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84: Return of the Cyst
Episode 8413th November 2023 • Febrile • Sara Dong
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Future internal medicine physician Christine Pho and Drs. Daniel Stanton and Clinton White provide a sequel story to “Revenge of the Cyst”!

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Sara Dong:

Hi, everyone.

Sara Dong:

Welcome to Febrile, a cultured podcast for all things infectious disease.

Sara Dong:

We use consult questions to dive into ID clinical reasoning, diagnostics,

Sara Dong:

and anti-microbial management.

Sara Dong:

I'm Sara Dong, your host.

Sara Dong:

Today's episode is actually a bit of a sequel or extension of a prior

Sara Dong:

episode, which I will mention at the end if you want to refer back, so

Sara Dong:

as not to give it away right away.

Sara Dong:

Although you may be able to guess when I introduce our guests.

Sara Dong:

So let's meet them.

Christine Pho:

My name is Christine Pho.

Christine Pho:

I am a medical student in my fourth year at UT Southwestern in Dallas.

Sara Dong:

Christine is planning to apply for an internal medicine residency.

Sara Dong:

Our second guest is Dr.

Sara Dong:

Daniel Stanton.

Daniel Stanton:

I'm Daniel.

Daniel Stanton:

I'm one of the first year fellows in infectious disease at UTMB in Galveston.

Sara Dong:

UTM B is the University of Texas Medical Branch in Galveston,

Sara Dong:

Texas, which is where Daniel also completed medical school and residency

Sara Dong:

And last but not least is our guest discussant

Clinton White:

Hi, I'm Clinton White.

Clinton White:

I'm a Professor in the Infectious Disease Division at the University

Clinton White:

of Texas Medical Branch.

Sara Dong:

Dr.

Sara Dong:

White's clinical interests and expertise include parasitology, tropical medicine,

Sara Dong:

HIV, and opportunistic infections.

Sara Dong:

He serves on the editorial board of a number of journals and

Sara Dong:

directs the IDSA-ASTMH guidelines committee for neurocysticercosis.

Sara Dong:

So before we get to the case, Febrile is everyone's favorite cultured

Sara Dong:

podcast, so we kick off the episode by having our guests share some culture.

Sara Dong:

So really it can be anything that's brought you happiness recently.

Sara Dong:

I'll start off with you Christine

Christine Pho:

Sure.

Christine Pho:

I recently had the opportunity to try some Asian American fusion restaurants.

Christine Pho:

So, I had Blood Bros.

Christine Pho:

BBQ in Houston, which is a Texas barbecue place that also has Asian spices and

Christine Pho:

influences, and I also got to try Cris and John in Dallas, which is a

Christine Pho:

Mexican Vietnamese restaurant as well.

Sara Dong:

Cool.

Sara Dong:

That sounds great.

Sara Dong:

what about you, Daniel?

Daniel Stanton:

So, I just got back from a trip to Florida, uh, Disney World,

Daniel Stanton:

and I got the opportunity to visit the Star Wars theme park section of the

Daniel Stanton:

Disney World, and I, uh, was blessed to be able to make my own lightsaber.

Daniel Stanton:

I'm like a huge Star Wars nerd, I got to make my own personal lightsaber finally.

Sara Dong:

And how about you Clinton?

Clinton White:

Um, yeah, I was actually a music major in college, and recently I've

Clinton White:

been listening to a lot of piano music, um, and particularly Chopin's Nocturne No.

Clinton White:

1 and some pieces by Eric Satie that have sort of a, a melancholy, uh, tone to them.

Sara Dong:

Oh, what?

Sara Dong:

This is such a great variety.

Sara Dong:

I love it.

Sara Dong:

Um, well, Christine, I'll hand it over to you to tell us about

Sara Dong:

the case and get us started.

Sara Dong:

. Christine Pho: A 41 year old male prison inmate with a past medical history of

Sara Dong:

hypertension presented with one year of worsening headache associated with

Sara Dong:

nausea, vomiting, and weight loss.

Sara Dong:

The headache is diffuse and worse while supine, radiates to

Sara Dong:

his neck and causes stiffness.

