things from there. Great.
Let's say that you've done the eye exam, maybe there is a little bit of evidence of swelling or papilledima, as we call it, the MRI's normal, the LP gets done, and they have a high opening pressure and there's no sign of meningitis. So you determine this is looking like pseudotumor cerebri. How do you go about treating it?
Shawn Aylward: The treatment, first of all, if one of the conditions that predispose it that we had talked about are found, so medication or weight or an issue, then we obviously try and resolve those. So if weight's an issue, weight loss medication, we usually recommend stopping if at all possible.
And then, we typically opt for what we call medical management first, so we try medications. We have a set of three medications that help to decrease the amount of spinal fluid that you produce to help bring you back into that balance of production versus absorption to help reduce the pressure.
If that does not work, then we do have two surgical interventions that we do perform. Actually, we don't, but we have specialists that do perform it.
The first would be an optic nerve sheath fenestration, which is done by an eye surgeon. Basically, they go in and they make tiny slits in the covering of the optic nerve to help get the pressure off of the optic nerve to reduce the visual problems.
Dr. Mike Patrick: Would that help the headaches, too?
Shawn Aylward: That typically doesn't help the pain as much. That's more of a…
Dr. Mike Patrick: Just sight-saving kind of…
Shawn Aylward: Yeah, to protect the vision.
The other option is a ventriculoperitoneal shunt, which is the same type of shunt that they use in hydrocephalus. That's obviously put in by a neurosurgeon. That one actually is better to help with the pain component, but it also does protect the vision because it does decrease the pressure overall.
Dr. Mike Patrick: So this is a plastic tube that they insert into a ventricle inside the brain where sort of a reservoir of cerebral spinal fluid, and then they tunnel it under the skin, and basically it comes down, goes into the peritoneum, which is the abdominal cavity, to drain the fluid off that way.
Shawn Aylward: Yes.
Dr. Mike Patrick: All right. Do most people, in your experience with pseudotumor cerebri, what percentage would you just guess end up needing a shunt?
Dr. Mike Patrick: We won't hold you to the… I mean, is it half, is it less than half, more than half?
Shawn Aylward: It's less than half.
Dr. Mike Patrick: Less than half.
Shawn Aylward: It's less than half the patients. A majority of our patients, we can manage medically.
Dr. Mike Patrick: How many of them can you manage, like through weight loss or through…?
Shawn Aylward: We typically don't focus on just weight loss. Usually we'll do correction of the offending issue, medication or weight loss, in addition to the pharmacologic.
Dr. Mike Patrick: So you want to get the pressure down as quickly as possible, but then perhaps you could do something with the weight loss or stop the offending agent, and then wean them off of the medical?
Shawn Aylward: Yes, because the weight loss and the medication, those are going to take time.
Dr. Mike Patrick: So it's for the long term.
Shawn Aylward: Yeah, by starting the medication to decrease the production, it's going to have a better effect, a faster effect.
Dr. Mike Patrick: What complications and long-term complications can arise from this, especially if it's not identified and corrected?
Shawn Aylward: The two major complications are vision loss and chronic headaches. Obviously, we're more worried about the former because that's going to have a bigger impact on the patient's life. If you are missing part of your vision, that's going to be more detrimental than the other.
Dr. Mike Patrick: What kind of complications can arise, then, from the treatment?
Shawn Aylward: There's not a whole lot. With the medication management, sometimes we can get some electrolyte abnormalities, but usually through either dose adjustments or more commonly just oral supplementation of the electrolyte that fixes itself.
With the surgical options, obviously surgery has its risks of infection, pain, bleeding. With the neuro sheath fenestration, there is some risk of visual injury. It's low. And then obviously with the ventricular shunt, there is the risk of it failing and having to be replaced.
Dr. Mike Patrick: Sure. And infection associated with it.
Shawn Aylward: Yes.
