8: USMLE and COMLEX Prep: Side Effects of Diabetes Medications
Session 08 Step 1 and Level 1 love to test the mechanisms or side effects of medications that treat diabetes. Follow along to test your knowledge of diabetic medications and side effects. Once again, we're joined by Dr. Andrea Paul, Chief Medical Officer at Board Vitals. Reminder to everyone is that you may know the diagnosis but the question is not going to be that simple. So be prepared for so many different levels of questions and knowledge that you have to know. Use the promo code BOARDROUNDS to save 15% off their QBanks. [02:00] Diabetes Medications There are lots of medications for diabetes so it makes it extra complicated and they have their own interesting set of side effects and mechanisms of action that you want to know because they're commonly tested. As you're studying medications, first look at the overarching category. You don't have to remember every single medication within that overarching category. But in some cases like insulin, it's helpful to know the different preparation because they may ask about short-acting or long-acting insulin preparation. But generally, other medications have the same mechanisms and side effects so you can combine those together and just remember by the generic names. Most often, what the test is going to be asking about is mechanism or side effect. [05:00] Question of the Week It's a 56-year-old man with adult-onset diabetes who's visiting his primary care physician. He's been on medication while controlled and his glucose levels have improved. But now, he is presenting with his glucose levels trending up over the last 6 months. His A1C trending up and they want to add a second medication. There's a worrisome side effect of the second medication and it's asking you to narrow down, looking at the different options of what you could add to what he's already on. So you need to think about which of those has a worrisome side effect. He's on Sulphonylurea and when you think about that category of medications, you start thinking that glucose normally triggers an insulin release from the pancreatic beta cells. They mimic the action of glucose so they close those channels in the cells and that depolarizes them which leads to insulin release. Then when you think about toxicity, that's the category of drugs where you think about disulfiram reaction and hypoglycemia. With insulin, if you take more than what's necessary, there's a worrisome side effect of hypoglycemia. Then you start thinking through which of the other categories have something that they would categorize as extremely worrisome. That would knock out things like hypoglycemia because that's the side effect of almost every antidiabetic medication. You'd start thinking down the path of severe toxicity and the only medication that has that is the Glitazone category. Those are the medications where their mechanism is they bind receptors that modulate insulin sensitivity. They will increase your insulin sensitivity and decrease gluconeogenesis, increase the number of insulin receptors. They're known for cardiovascular and hepatotoxicity which is something you have to remember about that category. If you look through all of the other diabetic medication categories, none of them have as worrisome or a severe side effect as that category does. [08:20] What's the Worrisome Effect? In this case, the answer is hepatotoxicity. The way you can narrow it down is knowing that he's already on a sulphonylurea and they're adding something that causes a very worrisome side effect. You can immediately narrow it down and find the medication in the list of options that fall into that category. Choices: Hypoglycemia Renal dysfunction Liver dysfunction Peripheral neuropathy Gastrointestinal dysfunction [09:30] Getting to Your Answer This is a two-step process where you have to both assume what the next medication to be added is and knowing which category has a worrisome side effect and then coordinating that side effect with the generic name of the medication within that category. It's a bit tricky but once you can cross out the other effects then it could lead you down the right path into the category they're asking for which is the Glitazone category. There are questions along the same lines where they don't say what medication was added to the patient and they come in with say, hepatotoxicity and just give you lab values indicating that. So that's an example of where they may give you a different option of medication and you'd have to identify the one that caused it. So you have to know the side effect as well as recognize the generic name. Not all categories for diabetes medications do have a common ending so there's some memorization required. But most of them have one or two different endings that you can remember. For instance, sulphonylureas tend to end in -ide or -mide. These are little things that can help you remember what category. But if you can remember the overarching categories, that will lead you down the right path where your memory might kick in and remember things. Specifically, the question is looking at adding a second medication and you can already cancel out one with the sulphonylurea. Then look down through the answer options. Just remember what the most severe side effect in each category is and be able to identify which one would be most worrisome or severe. [12:50] Brand Names The test doesn't look at brand names and it's nice there are these naming conventions. Brand names can be much more challenging to remember compared to generic names which have pretty repetitive patterns. In this case, besides insulin, most sulphonylureas and glitazones will have common endings you can remember. [13:30] Strategies for Insulin-Specific Questions Just one thing to note since they like to ask the onset and peak for different types of insulin and just the mechanism. So you should be able to know the mechanism of how insulin works and that cycle in general. Lispro starts to act most rapidly, 15 minutes. Regular insulin is half an hour to an hour. NPH is 1-2 hours and Glargine where the onset is one hour but it actually doesn't peak. This is something they may ask as well. They tend to follow the same pattern for their peak so the more rapid-acting, Lispro, also peaks first and then the peak extends out later as they go through NPH and Glargine. They would usually look for the basic pharmacology and pharmacodynamics and kinetics of medication on Step 1. They'd be probably asking something about the onset or peak of different preparations rather than combining them. Links: Board Vitals (promo code BOARDROUNDS)
13 Mar 2019
31: A Lung Tumor With Popcorn-Like Calcifications
Session 31 A 55-y/o heavy smoker is shown to have a peripheral, well-circumscribed mass with popcorn-like calcifications in the RUL. What is the lesion likely composed of? Dr. Karen Shackelford from BoardVitals joins us once again as we delve into another case to prepare you for your Step 1 or Level 1 exam. Save 15% off their QBank by using the coupon code BOARDROUNDS. BoardVitals has a powerful QBank with comprehensive explanation and rationales behind all of their questions. Get up-to-date board review questions. You can avail of their 3 or 6-month plan and ask a clinician. Ask one of the physicians behind all of the questions. Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points. [01:48] Question of the Week: A 55-year-old male with a 40-year history of smoking who undergoes a low-dose chest CT for lung cancer screening. Imaging results show a peripherally located, well-circumscribed 2-cm mass in his right upper lobe. It has a popcorn-like calcification. Which of the following describes the characteristics of this mass? (A) is composed predominantly of fattened cartilage (B) is composed of poorly differentiated neuroendocrine cells (C) is composed of significant glandular components (D) is caused by keratin production and intracellular desmosomes (E) is formed by caseating granuloma around the causative organism [03:00] Thought Process Behind the Correct Answer The correct answer here is Answer choice E refers to TB and this doesn't sound like TB as there are popcorn lesions with TB. Answer choice A would sound more or less of a benign tumor. B sounds like a malignant small cell lung cancer. C would make you think of adenocarcinoma. [03:00] Thought Process Answer choice A would sound more or less of a benign tumor. B sounds like a malignant small cell lung cancer. C would make you think of adenocarcinoma. Answer choice E refers to TB and this doesn't sound like TB as there are popcorn lesions with TB. The correct answer here is A. A well-circumscribed lung tumor with predominantly fattened cartilage is a hamartoma. A trick that helped me remember this back in medical school is that “popcorn isn’t bad.” It's the most common benign tumor of the lung. It usually contains connective tissue, fat, and cartilage. It's classically associated with popcorn-like calcifications on imaging. They are relatively large, well-demarcated and they rarely impinge on surrounding structures. For the management of pulmonary hamartoma, it would be more beneficial not to undergo surgery. The approach to those tumors is individualized unless it's diagnosed as a stable nodule. Karen stresses the importance of not overdiagnosing people. Once you figure out it's not causing any problems, you just leave it there. [06:08] Understanding the Other Answer Choices The poorly differentiated neuroendocrine cells is a small cell lung cancer. It's a really aggressive malignancy that is most common in smokers. They usually have irregular margins and has a really poor prognosis largely because it tends to metastasize. Significant glandular components are characteristic of adenocarcinoma. It's the most subtype of lung cancer. It has both solid and ground blast components on imaging. It's a pretty heterogenous-looking tumor. It's usually peripherally located. Keratin production and intracellular desmosomes are characteristic of squamous cell carcinoma. It's a common form of non-small cell lung cancer. It originates from epithelial cells along the airways. They're usually centrally located, often associated with the larger bronchi. Caseating granuloma is characteristic of pulmonary tuberculosis around the causative organism. It usually looks like a focal cavitary lesion often in upper lobes. The patients usually have a risk factor like travel to an area where TB is endemic. Or there's exposure to infected individuals or incarceration. Links: BoardVitals (coupon code BOARDROUNDS)
11 Sep 2019
37: Risk Factors and Signs of Kidney Disease
What does this patient's decreased creatnine clearance and oliguria tell you? What risk factors are behind his condition? Would you give him contrast dye?
15 Jan 2020
28: The Clinical Signs of Renal Allograft Rejection
Session 28 A patient with a 2-month-old kidney transplant has elevated creatinine, fever, and tenderness at the graft region. What other finding is likely present? As always, we’re joined by Dr. Karen Shackelford of BoardVitals as we dig into today’s case to help give you a better understanding. Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points. [01:02] BoardVitals If you're preparing for your USMLE Step 1 or COMLEX Level 1, check out how BoardVitals can help you prepare for your exam. Use the promo code BOARDROUNDS to save 15% off their QBanks. They have the 3-month version with over 1,700 questions. Once you're in medical school, they also have QBanks for the SHELF exams. [02:24] Question of the Week The patient who has a history of kidney failure as a result of multicystic kidneys has an allograft kidney transplant. Two months later, she presents with fever, malaise, and tenderness in the graft region. Her lab work shows a rise in creatinine. What other finding is characteristic of her condition? (A) Hypotension (B) Decreased graft size on the ultrasound (C) Patchy mononuclear cell infiltrates without tubulitis (D) Urinary obstruction (E) Oliguria [03:20] Thought Process The correct answer is E. The oliguria is a frequent finding. She has fever, malaise, and graft tenderness. Some patients can actually be asymptomatic during acute renal transplant rejection. They usually have hypertension that's why answer choice A is wrong. The graft may actually be enlarged on ultrasound. Creatinine only rises when there's significant histologic damage. If the graft rejection progressed, there would be weakness and fibrosis. You would have a decreased graft size but not at this point. Patchy mononuclear cell infiltrates without tubulitis is a pathological description of something that occurs in patients who have a normal functional renal allopath. So the histopathological findings in patients with rejection may have findings of interstitial infiltration with mononuclear cells, sometimes eosinophils. And the tubular basement membrane will be disrupted by these infiltrating cells. This is tubulitis. Along with inch-small arteritis, it's considered the primary lesion of acute cellular rejection. Acute antibody-mediated rejection is characterized by vasculitis with neutrophils, anti-glomerular and peritubular capillaries fibrin, thrombi, or nephrosis. Then there's interstitial hemorrhage, the presence of CD4 and antibody-specific to the donor suggest an antibody-mediated reaction. In chronic allograft dysfunction, you will see peritubular basement membrane splitting and multi-layering of the basement membrane. The antibody-mediated rejection is an albumin response that occurs as antigen-antibody complex fixes complement with the activation of multiple complement protein. C4D is the component of the normal complement pathway. When C4 is split into C4A and C4B, C4B is then converted to C4D. This binds covalently to the endothelial basement membrane and the collagen basement membrane. In a normal kidney, C4D can be found in the glomerular mesangium and at the vascular pole. But the excessive reduction of immune complex deposition disease results in accumulation in the glomerular capillaries. The CD4 deposition can be seen by monoclonal antibodies staining and fluorescent tissue immunofluorescence. Peritubular capillaries staining is useful in just renal allografts. In acute allogra rejection graft, they appear large. Urinary obstruction is not the mechanism of oliguria in patients with renal allograft rejection. [09:20] Definition of Acute Rejection Graft versus host reaction is an immune condition that occurs immediately after a transplant procedure when the immune cells from the donor attack the recipient patient's host tissue. Acute rejection goes the other direction that is characterized by oliguria, fever, malaise, and graft tenderness. So you're having this inflammatory reaction. When you have chronic rejection, like anything else she developed, there was significant tissue damage from chronic inflammation. The most common cause of graft failure after the first year is called chronic rejection under the Banff classification system. Chronic allograft nephropathy, which is chronic rejection, is characterized by interstitial fibrosis and tubular atrophy. Links: BoardVitals (Use the promo code BOARDROUNDS to save 15% off their QBanks.)
7 Aug 2019
Most Popular Podcasts
9: USMLE and COMLEX Prep: Renal Pathology Patterns
Session 09 In our renal question today we are asked to identify the pattern we would see on electron microscopy. See if you can find where the question leads you! Once again, we're joined by Dr. Andrea Paul from Board Vitals. If you're getting ready to start preparing for your Step 1 or Level 1exam, check out Board Vitals and their QBank. Use the promo code BOARDROUNDS to save 15% off your QBank purchase. For more resources, be sure to check out all our other podcasts on the MedEd Media Network. [02:50] A Challenging Area Renal tends to come up in the top 3 of questions where people are going back because they answered them incorrectly or that they're saving and redoing questions in this category. This indicates a level of less confidence or knowledge gap that needs to be filled for most students. Andrea thinks renal is a challenging area being a complicated system with a lot of memorization involved in the different syndromes. It's a combination of genetics and pathophysiology and pathology. You'd have to be able to do everything from figuring out the disorder and knowing what it would look like on biopsy, looking at diagnostic studies and the physiology involved in the different renal disorders. [04:22] Question A 16-year-old boy presents. He recently immigrated from Russiam, has no major medical problems. He does mention he had an episode of light red urine three weeks ago. At the same time, he had a mild cold. He has no known allergies, no recent drug use or medications. His family has traced positive for kidney disease in his maternal uncle, but both of his parents are healthy. He also mentions that he has had lately noticed that he has mild hearing problem but he's never thought much of that. It's asking a kidney biopsy. This patient would most likely show which of the following: (A) Linear pattern of IGG with fluorescent microscopy (B) Splitting of the glomerular basement membrane (C) Mesangial cell proliferation (D) Epithelial humps or a thickened basement membrane that looks like a train track [05:50] Finding the Diagnosis The first thing to note here is the hearing loss, which is something that would lead you down a specific road. So we're given a little hint here that can be very helpful. Based on history, the hearing loss would be due to Alport syndrome, which is a collage type 4 mutation resulting in abnormal basement membrane, that includes renal involvement, ocular involvement, and sensory neural hearing loss. In this question, the answer you'd look at is the splitting of the glomerular basement membrane. The other way to describe this is the basket weave appearance, also known as the glomerular basement membrane lamellation, characterized by the layering and splitting of the membrane. The key here is the Alport syndrome and remember what the findings would be and that specific disorder. [08:30] Potential Questions One possible question could be what other symptoms the patient may be experiencing. How is this commonly inherited because Alport syndrome can be inherited in a X-linked dominant way. You can also look through everything from genetics all the way through the pathology and electron microscopy for each disorder. Or maybe they won't mention hearing loss but vision symptoms or inheritance pattern they've seen in the family, which they did when they mentioned the maternal uncle. So they've hinted this as well. [09:50] What If There Was No Hint If the question would have left the hearing loss out, they would probably mention a more extensive family history so you could see the inheritance pattern. They're also mentioning hemoturia so you're led to a nephrotic syndrome. That would also help. But they'd probably give you additional information to lead you down a more specific road for one of these different nephrotic causes. [10:32] More Things to Know About Renal Stuff You need to know the different patterns for each of the different nephrotic syndrome causes. This is part of the reason people redo these questions over and over. There's a lot of memorization involved such as APGN and RPGN and what those look like, as well as microscopy. For this question, you would think through things like Goodpasture syndrome where you'd see a different pattern then you'd see that linear pattern which is that first option. And if it's in older males then you'd have respiratory symptoms because there's lung involvement. So you have to think through all the different associated organ systems with the different disorders and memorizing what the pattern looks like on each of them. As far as symptoms, inheritance, and treatment, there are different diagnostic studies and treatments and those are the ones you can reason through based on the different disorders and what the physiologic effects of each is. Lastly, keep in mind to know the demographics are. Some of them are more common in patients with specific histories, or ages or backgrounds – anything that can help you get to the answer more quickly will be helpful. The immigration component must have been put in there too since there's not a whole lot of medical history available. So they could actually put in things that could be helpful or completely just inserted for background information to make the case more robust, but not necessarily valuable. It's important to think through each piece of information in the question to make sure they tie together and you'd be able to eliminate something that clearly doesn't help you. So you don't focus too much on every specific part of the history. [14:32] Board Vitals Going over questions is the most beneficial thing you can do as a medical student preparing for your Step 1 or Level 1 exam. Check out Board Vitals for some help. They QBanks and over 1700 questions for Step 1 and almost as many for Level1. Have a free trial and check out their system to see if it works for you. Use the promo code BOARDROUNDS to save 15% off. Links: MedEd Media Network Board Vitals (promo code BOARDROUNDS) Specialty Stories Podcast
20 Mar 2019
25: What will we See with Potential Pediatric Infection?