Sara Dong:

Over the last three months, his headache now causes him to feel pressure behind

Sara Dong:

his eyes and he has developed nausea and vomiting several times per week

Sara Dong:

associated with 40 pounds of weight loss.

Sara Dong:

Patient has also had recurrent sudden falls that are associated with

Sara Dong:

sudden movement over the past year.

Sara Dong:

He denies any specific triggers or prodrome of symptoms before his falls.

Sara Dong:

Denies fevers, chills, night sweats, seizures, or focal neurologic deficits.

Sara Dong:

He has been incarcerated for five years and he works as a cook.

Sara Dong:

He is a Mexican immigrant who came to the U.

Sara Dong:

S.

Sara Dong:

in his teens and last visited Mexico six years ago.

Daniel Stanton:

So I just want to say a few things that stand out

Daniel Stanton:

about the case right off the bat.

Daniel Stanton:

All of his symptoms kind of are painting the picture of someone that has high

Daniel Stanton:

intracranial pressure, , including these, diffuse headaches that

Daniel Stanton:

are worse when he's laying down.

Daniel Stanton:

The pressure like features behind his eyes with nausea and

Daniel Stanton:

vomiting and weight loss now.

Daniel Stanton:

So it, it's just overall showing this picture of high intracranial pressure.

Daniel Stanton:

It's also based on the timing and the very slow progression of things

Daniel Stanton:

starting over a year ago with the worsening over the last three months.

Daniel Stanton:

This is a chronic process more so than like a quickly progressive process.

Daniel Stanton:

So we're thinking if infectious wise, very slow growing infections,

Daniel Stanton:

things like mycobacterial, maybe neurosyphilis, um, a fungal organism

Daniel Stanton:

or parasitic organism, maybe some of our opportunistic infections.

Daniel Stanton:

The next things we really would want to do in this case, get a very

Daniel Stanton:

detailed physical exam, particularly a neuro and a retinal exam.

Daniel Stanton:

Um, then we would obviously want to go to imaging to see if there's any features

Daniel Stanton:

that are changes on his anatomy from any of this increased intracranial pressure.

Daniel Stanton:

After the imaging if we don't find anything, any masses, we'd do a lumbar

Daniel Stanton:

puncture, really looking at the cells and the differential on the cells more

Daniel Stanton:

than anything, and then establish his HIV status and syphilis serologies.

Daniel Stanton:

Also, non infectious wise, things that might cause this are things like

Daniel Stanton:

malignancy if they've metastasized to the leptomeninges, or vasculitis,

Daniel Stanton:

things of that nature as well.

Daniel Stanton:

So, you want to tell us a little bit more about the physical exam, Christine?

Christine Pho:

Sure, his physical exam was significant for an ataxic gait,

Christine Pho:

some discomfort with neck flexion without rigidity, slight diffuse

Christine Pho:

hyperreflexia, and bilateral papilledema.

Christine Pho:

He didn't have any problems with mentation and no cranial nerve deficit

Christine Pho:

or weakness, and he had negative Brudzinski's and negative Kernigs sign.

Christine Pho:

So, we went ahead and got labs and imaging on him.

Christine Pho:

So, his labs were significant for leukocytosis of 12, 000 white cells

Christine Pho:

per microliter with eosinophilia.

Christine Pho:

He also had a HIV and syphilis test that were negative.

Christine Pho:

And he had a lumbar puncture that was performed with a CSF analysis that showed

Christine Pho:

undetectable glucose, high protein, and an elevated white count of 47

Christine Pho:

with a high percentage of eosinophils.

Christine Pho:

He had a CT of the head that showed severe hydrocephalus with transcentorial flow

Christine Pho:

of CSF but no other significant findings.

Christine Pho:

He then had an MRI brain with and without contrast, that was

Christine Pho:

limited by motion artifact.

Christine Pho:

It was notable for communicating hydrocephalus

Christine Pho:

and leptomeningeal enhancement.

Daniel Stanton:

So, with like we said before, this being a chronic

Daniel Stanton:

process, we now have more evidence that there's a meningitis going on.

Daniel Stanton:

The glucose consumption on the lumbar puncture, the really high

Daniel Stanton:

protein with the pleocytosis and this leptomeningeal enhancement

Daniel Stanton:

that's been showing up on the MRI.

