DIP Episode 473 - USMLE Step 2/3 Rapid Review Series 99

All right welcome my name is divine this is episode 473 of the divine intervention podcasts in today's podcast I'm gonna be continuing the rapid review series for the US Emily step-to-step three exams. This is gonna be series 99 series 99 Okay, so what if they give you a question? About a 70-year-old girl They tell you that for the past you know two weeks Appearance have been noticing that she's been having like really bad headaches in the mornings and they tell you that She has also noted they've also noticed some weakness in her extremities and Then you're told that they obtain imaging and you know you get the imaging I say like a big cerebellar mass in fact whenever the US may present this concept They say oh they show you a big cerebellar mass and in addition to that you see some lesions you they'll give you like a You know like a sagittal view of the spinal cord. I see all these white white white lesions in the spinal cord and One of the classic answers they're gonna throw your ways in us. They put multiple sclerosis as an answer And then you put me to do blasphomas and answer then a bunch of other fluff And you see something like this. I really hope you're thinking of a Fameda loblastoma, okay? Think of a meadow loblastoma. So maybe like okay divine. So how do I differentiate this from MS?

Well the thing is this MS does not cause a cerebellar mass Right because MS can cause brain lesions and you can also cause lesions in the spinal cord that's why many times you don't redact no see multiple sclerosis We're doing MRI of the brain and spinal cord But the thing is MS does not cause a cerebellar mass. So this person has been loblastoma you may be like divine like but Why are you not seeing this is one of the other cerebellar masses that can happen in kids like a Pilosidic astrocytoma or a humangeoblastoma or something like that.

Well, let me explain This cannot be Pilosidic astrocytoma because yes, Pilosidic astrocytoma can cause a cerebellar mass But it doesn't usually dip into the spinal cord This is not a humangeoblastoma because Humangeoblastomas again usually don't dip into the spinal cord and many times humangeoblastomas They're going to contain calcifications On the USMEL exams it's going to be a cerebellar mass contains calcifications Now that I've said something in the question about the person having polysiphemia because many times those things can be carried through Poetin in a pyrneoplastic fascia and that can cause polysiphemia So what makes this medalloblastoma well the big thing that makes this medalloblastoma is the presence of drop metastasis That's actually something that's pretty high to know for the USMEL exams We pretty much have Metz that literally go through the central canal of the spinal cord Right, they go through CSA pathways and they go from the cerebellum to the spinal cord So if you see a child cerebellar mass lesions in the spinal cord as well That's going to be a medalloblastoma on your test. Okay. That's going to be a medalloblastoma on your test And don't forget that those medalloblastomas the fancy thing to know about them is You're gonna see these These are sugar resets right so that's something these resets those are things you usually will find out Histology in a place in the has a medalloblastoma.

I'd encourage you to kind of look look those up if I were if I were you And then I guess if you're looking at the other things like Pylocytic astrocytoma remember what's going to be the thing you're going to see histologically with Pylocytic astrocytoma The thing you're gonna see for sure is you're gonna see these pink cox crow fibers those are things known as the Rose and thong fibers. I think those are basically like bundle so GFAP Leo Fibularia acidic protein which is in fact the tumor marker for Pylocytic astrocytoma so that's just something we want to keep at the back of your mind on exams and Then what if they give you a question What if they give you a question on a 50-70-year-old man and they tell you that for the last three months has been having severe morning headaches and now he's beginning to have like You know weakness of his lower extremities That are studied extending to his face and upper extremities When you see something like and then they show you an image Then you just see something nasty in the middle of the brain like it's like more has like many different Like heels like you see like very dark gray white In the middle of the brain and many times is going to roll both sides of the brain. Obviously. That's gonna be GBM.

That's gonna be glioblastoma motif for me When the presence of glioblastoma motif for me on the US and Italy exams there are many different ways they can take this thing but when a brain tumor is causing like Compressive symptoms you may want to go ahead and give that person like some steroids to reduce the swelling around the lesion Or glioblastoma motif for me is the most common primary brain tumor in adults. It's a very very nasty tumor It's literally a very very nasty tumor, right many times you're gonna see a lot of a dima around the tumor And it has an awful awful awful Prognosis I'm not saying people don't survive GBM. Well, that's more the exception than the rule So you know when you see glioblastoma motif for me on your exams, right? Many times it's just again to know like what many times you'll be a diagnosis question to just made the identification But I'm the thing that they also love to test with GBM is they can make this into like a healthcare systems question a Social sciences question if a person has GBM. What should you do on your exams?

In general, you need to have start having conversations with that person about hospice care Okay about hospice care and maybe like yeah, it's kind of weird, but I promise you that somebody can see on your test Because again GBM people are usually not gonna come back from from it Okay, people are usually not gonna come back from glioblastoma motif motif for me And again, remember the tumor marker for this is going to be a GFAB gliobularia acidic protein Again, the thing is for step two step three I mean, it'd be like who cares about these two markers? I promise you you certainly should care you certainly should care Because if you don't I mean, I kind of wish all the best But these days on the USM at least especially like over the last few months few weeks a little basic science stuff Things you want to make sure you want to start knowing especially when you're clinically relevant Just gonna keep that in mind. So glioblastoma motif for me the tumor marker is GFAB right Gliobularia acidic protein and again sometimes on the USM at least instead of colony glioblastoma motif For me they can actually just go ahead and call it an astrocytoma and live it at that, okay? So just be careful.

It's a kind of astrocytoma I get remember our friends at the USM at least the trading derivatives these days I don't mean like the trading the financial markets You know if you're finance person, but anyway, but basically like the critical thing I want to know is that On the USM exam, do you do the same these days of taking what you know and just describing in a different way right? So like oh glioblastoma motif for me Just why don't you go ahead and make it a Astrocytoma you're exempt so just just be be careful. Okay. Now what if they give you a question about a patient They tell you that over the last two hours the person has been having a The person has been having a very severe headache and they tell you that this person Has weakness of you know, they tell you that oh the person's right upper extremity, you know, the person has like 2 out of 5 strength in the right upper extremity and then you notice that the person also has weakness in the in the in the right lower face When you put all these things together, what should we be thinking about this is pretty easy? I just it's probably something I've actually mentioned this in the previous podcast But as well as say it again because I don't like to just Bunch this up on exams. This is something pretty straightforward.

This is a left MC is stroke Remember you need to know your homunculus for purposes of the USMLA exams You need to know your what your homunculus you need to know your homunculus your homunculus Classically again is gonna just basically tell you who what are the distribution of of problems, right? So if you see a stroke and it involves the Lower face and the upper extremities then you want to think about MC a stroke you want to think about a middle cerebral artery stroke a contra lateral Middle cerebral artery stroke to be honest with you. That's actually the most common vessel that is impacted in a present that has an Embolyx stroke the middle cerebral arteries the artery that's usually targeted, right? So you're gonna see the lower face and the upper extremities on the control outer side Remember the anterior cerebral artery is what controls the upper extra in the lower extremities, right? So anterior cerebral artery controls lower extremities middle cerebral artery controls lower face and upper extremities, okay? Just make sure you know those four patterns many times when you see an empty stroke question They're gonna give it to a person that has had a recent MI or a person that has a feb right because It's a reason why when you have a feb they put your anti-coagulation So you don't get these strokes because a feb causes, you know poor Movement of your myocardia, right?

It doesn't move in a coordinated fashion that can cause blood stasis if you remember verkylstrieth right stasis hypercualgillability And endophilial dysfunction. So that blood stasis is going to again I just kind of look at his like blood when he's hanging around doing nothing It does do an crazy stuff like forming a mullite then can flick off to the brain and brain and certainly cause a cause of problems Okay, now what if they give you a question about a five-year-old child and they tell you that this child his mom has noticed that for you know the last like You know two hours. He has had like a little bit of a mortal weakness and She tells you that you know sometimes she feels like the child has been panting and has not been doing very well and then we give you uh You know sometimes they can make this like a video question on your exams or you can give it like a picture of the child's skin And you see all these hypopigmented lesions on the skin and then they show you an echocardiogram again The USM is they're very smart people these days. They show you an echocardiogram And then the echocardiogram you see a mask within the heart when you put all those things together What should you be thinking about?

I really hope you're saying oh divine Sounds like you're describing tuberculosis to me I like wait what well let me explain Well first things first this person has always the cardiac mass Oh, okay, let's let's maybe break this down little by little So first things first what are the skin findings or the skin findings are gonna be those ash leaf spots the ash leaf spots Remember ash leaf spots are pretty characteristic of tuberous slurosis Ash leaf spots are pretty characteristic of tuberous sclerosis right and then you'd be like okay So divine like how did you get to the cardiac mass? Why would you show me an echocardiogram? The theme is Here's one thing I want to say we know that tuberous sclerosis is associated with cardiac ruptomioomas But some of you may be like divine how can I know from the echocardiogram that this is a cardiac ruptomiooma? You know, what is the classic characteristic feature of a cardiac ruptomioone exam? Let me tell you this You don't need to worry about that maybe like wait what? Yeah, you don't need to worry about that the thing is this many people studying for the USML exams they memorize a lot more than they need to The USML exams are about using the clues in the question to your benefit. I like to think of this term that I like to call like minimum needed information MNI minimum needed information many people did just memorize every single detail of every single blah blah blah blah blah blah blah blah And again, don't get me wrong.

