130B PANCE Prep for Infectious Neuro Disorders

Hello and welcome to the Physician Assistant Exam Review Podcast. My name is Brian Wallace. I’m the host and creator here at Physician Assistant Exam Review. And this week we’re doing one of our companion episodes. What we’re doing is we’re going to take infectious neurological disorders and make them stick. Make them sticky. Make them so that they’re available in your mind when you sit down to take your test.

That’s always the hard part, right? Covering information is easy. Retaining the information and then making it available to you. That’s the hard part. So that’s what we’re doing today. This is 130B in an effort to take the information from the last episode and make it available to you on test day, make it there for you. Last week, I ran into some longer hours in the operating room and just couldn’t possibly get a show out between that and baseball season kicking off.

It’s become challenging. So let’s just say that. This week, though, we’re going to definitely cover those infectious disorders and try to make them, like I said, stickier by going through some PANCE type questions, by going through some straightforward questions, by talking about them from a little bit different angles. The one thing I want to share with you before we jump into that is I finally set dates for another Master Class, which is going to be May 5th and May 6th. That’s, I think it’s a Monday and a Tuesday or Tuesday, Wednesday. I’m not looking at it right now. That’s going to be a Master Class on passing the PANCE.

It’s going to be a 45 minute course on everything I can pack into 45 minutes to help you jump your scores between, I want to say 5%, maybe 10% in just 45 minutes and give you some tools and some ideas in a more structured manner than what I can do here in the show. To register for that, just go to physicianassistantexamreview.com/masterclass, and that will send you to the registration page. Just go there. You will need to register in order to get access to that on those days. You can pick either date, that’s fine. And the people ask when I do these, I just do two separate dates to make it easy for everybody. But I do the same exact program both nights.

So either night’s fine. You don’t need to sign up for both. And I think that’s it. So just go to physicianassistantexamreview.com/masterclass.

All right, let’s jump in and look at what we covered. What we covered in the last episode was HSV-1 encephalitis, arboviral encephalitis, which I have trouble pronouncing, acute bacterial meningitis, viral or aseptic meningitis, fungal meningitis, and TB meningitis. So HSV-1 encephalitis, your key differentiator here is its temporal lobe hyperintensities on MRI. That should be the thing that you’re highlighting that you’re blocking out. It shows up with a classic triad of fever, altered mental status, and seizures. In the CSF, you get lymphocytic pleocytosis, elevated protein, normal glucose. The gold standard for diagnosis here is HSV PCR in the cerebral spinal fluid.

Treatment. What’s going to be the treatment for HSV-1 encephalitis? Do you remember? The treatment is IV acyclovir. Immediately, do not wait for the PCR. Just go ahead and get started. That’s the key there.

So, what about something like West Nile or arboviral encephalitis? I’m just going to stop saying that. The key differentiator here, what is it? Something you should definitely know. Flaccid paralysis. And then the other part with that is also mosquito exposure. It used to be based on location within the country, but that’s really a non issue in most cases at this point.

Symptoms. Fever, altered mental status, tremors, and myoclonus. In the CSF, you can get lymphocytic pleocytosis and elevated proteins. The diagnosis is going to be… Do you remember? What was it? It was IgM serology from serum or cerebral spinal fluid.

The thing that stands out to me here is we do not give antivirals for these. This is purely supportive care. Again, that’s an easy place to write a question on, right? It’s so distinct. What about acute bacterial meningitis? What’s our key differentiator here? Well, I would go with neutrophilic cerebral spinal fluid and a decreased glucose in there.

What are your most common pathogens for acute bacterial meningitis? Most common pathogens, strep pneumonia and Neisseria meningitidis. What happens on the CSF fluid? You get an elevated opening pressure and elevated protein and a decreased glucose. Treatment. What’s our treatment? Ceftriaxone plus vancomycin.

And you can give dexamethasone before or with that first antibiotic dose. How about aseptic meningitis or viral meningitis? Our key differentiator here is normal glucose, preserved mental status. Causes here are HSV2, varicella, or enterovirus. Symptoms, fever, headache, photophobia, mild neck stiffness. Cerebral spinal fluid will have normal glucose, mildly elevated protein, and lymphocytosis. What about treatment here?

Do we give antivirals? Here it’s going to be mostly supportive care. But if you have herpes or varicella, you can give acyclovir. What about fungal meningitis? Here you have a subacute course, so it’s not so rapid of onset. You get an elevated intracranial pressure, especially in an immunocompromised person. So that’s kind of what your fungal meningitis is going to look like, your cryptococcus.