Daniel Stanton:

Um, this leads to a really broad differential diagnosis just

Daniel Stanton:

thinking about chronic meningitis.

Daniel Stanton:

Um, things like Cryptococcus, maybe some endemic fungal infections in the U.

Daniel Stanton:

S.

Daniel Stanton:

like Coccidioides.

Daniel Stanton:

Um, Tuberculous meningitis comes into play since he's an incarcerated person.

Daniel Stanton:

Um, Brucellosis could have this appearance, neurocysticercosis, and

Daniel Stanton:

uh, other things like leptomeningeal cancers can also give you this kind of

Daniel Stanton:

changes and appearance of meningitis.

Daniel Stanton:

But because he's had this eosinophilic predominance of the pleocytosis, you think

Daniel Stanton:

of a much more narrow bit of of organisms.

Daniel Stanton:

The first few that come to mind are the ones you always get from a textbook.

Daniel Stanton:

Things like...

Daniel Stanton:

Angiostrongylus, or the rat lungworm, um, Baylisascaris, the neural larval

Daniel Stanton:

migrans, and, uh, Gnathostomiasis.

Daniel Stanton:

But no matter what we did on taking his history, I think we, uh, couldn't get

Daniel Stanton:

him to admit to eating any snails or traveling to Southeast Asia recently.

Daniel Stanton:

So we, uh, quickly dismissed those from our differential.

Daniel Stanton:

Things like drug allergies were high on things we were discussing, as

Daniel Stanton:

well as, uh, the neurocysticercosis.

Clinton White:

So, if you think about neurocysticercosis, the main way we make

Clinton White:

that diagnosis is with imaging studies.

Clinton White:

The CT can be done as was done in this case.

Clinton White:

It showed hydrocephalus and not a lot more.

Clinton White:

The CTs often will show cysts in the brain parenchyma or can show

Clinton White:

calcifications as well, neither of which was seen in this case.

Clinton White:

MRIs are considerably better than CT at demonstrating cysts, particularly in

Clinton White:

the ventricles and subarachnoid space.

Clinton White:

Um, there are other methods that can be used to confirm the diagnosis.

Clinton White:

For example, serologies can be used to suggest exposure.

Clinton White:

There are newer methods like antigen detection, um, quantitative PCR, and

Clinton White:

even in some cases are diagnosed by next generation sequencing of the spinal fluid.

Clinton White:

So there are newer sequences on the MRI scans, um, that can

Clinton White:

demonstrate things, particularly when they're missed on other sequences.

Clinton White:

Uh, one of them is called Fiesta.

Daniel Stanton:

Christine, you think you can tell us what we've done next?

Christine Pho:

MRI brain was repeated with three dimensional Fiesta sequence

Christine Pho:

and showed two large cysts with visible scolixes in the fourth ventricle

Christine Pho:

and enlargement of the cisterna magna with extensive cystic debris.

Christine Pho:

In addition, there was multifocal subarachnoid cysts consistent

Christine Pho:

with racemose neurocysticosis.

Christine Pho:

An MRI spine was performed with and without contrast that

Christine Pho:

showed no significant findings.

Christine Pho:

We sent out labs to the CDC for neurocysticercosis enzyme linked

Christine Pho:

immunoelectrotransfer blot, EITB, and it returned positive for both serum and CSF.

Clinton White:

So, this, uh, patient had neurocysticercosis.

Clinton White:

Um, a previous episode, number 64, had Dr.

Clinton White:

Christina Coyle discuss some aspects of neurocysticercosis.

Clinton White:

We'll, I'll reiterate a few of them, but focus on some things that she

Clinton White:

didn't have time to talk about.

Clinton White:

Um, it's important when you think about neurocysticercosis that

Clinton White:

you realize that it's a series of diseases and not just one infection.

Clinton White:

So if you told someone you had a Staph infection, you'd want to know,

Clinton White:

well, is this an abscess in the skin, or a bacteremia from a catheter, or

Clinton White:

endocarditis, and they'd all have a little bit different management.

Clinton White:

And the same is true for, uh, Taenia solium infections causing cysticercosis.

Clinton White:

Um, they're very different presentations, depending on whether the cysts

Clinton White:

are just in the brain parenchyma.

Clinton White:

If they are, whether they're viable cysts, degenerating cysts,

Clinton White:

or just residual calcifications.

Clinton White:

You also can have extra parenchymal cysts, which are the most serious forms of

Clinton White:

disease, including ones in the ventricle or ones in the subarachnoid space.

Clinton White:

And often you'll have multiple different forms at the same time.

Clinton White:

So in this case, he had both, uh, cysts in his ventricles and

Clinton White:

cysts in the subarachnoid space.

Clinton White:

So the diagnosis in this case was confirmed by the Fiesta imaging, which

Clinton White:

showed scolices within, uh, cystic lesions, the so called, uh, "dot and

Clinton White:

hole" sign, uh, which is pretty much diagnostic of neurocysticercosis.

Clinton White:

With neurocysticercosis, it's different from other infectious diseases in

Clinton White:

that the organisms are not in most cases proliferating a whole lot.

Clinton White:

And so the acute management, the initial management should focus on

Clinton White:

getting their symptoms under control.

Clinton White:

If they have seizures, the first order of business is to get

Clinton White:

them on anti seizure medicines.

Clinton White:

If they have hydrocephalus, that usually requires neurosurgery.

Clinton White:

If they have diffuse cerebral edema, it requires, uh, use of,

Clinton White:

uh, anti inflammatory drugs.

Clinton White:

So, those are all important aspects of the initial management.

Clinton White:

So, Christina, you want to follow up?

Christine Pho:

So just to go over his management, he was started on

Christine Pho:

high dose dexamethasone, and then subsequently in neurosurgery, performed

Christine Pho:

a suboccipital craniotomy, whereupon accessing the cisterna magna, enumeral

Christine Pho:

cysts were found and were removed.

Christine Pho:

The fourth ventricle was accessed inferiorly and the cysts removed

Christine Pho:

and confirmed by neuroendoscopy.

Christine Pho:

An extraventricular drain was placed and albendazole and

Christine Pho:

praziquantel therapy was started.

Christine Pho:

The extraventricular drain was converted to a ventricular peritoneal

Christine Pho:

shunt and methotrexate was started inpatient with plans to taper

Christine Pho:

the steroid slowly outpatient.

Christine Pho:

He is currently convalescing well.

Clinton White:

So in this case, he did have, some evidence of

Clinton White:

communicating hydrocephalus, which can be due to inflammation,

Clinton White:

and he was started on steroids.

Clinton White:

So when we treat this disease, particularly in those with mixed forms,

Clinton White:

we think about the more serious forms of infection, and the treatment should focus

Clinton White:

on what are the most serious forms, and what requires the most intensive therapy.

Clinton White:

So, in this case, he can have, um, antiparasitics for the subarachnoid cysts.

Clinton White:

Um, but, um, actually, it's very important to, uh, look at

Clinton White:

the cysts in the ventricles.

Clinton White:

The subarachnoid and ventricular cysts, it's interesting, tend to have a longer

Clinton White:

subclinical period before they present.

Clinton White:

Um, in a series we did from Houston, they were often 8 or

Clinton White:

10 years after immigration.

Clinton White:

So, this case, he had not been back in Mexico for a long period of time.

Clinton White:

And that's kind of typical.

Clinton White:

Um, so, seizures are associated with parenchymal neurocysticercosis.

Clinton White:

But extraparenchymal disease is associated with hydrocephalus, such as in this case.

Clinton White:

One of the interesting findings on this patient is he had these, uh, periodic

Clinton White:

drop attacks, where, and actually, there's a term, Brun's syndrome, uh,

Clinton White:

based on a neurosurgeon named Brun's who described this around 1900, just after

Clinton White:

1900 in Germany where a cysticercosis typically in the third or fourth

Clinton White:

ventricle moves around when you change positions and causes a sudden onset of

Clinton White:

an acute, obstructive hydrocephalus.

Clinton White:

So that was probably going on, in the past in this case and, would be a, real

Clinton White:

big risk factor, um, for him not doing well if it was not addressed right away.