There's nothing wrong with that. But the thing is What if the USML is choose to not emphasize a detail? I mean choose to emphasize a detail that you don't know The thing is one of the best ways to learn for the USML exams is to use context I say this to people all the time in my review courses I see it all the time when I work with people when I see this all the time You need to learn things in context. So, Hennis, we feel like for me. I don't care what are Uh, Rob Domayoma, which is the cardiac mass interversal ruses and let me don't care what it looks like But if I just look at the clues I see a child's picture. I see hypopigmented lesions on the skin And you know, maybe in the question they say this child has a history of seizures and all these things And then they show me an echocardiogram. I don't care what the echocardiogram shows I can predict literally what the echocardiogram has to be. It has to be a Rob Domayoma. Why? Because This this this this child very likely has tuberous sclerosis right so the thing is on the USML As you get better at learning with context you begin to acquire a lot of predictive ability You begin to acquire a lot of predictive ability because that's the thing like But what you see some people that don't learn with wisdom what they're gonna do is oh, okay Let me start looking at pictures of Rob Domayomas Oh, let me let me learn all the kinds of Rob Domayomas that exist Well, let me look at what it looks like on his stagy Um, you know what?

Okay, so an echocardiogram is usually here and is this and is that all that is good knowledge What is trash knowledge for the USML's is not gonna help you. It's not gonna help you right the thing is I know some of what I'm saying right now is pretty nuanced But if you're listening and reading the to listening between the lines you can be like oh, I see exactly what you're writing Right because like for example, I like to think of this like back from ideas studying organic chemistry You see people denombrize every single mechanism and I'm like man It doesn't make any sense. Why don't you learn the Concept and understand it and then learn the context when you do that You can then begin to predict what a mechanism should look like right?

So even if I don't let's say I'm a USML exam taker and I don't know what a Rob Domayoma looks like If I know that I get a tuberous lerosis question and it showed me an echocardiogram It literally doesn't make sense for them to test any other thing At least if you're just going based on probabilities the highest probability reason why they will show you any kind of Heart imaging in the person that has to wear sclerosis is because they are showing you the Rob Domayoma right and again Tuberous sclerosis right so that's why this child may have had a stroke because again So all these lesions can break off and cause problems remember cardiac masses on the USML Is have this weird tradition of breaking off and causing problems right like for example If people have like lefty trauma exomas those lefty trauma exomas Little bits of it can literally break off and become an embole stroke Right so that's just something I want to keep at the back of your mind here Right so what's the deal with tuberous sclerosis?

Tuberous sclerosis on your exams you should know that it's an orosomal dominant disease right Many times you can get it from one of two mutations You can either get it from a TSE1 mutation or a TSE2 mutation right TSE1 quotes for protein known as hemartin Is a protein final chromosome 9 a TSE2 goes for protein known as tuberin we find it on chromosome on chromosome 16 Right and you know basically like the problem that people have with tuberous sclerosis is that essentially They'll have abnormal mTOR signaling they'll have abnormal mTOR signaling okay abnormal mTOR signaling mTOR is a pathway that regulates a cell growth right so the thing is when you have abnormal mTOR signaling The thing that's going to happen is you're going to have like a lot of unregolytated cell growth a lot of unregolytated cell proliferation So because of these these people have a lot of hemartomas in different locations right because if you think of the proteins that I'm mutated hemartin and tuberine But what in the world does do hemartin and tuberin do well literally what their job their job literally their job literally is to Downregly the mTOR pathway so downregly the mTOR pathway So if they don't if they're mutated that you won't have downregulation of the mTOR pathway You have again crazy crazy crazy cell growth crazy crazy crazy cell proliferation So this will be a lot of start having hemartomas in many many different places right like for example You see them they have like these tubers in their brain right all these tubers in their brain can cause them to have seizures Remember one classic seizures is a sort that you love to test with tuberous chloroses on the exams are these infantile spasms Right sometimes we call that a west syndrome remember on an EEG you're gonna see a heaps a heaps a ribion Right again don't forget again these kids these kids they can have cardiac ruptomyomas the

y can have cardiac cardiac ruptomyomas And these kind of These kids that have tuberous chloroses they have cardiac ruptomyomas and many times They have the murmur of mitral regurgitation The reason I'm mentioning that is for you to be able to complete and contrast this with a with a left-itromic soma when people have a left-itromic soma Typically right the the The tumor obviously is a mixoma but mixomas typically create the murmur of mitral stenosis on the u.s.

Milly exams Right so mitral regurg with cardiac ruptomyomas and tuberous neurosis left-itromic soma's and mitral stenosis It's a kind of a subtle difference. But it's kind of a high-year difference to to know right And again if they give you like a question about a childhood tuberous chloroses and you see the creatinine is really really high But what's gonna cause that high-high creatinine? Well the thing is gonna cause that high-high creatinine it's gonna be an angio-mayo-lypoema right? It's a renomaster contains blood vessels that's angio-mayo-musso right and fat lipomas right? So those are all things you want to keep at the at the back of your mind right? And again remember they're gonna have these aschleaf spots on the skin those aschleaf spots They are high-po-pigmented macules sometimes they may use the term hypo melanotic macules on the skin right? You want to be able to compare and contrast that obviously With kaffee ole spots kaffee ole spots those are high-perpigmented macules on the skin But we see kaffee ole spots primarily neurofibromatosis Especially type 1 and type 2 right? That's something I want to keep at the back of your mind right?

So again, it's actually pretty pretty high-yield to know The different findings in tuberous chloroses right like the infantile spasms that I mentioned that causes seizures in these folks And usually you're gonna be in a kid that's pretty pretty young like you know very first few months of of life You're gonna treat that with acth You're gonna treat that with acth Although if you don't see that as an answer They can give a vi-gaba trait right? You can give vi-gaba trait And if you want to think about it like what's the most common cause of death in people that have tuberous chloroses? The most common cause of death is actually in your allergic disease right? They have just so many brain problems right? Your allergic disease is the most common cause of death The second most common cause of death is actually gonna be renal disease To be honest with you the easy way to remember this is just remember like NR not rated right? There are some movies that you know I like not rated you know Maybe they've not passed it through the board to get it rated as oh is it R-c 18 or whatever right? So not rated the N stands for not you know is the first letter right? And if you also think of it alphabetically N comes before R in the alphabet I believe so the N right the N The N the N your allergic disease is the most common cause of death the R Rino disease is the second most common cause of death.

Okay, so I'm gonna go ahead and pause here I think the this podcast was almost more like again I reviewed a ton of concepts but also like I try to introduce this concept of of the context Context and predictive ability. It's actually a very powerful thinking tool to use as you prepare for your exams And as you go through questions. It's something I want to build up over time. You always want to ask yourself This this answer I got to are there?

All the ways I could have got into this answer That's a very smart way to think and prepare as you study for the for the USML exams Again, I do offer one to learn for all the USML exams and for medical school exams And I have a bunch of review courses for step one step two and step three I literally have a podcast is like a five-minute podcast I meet recently on the class is coming up in August Those start on the third of August with a testicking class and then I have a biostatistics class I have a social sciences class Those are all for step one to step three and then I have a step two step three class Also in early August the 20-hour class and 25-hour step one class coming up in September So if you're interested in any of these classes listen to the podcast If you don't want to listen to the podcast just shoot me an email and I'll give you some more details on the on the classes And then I have these podcasts on the major apps Apple Google Spotify and then I Have a You Tube channel divine intervention Get some really podcasts and videos Then I have another website called divine intervention life lessons calm Basically I post two podcasts every week from a biblical perspective addressing the life lesson That's faced by many people so if you're interested just check those out There's actually an Apple podcast for that is called the divine intervention life lessons podcast Okay, and then also help with era's applications and personal statements and regulators and all those things Again, I've worked with tons of people that are now attendants residents at programs all over the country So if you're interested in any of these things just shoot me an email.

Well, thank you for joining me today I will see you in the next podcast. God bless you. Bye for now. Thank you

The tendency for leptomeningeal spread through the central canal of the spinal cord.

Ash leaf spots (hypopigmented macules).

Rorb Domeyoma.

Left Middle Cerebral Artery (MCA) stroke.

TSE1 mutation (codes for Hemartin) or TSE2 mutation (codes for Tuberin).

NR (Not Rated/Allergic Disease, followed by Renal disease).

Hemartin; Chromosome 9.

mTOR signaling (leading to uncontrolled cell proliferation).

Rosenthal fibers (or GFAP-positive eosinophilic/pink acellular material).

Rorb Domeyomas typically cause Mitral Regurgitation; Left Atrial Myxomas typically cause Mitral Stenosis.

Café au lait spots (hyperpigmented macules).

Middle Cerebral Artery (MCA).

Hemartin; Chromosome 9.

mTOR signaling (leading to uncontrolled cell proliferation).

Rosenthal fibers (or GFAP-positive eosinophilic/pink acellular material).

Rorb Domeyomas typically cause Mitral Regurgitation; Left Atrial Myxomas typically cause Mitral Stenosis.

Café au lait spots (hyperpigmented macules).

Middle Cerebral Artery (MCA).