Session 25 Dr. Karen Shackelford form BoardVitals joins us once again as we dig deep into a question about the hematopoietic and immune system. Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points. [01:05] About BoardVitals If you're ready to prepare for your Step 1 or Level 1, go to BoardVitals. Their QBank system is set up to simulate the real USMLE Step 1 and COMLEX Level 1 exams. They have questions that are equally as hard to get you prepared for your exam. Use the promo code BOARDROUNDS to save 15% off when you purchase any of their products. [02:20] Question of the Week A 16-year-old male presents with a complaint of sore throat, fatigue and low-grade fever for three days. Exam reveals glossopharyngeal erythema with white exudates on his tonsils. He has enlarged posterior cervical lymph nodes and the posterior auricular lymph nodes are slightly enlarged. His spleen is palpable on abdominal exam. The throat culture is negative for strep and the monospot is positive. Which of the following findings are associated with the patient's diagnosis? (A) Atypical lymphocyte (B) Eosinophilia (C) Howell-Jolly bodies (D) Sickled erythrocytes (E) Target cells [Related episode: USMLE and COMLEX Prep: Glossopharyngeal Nerve Anatomy] [03:20] Thought Process Behind the Right Answer The correct answer here is A. The enlarged spleen could throw students off as it may make you think about Howell-Jolly bodies. But this is a case of classical mononucleosis with fever, exudative pharyngitis, the tender lymphadenopathy, particularly posterior in the cervical and posterior auricular nodes. Adenopathy in the anterior nodes and the atypical lymphocytosis are the hallmarks of classic infectious mononucleosis. The explanation to this question goes on to discuss the infection of the Epstein-Barr virus. It's a viral replication that begins in the oral pharyngeal epithelial cells with dissemination and infection of B-lymphocytes and the oropharyngeal lymphoid tissue. There is more Step 1 detail here. The infected B-lymphocytes produce antibodies to the viral antigens. But they also produce another type of antibody which could be heterophile antibodies that are not antibodies to the virus, but antibodies to other tissues. Active infection and the reinfection are regulated basically by the Epstein-Barr virus-specific T-lymphocyte. And atypical lymphocytes are activated. CDA plus T-cells and CD16 after killer cells appear in the blood at least 1-3 weeks after symptom onset. Fatigue can persist forever – 6 months or longer in 13% of patients. The splenic enlargement is a big caution for practitioners to remind their patients to avoid contact. The enlargement usually resolves after about 3 weeks. But even without contact, spontaneous splenic rupture is responsible throughout half of the cases. This usually occurs 2 weeks after symptom onset. [06:50] Understanding the Other Answer Choices Eosinophilia is usually associated with parasitic infection. The Howell-Jolly bodies were good distractor. They refer to the basophilic remnants of DNA. The circulating erythrocyte is usually removed in the spleen so they're found in patients who have either no spleen or 07:15. Sickled erythrocytes are associated with sickle cell disease. Target cells are associated with this disorder where the erythrocyte's cell surface is increased disproportionately to the cell volume. An example would be spherocytosis. Links: BoardVitals (Use the promo code BOARDROUNDS to save 15% off when you purchase any of their products.)
17 Jul 2019
12: USMLE and COMLEX Prep: 65 y/o Female with a GI Bleed
Session 12 Today, we have a question regarding a 65 y/o patient with a GI bleed. Our job is to find where in the GI tract she is most susceptible to ischemia We're joined once again by Dr. Andrea Paul from Board Vitals. If you're looking for a QBank to help you with your Step 1 or Level 1, check them out. Use the promo code BOARDROUNDS to save 15%. You may also sign up for a free trial to get a feel of what their platform is all about. They have over 1,750 questions for Step 1 and over 1,500 questions for Level 1 – enough to help make sure you have the knowledge necessary to get the best score possible. [02:55] Question of the Week A 65-year-old female develops abdominal pain, bloody diarrhea 24 hours after undergoing hemicolectomy for recurrent diverticulitis. Her surgery was complicated by hypotension, blood pressure down to 70/50, treated, and her medical history is remarkable for diverticulitis, hypertension, dyslipidemia, coronary artery disease, no other episodes of any GI bleeding in the past. Her last colonoscopy was normal four years ago. The patient's current condition most likely involves pathology affecting which of the following portions of the intestine? (A) Cecum (B) Splenic flexure (C) Ascending colon (D) Transverse colon (E) Hepatic flexure [04:25] Understanding the Question The key here is that the patient underwent hemicolectomy for diverticulitis which led to hypotension. So there was some interop issue. And reading her problem list, she's got a coronary vascular disease. She's prone to having some sort of ischemia somewhere. But first, we need to understand what is being asked for. So here, they're asking where along the chain of the GI tract is someone most vulnerable to ischemia. "Read the question first so you have that in mind when you're reading the whole case." [06:35] Thought Process in Answering the Question The arterial supply to the intestine is pretty complicated and not really something that makes sense intuitively. What you need to remember here is that for most of the blood supply is from the superior mesenteric artery as well as the inferior mesenteric artery. Then there's a lot of collateral blood supply too and this great. But there are some couple of areas that are particularly prone to ischemia, even a brief hypotensive episode and someone who's vulnerable like this patient. Those are sometimes called watershed areas. They're in between those major vessels and there are not a lot of collateral supply. The two most common places this happens are the splenic flexure and the rectus sigmoid junction. This is because the large vessels are compromised. There is no adequate collateral blood flow specifically in those two places. Hence, the correct answer here is B. [08:30] Understanding the Other Choices The cecum is supplied by the branches right off the superior mesenteric. It's not particularly prone. The same with ascending colon. Transverse colon receives its blood supply from the middle colic artery, which is a branch of the superior mesenteric. Hepatic flexure is also supplied by that large vessel. [09:30] Some Studying Tips Again, the key to this was the hypotension interop. Andrea says that if you've done a few hundred GI questions, you will see something about hypotension and ischemic colitis somewhere in your readings. If you haven't, the key is looking at the word "current." So it's trying to indicate not what they came in for but it's their current problem. So this could help you rethink and realize that they're not asking for diverticulitis but what happened. Ultimately, you have to make sure you understand what you're reading. A lot of the questions may not be a post-operative situation. It could just be a question about a patient coming in with bloody diarrhea, the most common sign, along with severe abdominal pain. So when you see bloody diarrhea and severe pain, then you can right away think that it's ischemic. Also see the history of coronary heart disease, diabetes, and all those things that go along to decrease blood flow. Links: Board Vitals (Use the promo code BOARDROUNDS to save 15%.)
10 Apr 2019
27: Peptides and Isolated Cardiac Amyloidosis
Session 27 A patient with a history of arrhythmia is found to have atrial amyloid deposition on autopsy. Do you know what peptide is associated with this finding? Dr. Karen Shackelford joins us for another round of interesting questions to help you ace your boards. If you haven’t yet, check out BoardVitals and use the promo code BOARDROUNDS to save 15% off. Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points. [02:14] Question of the Week The autopsy of the patient with a history of arrhythmia revealed amyloid deposition in the atria but no other amyloid was found in the ventricles. Which of the following peptides is associated with amyloid deposition in the atria? And what is that peptide's function? (A) Calcitonin and reduction of blood calcium concentration (B) Prolactin and gastric emptying (C) Acetylcholine and positive chronotropy to sinoatrial node (D) Immunoglobulin and cell-mediated immune response (E) Atrial natriuretic peptide and vasodilation [Related episode: Cardiac Electrophysiology—What is it?] [03:15] Thought Process Behind the Correct Answer The correct answer is E. An amyloid is a group of diverse extracellular proteins in variable amino acid sequences and they have common physical properties. Amyloid deposition and the extracellular deposition of the fibrils are composed of the subunit of varied serum proteins that form beta-pleated sheet configurations that lead to the histologic changes seen in amyloidosis. Isolated amyloidosis is found only in a single organ such as this cardiac amyloidosis. Alpha-atrial natriuretic peptide is responsible for deposition in this isolated cardiac amyloidosis. This is what's responsible for amyloid deposition in part. The incidence appears to be maybe part of the normal process of aging. In one autopsy series, 86% of the patients between the age of 81 and 90 had isolated atrial amyloidosis. It may lead to heart failure. Although diuretics are commonly given to patients with heart failure due to cardiac amyloidosis, beta-blockers, calcium channel blockers, and ace inhibitors may be harmful. [05:55] Understanding the Wrong Answer Choices Calcitonin is associated with isolated amyloidosis of the thyroid. Prolactin is associated with lactation found in amyloidosis that is isolated to the pituitary gland. Acetylcholine is the negative chronotropic sinoatrial node in the right vagus nerve. The stimulation of the nerve decreases the firing of the SA nodes, increasing potassium and decreasing sodium and calcium movement to the cell. Finally, immunoglobulin amyloid deposition is widespread and it's the result of its light chain immunoglobulin deposition. The point of the question was that isolated amyloidosis can affect many particular organs. This is different from more widespread amyloidosis related to immunoglobulin in terms of ideology and distribution. [07:10] The Big Takeaway Amyloid is not just that atrial natriuretic factor but you have to ask yourself where is it is as you're reading this question. Is it in the parathyroid for prolactin or widespread for the immunoglobulin or is it in the atrium for the atrial natriuretic peptide? [08:11] BoardVitals Check out BoardVitals for their Step 1 and Level 1 QBanks. Use the promo code BOARDROUNDS to save 15% off. This can be used for your SHELF exam QBanks as well. Links: BoardVitals
31 Jul 2019
39: USMLE and COMLEX Prep: Spinal Cord Pathology
A 70-y/o male has hypoesthesia of the trunk, hypoalgesia, and decreased temperature discrimination. Which diagnosis accounts for residual pallesthesia and fine touch? Links: Full Episode Blog Post Meded Media BoardVitals (promo code BOARDROUNDS and save 15% off) PMY 373: From Art School to Med School with Dr. Mike Natter Follow me on Instagram @medicalschoolHQ. Follow Dr. Mike Natter on Instagram @mike.natter and check out all his amazing artwork.
12 Feb 2020
47: USMLE and COMLEX Prep: Cranial Nerve Nuclei
Using our knowledge of cranial nuclei and some spacial awareness, which cranial nerve nuclei receives fibers from the carotid baroreceptors? Let's find out! Links: Full Episode Blog Post BoardVitals (Use the promo code BOARDROUNDS to save 15% off.) Meded Media
8 Apr 2020
11: USMLE and COMLEX Prep: Glossopharyngeal Nerve Anatomy
Session 11 Today, we discuss a more straightforward, neuro-anatomy question about the glossopharyngeal nerve. As always, we’re joined by Dr. Andrea Paul of Board Vitals. If you’re in the market for QBanks and practice tests for the USMLE/COMLEX, check out Board Vitals. Use the promo code BOARDROUNDS to save 15% on your purchase. [02:00] Question Which of the glands of the options below are innervated by the efferent autonomic fibers of the glossopharyngeal nerve? [02:14] Answer Choices You have to know what the glossopharyngeal nerve and what type of fibers are innervating the glands. Answer choices: (A) Nasal (B) Submandibular (C) Sublingual (D) Parotid (E) Lacrimal [02:45] Thought Process in Answering the Question Glosso refers to the tongue and pharyngeal refers to the pharynx area. So this is somewhere around the mouth. The interesting with glossopharyngeal is that it has a range of effects. Some of the places it touches would surprise you. But first, you can eliminate nasal. But the rest of the choices could be fair game. This specific nerve has a lot of sensory – parasympathetic and motor functions. It's tough to answer so this can be challenging to people. This nerve starts at the medulla and coming out of the jugular foramen. It's traveling through both anteriorly and posteriorly. So it has a branch that goes to the inner ear. Lacrimal refers to the tear ducts so you can get rid of this one too. Now, we're down with three choices. [06:55] Choosing Among the Three First, remember the motor functions. So it's innervating the muscle in the pharynx and then you think through the sensory functions. Glossopharyngeal is sensory to the posterior third of the tongue or the back half of the tongue. If you can remember that section of the tongue, it leads you closer to the location of the gland that may be in that area. It's also going up into the middle ear, the Eustachian tube for sensory function. Anatomically, you start to think more up anterior than sublingual. Think of it as more of in the ear area. So the correct answer here is the Parotid gland, which is the only gland that doesn't receive any autonomic innervations from the facial nerve. So it receives that from the glossopharyngeal nerve. This is the main differentiator. Hence, the exam likes to ask about it. The posterior third of the tongue and the middle ear are things they love to ask about glossopharyngeal. Also, know which muscles are innervated, which is the stylopharyngeus in the pharynx. Also, try to remember the path and the branches. It sends a branch up to the middle ear. There are five other branches. One goes to the stylopharyngeus muscle, one is the pharyngeal branch, one is tonsilar, one is sublingual, and then one goes to the parotid body and sinus. You can draw this to help give you a visualization. Afferent refers to the sensory nerves coming back towards the central nervous system and efferent refers to "going away" for motor function. In terms of understanding parasympathetic vs sympathetic, just remember that most glandular effects are parasympathetic just like most of your organs. [12:24] Board Vitals Check out the QBank and practice tests over at Board Vitals to help you be prepared for your exam. They have over 1,750 questions for USMLE and over 1,500 questions for COMLEX. Get a 1-month, 3-month, or 6-month plan. They all come with a free trial. No credit card required. Use the promo code BOARDROUNDS to save 15% on your purchase. Links: Board Vitals (promo code BOARDROUNDS)
3 Apr 2019
46: USMLE and COMLEX Prep: Glossopharyngeal Nerve Innervation
More glossopharyngeal neuroanatomy! This gland is innervated by the efferent autonomic fibers of the glossopharyngeal nerve. Name that gland!
1 Apr 2020
22: What is Causing This Pancreatitis?
Session 22 Today, we tackle a pathophysiology question related to pancreatitis. Once again, we're joined by Dr. Karen Shackelford from BoardVitals. Check out their QBanks containing 1,700+ questions for Step1/Level 1. Use the promo code BOARDROUNDS to save 15% off. [01:50] Question of the Week A 45-year-old male presents to the hospital with abdominal pain and vomiting. He began to experience a dull pain in the epigastrium two days prior to admission that has progressively worsened. The pain radiates to his back. He's had several episodes of bilious non-bloody vomiting. He has no prior medical conditions. And he takes no medications. He has a 20-pack per history of tobacco and drinks 6-10 beers daily. The vital signs vary, has a temperature of 100 degrees Fahrenheit, and a heart rate of 102 beats per minute. He appears uncomfortable. On exam, his abdomen is soft and mildly distended, with marked right upper quadrant in epigastric tenderness to palpation. There is no rebound or guarding. He has hypoactive bowel sounds and no palpable masses or hepatosplenomegaly are appreciated. Laboratory studies through the hemoglobin of 12.8 g/dL, leukocytes 14,500 cells per mm3, with 81% PMNs and 16% lymphocytes. Platelet count is 178,000 and total bilirubin is 1gm/dL with the direct bilirubin of 0.4 g/dL. Alkaline phosphatase is 90 IU/L and aspartate aminotransferase (AST) is 88, alanine aminotransferase is 78, and serum amylase is 1,447 IU/L. What is one of the pathophysiological mechanisms of this patient's condition? (A) Pancreatic duct obstruction due to a stone (B) Activation of pancreatic stellate cells (C) Viral infection (D) Intraductal stone formation (E) Toxic fatty acids in pancreatic microcirculation [04:00] Thought Process Behind the Correct Answer Hemoglobin is normally low. White blood cells are minimally elevated. Platelets are normal. Bilirubin is a little bit elevated. Alkaline phosphatase is slightly elevated as well as the aspartate aminotransferase (AST), alanine aminotransferase and amylase. The condition of the patient is actually pancreatitis. The lipase is also slightly elevated which is more specific for pancreatitis and amylase which can be released by other cells as well. The most common cause of pancreatitis is gallstone pancreatitis but this guy has a history of pretty heavy drinking. The second most common cause of pancreatitis is related to alcohol. It's not clear though exactly how they're related but most chronic alcoholics do not end up with chronic alcoholic pancreatitis. But there may also be other risk factors to be considered here. One of the mechanisms is the hyperactivation of the pancreatic stellate cells. These cells that get activated by alcohol as well as by acetaldehyde. They regulate the deposition and the degradation of the pancreatic extracellular matrix protein. They secrete the matrix proteins and metalloproteinases that degrade the matrix proteins. So they regulate all the extracellular matrix proteins in the pancreas. Whenever they're overactivated by phenol and acetaldehyde, the metabolite of ethanol, the matrix becomes fibrotic. That's one of the mechanisms of chronic pancreatitis. Another interesting thing is that the stellate cells also express ADH and whenever overactivated, it seems to perpetuate a cycle of autocrine reactivation. So it's self-perpetuated. Another mechanism of alcoholic pancreatitis is that the alcohol is metabolized by both oxidative and non-oxidative mechanisms. There are changes in acinar cells that increase the activation of intracellular digestive enzymes. Hence, there's an autodigestive component. There is a transient decrease in pancreatic blood flow that results from the action of ethanol. 10:17 There's also an increase in ductal permeability related to alcohol use. It then makes it possible for these improperly activated enzymes to leak out of the duct into the surrounding tissue which just adds to the inflammation and fibrosis. Any of those mechanisms could be asked on the USMLE. [11:00] Understanding the Other Answer Choices It's not completely known what causes pancreatitis. After an obstruction, there's an increase in pancreatic pressure. Studies showed that the flow of biliary salts itself does not cause pancreatitis. This patient doesn't have a previous history given the biliary colic. Bilirubin is relatively normal and patients with a stone obstruction usually have a direct hyperbilirubinemia. The viral infection mumps and Kawasaki virus have been implicated in some sporadic cases of pancreatitis. But this is unusual and this patient doesn't have a history of it. Intraductal stone formation is what causes pancreatitis in patients who have hypercalcemia due to hyperparathyroidism or some other conditions. They usually have additional features mentioned in the history that are associated with hypercalcemia. These may include constipation or kidney "stones, bones, groans, and moans." Finally, fatty acid deposition with ensuing inflammation is the mechanism of pancreatitis in patients who have familial hyperlipidemia. They have those really high triglycerides. They would usually have other features mentioned like xanthelasma or early atherosclerosis or family history. Links: BoardVitals (Use the promo code BOARDROUNDS to save 15% off.)
26 Jun 2019
45: USMLE and COMLEX Prep: Glossopharyngeal Nerve Anatomy
Where does the branchial motor component of the glossopharyngeal nerve originate? Join us and see how well you know your neuroanatomy.
25 Mar 2020
23: Etiology of an Absent Nerve Reflex of the Palate
Session 23 We're joined by Dr. Karen Shackelford from BoardVitals as we tackle a neuro question this week. Maximize your Step 1/Level 1 prep by checking out BoardVitals. They have an amazing QBank that contains targeted questions. If you have a question about a question or explanation, for instance, simply click a button. This will allow you to ask a doctor and get a response within 24-48 hours. Use the promo code BOARDROUNDS to save 15% off. Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points. [01:13] Question of the Week A patient has a decreased level of consciousness and they're testing the gag reflex. The elevation of the soft palate is symmetric when he touched the left side. But when he touched the right side, there's no response. Which of the following is true relating to this patient's condition? (A) The glossopharyngeal nerve carries efferent fibers that mediate the gag reflex. (B) The ideology of that absent reflex is a lesion of the right glossopharyngeal nerve. (C) The cause of the patient's absent reflex is a lesion of the left vagus nerve. (D) The reflex is mediated through the dorsal motor nucleus of the vagus. (E) Both the glossopharyngeal nerve and the vagus nerve are damaged on the right side. [Related episode: USMLE and COMLEX Prep: Glossopharyngeal Nerve Anatomy] [02:11] Thought Process Behind the Correct Answer The correct answer here is B. The motor limb is mediated by the vagus nerve. Sensory, however, is mediated by the glossopharyngeal nerve. The vagus nerve also carries some sensory fibers through the recurrent laryngeal. If the gag reflex is intact, the soft palate will rise symmetrically regardless of which side is touched. If both the glossopharyngeal and the vagus are damaged on one side, there is no response when touching the contralateral side. The soft palate will rise unilaterally on the side that's intact. Also, there won't be any response whenever you're testing the affected side of the lesion if both nerves are damaged. The vagus nerve is the only nerve damaged and there's a lesion on the single side of it. And the soft palate rises and pull to the intact side. Regardless of the pathway, this is something worth remembering. If the glossopharyngeal is only damaged on a single side, there's not going to be a response on either side when you test the reflex on the affected side. This is because you're not receiving the sensory impulse. Whenever you test the intact side, the palate will rise on both sides because the motor fibers of the vagus nerve are still intact. [06:40] Understanding the Other Answer Choices The afferent fibers of the glossopharyngeal nerve mediate the sensory component of the gag reflex. Hence, answer choice A is wrong. For C, if the left vagus nerve or the motor nerve was damaged on the left side resulting in an elevation of the soft palate on the right no matter which side was tested. In other words, this is the lateral lesion of vagus nerve. There's also the elevation of the soft palate to the contralateral side regardless of which side you're testing. For option D, this is also wrong because the reflex is mediated through the nucleus ambiguus. For E, if that were the case, then there would be no response at all when testing the right side or the side of the lesion. There would also be no response when testing the left side because the motor portion is damaged on the side of the lesion. Hence, there'd be an asymmetric elevation of the soft palate on the contralateral side. [08:45] BoardVitals Maximize your Step 1/Level 1 prep by checking out BoardVitals. They have an amazing QBank that contains targeted questions. If you have a question about a question or explanation, for instance, simply click a button. This will allow you to ask a doctor and get a response within 24-48 hours. Use the promo code BOARDROUNDS to save 15% off. Links: BoardVitals (Use the promo code BOARDROUNDS to save 15% off.)
3 Jul 2019
18: Determining Causative Agent of a Severe and Painful Rash
Session 18 As always, I'm joined by Dr. Karen Shackelford from Board Vitals. If you haven't yet, check out Board Vitals and use the promo code BOARDROUNDS to save 15%. They have a huge database and question bank to help you get the practice you need to get the score that you need. [01:35] Question of the Week An older patient comes in with a painful rash. We have a 64-year-old female who presents complaining of a severe painful rash that is localized to the left side of her upper back and neck. She knows that the area of the rash feels hot and burning and extremely painful. She is otherwise healthy with no significant past medical history. On exam, her vital signs were within normal limits. And her exam is significant, primarily, because she has a large, red vesicular rash running along her left shoulder in confluent patches. She remarks that the lesions were smaller a few days ago and they quickly start to bubble over into larger 02:39. The physician performed a Tzanck smear to confirm her suspicions. She found the test to be positive for multinucleated giant cells. The patient will have which of the following characteristics? (A) Gram-positive, catalase-positive, beta-hemolytic and arranged in clusters (B) Branching pseudohyphae with budding yeast cells (C) Enveloped-virus with double-stranded DNA (D) Enveloped-virus with positive-strand RNA virus [04:30] Thought Process The correct answer is C. Varicella zoster virus would probably come to mind as well as shingles as the Tzanck smear showed multinucleated giant cells – herpes simplex virus 1 and 2 (HSV 1 and 2) as well as pemphigus vulgaris. Other findings you would probably see on the Tzanck smear would include acantholytic cell and keratinocyte ballooning. This test is not typically performed usually as a clinical diagnosis. But it can be performed in the office. The patient can be immunocompromised with atypical looking lesion or atypical presentation. So we'd think of herpes and varicella zoster. For the other answer choices, Choice A is Staphylococcus aureus, which isn't a choice for a skin infection. Choice B is a fungus. A fungal disease like Candida can cause a really nasty rash. But it won't be the vesicular nor the dermatomal, which this question suggests. Varicella zoster virus is latent in the sensory ganglion so it tends to erupt on one or two contiguous dermatomes, although it can erupt outside of the dermatome. But it's not going to be a big eruption and just one or two vesicles scattered somewhere else from reactivation of the viral particles. Option D is Rubella. It causes a rash and it's usually tested for IgM antibodies. If a test is needed, it's not the Tzanck smear. [07:45] Possible Question Points About the Herpes Virus About 30% of Americans will have it at some point in their lives coming from reactivation of the virus. It causes two clinically distinct diseases including chicken pox. Chicken pox would be characterized by vesicular lesions but they're on different stages of development. They're concentrated on the face and the trunk. It's an airborne virus that invades the lymphoid tissue in the nose or nasopharynx. The virus overcomes local host defenses. The epidermal cells usually react by making alpha-interferons. That's the incubation period. When the virus can overcome the local host defenses, then you've got a viremia. Then the virus downregulates your immune response through a variety of mechanisms, such as the inhibition of the expression of interferon response genes. When the virus remains latent for years in most cases, you're more at risk of reactivation as you get older because you have a diminished T-cell response. This is the same reason that people with immuno-compromise are more likely to erupt with shingles. It's a unilateral vesicular eruption, usually in the dermatome. The reactivated varicella can travel either way. It can travel peripherally through the sensory ganglion and go down the sensory nerve. This results in a skin infection or the characteristic rash. It can also reactivate and move centrally from the ganglion. This is seen in those who are severely immuno-compromised. But this results in some of the complications associated with herpes zoster like meningitis-encephalitis. Some of the syndromes include the Ramsay Hunt syndrome but it's a random thing. It occurs whenever the virus replicates in the geniculate ganglion. It travels down the 8th nerve and you have vesicles on the auricle or in the ear canal – ipsilateral facial paralysis. Herpes 11:12 is a pretty significant complication. You have to recognize it really early on because it can cause blindness. You can get herpes keratitis and acute retinal nephrosis. The treatment is going to be an antiviral ganciclovir or acyclovir. Postherpetic neuralgia is another big complication with severe significant pain (3 out of 10 and higher for about 90 days or more). Some people can have sensory changes. It can be intensely pruritic. If you get vesicular lesions on the nose then the nerve distribution is pretty worrisome so you have to be aware of that. [12:50] Board Vitals Check out Board Vitals and use the promo code BOARDROUNDS to save 15% off your QBank purchase. Whether you're studying for the COMPLEX or USMLE, Board Vitals has the QBank you need to help prepare you the best possible way. Links: Board Vitals (use the promo code BOARDROUNDS to save 15%)
29 May 2019
40: Do You Know Your Anatomy in Reference to a C-Section?
A 28-y/o female presents with a painful, lower-abdominal mass two days after a c-section. What is the most likely site of injury that led to this hematoma? Links: Full Episode Blog Post BoardVitals (promo code BOARDROUNDS to save 15% off) Meded Media
19 Feb 2020
41: Thinking Through a Facial Neuroanatomy Question
A 62-year-old female presents with impared taste and drooping on the right side of her face, but her hearing is normal. Where is the probable lesion located? Links: Full Episode Blog Post BoardVitals (Use the promo code BOARDROUNDS to save 15% off) Follow us on Instagram @medicalschoolhq and @mike.natter.
26 Feb 2020
16: USMLE and COMLEX Prep: 26 y/o Pregnant Immigrant
Session 16 We're joined once again by Dr. Karen Shackelford from BoardVitals. This week, we discuss a case about an immigrant from Central America who's pregnant. [01:30] Question of the Week: A 26-year-old, G1P0 female is a recent immigrant from Central America and she presents with crampy abdominal pain and vaginal bleeding. By her dates, because she hasn't received prenatal care. She's of 25 weeks gestation and her past medical history is unremarkable. She takes an over-the-counter multivitamin but no other medication. She denies alcohol, tobacco, or illicit drug use. And she spontaneously delivers a stillborn fetus. The fetus is noted to have microcephaly and imaging performed reveals thinning of the cerebral cortices, ventriculomegaly, and subcortical calcifications. Viral RNA is identified in both maternal and fetal body fluids. The virus is a neurotropic virus that disrupts proliferation migration and differentiation of neural precursor cells in the developing fetus. Which of the following is the most likely pathogen? (A) Herpex simplex virus (B) Rubella (C) Zeka virus (D) Cytomegalovirus (CMV) [03:50] Thought Process The pathogen here is Zeka virus. CMV is a pretty good distraction here since the question mentioned ventricular calcification. But with respect to being a neurotropic virus, Zeka is and has been in the news a lot. It's a single-stranded RNA virus transmitted by mosquitoes. It's also related to dengue virus and the yellow fever virus. The infection results in clinical manifestations in about 20% of people and the rest would not know they've had it. If you're infected, you're symptomatic. You have a low-grade temp. You can develop a maculopapular rash, arthralgia, and conjunctivitis. There are other neurologic complications besides the general microcephaly. You can end up with Guillain-Barre, myelitis, meningoencephalitis, seizures, and congenital spasticity which the mother has vertically transmitted during delivery or it can be transmitted through the placenta. It can also be sexually transmitted and through other body fluids. It can also be caused by laboratory exposure such as the transplant of infected organs. It's fairly infectious. [05:42] Pregnant Women Should Avoid Infested Areas Pregnant women in the United States have been advised across the board to avoid travel in regions where mosquito transmission of Zeka occurs if they're going to be less than 6500 feet in altitude. This is the same thing with malaria in some parts of Kenya. [06:12] Understanding the Other Viruses CMV is a double-stranded DNA virus. The question mentioned specifically that the virus was an RNA virus. So this would be one reason you would disqualify CMV from your correct answers. But general CMV infection can result in chorioretinitis, hearing loss, jaundice, and periventricular calcification on imaging studies. CMV is not associated with tropical travel or immigration. Rubella is a single-stranded RNA virus. Congenital exposure is primarily associated with hearing loss, cataracts and congenital cardiac defects instead of neurological defects. HSV is a double-stranded DNA virus. Congenital exposure is associated with skin lesions and obstruction of brain tissue. The candidate here can rule out HSV for no other reason than it's a DNA virus. [07:55] Expand Your Knowledge and Be Up-to-Date Zeka has been in the news a lot lately. And content gets updated on USMLE. So you should be aware of these things even if you just hear about them once or twice while you're studying. You're more likely to diagnose it than if you don't remember hearing about it at all during your studies. "You have to be aware of what is potentially out there because you can't diagnose something you don't think of." [08:40] BoardVitals Check out the QBanks at BoardVitals.com. With over 1700 questions for Step 1 and over 1500 questions for Level 1, you will have plenty of content to cover to make sure that you are prepared for your board exam. You board exam score is vital for you to be able to match into your specialty of choice. So there is no such thing as being over prepared for your board exams. Start now. Sign up for a 6-month plan or a 3-month plan. Get started early. Get through the content because the more questions you do, the better you do on your board exams. Use the promo code BOARDROUNDS to save 15% off. Links: BoardVitals (promo code BOARDROUNDS to save 15% off)
15 May 2019
43: USMLE and COMLEX Prep: Chemical Composition of Gallstones
A 32-y/o woman with acute cholecystitis has a past medical history of autoimmune hemolytic anemia. Which substance is likely to be found in her gallstones? Links: Full Episode Blog Post Meded Media BoardVitals (Use the promo code BOARDROUNDS to save 15% off.) Follow us on Instagram @MedicalSchoolHQ and @mike.natter.
11 Mar 2020