A 15-year-old boy is brought to the physician by his father because he has been waking up frequently during the night to urinate. Apart from occasional headaches, he has no other complaints. His family recently emigrated from Tanzania and his medical history is unknown. His father was diagnosed with sickle cell disease at the age of 5. Physical examination shows no abnormalities. Laboratory studies show:
Hemoglobin 14.5 g/dL
Hematocrit 44%
MCV 90 fL
Reticulocytes 1.5%
A hemoglobin electrophoresis shows:
HbA 55%
HbS 43%
HbF 1%
This patient is at greatest risk for which of the following conditions?
Q1152
A 59-year-old woman comes to the physician because of a 1-month history of episodic cough and shortness of breath. The cough is nonproductive and worsens when she climbs stairs and during the night. She has not had chest pain or palpitations. Eight weeks ago, she had fever, sore throat, and nasal congestion. She has a 10-year history of hypertension. She has smoked half a pack of cigarettes daily for 16 years. Her only medication is enalapril. Her pulse is 78/min, respirations are 18/min, and blood pressure is 145/95 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Diffuse end-expiratory wheezes are heard on pulmonary auscultation. An x-ray of the chest shows no abnormalities. Spirometry shows an FEV1:FVC ratio of 65% and an FEV1 of 60%. Which of the following is the most likely diagnosis?
Q1153
A previously healthy 32-year-old man comes to the physician because of a 1-week history of upper back pain, dyspnea, and a sensation of pressure in his chest. He has had no shortness of breath, palpitations, fevers, or chills. He emigrated from Ecuador when he was 5 years old. He does not smoke or drink alcohol. He takes no medications. He is 194 cm (6 ft 4 in) tall and weighs 70.3 kg (155 lb); BMI is 19 kg/m2. His temperature is 37.2°C (99.0°F), pulse is 73/min, respirations are 15/min, and blood pressure is 152/86 mm Hg in the right arm and 130/72 mm Hg in the left arm. Pulmonary examination shows faint inspiratory wheezing bilaterally. A CT scan of the chest with contrast is shown. Which of the following is the most likely underlying cause of this patient's condition?
Q1154
A previously healthy 13-year-old girl is brought to the physician for evaluation of a 2-month history of fatigue. She reports recurrent episodes of pain in her right wrist and left knee. During this period, she has had a 4-kg (8.8-lb) weight loss. Her mother has rheumatoid arthritis. Her temperature is 38°C (100.4°F). Examination shows diffuse lymphadenopathy. Oral examination shows several painless oral ulcers. The right wrist and the left knee are swollen and tender. Laboratory studies show a hemoglobin concentration of 9.8 g/dL, a leukocyte count of 2,000/mm3, and a platelet count of 75,000/mm3. Urinalysis shows excessive protein. This patient's condition is associated with which of the following laboratory findings?
Q1155
A 27-year-old Asian woman presents to her primary care physician with joint pain and a headache. She has had intermittent joint and muscle pain for the past several months in the setting of a chronic headache. She states that the pain seems to migrate from joint to joint, and her muscles typically ache making it hard for her to sleep. The patient's past medical history is non-contributory, and she is currently taking ibuprofen for joint pain. Physical exam is notable for an asymmetrical pulse in the upper extremities. The patient has lost 10 pounds since her previous visit 2 months ago. Laboratory values are notable for an elevated C-reactive protein and erythrocyte sedimentation rate. Which of the following is the best next step in management?
Q1156
A 49-year-old woman presents to her primary care physician for a routine health maintenance examination. She says that she is currently feeling well and has not noticed any acute changes in her health. She exercises 3 times a week and has tried to increase the amount of fruits and vegetables in her diet. She has smoked approximately 1 pack of cigarettes every 2 days for the last 20 years. Her last pap smear was performed 2 years ago, which was unremarkable. Her past medical history includes hypertension and type II diabetes. Her mother was diagnosed with breast cancer at 62 years of age. The patient is 5 ft 5 in (165.1 cm), weighs 185 lbs (84 kg), and has a BMI of 30.8 kg/m^2. Her blood pressure is 155/98 mmHg, pulse is 90/min, and respirations are 18/min. Physical examination is unremarkable. Lipid studies demonstrate an LDL cholesterol of 130 mg/dL and an HDL cholesterol of 42 mg/dL. Which of the following is the best next step in management?
Q1157
A 28-year-old woman presents with severe vertigo. She also reports multiple episodes of vomiting and difficulty walking. The vertigo is continuous, not related to the position, and not associated with tinnitus or hearing disturbances. She has a past history of acute vision loss in her right eye that resolved spontaneously several years ago. She also experienced left-sided body numbness 3 years ago that also resolved rapidly. She only recently purchased health insurance and could not fully evaluate the cause of her previous symptoms at the time they presented. The patient is afebrile and her vital signs are within normal limits. On physical examination, she is alert and oriented. An ophthalmic exam reveals horizontal strabismus. There is no facial asymmetry and her tongue is central on the protrusion. Gag and cough reflexes are intact. Muscle strength is 5/5 bilaterally. She has difficulty maintaining her balance while walking and is unable to perform repetitive alternating movements with her hands. Which of the following is the best course of treatment for this patient’s condition?
Q1158
A 50-year-old woman comes to the physician because of worsening pain and swelling of her left knee. For the past year, she has had pain in her knees and hands bilaterally, but never this severe. During this period, she has also had difficulties moving around for about an hour in the mornings and has been sweating more than usual, especially at night. She has been sexually active with a new partner for the past 4 weeks, and they use condoms inconsistently. She occasionally drinks alcohol. The day before she drank 6 beers because she was celebrating a friend's birthday. Her temperature is 38.5°C (101.3°F), blood pressure is 110/70 mm Hg, and pulse is 92/min. The left knee is erythematous, swollen, and tender; movement is restricted due to pain. There is swelling of the metacarpophalangeal joints and proximal interphalangeal joints bilaterally. Arthrocentesis of the knee with synovial fluid analysis shows a greenish, turbid fluid, a cell count of 68,000 WBC/μL and Gram-negative diplococci. An x-ray of the affected knee is most likely to show which of the following findings?
Q1159
A 74-year-old man presents to the emergency room with abdominal pain. He reports acute onset of left lower quadrant abdominal pain and nausea three hours prior to presentation. The pain is severe, constant, and non-radiating. He has had two maroon-colored bowel movements since the pain started. His past medical history is notable for hypertension, hyperlipidemia, atrial fibrillation, insulin-dependent diabetes mellitus, and rheumatoid arthritis. He takes lisinopril, hydrochlorothiazide, atorvastatin, dabigatran, methotrexate. He has a 60 pack-year smoking history and drinks 1-2 beers per day. He admits to missing some of his medications recently because he was on vacation in Hawaii. His last colonoscopy was 4 years ago which showed diverticular disease in the descending colon and multiple sessile polyps in the sigmoid colon which were removed. His temperature is 100.1°F (37.8°C), blood pressure is 145/85 mmHg, pulse is 100/min, and respirations are 20/min. On exam, he has notable abdominal distention and is exquisitely tender to palpation in all four abdominal quadrants. Bowel sounds are absent. Which of the following is the most likely cause of this patient’s condition?
Q1160
A 66-year-old man undergoes a coronary artery bypass grafting. Upon regaining consciousness, he reports that he cannot see from either eye and cannot move his arms. Physical examination shows bilaterally equal, reactive pupils. A fundoscopy shows no abnormalities. An MRI of the brain shows wedge-shaped cortical infarcts in both occipital lobes. Which of the following is the most likely cause of this patient's current symptoms?
Cardiology US Medical PG Practice Questions and MCQs
Question 1151: A 15-year-old boy is brought to the physician by his father because he has been waking up frequently during the night to urinate. Apart from occasional headaches, he has no other complaints. His family recently emigrated from Tanzania and his medical history is unknown. His father was diagnosed with sickle cell disease at the age of 5. Physical examination shows no abnormalities. Laboratory studies show:
Hemoglobin 14.5 g/dL
Hematocrit 44%
MCV 90 fL
Reticulocytes 1.5%
A hemoglobin electrophoresis shows:
HbA 55%
HbS 43%
HbF 1%
This patient is at greatest risk for which of the following conditions?
A. Avascular osteonecrosis
B. Renal papillary necrosis (Correct Answer)
C. Clear cell renal carcinoma
D. Functional asplenia
E. Ischemic stroke
Explanation: ***Renal papillary necrosis***
- The patient has **sickle cell trait (HbAS)**, evidenced by **55% HbA** and **43% HbS**. Individuals with sickle cell trait are at increased risk for **renal papillary necrosis** due to vaso-occlusive events in the renal medulla, exacerbated by the hypoxic, hyperosmolar, and acidic environment.
- Clinical manifestations of renal papillary necrosis include **hematuria**, **flank pain**, and **polyuria/nocturia**, which aligns with the patient's presenting symptom of frequent nighttime urination.
*Avascular osteonecrosis*
- While individuals with **sickle cell disease (HbSS)** are at high risk for **avascular osteonecrosis** due to bone infarction, it is *less common* in those with sickle cell trait.
- The patient's hemoglobin electrophoresis results (HbA 55%, HbS 43%) confirm **sickle cell trait**, not sickle cell disease.
*Clear cell renal carcinoma*
- **Clear cell renal carcinoma** is not directly associated with sickle cell trait.
- While other renal malignancies like **renal medullary carcinoma** can occur in sickle cell trait patients, clear cell renal carcinoma typically presents later in life and is not the most likely complication given the patient's symptoms and genetic profile.
*Functional asplenia*
- **Functional asplenia** is a common and serious complication of **sickle cell disease (HbSS)**, leading to increased susceptibility to encapsulated bacterial infections.
- It is *not typically seen* nor is it a major risk in individuals with **sickle cell trait**.
*Ischemic stroke*
- **Ischemic stroke** is a significant complication in patients with **sickle cell disease (HbSS)** due to chronic hemolysis and vaso-occlusion.
- While there might be a *slightly increased risk* in sickle cell trait compared to the general population, it is *not as pronounced* as in sickle cell disease, and the presenting symptoms do not suggest an acute stroke.
Question 1152: A 59-year-old woman comes to the physician because of a 1-month history of episodic cough and shortness of breath. The cough is nonproductive and worsens when she climbs stairs and during the night. She has not had chest pain or palpitations. Eight weeks ago, she had fever, sore throat, and nasal congestion. She has a 10-year history of hypertension. She has smoked half a pack of cigarettes daily for 16 years. Her only medication is enalapril. Her pulse is 78/min, respirations are 18/min, and blood pressure is 145/95 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Diffuse end-expiratory wheezes are heard on pulmonary auscultation. An x-ray of the chest shows no abnormalities. Spirometry shows an FEV1:FVC ratio of 65% and an FEV1 of 60%. Which of the following is the most likely diagnosis?
A. Pneumonia
B. Side effect of medication
C. Asthma (Correct Answer)
D. Chronic bronchitis
E. Gastroesophageal reflux disease
Explanation: ***Asthma***
- The **episodic nature** of cough and shortness of breath, worsening with exertion and at night, along with diffuse **end-expiratory wheezes** and **obstructive spirometry** (FEV1:FVC ratio of 65% and FEV1 of 60%), strongly suggests asthma. The prior viral illness could have triggered airway hyperresponsiveness.
- While she has a smoking history, the **episodic symptoms** and the degree of reversibility often seen in asthma (though not tested here) make it more likely than purely chronic obstructive conditions.
*Pneumonia*
- Pneumonia typically presents with a **productive cough**, fever, and often **abnormal chest X-ray findings**, none of which are consistent with this patient's presentation.
- The symptoms of pneumonia are usually more acute and progressive, rather than episodic and triggered by activity or at night.
*Side effect of medication*
- **Enalapril**, an ACE inhibitor, can cause a **nonproductive cough**, but it's typically persistent and not episodic, nocturnal, or associated with wheezing or shortness of breath.
- The spirometry findings of obstruction are not a typical side effect of enalapril, which primarily irritates the airways.
*Chronic bronchitis*
- Chronic bronchitis is characterized by a **chronic productive cough** for at least 3 months in 2 consecutive years, which is not described.
- While chronic bronchitis can cause obstructive spirometry, the **episodic nature** of symptoms and nocturnal worsening are more characteristic of asthma.
*Gastroesophageal reflux disease*
- GERD can cause a **chronic cough**, often nocturnal or post-prandial, but it is typically not associated with **wheezing** or **shortness of breath** or the specific obstructive spirometry pattern seen.
- Treatment for GERD would typically target acid suppression, and symptoms are not typically exercise-induced.
Question 1153: A previously healthy 32-year-old man comes to the physician because of a 1-week history of upper back pain, dyspnea, and a sensation of pressure in his chest. He has had no shortness of breath, palpitations, fevers, or chills. He emigrated from Ecuador when he was 5 years old. He does not smoke or drink alcohol. He takes no medications. He is 194 cm (6 ft 4 in) tall and weighs 70.3 kg (155 lb); BMI is 19 kg/m2. His temperature is 37.2°C (99.0°F), pulse is 73/min, respirations are 15/min, and blood pressure is 152/86 mm Hg in the right arm and 130/72 mm Hg in the left arm. Pulmonary examination shows faint inspiratory wheezing bilaterally. A CT scan of the chest with contrast is shown. Which of the following is the most likely underlying cause of this patient's condition?
A. Atherosclerotic plaque formation
B. Large-vessel vasculitis
C. Cystic medial necrosis (Correct Answer)
D. Congenital narrowing of the aortic arch
E. Infection with Trypanosoma cruzi
Explanation: ***Cystic medial necrosis***
- The patient's tall stature, Marfanoid habitus (BMI 19 kg/m2), and differential blood pressures are highly suggestive of **Marfan syndrome**, which is primarily caused by **cystic medial necrosis** of the aorta.
- **Cystic medial necrosis** is a degenerative process in the aortic wall leading to loss of smooth muscle cells and elastic fibers, predisposing to **aortic dissection** or aneurysm, explaining the chest and back pain.
*Atherosclerotic plaque formation*
- This patient is young, has no traditional risk factors for atherosclerosis (e.g., smoking, obesity, diabetes), and **atherosclerosis** typically does not cause **aortic dissection** at this age in the absence of other risk factors.
- While atherosclerosis can cause aortic aneurysms, it is less likely to present with the acute pain and differential blood pressures seen here in a young, otherwise healthy individual.
*Large-vessel vasculitis*
- **Large-vessel vasculitis** (e.g., Takayasu arteritis) can cause differential blood pressures and aortic involvement, but it is less likely given the patient's presentation with acute pain and the strong clinical features of **Marfan syndrome**.
- Vasculitis would typically present with more systemic inflammatory signs and symptoms, which are absent in this case.
*Congenital narrowing of the aortic arch*
- **Coarctation of the aorta** is a congenital narrowing that can cause differential blood pressures and hypertension, but it would typically present earlier in life, often with signs of left ventricular hypertrophy, and is less likely to lead to acute aortic dissection or the Marfanoid habitus.
- The CT scan would show a distinct localized narrowing rather than the more diffuse aortic changes associated with connective tissue disorders.
*Infection with Trypanosoma cruzi*
- **Chagas disease** (caused by *Trypanosoma cruzi*) can cause **cardiomyopathy** and **megaesophagus/megacolon**, but it does not typically lead to acute aortic dissection or the specific connective tissue abnormalities seen in Marfan syndrome.
- While the patient emigrated from Ecuador, the clinical picture strongly points away from Chagasic aortopathy as the primary cause of his acute aortic symptoms.
Question 1154: A previously healthy 13-year-old girl is brought to the physician for evaluation of a 2-month history of fatigue. She reports recurrent episodes of pain in her right wrist and left knee. During this period, she has had a 4-kg (8.8-lb) weight loss. Her mother has rheumatoid arthritis. Her temperature is 38°C (100.4°F). Examination shows diffuse lymphadenopathy. Oral examination shows several painless oral ulcers. The right wrist and the left knee are swollen and tender. Laboratory studies show a hemoglobin concentration of 9.8 g/dL, a leukocyte count of 2,000/mm3, and a platelet count of 75,000/mm3. Urinalysis shows excessive protein. This patient's condition is associated with which of the following laboratory findings?
A. Anti-citrullinated peptide antibodies
B. Anti-dsDNA antibodies (Correct Answer)
C. Leukocytoclastic vasculitis with IgA and C3 immune complex deposition
D. