DIP Episode 109 - USMLE Step 1 Rheumatology Review Part 2 (Final Part)

Okay, welcome. My name is Devine. I am a PGOIWANA transitional year resident that's gonna be studying a real-terreality residency pretty soon. This is the 109th episode of the Devine intervention podcast and into this podcast I'm going to be finishing up my review for step one rheumatology. The very first half I believe those episode 99 so this is episode 109 and I'm finishing my rheumatology review for the USML step one exam.

So what if you get a question about a patient this is doc this is a 30-year-old female tells you the doc she feels like morning stiffness in the morning and then when she goes about her business for like an hour and a half the stiffness kind of gets better and you look at her hands and her hands have like honor deviation and you notice that she has like some redness and soft like sweat like soft tissue sweat what's your diagnosis here really hope you're thinking about rheumatoid arthritis right so let's talk about rheumatoid arthritis I real quick I'll try to make this podcast a relatively short but I'll make it very high-yout so pay attention right so my third arthritis right we know that it's one of those autoimmune pathologies that attacks the attacks joints right and remember I believe I said this in one of my earlier I've said this in one of my earlier podcast where I said that if you perform a joint aspiration right so an atrocent thesis in a patient that has osteoarthritis they'll classically have less than 2,000 white blood cells but if it's rheumatoid arthritis because it's a kind of inflammatory arthritis their white cell count is usually like greater than 2,000 but it's usually like less than 30,000 on exams I feel like the key thing you want to be able to do with regards to rheumatoid arthritis is being able to compare that property with osteoarthritis right so rheumatoid arthritis you it's a kind of arthritis right but it's more of an inflammatory arthritis tends to occur more in women right like most autoimmune pathology tends to occur more in women and don't forget certain key antibodies and HLE associations right so remember rheumatoid arthritis is as really like HLE DR4 there's this numonic that I believe I've seen in first-eat back in the day it's like the they are four walls in a room so rheumatoid arthritis has HLE DR4 okay and remember that there

are some autoantibodies right that we find the rheumatoid arthritis so there's like the anti there's the rheumatoid factor right remember rheumatoid factor is like an IgM antibody against the constant region of IgG right so that's rheumatoid factor it's very sensitive for the diagnosis of rheumatoid arthritis and the thing is your rheumatoid factor titers actually correlate pretty well with like the amount of rheumatoid nodules and what node that you have is sort of has a correlation with with a disease activity contrast that with your anti-CCP antibodies where so your anti-cyclic citrallynithic peptide antibodies that are more specific they're not as sensitive they're more specific for rheumatoid arthritis compared to rheumatoid factor right and remember rheumatoid factor I mean like if you understand what rheumatoid factor means IgM against IgG that already tells you that if you're forming an IgM against IgG who knows maybe the constant region of that IgM can record a compliment and cause damage right so you're already thinking about like some kind of anti-gen antibody complex IgM is the antibody IgG is the anti-gen right so on those circumstances you can already begin to presuppose that you may have some kind of type three hypersynsitivity reaction in the setting of a rheumatoid arthritis and rheumatoid arthritis I mean like you want to make sure you know your hand distribution right so remember that classically also arthritis you affect the PI Ps and DI Ps right contrast that with RA where you affect the MC Ps and the PI Ps the DI Ps are classically spared in a rheumatoid arthritis and then some other high-yoda hand findings in rheumatoid arthritis right so they may have like deviation of the honor right so like honor deviation so basically their hands deviate towards the pinky towards the pinky side right that's classic for rheumatoid arthritis and then the thing is w

hen you have all that joint and cartilage destruction you can then begin to have something called a joint sub-location right so like one joint moving relative to the next if the configuration of your joints so let's assume like you have like the PIP being extended and the DIP being flexed from that joint sub-location that's something that's called a swanic deformity right so swanic deformity and I mean so I'm gonna see divine it's kind of hard to remember that do you have a good morning for that well I do thankful right so just remember like Seth like S E F so S stands for swanic e stands for the extension of the DIP of the PIP and then F stands for the flexion of the DIP okay so those are all high yield things you want to keep at the back of your mind and butoniers deformity is the opposite of that right so I guess I can mention it out loud but again remember I've said this thing many times in many podcasts you want to learn the least amount of information to control the most amount of knowledge right so butoniers deformity is the opposite right so butoniers deformity you can already predict that it's flexion of the PIP and extension of the DIP right contrast this will host your Friday swear remember it host your Fridays you can have osteophytes right it's kind of like extra bone growing along the joint line right if you have osteophytes at the PIP that's what's known as a bushard node if you have osteophytes at the DIP that's what's known as a hebridine node remember that the easy way to remember like which comes before which I think about it PI Ps come before DI Ps right so your proximal interfalange joints come before your distal interfalange joints so bushards that's what it would be it comes before H hebridines in the alphabet so that's the way to remember those now some other key things you also observing in a in rheumatoid arthritis right there can be like some