Usually we talk about that like in an AIDS patient, in an HIV patient. That’s what you want to be considering. You get elevated opening pressure, low glucose, high protein, and a lymphocytic CSF. Thoughts on how you diagnose this? So, an India ink stain, a fungal culture, obviously that’s going to take a while, cryptococcal antigen. Treatment. This should be an easy one.

Amphotericin B. And then you use fluconazole for maintenance. What about TB meningitis? Here we get very low glucose and very high protein in that CSF. This also has a gradual onset. This thing about this is a slow growing bug, right? So, it’s going to be a gradual onset.

These patients can also have night sweats, right? So, maybe that’ll clue you in. Weight loss, cranial nerve deficits, and a fever. Imaging. MRI shows basilar meningeal enhancements. I don’t know if you’re going to be able to hold on to that. It’s not something I would be able to keep, but it’s definitely helpful.

A treatment is going to be the same as our TB treatments we talked about last week, plus a steroid.

All right, let’s run through some questions.

Let’s see if we can lock some of that in. What virus is the most common cause of sporadic fatal encephalitis in the United States? Which virus is the most common cause of sporadic fatal encephalitis in the United States? HSV-1. What’s the gold standard diagnostic test for HSV encephalitis? We just covered this. What’s the gold standard diagnostic test for HSV encephalitis?

We’re going to look at the cerebral spinal fluid and you’re going to do a PCR test for HSV. Here’s what we didn’t cover today. Which pathogen causing meningitis is associated with a petechial rash? Which pathogen causing meningitis is associated with a petechial rash? Neisseria meningitidis. What organism is most commonly responsible for fungal meningitis in HIV or AIDS patients? Literally, I just said this one.

Cryptococcus. Which empiric antibiotic must be added for listeria coverage in neonates? Ampicillin.

Let’s do one more. What CSF glucose finding is most suggestive of bacterial meningitis? I like this one because it kind of breaks it. I kind of want to break these up into the two categories, right? Viral versus… I guess there’s more than two categories because you have your TB and you have your fungal, but really you have your viral and your bacterial. Which type of meningitis…

Sorry, what CSF glucose finding is most suggestive bacterial meningitis? It’s going to be a low glucose.

All right. Let’s jump into some longer form questions. A 36 year old man with advanced HIV, so you should already be thinking in a specific way, right? Presents with several weeks of headache, low-grade fever, and malaise. Lumbar puncture reveals elevated opening pressure, lymphocytic pleocytosis, low glucose, and a positive cryptococcal antigen. What’s the first line treatment? So this is really, although there’s a lot of words in this question, it should be very straightforward to you as to what’s going on here.

A, fluconazole only, B, amphotericin B plus flucytosine, C, voriconazole, got nailed that one, D, acyclovir, and E, RIPE therapy, R-I-P-E. Well, as you go through this, it tells you positive cryptococcal antigen. So there’s not much more you need to know. You have a patient with HIV who’s a positive cryptococcal antigen. You’re thinking that you have a fungal infection. RIPE therapy is for TB. That one’s pretty easy to get rid of.

Acyclovir is going to be for HSV. Hopefully you can hold onto that because it treats herpes in all kinds of different ways. So that’s easy to get rid of. So now we’re down to A, B, or C, fluconazole only, amphotericin B plus flucytosine and voriconazole. Well, again, to me, this isn’t that difficult because I have a 36-year-old who has HIV and has a cryptococcal meningitis. So I want to, that means I have something that’s bad on my hands, right? So I’m going to go to my heavy hitting drug, which is amphotericin B, and then plus flucytosine.

Fluconazole, if you recall, we just said was for maintenance. It’s not for knocking it down initially.

Perfect. All right, question two. A 70-year-old woman presents with fever, confusion, and a history of chronic steroid use. Cerebral spinal fluid shows lymphocytic pleocytosis, very low glucose, and very high protein. MRI reveals basilar meningeal enhancements. What’s the most likely diagnosis? So, this has pretty much every key term in it, right, that we just covered.

Now, this looks pretty easy and pretty straightforward because we just did it. But if you wait a month and then mix this in with a whole bunch of other things, 300 other questions, this is going to look really hard. And you’re going to wonder how you’re supposed to remember all of these pieces. And the answer is you don’t really need to. If you remember that basilar meningeal enhancements, that would be huge. If you remember very low glucose and very high protein, that would be huge, right? Those would point you towards tuberculosis meningitis.

And even if you didn’t know that, how would you get rid of some of these? Well, if you look at HSV encephalitis, how could you remove that and know that that’s not right? Well, you could know it because if you knew that you should have seizures, altered mental status, and temporal lobe involvement, we’re going to talk about any of that here. For cryptococcal meningitis, I don’t have anything that’s immunocompromised here. For bacterial meningitis, I would be looking at something with a more, and this is also with the HSV, but I’d be looking for a more acute setting, not someone who presents with a fever and confusion and a history of chronic steroid use. I’d be looking for something more acute, but also, I wouldn’t be looking at that very high and very low glucose and protein. And if the other answer to this you can get rid of pretty fast is arboviral encephalitis, right?

Because what was our main thing there? What was that flaccid paralysis? And that’s not in this question. Number three, a 25-year-old man presents with fever, seizures, and hallucinations. Whoa, so this pretty much jumps off the table for me, right? I already, just the way we described the last one, I know what this diagnosis is. Fever, seizures, and mental status changes.

Says hallucinations, but it means the same thing, right? CSF shows lymphocytic pleocytosis with normal glucose. What’s the gold standard for confirming the diagnosis? Well, what’s our diagnosis? This comes in much different than TB. This comes in much different than cryptococcal. This is HSV.

This is an HSV infection. So what is our treatment for an HSV infection? We went through that a couple of times. Our gold standard is going to be the PCR of the CSF, right? So I can give you the answer choices, but I like it even better if you know before you get to the answer choice. Now the answer choices were brain biopsy, EEG, CSF PCR for HSV, serum IgM, and gram stain.

Now, if I know that this is not a bacterial infection, I’m going to get rid of gram stain. I’m not going to do a brain biopsy. An EEG is not going to be my gold standard. It may help with some of these, but it’s not going to be my gold standard. So, I’m already down in my head. I’m pretty much down to three to two pretty thing two answer choices that I have to pick between. But because I can know that it’s HSV because of that triad, this one becomes pretty straightforward.

All right, let’s do another one. A patient presents during late summer with fever, altered mental status, and new onset of flaccid paralysis. See, and even as I’m reading this, I see that late summer, and I’m like, hmm, why is late summer in here? You know, if you were looking at a bacterial meningitis, you might think when kids go back to school because it tends to be a college issue, but late summer doesn’t mean that. The only thing late summer would mean as far as meningitis goes, and again, if we’re looking at a whole bunch of different things, it’s harder, but if I’m only looking at questions about meningitis, late summer is going to mean mosquitoes, fever, altered mental status, and new onset of flaccid paralysis. That goes even further. So as I’m reading through this, I see that late summer and I’m thinking, hmm, that’s interesting.

And then I see flaccid paralysis and now I know that’s my confirmatory clue, my confirmatory breadcrumb that keeps leading me down that path until I see that full-on sign. MRI is nonspecific, CSF shows lymphocytic pleocytosis, serology confirms IgM antibodies against West Nile virus, what’s the treatment of choice? So they gave me the diagnosis as we went, right? So maybe I didn’t need to figure all that out, but I still like to work it through myself. I still like to read the story in order. What’s the treatment of choice? So what’s the treatment of choice for West Nile virus?

Well, we just went through this as well. Is it A, IV acyclovir, which definitely would come into my head, right? And I’d be wondering, hmm, it’s a virus. Do I do acyclovir? Is it ceftriaxone and vancomycin? Nope. Is it amphotericin B and flucytosine?

Nope. Is it supportive care? Maybe. Is it oral valacyclovir?

Now, I’d probably get rid of oral because, again, I’d be worried in a meningitis, I have someone who’s more sick. So, I’m going to be choosing, if I’m doing this question and I don’t really know what’s going on, I’m going to be choosing between IV acyclovir and supportive care only.

Now, because we just covered it, I know, and I just talked about it, I know that for West Nile it’s supportive care only, so we’re good there. And that’s our answer. But I want you to see how you can walk through these, whether or not you know them specifically. Sometimes you do, and that’s great, but sometimes you don’t, and it’s how do you get there when you don’t.

All right, well, we’re going to sign off for today. That’s going to be it in our companion episode. Thank you so much for joining us. I hope these are helpful. I’d love to hear from you if they are or if they aren’t. That would be great as well. If you’re interested in the June cohort of the 33 Days to Pass the PANCE program, that registration will go live in the middle of May.

If you want information on that, just go to physicianassistantexamreview.com/33 to find out more about the June cohort. And of course, if you are interested in boosting your scores by 5% on pretty much every exam, but specifically for the PANCE, look into that Master Class coming early May, May 5th and 6th, physicianassistantexamreview.com/masterclass, all one word.

All right, great. Take care. Can’t wait to talk to you next week. Oh, I have something really special for you planned next week. I have a student who absolutely blew the doors off her exam and I did an interview with her, and I’m going to share it with you guys next week. It is fantastic. Can’t wait to…

see it. Talk to you then.