Clinton White:

So in the fourth ventricular cysts, you really don't want to treat that medically.

Clinton White:

And in fact, if you gave antiparasitics, it actually might interfere with his long

Clinton White:

term treatment, uh, so that wasn't done.

Clinton White:

Instead, we had a, a discussion with our neurosurgeons.

Clinton White:

And, um, they said, well, why don't you just treat him medically?

Clinton White:

And I said, well, he's got the cysts in the fourth ventricle.

Clinton White:

And really, if that's not taken out, he's at risk for sudden death, which

Clinton White:

is not something we like to happen in our patients under our care.

Clinton White:

Um, So because of that we discussed this with the surgeons.

Clinton White:

Well how do you get to the fourth ventricle?

Clinton White:

Well there are two approaches.

Clinton White:

Some cases of neurocysticercosis, they actually take a flexible neuroendoscope,

Clinton White:

go up through the lateral ventricles, the third ventricle, and there are

Clinton White:

descriptions of snaking it through the aqueduct and just pulling the cyst out.

Clinton White:

However, there are critical structures on each side of the aqueduct, so

Clinton White:

you don't really want to do that unless the aqueduct is quite dilated.

Clinton White:

The other approach, is to approach it from behind and do a

Clinton White:

craniotomy in the occipital lobe.

Clinton White:

And then, either by micro dissection, by stereotactic approaches, or with

Clinton White:

neuroendoscopy, you can get into the fourth ventricle and take the cyst out.

Clinton White:

So, our patient had ventricular and subarachnoid cysts, and they

Clinton White:

went in from a posterior approach.

Clinton White:

As soon as they got in the subarachnoid space, they were...

Clinton White:

enumerable, , cysts that sort of came out.

Clinton White:

And so it, he clearly had a heavy burden of, subarachnoid disease.

Clinton White:

The cysts in the ventricle could be removed easily.

Clinton White:

And if that was all that had gone on, uh, he would be cured.

Clinton White:

So ventricular cysticercosis, if you can take the cysts out

Clinton White:

and cure them, that's great.

Clinton White:

But he had so many cysts in the basilar cisterns and subarachnoid space, that he

Clinton White:

was going to require long term therapy.

Clinton White:

The debulking that was done in this case, uh, is helpful.

Clinton White:

If you've got a lot of uh, parasites that you kill in the subarachnoid

Clinton White:

space, it takes the body a long time to get rid of them, and so you'll have

Clinton White:

chronic inflammation causing problems.

Clinton White:

However, there are some cases that suggest maybe if you can get some of

Clinton White:

them out, it might improve your outcome.

Clinton White:

Typically, subarachnoid neurocysticcercosis has not responded

Clinton White:

to the regimens of anti parasitic drugs that we use for other forms

Clinton White:

of disease, for parenchymal disease.

Clinton White:

And there are three approaches that have been, um, used in this

Clinton White:

case.

Clinton White:

In Mexico, they give high dose albendazole for a month and then repeat it again.

Clinton White:

Some centers in the U.

Clinton White:

S.

Clinton White:

have used prolonged courses of albendazole, often lasting

Clinton White:

months to even over a year.

Clinton White:

More recently, there are studies using a combination of two anti parasitic

Clinton White:

drugs, praziquantel and albendazole.

Clinton White:

And the praziquantel is parasiticidal in itself, but even more importantly

Clinton White:

elevates the levels of the active metabolite of, um, the albendazole, so

Clinton White:

you get, uh, higher steady state levels.

Clinton White:

Um, so, you know, that's often required and still may require

Clinton White:

a long course of therapy.

Clinton White:

So he's gotten debulking, his antiparasitics.

Clinton White:

Um, it's really important that if you kill the parasites, you can

Clinton White:

cause worsened inflammation.

Clinton White:

And the inflammation really is the cause of a lot of the chronic processes.

Clinton White:

So it's really important to get them on anti inflammatory medicines.

Clinton White:

Typically, we'll start out with, uh, very, very high doses of, of steroids.

Clinton White:

Um, I think he was started out on 24 milligrams a day of dexamethasone.

