DIP Episode 48 - Neurology Clerkship Shelf Review Part 5

Okay, welcome. My name is Divine. This is the fourth-eventh episode of the Divine Intervention Podcasts and we're going to continue reviewing material for the Neurology shelf. Neuro is a relatively large subject but I'm trying to break these up as well. But in today's podcast, Fair Warning, there's gonna be a lot of hairy stuff that's high yield but classically difficult for people to understand. So I will probably try to take my time here but I'll try to be as quick as possible as one. So let's begin. So the first question says a 32-year-old Asian male presents with severe right eye pain. Physical exam reveals a rock hard unreactive pulpill. So the question asks for the diagnosis, right? So this is obviously a cute and go closure glaucoma, okay? And I mean you can diagnose this with like tonometry and in general the way you treat this is ultimately you require some kind of surgery and usually it's a laser erudotomy but if that's not an answer choice and they're asking for drugs you could use you could give like a manateal to decrease in chocolate pressure you could give us a dizolomy that works as well. You can give a moschronic agonist like pylocarpin right? So if you remember from an earlier podcast if you give pylocarpin, pylocarpin is a moschronic receptor agonist so that will constrict the pulpill right and that will relieve pressure around the canals of Schlem okay?

Alternatively you could also give like a bit of blocker like Timolong okay but you're like Timolong acidosolomy, manateal, pylocarpin you probably want to do surgery, laser erudotomy and you can meet the diagnosis with tonometry okay? Good. So next question a three-year-old female is brought to the ED by her dad she has been using the potty continuously for the last three hours. Physical exam is notable for pupillary neosis and profuse sweating. She played in the farm ding ding ding this morning. What's your diagnosis right? So this is clearly organophosphate poisoning right? This patient is leaky from everywhere so this is a colonergic toxic drum and because remember your parasympathetic system right makes you pee makes you poop makes you sweat and all that stuff. Although your sweat glands are technically controlled by your sympathetic nervous system but they use a little colon as the neurotransmitter to mediate that that effect okay? The suspicion is leaky from everywhere this is organophosphate poisoning right? And for organophosphate poisoning there's two things you want to do right? But first off what do organophosphates do? Organophosphates right? The inhibitor cell colonester is and if you inhibitor cell colonester is right? Your levels of acido colon will build up because you're no longer breaking down acido colon okay?

So this is organophosphate poisoning so obviously if there's too much acido colon causing this problem you want to probably block acido colon receptors right? So that's what atropin will do for you. You can give atropin atropin will block the acido colon receptors and sort of like a maliorate many of those are pro-colonergic effects that are causing the clinical presentation and then if you want to regenerate the acido colonester is you want to use a pre-lidoxin okay? In the hospital I believe it's known as two pym okay? Pre-lidoxin regenerates the acido colonester is so again organophosphate poisoning give atropin plus a pre-lidoxin. Now flasey paralysis after consuming home canned goods right? That's botulism right? So this person has a flasey paralysis not a spastic paralysis. A spastic paralysis is associated with a clostridium tetmine but a flasey paralysis is associated with a clostridium botulinum. Remember the botulinum toxin prevents the release of acido colon at the neuromuscular junction. Next one difficulty getting out of a chair in a patient with a 45-pack here smoking history that improves with muscle use right? So hopefully you see this to be lumbarity myastenic syndrome right? So lumbarity myastenic syndrome is not the same thing as myastenia gravies okay? Myastenia gravies worsens with use. Lumbarity myastenic syndrome gets better with use okay?

And remember the pathophysiology behind LEMS is that you have the formation of auto antibodies against the presynaptic voltage-gated calcium channel okay? And that's a classic finding in an patient with small cell long cancer right? So he could arise as a primary or plastic phenomena. Now and one thing you may see on a neural shelf is that I told you that myastenia gravies gets better with no gets worse with use. Lumbarity myastenic syndrome gets better with use. One way they could present that to in an answer choices they could say oh the patient has increasing muscle contractility with repetitive nerve stimulation. If you see that the muscles are contracting better with repetitive nerve stimulation think about lumbarity myastenic syndrome but if you're thinking about a decrement in muscle contraction with repetitive nerve stimulation think more about myastenia gravies. Next question says difficulty swallowing and droopy eyelids in the 35 year old female with an anterior medius tino mass right? So again obviously this is myastenia gravies. The anterior medius tino mass is likely what? A thymoma right? Remember thymomas have an association with myastenia gravies and just while we're on the subject anterior medius tino mass is right those are your terrible t's like a thymoma or a teratoma okay?

A lymphoma could also be an anterior medius tino mass contrast that with the posterior medius tinum that tends to have mostly neuro tumors like a neuroplastoma or a paragon glioma right? Or if a feel if a feel cromo cytoma was to shop in the medius tinum it'll be in the posterior medius tinum okay? Very high you to know that. If you have interested more in why that's the why that's a thing I would encourage you to look up the organs of zooker candle but I don't have the time to talk about those right now okay? And again myastenia gravies you are making auto antibodies against the nicotinic acetylcholine receptor okay? So those antibody serve as competitive inhibitors of those of those receptors so the thing you do to fix that problem is you give an acetylcholine estrize inhibitor like like pyridostigmin remember pyridostigmin helps you get rid of myastenia. So pyridostigmin will inhibit acetylcholine estrize when you do that. They'll boost your levels of acetylcholine and that can outcompete those nasty antibodies that are attached to the nicotinic acetylcholine receptor and that would fix the problem. And if the patient has the anterior stenoma as the thymoma you should also get rid of that mass okay? You should get rid of that mass very high you to know that.

And then you give your non-specific question where like a patient has like myastenia gravies like you know from the clinical presentation that is myastenia gravies and then they could say oh in addition to tripping with pyridostigmin what is the next best step in the management of this patient? And the right answer may be to get like a chest CT or a chest x-ray because you just want to screen them for a thymoma right? Because if they have a thymoma that's causing their problems you get rid of the thymoma problem goes away. So sort of watch out for that non-descript scenario on an exam. Now how do you distinguish myastenia gravies from chat deficiency? So some of you may not know what chat is right? So the thing is chat is calling acetyl transfer is right? It's basically the right limiting enzyme in acetyl cooling synthesis. It combines cooling and acetyl co-e to make acetyl co-e okay? So the thing is it can actually a chat deficiency can actually cause like a congenital myastenic issue right? So the phenotype well I guess the clinical presentation will be the same as myastenia gravies but the way you differentiate between them is based on the response to tens cell and tens cell and is an adrofoneium adrofoneium is a super short actin acetyl co-e in esterase inhibitor right? So the thing is think about it if a patient has myastenia gravies. You give them adrofoneium you can give it acetyl co-e in esterase the acetyl co-e levels go up right?

That will go that acetyl co-e in will outcompete the nasty antibodies and your problem is fixed. Note that in myastenia gravies these people have no issue making acetyl co-e they're making acetyl co-e in just fine but there is something taking the place of acetyl co-e in on an acetyl co-e in receptor. Now if a patient has a chat deficiency they're not making acetyl co-e in at all right? So even if you give those people adrofoneium which is an acetyl co-e in esterase inhibitor you will not boost their levels of acetyl co-e right? Because there's no acetyl co-e in being made in the first place. So failure I guess the way I'll put it is if your symptoms improve with the administration of adrofoneium you're thinking about myastenia gravies. If your symptoms do not improve with the administration of adrofoneium that argues against myastenia gravies as a diagnosis. That is more likely a chat deficiency of co-e in acetyl transfer is deficiency. Although the diagnostic test these days for myastenia gravies is just to check for anti acetyl co-e in receptor antibodies okay? So no one really does the tensile test anymore. Now the neuromuscular junction right? The pathologies are basically highlighted all of them. A highlighted lumbarity and myastenic syndrome where you make autoantibodies against the pristine apthic voltage gated calcium channel okay? Gets better with use okay?

You have increasing muscle contraction with repetitive nerve stimulation and don't forget the association with a small cell lung cancer. And then myastenia gravies autoantibodies against nicotinic acetyl co-e in receptor. You can do a thymectomy to get rid of the thymoma or you can also give a pyridostigment to get rid of myastenia gravies. And then I talked about chat deficiency and then I talked about botulism right? You're no longer by cleavant snare proteins right? So that's more throwback to step one. You're not letting vesicles that have acerocholine in them released that acerocholine at the level of the your muscular junction. So you get a flasiperalis okay? Versus tetanus where you the tetanus spasmin right? He prevents the release of glycine and GABA at the neuromuscular junction right? And sorry not at the neuromuscular junction right? So you prevent the release of glycine and GABA from arrhynsia cells. And if you don't release those inhibitor in neurotransmitters your muscles will stay like tonically contracted if you make okay? So you have a spastic paralysis in tetanus versus the flasiperalis that accompanies that accompanies botulism. And again I've talked about the pharmacology for myastenia gravies for example right? You give an acerocholine esterase inhibitor that will boost your levels of acerocholine you out compil those nasty antibodies.

I also talked about organophosphate poisoning again you give an acerocholine no you give a muscarinic receptor blocker like atropine okay? And then you also give something that will regenerate the acerocholine esterase like prelydoxy. And then for botulism generally you give like like like botulinum immunoglobulin to bind up the toxin okay? And then you may need to like into be the patient to give them like respiratory support okay? And if a patient has like an acerocholine like deficiency right? So in the first part like the Kipling in the farm that was organophosphate poison that was a procholineurgic toxidrum right? An anticholineurgic toxidrum classically on exams they will arise with like drugs that have anticholineurgic activity like a diphenhydramine right? It's a patholantiestamine but it's very good at blocking muscarinic receptors. Another classic one on exams is tricyclic antidepressant okay? Remember TCA's have anti-hamm side effects right? So they have anti-hammistamineurgic so they can cause sedation, anti-alpha one effect so they can cause both steric hypotension and then they also have anti-muscarinic effects okay? So they can cause like an anticholineurgic toxidrum. Another classic group that causes the same thing are your first generation low potency typical anti-psychotics okay? Like clopromazine for example okay? Has very significant anti-hamm side effects right? So the M distance one time muscarinic effects okay? Very high yield to know those.

So the person will be like hot as a hair, dry as a bat or whatever it's called but you know what I'm talking about I believe I've talked about it in a in a previous podcast okay? So next slide yeah that was a long one. So thong fast equalitions in a six month old right? So hopefully you know this to be what? I've mentioned this in actually it's one or two previous podcasts right? This is spinal muscular trophies okay? So they will describe a kid six months starts losing Muromal stones that's by normal muscular trophy. Remember it's in herithelin and rosomor recessive fashion okay? And the pathophysiology involves having mutation in the survival Muron urine one gene okay on chromosome five. So your lower Muron urans are affected it's a pure lower Muron urine disease okay? Don't forget that the West now virus and the polio virus also preferentially nuclear anterior horn cells right? So your low Muromodo neurons okay? Now thong fast equalitions in a 65-year-old male with asymmetric weakness right? So I really hope you're thinking about ALS okay? Myotrophic lateral sclerosis also known as Lou Gehrig's disease okay? ALS it's characterized right by like upper and lower Muron urine problems right? And really like if they want to go after a neuron not a million-year test they could ask you like what are the specific structures that are destroyed that lead to the clinical presentation of ALS? The things that are destroyed are three okay?

You destroy your upper Muron urans so that's your corticospinal tract you destroy your lower Muron urans that's the anterior horn of your spinal cord okay? And please do not forget that your cranial nerves are also lower Muron urans at least some of them okay? So at least the ones that are Muromodo cranial nerves okay? Your cranial nerves actually lower Muron urans the upper Muron urans that correspond to your cranial nerves are what constitute the corticobal tract? There is such a thing as the corticospinal tract which controls the lower Muron urans that constitute the anterior horn of your spinal cord but the upper Muron urans that actually correlate with the lower Muron urans that are your cranial nerves is at least your Muromodo cranial nerves that's actually the corticobal tract it's a concept that's not often discussed but it's actually kind of high you to know if you really think about it and then the third thing that's so three things corticospinal tract cranial nerves because they also lower Muron urans unless your Muromodo cranial nerves and also the anterior horn of the spinal cord right? And familial ALS right? Hopefully you remember like a superoxide dismitis one mutation and SOD1 mutation okay? There's another one that may shop out of the blown an exam so I'll just mention it it's C9 or F72 is just some of those things you're like divine come on there's no way this will shop on a test well think again okay?

Just sort of file that somewhere in your mind C9 or F72 but the most common one you'll see on exam says an SOD1 a superoxide dismitis one mutation okay? And remember sensation is spared in ALS sensation is spared and ALS on exams generally does not involve extra ocular muscles okay? does not involve extra ocular muscles and there's almost never bowel or bladder dysfunction in ALS on MB Ms so you want to keep those facts at the back of your mind? And the thing is many times on MBM is they may give you an answer that describes an EMG finding the thing is I mean like to read EM Gs you probably need to complete like some kind of neurology fellowship right? So obviously we can't do that right? So there are certain buzzwords I'm going to say out loud that I think you should remember for ALS they love to test test those are weird things right? So the buzzwords we want to remember on EMG for ALS is that you'll see chronic denervation and like evidence of chronic denervation and innervation or you may see a buzzword that says like a Fibrileation potentials okay? If you see those buzzwords think about ALS right? I already talked about a buzzword for myastinia gravis decremental muscle response with repetitive nerve stimulation right? Or for um what is this other thing I just talked about? For Lumberid etymasthenic syndrome right? You have an incremental not decremental decremental is like a decrease that's myastinia gravis incremental is an increase right?

That's Lumberid etymasthenic syndrome an incremental response with with repetitive nerve stimulation think more about a Lumberid etymasthenic syndrome okay? And the thing is there is actually only been two things that have been shown to improve survival in ALS okay? One is Ryluzol remember Ryluzol is used to treat Lou Gehrig's disease okay? Ryluzol is an NMG receptor antagonist so they think that by blocking NMG receptors it sort of shuts down that whole concept we throw around in medicine of a glutamate excitotoxicity so that you don't destroy the neurons that are noctinum in ALS. The other intervention that has actually been shown to improve survival is the use of BIPAP okay? So that's just something you want to keep at the back of your mind. And then an off point is a really tested factoid but I'll just throw this in there. If a patient has ALS and they have spasticity or they have like MS like multiple slurs and they have spasticity or they have a cerebral palsy and they have spasticity you could give them backlofen. Backlofen is a GABA B receptor agonist okay? So it sort of calms down the spasticity. Alternatively it's like a foco spasticity right? So like if a patient has like a foco dystonia or something like that you can inject Botox and calm down those muscles because those muscles will stop kind of contracting because you're no longer releasing acetylcholine at the neuromuscular junction. Another way to draw your mission and examine is Tisanidin.

Tisanidin sounds eerily similar to Chlonidin right? So it's an alpha-2 agonist. It decreases the release of Norepinephrine and that actually reduces spasticity in ALS as well. Any other kind of hyper spasticity disorder? Okay so next question next question next question says differentiating the model from polymyocides right? So age demographic, cell type, mediating, muscle destruction, histologic findings right? And then I'm asking for the classic presentation. I'm asking for the associative autoantibodies right? And then I'm asking about the stepwise diagnostic testing and the treatment and then associated malignancy. So that's a lot of questions so let me just sort of deal with all of them along with ones. Okay so the thing is if I review if you're listening to this podcast right now I would make a chart okay I also talked about these differences in the medicine review video. So the thing is the meromaocytis right occurs in kids okay? Polymyocytis occurs generally in adults on exams that's one different second one the meromaocytis is mediated by CD4 positive B cells. I mean sorry CD4 positive T cells. Polymyocytis is mediated by CD8 positive T cells.

So here's the thing you may say how divine come on this is kind of hard to remember let me just give you a trick that I use but the thing is it does not work in one instance so you need to memorize that other one instance but the thing is if you notice if you're looking at the alphabet D comes before P in the alphabet so the meromaocytis comes before polymyocytis in the alphabet okay? So that's like the strategy like what comes before what logically? Now next thing notice I said the meromaocytis is more common in kids. Polymyocytis is quite common in adults right? So before you become an adult you're a kid first okay? But don't take this to mean that the meromaocytis does not occur in adults. In fact the most common person that gets the meromaocytis on exams is an adult okay? But the meromaocytis is quite common in kids. Polymyocytis is quite common in adults okay? So that's the high you thing to know. Now third thing notice four comes before eight if you're looking at the number line right? So CD4 positive for the meromaocytis CD8 positive for polymyocytis okay? And those are T cells. And then don't forget that you have so this is the one instance you need to memorize where that does not work. You have perifacicular damage or inflammation in dermatomyocytis and you have endomisial endomisial damage in polymyocytis. So it's like oh P actually comes after in the alphabet okay? So that's just another weird thing you sort of have to like stone your brain okay?

And yeah so she did auto antibodies right? There's like anti-jewon anti-MI2 they have like weird names. There's another weird one it's called like an anti-signore recognition particle. So anti-SRP. For those of you that hopefully study for step one in the past right? The signal recognition particle is what snakes in and incompletely synthesized protein to the endoplasmic reticulum. When it's been made on a bound ribosome remember a bound ribosome is one that is attached to the endoplasmic reticulum but that's the one for them not gonna go there any further. If you have any questions and that just send me a message or something. Okay now the thing is before the diagnostic test for polymyocytis the metomyocytis was to do a muscle biopsy but that is no longer the first line diagnostic test okay? The first line diagnostic test for I mean obviously you'll check the creatine kinase will be high well big surprise. The first line diagnostic test these days for polyodemato myocytis actually to do a muscle MRI. Okay? Many times you can make the diagnosis just by doing an MRI but if the MRI does not show you what you're looking for then you can proceed to doing some kind of muscle biopsy okay? And usually they also do some kind of imaging with that as well. And don't forget that polymyocytis the metomyocytis they actually show up as per neoplastic phenomena in the certain in the setting of lung cancer okay?

Especially like small cell lung cancer so that's one thing you want to keep at the back of your mind. So one weird thing I just decided to throw in here because I can easily see them putting this on a test and like essentially everyone will get it wrong but you don't get it wrong because you listen to this podcast is if they give you the combination of dysatria trunco, gait and limbic taxia in a patient that is subsequently found to have lung cancer. So the thing is this if you're thinking like itaxia, limbic taxia, dysatria, right? That's sort of localizes to the cerebellum right? And the thing is if I'm giving you a question in the context of lung cancer I'm really really hoping that you're thinking about a per neoplastic phenomena okay? The per neoplastic phenomena I'm actually going after here is something known as a per neoplastic cerebellidigeneration okay? Per neoplastic cerebellidigeneration has a very strong association with lung cancer but it also has a pretty solid association with breast cancer as well okay? So the on the line pathophysiology I mean people are not exactly sure but what I've already read in the literature is that these tumors express cerebelloproteins and then when the tumors express cerebelloproteins the anti tumor response that your immune system mounts right? Again those cerebelloproteins ends up like as an off target effect destroying the cerebellum okay?

So the phenomenon is known as per neoplastic cerebellidigeneration and it's actually kind of high yield to know that there are two classic autoantibodies associated with per neoplastic cerebellidigeneration they are known as anti-hue so anti-hue and anti-u so that's like anti-y-o okay? So anti-hue and anti-uantibodies very high yield to know that it's just one of these things I can sort of like fill in my veins that it may shop on an exam in the future if I'm not mistaken I may have actually seen this tested already okay? So that is let me see is there any other thing I want to cover on this like um no that's it so let's move on to the next one so confusion of thermoplysion attacks in an alcoholic right? so this is wani kis right? and then what's the diagnosis if you added a forgetfulness to the picture or making stuff up to the picture right that's a confabulation that's korsakovsikosis right? so it's a longer spectrum wani kis is reversible korsakovsikosis is not reversible okay? and in general the way you treat these problems is with ivy thiamine vitamin B1 right? because remember they think that oh people that have wani kis they have problems with the transketolise that's one of the big enzymes in the non-oxididi phase of the hexal monophosphate shunt which I believe is also known as the pentose phosphate pathway um and then I didn't really see any place to throw this in so I decided to put this here how do you manage hepaticansephalapathy right?

the thing is hepaticansephalapathy there's a couple of things you could do right? so you can give lactilos right? it'll convert ammonia in the gotroamonium so you pop out the ammonia that way because ammonia is not reabsorbed at least for the most part and then you could also give antibiotics right? because remember a lot of ammonia in the body actually comes from the bacteria in your GI tract so you can just kill them I don't know if that sounds kind of morbid you just kill all of them and you can kill them with a bunch of drugs if you see this drug on your exam go with this drug first refaxamine refaxamine is actually a preferred agent for killing off GI flour okay? because it has very few side effects but other drugs you may see on an exam is like new micein remember new miceins and amino glycoside those are your 30 years back to your side all agents um you could also give vancomycin or like oral vancomycin because remember oral vancomycin is not reabsorbed right? so he stays in the GI tract and kills off everything alternatively you could also give metronidosol but the problem with metronidosol is in patients with hepaticansephalapathy there's been a lot of studies that show that they tend to get peripheral neuropathy when they take metronidosol okay? so think more about lactolose refaxamine okay?

in fact I'll tell you this let's assume you got like the most evil question in the world where they put lactolose and refaxamine as answer choices go with refaxamine refaxamine is if I'm not mistaken the first line medication these days for the treatment of of hepaticansephalapathy okay? so next question simple partial seizures right? so there is no loss of consciousness with simple partial seizures and now classic presentation with respect to localizing principles right? and then I'll sort of talk about the different simple partial seizure types okay? so again this is high yield this is one of those things you can almost guarantee you'll potentially see on an exam so the thing is a simple partial seizure right? it's essentially a focal seizure okay? and you don't lose awareness you don't lose consciousness with a simple partial seizure and the thing is there are four kinds of simple partial seizures right? there's like a motor seizure there's like a motor simple partial seizure there's the sensory kind there's the autonomic kind there's the psychic kind right? and the thing is I will just encourage you to sort of pay attention to these bus phrases that I'm going to rel out over the next minute so the thing is the motor seizures right? those ones tend to present as like a focal like rigidity or jerking or van extremity right?

so they can just say oh patient suddenly feels that one hand is uh one hand is uh uh uh one hand is like like very stiff and very rigid if you see that I really want you to think about um I really want you to think about a model simple partial seizure and another thing for a simple partial seizure like I said earlier is a focal seizure without loss of awareness okay? so um if they tell you that the patients have like has like focal massuridity or like jerking of one extremity that's most likely a model simple partial seizure and then a sensory one they may describe like a patient saying that they hear like a hissing sound so basically like like sense like weird sensations right? like uh like oh they can't see during the uh the seizure episode or they can't hear or they hear like a hissing sound or they smell like burnt rubber or stuff tastes weird to them or they feel like where touches on their face think about a sensory kind of simple partial seizure for the other dynamic kind you want to think more about like they may say like oh they sweat during the episodes or they have like my dry asses during the episodes or um they have like um a rise in sensation in the abdomen uh during the episode right? those are more autonomic um issues um and then the psychic kind that's the one where um there's almost always no real symptom there so that one I'll say is probably you'll probably never see it on an exam okay?

and the thing is localization so the thing is your homunculus is actually pretty helpful here so if for example a patient has like focal sensory or motor problems right? um you can basically look at like that to like the contralateral like frontal or parietal loop okay? but if they tell you that the patient has like errors and it's like a simple partial seizure like errors of fear or they say like they have like the smelly weird stuff or they're hearing weird stuff like a hissing sound or like a deja vu experience where they're like this thing looks like something that has happened to me before or they have like a rise in sensation in the abdomen think more about the temporal loop just think of the temporal loop as being associated with weirdness okay? so that is all I believe I'm going to say with respect to simple partial seizures so next slide the next slide says required imaging before recommended sports in a fish in a 12 year old with a history of trisomy 21 this concept I must tell you is like ridiculously high for exams like you like this can essentially be tested on any shelf exam even psychiatry very high you to know this the thing is this child you want to go ahead and do a lateral neck x-ray because you're trying to roll out something known as Atlanto axial instability okay? Atlanto axial instability you don't want to have them like a half spinal cord injury because you didn't do a lateral neck x-ray okay?

so Atlanto axial like sub-location on stability has a very strong association with Down syndrome now there's some other high-yield disorders that have that association right?

so rheumatoid arthritis the classical wheel test that is they'll talk about a patient with R a that is about to get surgery right that requires intuition before you into being a patient with R a if they've not done that study before make sure they get a lateral neck x-ray to allow that mantle axial sub-location and then the last group is a patient with a histro vanquilo since on the lightest again you want to roll out Atlanto axial sub-location with this I promise you like over the next year if you're like a 30-year-old student you'll see this concept tested about 15 times and they always put it as a non-descript question so people get it wrong and also a lateral neck x-ray I'll also say this probably more for a surgery shelf is indicated for a patient that's that like a trauma patient we are trying to roll out C-spine injury okay choose a lateral neck x-ray as against the CT scan the thing is in the real world everybody does a cat scan because it gives you better like better pictures right but on NBM is a lateral neck x-ray until the make changes at least in my experience is what is correct for ruling out C-spina injury okay good next question so next question says 25 year old male goes into respiratory failure he recently recovered from a 70 episode of bloody diarrhea ding ding ding physical exam is notable for pronounced ear reflexion the low extremities bilaterally his parents report that he had muscle weakness that started in the legs and progress upwards okay symmetric ascending flaccid paralysis okay initially complete of leg tingling and numbness before his other symptoms started what is your diagnosis and this person patient recently had bloody diarrhea well I really hope you're thinking about GBS Guillembray syndrome okay remember it's an autoimmune disease that affects myelin proteins right it's like a peripheral demylineating disease if you make okay so th

e cells that are affected right in this case will not be oligodendrocytes the cells that we affected will be your shwan cells right because those are the things that myelinita axons in the peripheral nervous system okay I remember one shwan cell myelinita one axon versus saline oligodendrocytes that like a single elingo oligodendrocytes myelinita multiple axons okay and classically on exams right it's appreciated by like a viral or like a bacterial infection of some sort okay both classically on tests think about bloody diarrhea from Campilo Bacterge Junai very high you to know that and the classic CSF findings writing Guillembray syndrome right I've talked about this in a prior neuro podcast is this thing known as a abumino cytologic dissociation right because remember when I talked about the I had like a meningitis spilling one of the podcasts I said that if the white cell count in your CSF is high on a lumbar puncture usually your white cell usually the protein like the proteins if you measure the protein in the CSF will also be high right so there is an agreement between the amount of protein being high and the amount of white cells being high okay so you have like let me invent let me invent a word like you have agreement you have like a biuminosidologic agreement if you may that's the normal situation but in Guillembray syndrome you classically see a very high protein count in the CSF you you check the number of white cells and they almost nonexistent okay there is not a agreement between those two that is why the buzz word is known as a abumino cytologic dissociation very high you to know that and the thing is on exams here's one way they can mess with your head instead of putting Guillembray syndrome as an answer choice they may put this term a IDP a IDP stands for acute inflammatory demylineating pulineuropathy okay that's one way they like a IDP like basical

ly it's Guillembray syndrome that's just a fancy shmanseeming for Guillembray syndrome so just sort of keep that in the back of your mind and really the way you treat this is with you can do like plasma for recess or you can do IVIG IVIG is probably the preferred answer on exams okay and then we had an association at the bottom because your neurologist they love the atrivia right just like the radiology people as well but basically if they tell you that a patient has like a Guillembray like presentation but they also tell you that the patient has mastagmas and ataxia I want you to think about Miller Fisher syndrome okay Miller Fisher syndrome that's all I'm gonna say about that it's just something you want to be able to recognize on a test and then the next question says pathophysiology of the subclavian steel syndrome and I'll talk about the classic exam presentation and then I have a slide where I try to like draw something to sort of make the point clear okay so let's talk about subclavian steel syndrome right so basically they will describe a patient that when they use their arms they have like syncopy or like neurologic deficits or they have like a blood pressure differential in the arms okay think about subclavian steel syndrome so I'll encourage you to jump to the next slide let's talk about the pathophysiological quick so the thing is the sort of like the inciting event for Guillembray so cleviants steel syndrome so triple S so I'll just call it SSS so the inciting event for SSS is that usually what happens is you have like some kind of proximal subclavian stenosis okay but remember that the subclavian artery has many branches right like the vertebral arteries for example so the thing is if you have a proximal subclavian stenosis right there will be less blood flow prior to that stenosis so it's like you essentially have like more blood flowing on the opposite

side that does not have the subclavian stenosis so in this diagram for example if you take a quick look at this you'll see that the stenosis the proximal subclavian stenosis is on the left side so you have increased blood flow in the right vertebral artery okay so the you have many increased blood flow in the right subclavian so you have increased blood flow in the right vertebral okay so it's like blood flows boom boom boom right vertebral and then it gets it approaches the basilar artery okay but if you look at the diagram which is actually somewhat realistic although I know I'm not the best at art but you get the point the basilar artery and the vertebral arteries bilaterally is actually kind of like a closed loop system and the thing is distal to the stenosis of the left subclavian right you're basically creating like a low pressure system right because if you compare the vertebral artery and subclavian artery in this case the distal subclavian artery the distal subclavian artery is longer than the vertebral artery and the distal subclavian artery is wider than the vertebral artery if you're thinking about Poiselle's Loll and encourage you to go back and do like your cardiology research although I think actually talked about this in one of the first podcasts I ever made it's probably like episode four or something like that but basically according to Poiselle's law right the vertebral the left subclavian artery is wider right so because the radius is bigger the resistance there is lower okay so relative to the left vertebral the left subclavian at least the left distal subclavian so distal to the stenosis has lower pressures so that actually creates like a suction like effect that draws blood from the vertebral arteries okay so you're basically still in blood that would have gone off the basilar artery and you're still in it to the subclavian artery on the side w

ith the stenosis especially when you use that epsilon lateral upper extremity because you're calling on more on more oxygen and nutrients okay so that's why it's called the subclavian still syndrome so really hope this gives you like an idea as to what's going on and the vertebral basilar problems they get right is again because your hyper perfusing the brain stem because not enough blood is flowing in the in the subclavian I mean in the basilar artery and then the last thing I'll just say this just came to mind there's this weird thing known as paje shoulder disease okay basically it's like thrombosis that occurs in an upper extremity vein if a patient uses that upper extremity like a ton like if the patient is like a jackhammer or a weightlifter or something okay just of those weird things you just want to like follow in your mind for the future it may show up on an exam you you see okay so let's jump to the next slide okay so this is the really hairy part of this presentation in fact I'm not making this a question I'm just gonna explain okay and the thing is I'm going to explain this in in two different ways just to make sure that I really get the point home so the Weber and René tests okay the Weber and René tests so the thing is these tests they are quite annoying to learn actually okay so I'm gonna try to simplify them for you the thing is I think the first thing we should try to establish is knowing what the Weber test does and what the René test does okay the thing is the purpose of the Weber test or if you're German I guess you could call it Weber but whatever so the Weber test it basically compares bone to conduction in both ears okay so it's a test of both ears it compares bone conduction in both ears the René test what it does is it compares air conduction to bone conduction for each ear so the Weber test is a double ear test the René test is a single ear

test okay the René test compares air conduction to bone conduction in each ear okay now one big thing you want to realize is that none of these tests can be performed in isolation okay you need to do both pretty much at the same time to be able to localize the exact kind of of hearing loss and the thing is I mean a couple of approaches you could take with this right you could just memorize a chart it's probably an easy thing to do but the thing is on exams you're very good at writing the questions in like weird ways where like all those patterns you sort of like at least the stuff you memorize like word-for-word may just sort of fall apart okay and the thing is almost always people forget the chart they've memorized so just actually try to understand it if you understand it then you can sort of reason through whatever scenarios thrown in front of you on an exam so let's go to the next slide so let's talk about some rules I'll talk about it in words and then I'll talk about it and then I'll go with them just to again press this point home so the thing is under normal circumstances air conduction is better than bone conduction okay air conduction is better than bone conduction right and again that should make some sense because before you hear something in your brain right it has to go through your outer ear first so that's like the conduction part of things right and then it then has to go through your cochlea that is like the sensation part of things like the sensory neuro part of things so think of air conduction as dealing with conductive hearing and bone conduction as dealing with sensory neuro hearing okay so air conduction is better than bone conduction that is the normal circumstance now when bone conduction is better than air conduction in a given ear okay so this is another you want to keep in mind when bone conduction is better than air conduction that is abn

ormal okay but that just means that things sound louder in that ear okay things sound louder in that ear and the truth is no one really knows why this is the case at least from all the like literature reviewing that I have done but people think that oh it may relate to having increased hair cell sensitivity in the ear that has bone conduction being better than air conduction okay but the thing is if something sounds louder in an ear right and bone conduction is better than air conduction it means that that singular ear has an issue with the conductive component of hearing okay because that means that air conduction has been knocked out in some way shape or form okay so the Weber test again helps compare bone conduction in both ears okay again normally bone conduction in both ears should be the same okay things should sound the same in both ears that's why men shouldn't say oh they put one their hand by your ear to test cranial nerve eight do you hear this do you hear this so this sound similar you say yes that's that's that's that's that's that means not a Weber test exactly but this sort of testing cranial ape function things should sound the same in both in both ears okay so but if things sound louder in one ear compared to the other so let's say like things sound louder in ear a the other ear will be ear b okay so just kind of stick with me here this is where things get a little hairy if things sound louder in one ear so let's say oh things are sounding louder in ear a based on your Weber test there's something bad going on okay now the thing is there are two potential explanations for why things are sounding louder in ear a one explanation could be based on what I already said it could mean that ear a has a conductive hearing loss problem okay as I mentioned again like literally in the second paragraph on this slide okay but another thing that may be happening is

that ear b the other ear may actually have a sensory neuro here in problem okay so that things as sounding softer in ear b relative to ear a so things as sounding softer in ear b then obviously ear a things will sound a lot louder in ear a compared to ear b okay so again if you were like oh something sounds louder in one ear they are one of two explanations for it is either um you have a conductive hearing problem in the epsilon error ear that things are sounding louder or you could have a contralateral sensory neuro hearing loss because if you have a contralateral sensory neuro hearing loss that contralateral ear things will sound softer in that ear and if things sound softer in that ear then the epsilon error ear that actually has no problem that things are sounding louder in will obviously sound louder relative to the other ear okay so again let me exceed this again if things sound louder in one ear compared to the other on a Weber test that is not normal there are two potential explanations you would either have a conductive hearing loss in the ear ear thing sound louder or you could have a contralateral like a sensory neuro hearing loss in the ear that things in the ear that is contralateral to the ear ear things as sounding louder I know it's very annoying uh a neuro can be a very frustrating subject for people but it's actually kind of fun if you understand what's going on and again I will explain this in another fashion in fact this is me repeating it again for emphasis things could be sounding better in ear a because it has a conductive hearing problem that's deep cellar or ear where things are sounding louder because again remember on the previous slide I slide I said that um thing sound louder when bone conduction is better than air conduction in a given ear okay so ear B could be totally normal that is one explanation the second explanation could be that e

ar B could have a sensory neuro hearing loss okay so ear B could have a I'm correct myself I typed in the wrong thing let me just do it right now so I don't forget so ear B could have a sensory neuro hearing loss so things sound softer in this in ear B relative to ear A or you can express it another way stop sounds louder in ear A relative to ear B okay so please make sure like if you need to pause and rewind make sure you understand this it's like I promise you it is very important because most people just give up give up on this concept and just sort of say no I'm not gonna bother about this okay so please just um be here with me and rewind and listen to this again and again I will explain this on the next slide just for emphasis again so how do we basically determine which of these two potential issues is true the thing we do is we then do the rene test that's why the rene test is done in uh in association with the Weber test so the thing you're doing the rene test is you place a sound tuning fork on the mastoid process okay and then you place it just outside the ear um the thing that should happen is that so well let me explain the test right so sound the tuning fork you place it on the mastoid process when the patient says oh they've stopped hearing when you place it on the mastoid process you're testing bone conduction when the patient says oh doc have stopped hearing you then move that tuning fork to like the outer ear right the normal situation is that they should still hear something in the outer ear because again I say that the normal situation is that air conduction is better than bone conduction now if from the rene test your results are that oh air conduction um is not as good as bone conduction then some kind of conductive hearing loss is present and since we already said from the previous slide that oh um one of the two scenarios that could create that

issue is having a conductive hearing loss in the epsilon error here so like ear A then that means ear A is the lesioned ear okay but I think for this last part probably the next slide where I have the algorithm will help make things make more sense so let's talk about this real quick so I made this in one note so hopefully you see my writing so the rows again normally air conduction is greater than bone conduction okay and AC is air conduction BC is bone conduction okay so basically like your conductive hearing is better than your sensor and your hearing okay next really is that things should sound the same in both ears things should sound the same in both ears that's the normal situation okay um so let's say you do the Weber test and remember I said that the Weber test contacts bone compares bone conduction in two ears in both ears okay if you do the Weber test and things sound louder in one ear that is abnormal okay one of two things are going on either you have an epsilon error conductive hearing loss or a control lateral sensor on your hearing loss and notice the parentheses I put that things sound softer in the control lateral ear okay so that means the normal ear like things sound relatively louder in that ear okay so the so those two things out you do are the rene test and I say that the rene test is job is to compare air conduction and bone conduction in a singular ear if the air conduction is greater than bone conduction that is the normal situation so that means the ear that things are sounding louder it does not have that will then tell you that you have a control lateral sensor in your hearing loss but if you do the rene test and the bone conduction is greater than air conduction that is what you see with a conductive hearing loss and we said that one of the two options is having a conductive hearing loss in the epsilon error ear so that would that be then

be that the epsilon error ear has a conductive hearing loss so please make sure you understand this if you have any questions on this let me know and I'll be happy to explain this to you because this is just something that I think is very understandable it's confusing at first once you get you be like quick wow I suffered some for so many years trying to understand this stuff okay so try to make sure you understand this here in business so our last question and then I'll sign off many anxieties in a HIV positive patient right hopefully you're thinking about a Coxibioid is imitis okay and the way you treat this is with amphoterrable okay give amphotericin B plus five flu cytosine okay and then chronically for like a year you give like flokonazo and remember that you can identify cryptococcus whoops did I say Coxibioid is whoops sorry if I said that meningitis in an AIDS patient sorry about that is a cryptococcus near formance okay and remember you can I did that with with the india ink stain or you can do like a latex agrotination or acid or something okay now but the treatment is correct amphoterrable so amphotericin B does the agostral binder plus five flu cytosine which is converted by cytosine the aminist to five FU which inhibits timidilitsin these in the bug and then multiple ring enhancing lesions on MR imaging in a HIV positive patient right so your differential is one of two things is either primary CNS lymphoma which is usually a solitary lesion or neurosis dysercosis which is usually multiple lesions okay so ring and enhancing lesions brain HIV patients think about primary CNS lymphoma or neurosis dysercosis so how do you treat neurosis dysercosis?

Nursysysercosis you treat that with sofford diazine and pyramethamine okay and the way you profile acts against this right what am I seeing with things today I'm sorry I'm sorry I'm sorry I've just sorted through way too much material today it's not neurosis dysercosis is toxoplasmosis toxoplasmosis toxoplasma gondii and you treat that with pyramethamine and sofford diazine that is correct no one mixing up these bug names for some reason today apologize so you treat that with pyramethamine sofford diazine and the thing is if your cd 4 count is less than 100 right so it's supposed to give back trim trimethoprem sofford methoxazone as prophylaxis against toxoplasmosis and then for CNS lymphoma right classically that's actually with EBV okay but usually the way you diagnose CNS lymphoma is you're like oh patient has HIV the hovering and hands in each other like okay this likely um um toxop toxop right and then you give pyramethamine sofford diazine you're like this person does not appear to be getting better like okay that's not good and then you maybe do like some kind of biopsy and then discover that it's primary CNS lymphoma primary CNS lymphoma is not very treatable although if you give highly active antitrivial therapy that would actually reverse course with that disorder sometimes they also give chemo but I wouldn't worry about the treatment of primary CNS lymphoma that's really if ever tested on NBM is at least at the the level I'm discussing um so next question is mini mental so again first bug meningitis HIV patient is crypto ring enhancing lesions HIV patient is toxop okay and you prophylaxis with back trip when the cd 4 count falls below 100 now next question mini mental status exam is uh mms is 20 over 30 in a patient with a cd 4 count of 25 and a high viral load he lost so his pcp um after an initial diagnosis 21 years ago so this is HIV associated dementia oka

y um does the diagnosis this is almost terminal basically if you have HIV associated dementia these people are probably they don't have a very good prognosis at that point where you can try highly active antitrivial therapy you can give uh the drugs that I use for Alzheimer's dementia like a donepasil gallantamine rivestigmin otacrin but um yeah once you have HIV as really dementia that's usually an umino sun okay and then last question HIV positive patient with neuro deficits are multiple areas of demyelination on MR imaging right so hopefully you're thinking about the JC virus and progressive multifocal lukuan cell phyllopathy okay um and there's a drug that also has this association in fact this drug is used classically in the treatment of multiple sclerosis that will be um not a lizio map remember it's like an alpha-pointed green inhibitor okay so I know this has gone long and but this podcast I made it specifically because it goes over like hairy concepts that just seem to like make people just uh be very angry or like bang their heads on the table during a new exam so hopefully found find this helpful if you have any questions uh just reach out I'll be more than happy to point you in the in the right direction so I um we show the best if you need to do anything like that you can reach out to me um have a wonderful day and um god bless I'll see in the next podcast

Albuminocytologic dissociation (high protein with normal/near-normal white cell count).

Atropine (muscarinic blocker) and Pralidoxime (regenerates A ChE).

Flaccid paralysis; it prevents the release of acetylcholine at the neuromuscular junction.

Anti-Hu (anti-Human) and anti-Yo.

The corticospinal tract (upper motor neurons), anterior horn cells (lower motor neurons), and cranial nerves.

MG shows a decremental response; LEMS shows an incremental response.

Acetylcholine (A Ch); Atropine (muscarinic blocker).

Spastic paralysis; it prevents the release of inhibitory neurotransmitters (GABA/Glycine) from interneurons.

Amphotericin B plus Flucytosine.

Spinal Muscular Atrophy (SMA); Mutation in the SMN1 gene.

Primary CNS Lymphoma or Neurocysticercosis (Toxoplasmosis).

It is an acetylcholinesterase inhibitor that boosts A Ch levels, allowing them to outcompete antibodies.

The sound appears louder in the affected (conductive) ear.

Acetylcholine (A Ch); Atropine (muscarinic blocker).

Spastic paralysis; it prevents the release of inhibitory neurotransmitters (GABA/Glycine) from interneurons.

Amphotericin B plus Flucytosine.

Spinal Muscular Atrophy (SMA); Mutation in the SMN1 gene.

Primary CNS Lymphoma or Neurocysticercosis (Toxoplasmosis).

It is an acetylcholinesterase inhibitor that boosts A Ch levels, allowing them to outcompete antibodies.

The sound appears louder in the affected (conductive) ear.