Dr. Mike Patrick: What's the long-term prognosis for this? If you have someone, you've got it under pretty good control, is it likely to come back, or you treat it and it's a done deal?
Shawn Aylward: Generally, the prognosis is pretty good. At the time of diagnosis, roughly about 20% of patients will have some form of visual acuity or even vision deficit, so loss of vision. But fortunately, only about 10% of that 20%, so a very small proportion of those patients, will actually have a permanent issue related to their vision. If we catch it and we don't have any vision problems and the patient does well, we are able to wean off. Generally, the patients do pretty well.
The recurrence rate of it is about 10% to 20%. Usually that's more in patients where weight was an issue and either they didn't achieve the weight loss or they did but then unfortunately they gained the weight back.
We're seeing a proportion of patients that sometimes can go on to develop a migraine type of picture. Those are usually just treated with our normal migraine preventative therapies, and they do pretty well.
Dr. Mike Patrick: Being associated with obesity, we talk about the childhood obesity problem and we're seeing more and more kids and teenagers who are obese, do you think that we're seeing an increase in the incidence of this in kids because of that obesity problem?
Shawn Aylward: That's an interesting question. I don't know if it's more that there is more obesity going on or there's just more awareness of the condition in general, so it's not really that clear-cut.
Dr. Mike Patrick: In some kids, could it be prevented by maintaining a healthy weight, do you think?
Shawn Aylward: That's really the best advice that we can give, because that's the only real link that we've seen, obviously, is maintaining a healthy weight will reduce the risk of it.
Dr. Mike Patrick: Great. In terms of a cure, since we don't really know what causes it, it's kind of hard to address the underlying physiology that's going on to try to come up with something, but maybe in the future, as we learn more about it and the mechanism of it, maybe that's something for the future, right?
Shawn Aylward: That's our ultimate goal, yes.
Dr. Mike Patrick: To be able to make it go away very quickly.
I really appreciate you stopping by today to talk about pseudotumor cerebri. We at Nationwide Children's have a very well-thought-of neurology department, and certainly if there are parents out there or physicians out there, no matter where you are in the country, you can always call and get a consult to talk to you about. Is that right?
Shawn Aylward: Yes, we have. We have the Pseudotumor Cerebri Clinic and we accept referrals from all over the country.
Dr. Mike Patrick: Right, and a great Ronald McDonald House if parents have to come out and stay with their kids while they're being evaluated.
Shawn Aylward: Yes.
Dr. Mike Patrick: We'll put the contact information for the neurology clinic here at Nationwide Children's so that parents and practitioners anywhere out there, anywhere you are, can get a hold of you, and then also a link to our pseudotumor cerebri information page here at Nationwide Children's, we'll put on there as well.
All right. Well, before you take off, one thing that we've been asking all of our studio guests here recently, we're really trying to encourage parents to do more stuff with their kids that doesn't involve screen time, so just activities, and we've been kind of focusing here on board games, I don't know if you remember from your own childhood, what is your favorite board game that you have played in the past or do play?
Shawn Aylward: My favorite board game. Well, I think that one's a tie. I used to enjoy, oddly enough I'm a doctor, but the game of Operation as a kid.
Dr. Mike Patrick: Oh, sure. Yeah.
Shawn Aylward: But also I think I enjoyed more Monopoly.
Dr. Mike Patrick: Yeah. Dr. Koranyi who was just here a couple of days ago, Monopoly was her favorite as well. My kids love to play that. Gosh, it just takes so long. Here I am saying, 'Hey, let's spend time with your kids,' and then, 'Yeah, but it's so long!'
Shawn Aylward: Oh, it doesn't necessarily have to be finished in one night.
Dr. Mike Patrick: Yeah, that's a good point. She said they play a shortened version of it where you pass out all the cards and you start wheeling and dealing right off the bat.
Shawn Aylward: I've never thought of playing it that way.
Dr. Mike Patrick: So Operation and Monopoly. All right. Well, again, we appreciate you stopping by.
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