Clinton White:

You don't want to keep people on that forever, and so drugs like methotrexate or

Clinton White:

TNF inhibitors have been used as steroid sparing agents for chronic disease.

Clinton White:

But he also has communicating hydrocephalus.

Clinton White:

And, If you just give him antiparasitics, that's still going to be present.

Clinton White:

And so in his case, he required, um, a placement of an external ventricular

Clinton White:

drain and then a ventricular peritoneal shunt to manage the hydrocephalus.

Clinton White:

But he also needs chronic anti inflammatory drugs

Clinton White:

and chronic antiparasitics.

Clinton White:

And, um, by the time he'd gotten his cysts out of the fourth ventricle and the ones

Clinton White:

from the, uh, posterior fossa removed.

Clinton White:

He was feeling great.

Clinton White:

And I saw him in the hospital and he said, why can't I go home?

Sara Dong:

Thank you so much.

Sara Dong:

You know, we crammed up a very complex case into a fairly short timeframe.

Sara Dong:

So I actually was hoping maybe you could give a quick overview

Sara Dong:

and summary of the case again.

Sara Dong:

And I'd love to hear any additional thoughts you have about how you

Sara Dong:

follow these patients in the clinic and, as they are recovering.

Clinton White:

So, this patient had ventricular cysticercosis,

Clinton White:

and that's a, that's typically requires, uh, it's a surgical

Clinton White:

disease, it's not a medical disease.

Clinton White:

So if you've got obstructive hydrocephalus or hydrocephalus rather than just

Clinton White:

diffuse cerebral edema, that's a medical emergency and requires neurosurgery.

Clinton White:

Uh, the ventricular cysts can be popped out, uh, most of the time

Clinton White:

they're not very inflamed and, can come out easily by neurosurgery.

Clinton White:

The ones in the lateral and third ventricle can be removed by these

Clinton White:

neuroendoscopes and once you've taken them out, uh, the patient's cured.

Clinton White:

Um, however, subarachnoid neurocysticercosis requires more

Clinton White:

prolonged therapy and that includes chronic anti-inflammatory drugs, uh,

Clinton White:

steroids and maybe steroid sparing agents and intensive, um, antiparasitic drugs.

Clinton White:

We're not completely sure of the best antiparasitics, but praziquantel plus

Clinton White:

albendazole may be better in some cases.

Clinton White:

And since this disease takes a while, you need things to follow.

Clinton White:

And we will typically follow the MRI scan.

Clinton White:

But sometimes the MRI will not completely normalize.

Clinton White:

And so there are other things that can be followed, and there are a

Clinton White:

couple of tests that can be used to determine if you have viable cysts.

Clinton White:

Those include a quantitative PCR assay and an antigen detection assay,

Clinton White:

both of which can be performed in the serum or in the spinal fluid.

Clinton White:

And if those have turned negative, um, you can actually stop the treatment, stop

Clinton White:

the antiparasitic treatment, taper the steroids, and declare the patient cured.

Clinton White:

So, you know, this patient had a good outcome.

Clinton White:

It required aggressive treatment, a discussion with the neurosurgeons,

Clinton White:

holding off on antiparasitic drugs until the cysts in the ventricles

Clinton White:

were removed, and eventually starting a prolonged course of anti

Clinton White:

inflammatory and antiparasitic therapy.

Clinton White:

Thank you.

Sara Dong:

Thank you to Christine, Daniel and Clinton for joining Febrile today.

Sara Dong:

As a quick reminder, you can also check out episode number 64, which is called

Sara Dong:

Revenge of the Cyst and featured Dr.

Sara Dong:

Cesar Berto and Dr.

Sara Dong:

Christina Coyle who also discussed a different case of neurocysticercosis.

Sara Dong:

Thanks again for listening to Febrile.

Sara Dong:

As always, you can check out the website, febrile podcast.com where

Sara Dong:

you'll find the Consult Notes, which are written complements of

Sara Dong:

the show with links to references, our library of ID infographics

Sara Dong:

and a link to our merch store.

Sara Dong:

Please reach out if you have any suggestions for future shows or want

Sara Dong:

to be more involved with Febrile.

Sara Dong:

Thanks for listening, stay safe and I'll see you next time.

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