you guess you can sort of think of them as like extra ticula manifestations right so for example people with rheumatoid arthritis they can get I mean I said that they can form these rheumatoid nodules like on the hands and in general you find them on extensive surfaces right so you can find them like on the olecranum bursa like on the extensive surface of the elbow joint stuff like that but unfortunately you can also find rheumatoid nodules in the lungs right and when you have like rheumatoid nodules in the lungs in the setting of rheumatoid arthritis and you have like some pneumoconiosis going on that's what's known as Kaplan syndrome right I mean they could also give you a question on the exam show you a person's like absolute nitrophilic count is like 500 or 400 and then they tell you that the person has like left upper quadrant fullness and they have rheumatoid arthritis right if you see that right so that combination of like spinoe megaly, nitropenia rheumatoid arthritis that was known as felti syndrome okay felti syndrome and remember I just said that oh a person that has a rheumatoid arthritis right they have like erosion of the joint so they can have like sub-location one classic MDM exam question they can present to you is they can give you a question about a person that has a history of rheumatoid arthritis and then they tell you that this person is about to go for surgery right and then they ask for the next best step in management your next best step in management usually for those people is to perform a lateral neck x-ray or you can basically do like a cervical x-ray where like you sort of hold the head in extension and the head inflection and take images in both views the reasoning behind that is right remember that joint the erosion in addition to occurring in the hands in the elbows in the knees whatever it can also occur between the atlas and the axis

right so the atlantoaxial joint so people rheumatoid arthritis they actually have a pretty high risk of what atlantoaxial instability right because they have atlantoaxial sub-location and classically right that I mean if a person if a person has like surgery you manipulate the neck because you're trying to like into be the patient or something you can basically smash that atlanta atlantoaxial sub-location can basically cause an entrapment of the spinal cord and those patients can get like a cord rupligia so thanks you can even compress the vertebral arteries and get like an ischemic stroke from that okay so those are kind of high ill things you want to keep at the back of your mind and it can be fatal in fact there are some if you have pretty bad atlantoaxial instability and you manipulate the neck the wrong way you can actually disengage the head from the spine and obviously that's fatal right no one's gonna come back from that so before you perform this is even a clinical pro if you want to send the person on r-if to surgery you better make sure that they don't have atlantoaxial instability there are two or three other groups of patients where you tend to check for those things as well down syndrome is another classic one classic leoninbium is the present that has a down syndrome patient that's begin that's about to begin participation in sports also in ankylucin spondylitis right that's another classic association with with with atlantoaxial instability and then also driven out of theopathic arthritis that's another one but they will make that more of a pediatrics question kind of like down syndrome so sort of keep those four things at the back of your mind with atlantoaxial instability JIA and kylucin spondylitis rheumatoid arthritis and command divine think was the fourth one so JIA and spawn rheumatoid arthritis and down syndrome okay good so some other things

you can also find your rheumatoid arthritis again I've talked about this multiple podcasts but if they give you a question about a patient with r a and this person is having like sensory loss over the first like motor weakness of their first like three and a half digits and they have sensory loss on like the ventrum or like the palm of surface of their first three and a half digits a really really hope you're thinking about like a couple of tonal syndrome right so anything that makes you a demotus like rheumatoid arthritis or having hypothyroidism or being pregnant those are all things that can increase your risk for a couple tonal syndrome remember that's where the median nerve is median median nerve is compressed under the flexor right macula right and then also don't forget another classic thing is rheumatoid arthritis can cause a lot of like heart problems it can cause like pericarditis it can cause myocarditis it can cause blurring of fusions it can cause even like they can tell the squeevee a question about a person that has like pain behind their knee joint or they have like funes behind their knee joint that's a bigger cyst that's actually a pretty classic finding in patients with a with a rheumatoid arthritis right and the thing is again if you perform imaging of rheumatoid arthritis you'll see like the joint space narrowing like you find in osteoarthritis but in osteoarthritis the joint space narrowing is asymmetric in rheumatoid arthritis the joint space narrowing is symmetric okay and in general you will you'll find osteopenia in rheumatoid arthritis you'll find osteophytes in osteoarthritis so osteophytes in osteoarthritis osteopenia in rheumatoid arthritis okay so it's like in osteoarthritis you're almost like forming new bone does the osteophytes in rheumatoid arthritis you're pretty much treating away at bone because it's an inflammatory process okay t

hat's rheumatoid arthritis now in terms of treating a rheumatoid arthritis right so in general like how do you treat the big things you kind of want to keep at the back of your mind are you start with a demark right so a demark is like basically a drug so demark stands for like disease modifying anti-romatic whatever drug but basically those agents are the things that can change outcomes in the setting of rheumatoid arthritis right so like you can start with methotrexate that's the classic one that's used on MBM Es you can sell methotrexate you can use sulfosalazine you can use hydroxychloroquine although hydroxychloroquine on MBM Es is usually used more for lupus but you can use any of those agents but if a patient patient is having like acute symptoms like they're having like really severe joint pain and sets help them acutely but and says do not alter the course of the disease if I remember methotrexate right there's some key classic I guess oh come on divine think there's some key and bad reactions the present can get methotrexate right so like complications so things like I don't know like what am I thinking about like pulmonary fibrosis right that's one classic thing that can be observed in a rheumatoid arthritis I mean with methotrexate you so pulmonary fibrosis remember you can cause liver problems and remember you obviously don't want to give it to a pregnant woman right that says probably not a great idea if a person has rheumatoid arthritis and you need to treat them with a demoderm pregnancy you can consider like hydroxychloroquine hydroxychloroquine is not a teradoget and remember if a person has like performabumarous oppression with with methotrexate use you can rescue the boomer with a lukovore remember lukovore is a folinic not folic folinic aceda analog there's some pathophys there but I'll let you deal with that when you watch my biochem video but if a

demod right is let's assume methotrexate is not cutting it for these people what else can you use right you can go to the second line agent right so you can go to things like like lefluno might lefluno might I believe I talk about in my biochemistry podcast it's like it's an inhibitor of a dihydro-rederated dehydrogenase that's one of the enzymes I believe is involved in a pyramegine synthesis but usually on mbm is the second line agent is like your tnf inhibitors right so like you ate a tonne receptor remember that's like a decoy receptor for tnf infleximab adalimumab stuff like that right so your tnf inhibitors and remember those tnf inhibitors there's some key things you kind of want to know about that right so you want to make sure that you do like a tb they can ask you a question like prior to initiation of adalimumab therapy what is the next step in management and it may involve like doing like a tb skin test right like or like a quantifier and test okay because remember that tnf inhibitors are associated with a reactivation of tb okay so you want to kind of make sure these people don't have tb before you initiate those agents if a person is having like an acute infection probably not a smart idea to initiate those agents and I mean if they give you a question about a person that will study it on a tnf inhibitor and then they have like this Miller rash that spares the measly bio folds and they have lupus-like symptoms I really hope you're thinking about like a tanner sept and the drug induced lupus right remember a tanner sept can cause a drug induced lupus remember the classic association with the anti-histona antibodies so let's see is there anything I want to say about rheumatoid arthritis again it's an inflammatory disorder right so like most autoimmune disorders inflammatory issues your ESRCRP will be high and I mean rheumatoid arthritis right it can cause

a bad anemia right because again you're having like chronic inflammation right so you'll sort of kind of have like an anemia of chronic disease so just as a reminder because I know I've talked about all these things in my email podcasts what are the classic things that are such that what are the classic iron laps in anemia of chronic disease will be trove your serum iron it will be decreased right because remember your main goal in anemia of chronic diseases you are like thinking that you have been ravaged by bacteria and bacteria need iron to grant survived so you're like hmm you know what bacteria I am going to deprive you of iron right I'm going to deprive you of iron so you won't want to put as much iron in your serum but rather what will happen so your serum iron will be low but the thing you want to do is you want to lock it up in the bone marrow so that your bacteria don't have access to it so your ferritin will be high and remember that pathoma relationship that it's kind of like an inverse relationship between ferritin and tibc if your ferritin is high your tibc will be low okay so I really hope you sort of keep those things at the back of your mind and personally I think that is all I want to say about rheumatoid arthritis yeah I think that's all I want to say about a rheumatoid arthritis okay so let's go to that's next thing right so what if they give you a question about a patient that this disease is probably like one thing you need to know about it and it's usually very easy because they have to give you that one thing if not it's almost impossible for you to ever get it right on an MBA exam but what if they give you a question about a patient that has like they have like muscle pain they have like non-specific joint pain they sort of have like like when they step out in the cold the fingers sort of turn blue and then they tell you that the anti-U1 ribo

nucleopro team is like the tighter is elevated what are you thinking about right this is mixed connective tissue disease that is pretty much all you need to know about mixed connective tissue disease it's kind of like a mix and match of many rheumatologic issues like it has like some lupus some lupus problems it has some some scleroderma problems it has like some muscle pain problems just they'll usually give you like the anti-U1 RNP is positive if you see that that's it like that's that's all you pretty much need to know that's mixed connective at tissue disease although one thing I guess I can sort of say that can maybe help you on tests is I mean in terms of treatment you can give them like steroids like most autoimmune disorders but one other thing you want to keep at the back of your mind is because sometimes they may write the mixed connective tissue disease questions to look very very much like scleroderma especially like crest scleroderma the Reynolds phenomenon just be careful scleroderma tends to knock the kidneys mixed connective tissue disease tends to not knock the kidneys so that is a very key differentiating factor that you want to keep at the back of your mind on NV Me exams now let's sort of go to our next case so what if you get a question about a patient and let's assume it's like a 56 year old female and she tells you that doc I have like my my shoulders hurt my so my shoulders hurt my hips hurt and I have true when I true my just sort of hurts right so what are you thinking about on the little circumstances I really really hope you're thinking about pulling my algebra America right so pulling my algebra America the other thing I was describing where the person has like oh and the true their jaw hurts right that's jaw cladication so all these things you're sort of keeping together you're hopefully thinking about like a leading to temporal arthritis

if you and the thing is and again I will talk about the vasculidities but that's probably a different podcast but pulling my algebra America classically affects like your like your proximal joints right so like your shoulder joint your hip joint it actually is not this is actually very high you to know it's actually is not a problem of muscle okay so in fact I'll tell you that's classicly on mbmi exams in polymigral germarica that creating kinase may be mildly elevated or not elevated I'll say most of the time it is not elevated because the thing is your friends at the mbmi they love to write questions where polymigral germarica they are rated to very closely parallel polymigral sites under mario-sitis polymigral sites and mario-sitis and myopathics so those problems affect muscle so your creatine kinase will be elevated in those problems contrast our polymigral germarica that's more of a problem of the joint okay it's not your muscle right so your esrcrp will be high in both like polymigral sites the mario-sitis and polymigral remarica but your ck classically is the key differentiator it will not be elevated in pmr you'll be elevated in polymigral sites or mario-sitis right and remember that again polymigral remarica has a very strong association with a giant cell or temporal arthritis and the fact if a patient presents with like polymigral germarica symptoms or or or jaw clodication i'm actually saying they can make a unique question where they say what's the next best step in management and it may be to actually obtain a temporal artery biopsy even if they don't have like pain over the temporal region or like visual problems because there's such a strong association one thing you may want to go ahead and do is to perform a temporal artery biopsy just to make sure they don't have like concurrent temporal arthritis going on so and i mean polymigral remarica the way i

t treat is just low-dose steroids it responds extremely well to like low-dose or prednisone and then what did they give you a question about a patient that has a history of like depression and this patient notice i'm going a little quick today it's almost 11 30 so i want to try to go to bed soon but basically right if they give you a question about a person that it just sort of hurts in many different specific points throughout the body and they have a history of like some psychiatric problem like depression or pts or whatever and then they tell you that you obtain labs the ESR is fine the CRP is fine the creatine kinase is fine what are you thinking about i hope you're thinking about fibromyalgia right fibromyalgia these people they no one really knows the etiology of fibromyalgia but it has like an association with like psychiatric problems and it's almost always in a female on mbmi exams again not trying to be sexist here just that's the way it presents that's the way it works epidemiologically okay and really fibromyalgia um really the treatment the only treatments right like you can tell the patient like reassure the patient tell them to exercise more sleep better if you're looking for pharmacological treatment on mbmi's i would encourage you to go for like an SNRI so like do locks a team for example or you can go for a tricyclic antidepressant like emi premin or whatever those are usually like the big time agents you can use like gabapentin pre gabalin on mbmi's but i will see usually SNRI's like do locks a team at the drugs that are most commonly tested on the mbmi's for fibromyalgia and just again i guess to sort of summarize this thing so that you don't miss mess it up on an exam remember i said that in polymyalgia remarica your ASR and CRP will be elevated but your creatine kinase will be normal or just a ting elevated on exams contrast that we polymyalgia s

ide is and dermato myocytes where the ASR will be high the CRP will be high and the creatine kinase will be high as well okay and then contrast this with fibromyalgia where everything will be normal ASR CRP creatine kinase those will all those will all be normal okay those are very key things right because again the thing is many times the doing well on the mbmi is not a function of oh how i mean yeah if you're smart you probably do well but also just being able to differentiate closely related conditions right because the right the questions well because i mean think about it if you're a test rider the only way you can write a test for it to be hard right is to write it closely like write a question that you're like hmm it could be this it could be this it could be this or it could be this and then you put like a differentiating factor right all all across the question that can sort of tell you that oh you're dealing with this pathology versus the other so again just something to kind of keep at the back of your mind with with these with these are problems okay now what if you get a question about a 25 year old African-American female and she presents with like a six month history of like dry cough and shutness of breath and then just giving you that just African-American female shutness of breath and dry cough what do you think it is it's sarcoidosis right it's sarcoidosis that's pretty easy many sarcoidosis right if you're purf if you obtain like an image of the chest what do you see you see bilateral hyalurgyl lymphatic anapathy right so in fact sometimes in radiology they call it like the 123 sign they'll have like bilateral hyalurgyl anapathy and then they may have like a paratricula anapathy but yeah think more about the bilateral hyalurgyl anapathy for the USMLXM's so one of the big big things you want to know about the about sarcoidosis right you want to know

the long findings the bilateral hyalurgyl anapathy remember right one of all the long findings like the intestinal long disease right so it can cause like restrictive long disease basically remember I believe I've said this role many times in many podcasts if something ends in osis that pretty much tells you that you are dealing with it can pretty much cause some kind of restrictive pathology especially in the lungs and in the heart okay in fact and the way remember that role is just remember the term roses right so like given a person like a rose on Valentine's Day so roses so roses osis means like osis and then the armines restrictive so it's like restrictive long disease can be caused by sarcoidosis right so it can cause like a pulmonary fibrosis kind of picture where they're Fav 1 to every C ratio is like normal or mildly increased and then they'll have a decreased DLC right so you can cause restrictive restrictive long disease you can cause restrictive cardiomyopathy you want to know your skin findings right your skin findings like your classic like erythemano dosa that's like a classic classic classic classic association with with um with um sarcoidosis remember another disease that classically has erythemano dosa on NV Me is coxidiumicosis right so if they describe a person from our zone our the Texas or California Las Vegas whatever and then they have like a pulmonary infection and then you find a skin whatever that's erythemano dosa it has a very strong association with uh with coxidiumicosis and sarcoid right what kind of granuloma would you obtain would you find if you perform the biopsy of like lymph node with uh with a person that has a sarcoid it'll be a non-key skin granuloma right it'll be a non-key skin granuloma um and really sarcoidosis for most people it kind of resolves on its own for most people they actually don't have very significant symptoms b

ut if you really want to treat and they ask him for pharmacology and the NV Me is consider uh given uh those people are steroids they respond really well to steroids and some other things you may find in sarcoidosis right so like some lab findings right so they may have like increased like uh angiotensin converting enzyme right so increased levels of ACE another thing that you may also find is like hypercalcemia in a patient that has um sarcoidosis and the mechanism behind that right i mean i believe i've talked about this in a prior podcast like an endocrine podcast um the granulomas in sarcoidosis produce uh one alpha hydroxylase i remember that one alpha hydroxylase converts a calcium dial to calcium trial right um so that one alpha hydroxylase i converts the 25 hydroxy vitamin D to the 125 uh die hydroxy vitamin D right so you're basically making active vitamin D i remember that vitamin D does a ton of stuff right so vitamin D like for example increases the reabsorption of calcium and phosphating the gut right so um that will cause like a hypercalcemia so they can have like the stones, bones, groans, psychic overtones kind of deal um they can also have like uh uh very actually unique way to test hypercalcemia on an NV Me is to test what the EKG fine dune will be i really hope you're thinking about um um like a short qt interval on that those are circumstances so i will say that those are probably the big things you want to know about a sarcoidosis i mean uh sarcoidosis um there is actually this property shares with this problem um in fact that's kind of like the next time leading to come on divine think what did you want to talk about um it shares a similar presentation with um um um like a posiarticola gia right so like j that affects like i think like three or less like two i think is like two to four joints or less um that kind of gia tends to um involve uh the i

so you can cause like anterior uveitis so you tend to do like routine slit lump exams on those people kind of the same thing in sarcoid sarcoid if they give you a question about a patient that has sarcoidosis and you have like i pain you really want to think about anterior uveitis anterior uveitis is actually quite commonly associated with uh with a sarcoidosis and then some other stuff that sarcoid shares with other disorders right so like you know the way like HSV and Lyme disease can cause like belspalsy sarcoidosis can also cause a belspalsy and then uh one weird thing that you may see this is super loyal but it may shop on an mbm exam is if you perform like a bronchio aviola lavash um in a patient that has like sarcoidosis you will actually find more cd 4 cells than cd 8 cells so like the cd 4 to cd 8 cell ratio will be elevated again i think that's like super super loyal but um that's all i think i'm gonna say about our sarcoidosis i know i i know i promised to make this podcast show that i'm already at 30 minutes um but i'm almost done um let's see what else i want to talk about uh i guess i was kind of talking about a juvenile apyric arthritis right so uh jia right the big big one you probably want to know about is like the uh there's the postiarticular kind where uh those patients tend to have like anterior uveitis that's like the big thing you want to know and they tend to uh you want to do like routine slit lump exams on those patients and then the big the most systemic one right uh before it was called like stale's disease well these days people just call it systemic jia um essentially the classic way that this will present on an mbmi examis they'll give you a question about a kid that is having like fever's that seem to come up at a specific time during the day in fact i tend to call them like picket fence fevers right so it's like the temperatures rise and

then it falls temperatures rise and they're like oh the mom says i in the evening you know this child he's standing he gets this high and as he gets this high fever a rash seems to seems to come alongside right then classically on mbmi's is described as a summon colored rash if you see those things um you really really want to think about um um systemic jia um and really a systemic jia that's pretty much all you need to know about it again because it's a rheumatologic issue yes rc rp will be high you can have an email chronic disease and all that stuff but that's pretty much all you need to know and again it tends to show up in kids right so again just gamesmanship for exams do not pick jia as an uncertain person that's 30 years old right that will be on prudent on an mbmi exam you want to do that more for again it's going to be a pediatric's question on any mbmi exam you ever take and again in terms of treatment anti-inflammatories like n-sense you can give like your steroids you can give your tnf inhibitors and all that stuff i think that's pretty much all you need to know about them um jia and i guess just to sort of round this out um let me talk about one more thing right so what if you get a question about a guy that has a history of lung cancer and he tells you that doc you know what it's kind of hard for me to uh stand up from a chair and um sometimes i have like like just weakness in my shoulders um what disease are you thinking about really hope you're thinking about like the lumbar it in a myesthenic syndrome right so lumbar it in my esthenic syndrome um remember that um uh this patient likely has what kind of lung cancer small cell lung cancer remember small cell lung cancer is that lung cancer that tends to have all this like pernioplastic crap going on right so you can make like 80 so you can get like s80 so they can give your patient with like um uvulimi

c hypo nitrimi or like a hypo-smola serum and a hyper osmolaryring right they can give your patient like moon faces and obesity and all that stuff and then you're thinking about like the acthia production um remember that um they can also make auto antibodies against the pristine actica voltage-gated calcium channel right so that's kind of like the pathophys behind the lumbar it in myesthenic syndrome right so you make these antibodies against the pristine actica voltage-gated calcium channel and when you make those auto antibodies right basically the thing that happens is calcium cannot come in through that voltage-gated channel if calcium doesn't come in then your vesicles will not be able to get to the synapse and exosite toes basically dump off a neurotransmitter right so if you cannot dump off a cell calling at the synapse then you get like weakness but the thing is as you keep using those muscles um as you keep like using the muscles using the extremity involved um more and more calcium will come and that calcium will outcompete the pristine actica voltage-gated calcium channel or auto antibodies and once the outcompete right then you have things sort of like restore to like their baseline okay so in general the more you use the muscle the more calcium is recruited the more calcium is recruited the more the calcium outcompete those bad antibodies and the better the presence of muscle weakness that becomes okay so um one very nifty way they can present that on an mbmb right because it's like oh it improves with use everyone has memorized that crap from like every resource so the thing your friends at the mbmb enough to do these days is to say that there is an incremental response of the muscle with repetitive nerve stimulation so an incremental response incremental something is increasing okay if you see that you really want to think about a lumbaritina myastenic

syndrome contrast that with a decremental response or decremental decreasing with repetitive nerve stimulation I hope you're thinking more about myastenia gravies under those circumstances so again um lambardini myastenic syndrome it tends to affect like again proximal muscles right so like they'll have like proximal shoulder weakness proximal hip weakness so the classic presentation on mbmb is like they have trouble like coming their hair or they have trouble rising from a seated position if you see that with a significant smoking history think about a lumbaritina myastenica syndrome and then um if you sort of want to contrast that with myastenia gravies right so myastenia gravies you basically make autoantibodies against the nicotinic acetylcholine receptor right that you find that in your muscular junction and if you make those autoantibodies right I mean that's kind of like a type 2 hypersensitivity right because you're making antibodies against like a fixed thing in your body not something that's sort of like moving around so you make those autoantibodies and then complement calms and boom you destroy those and nicotinic acetylcholine receptors or you like endosythose those nicotinic acetylcholine receptors and then you basically have nothing for acetylcholine to bind to right or those antibodies right they already sitting on where acetylcholine wants to bind to in the first place right so these people they tend to get like muscle weakness and classically classically classically on mbms those patients tend to present with like diplopia right so like double vision or like a droopy eyelid so like toses that's the classic presentation and they'll say that doc this thing like I'm working in the morning but by the end of the day I have trouble seeing I have trouble like keeping my eyes open if you see that think about myastenia gravies right and really the way you ma

ke the diagnosis of myastenia gravies is actually to perform this thing called like basically looking for anti acetylcholine receptor antibodies sometimes I think they're called like anti-musk MUSK antibodies so you look for those autoantibodies in the serum I know there's this tensilon and drifonium crap that you've heard about I may still see it on step one but that is not the diagnostic test of choice the diagnostic test of choice in in myastenia gravies is to actually look for the anti acetylcholine receptor antibodies so but you can do the tensilon test so you may say oh divine what is this tensilon test you are reviewing all about the tensilon test basically is where you use an acetylcholine esteris inhibitor adryphonium adryphonium is the drug you use adryphonium is an acetylcholine esteris inhibitor if you inhibit acetylcholine esteris what do you think happens to your levels of acetylcholine it goes up very good if that goes up right that will not compete those nasty antibodies that you find on the surfaces of your nicotine acetylcholine receptors and the presence of muscle weakness will improve because you have it more acetylcholine abind it okay but it's a very short actin agent so you can obviously not use it for treatment the thing is in general for myastenia gravies you give a pyridostigmin it's a more like longer actin nicotinica acetylcholine it's a longer actinacetylcholine esteris inhibitor okay so you use it to get red of myastenia right so you can get red of myastenia gravies with pyridostigmin okay that's a kind of like a nice way to remember that and some other things you want to keep at the back of your mind with my astenia gravies right so my astenia gravies can can be associated with like a phymic mass right so like a thymoma right so it will not be unrealistic for the mb me to give you a question about a person that comes from like droopy eye

lids and all that stuff that's been going on for a few months and then they ask for the next best step in management and involves getting like a chest CT or like a chest x-ray to see like the thymoma remember that'll be an anterior medias thymoma right remember your your your t your t-mass is tend to shopping the anterior medias thymoma versus your neorgineic masses that tend to shop in the in the posterior medias thymoma and then one weird thing that they can actually do to you on an on an nb me exam we're like man I have no clue what's going on here is they may actually give you a question where they essentially describe a child with my astenic symptoms but they tell you that you perform the adrofonium test and the child's muscle weakness does not improve so basically like muscle weakness that is not responsive to adrofonium augmentation um under those circumstances the main thing you want to think about is something called a chat's deficiency so like a colin acetyl transfer is deficiency this is one of those like 270 style questions on the usml is I'm pretty sure I've talked about this in like a remote podcast like probably like my new form of ecology podcast or something like that but basically um colin acetyl transfer is the really limiting enzyme in acetyl colin synthesis right so if colin acetyl transfer is no working right then you're not making any acetyl in the first place right for acetyl colin esters to even think of breaking down so for those people give all the acetyl colin esters inhibitor you want like adrofonium blah blah blah um because they are just not making acetyl colin the first place there is nothing that can increase because you are inhibiting acetyl colin esters so those people don't respond to adrofonium augmentation I can sort of see them making this as like an experimental question on the usml is like an experiment style not I don't mean l

ike experimental like they won't grade it like an experienced style question where they give you like all these weird words but that's the concept they're going after so just sort of kind of keep that at the back of your mind I think it's actually a very high yield uh but it's like high yield to know but it's one of those things that most people will get around but hopefully you don't get around because you listen to this podcast okay that's like an example of a congenital amyastenica syndrome okay so I'll encourage you to sort of keep that at the back of your mind so personally I think that is all I want to say um in this podcast again I apologize I know it's 41ish minutes now um but I think pretty much if you understand and assimilate all I have talked about in this podcast and you should be in this podcast and episode 99 pretty much all the rheumatology stuff with the exception of vasculitis I'll talk about it in a little podcast you'd pretty much know for your mbm exam so as I round up as I always do I offer one on one tutoring for the usm is step one two ck two cs and step three exams the preclinical med school exams the 30th shelf exams the medicine-intering exam that you take as a medicine resident you that's like around like september October um and also the medicine board exams if you're like hey divide um how you offering tutoring for the medicine board exams just send me an email um I can sort of explain how I do that kind of tutoring but I've definitely tutored a bunch of people actually for the abiam exam and then if you're a med student applying to residency so an urs application or college student applying to med school so an amcass application I do want to want again consulting for those so like application prep personal statement prep mocking interviews um I mean I've again I've been on the admissions committee of a top two med school for like a year

so I have shifted through thousands of outstanding like super outstanding applications so um I know the things to look out for that can sort of like make you put your best foot forward um with regards to the application process and again advice tons of people that have applied for residency and pretty much most of them have much of their first choice and then if you're also a college student or you know a college student that needs to learn for like organic chemistry general chemistry physics um biochemistry physiology histology I do offer tutoring for all those things okay so um those are pretty much the other things I offer but this is one on one basis um but all the stuff on my website is free so you can always have access to those so I wish all the best have a wonderful night sleep well and I am glad the Raptors won their game yesterday and I'm really praying that they win their game tomorrow um I know I've probably have completed a bunch of a goad instead of fans that probably hate me but even if you hate me please don't hit my message listen to my podcast because I think they are really helpful so have a wonderful night I'll see you next time and God bless you thank you

Anti-U1 RNP antibodies.

RA affects the MC Ps and PI Ps; the DI Ps are classically spared.

Bilateral hilar lymphadenopathy (the 1-2-3 sign).

CK levels are typically normal or only mildly elevated; this helps differentiate it from polymyositis.

Fluctuating weakness, particularly involving ocular muscles (diplopia/ptosis), which worsens throughout the day.

Sarcoidosis (due to active vitamin D production).

The formation of immune complexes involving RF (IgM against IgG) can lead to complement activation and damage.

Swan-neck deformity (hyperextended PIP, flexed DIP) and Boutonniere deformity (flexed PIP, extended DIP).

MCTD tends to spare the kidneys, unlike Scleroderma.

Granulomas produce 1-$\alpha$-hydroxylase, converting 25-hydroxyvitamin D to active vitamin D (calcitriol).

Picket fence fevers (temperatures rising and falling at specific times of day).

Polymyalgia Rheumatica (PMR).

Testing for anti-acetylcholine receptor antibodies.

The formation of immune complexes involving RF (IgM against IgG) can lead to complement activation and damage.

Swan-neck deformity (hyperextended PIP, flexed DIP) and Boutonniere deformity (flexed PIP, extended DIP).

MCTD tends to spare the kidneys, unlike Scleroderma.

Granulomas produce 1-$\alpha$-hydroxylase, converting 25-hydroxyvitamin D to active vitamin D (calcitriol).

Picket fence fevers (temperatures rising and falling at specific times of day).

Polymyalgia Rheumatica (PMR).

Testing for anti-acetylcholine receptor antibodies.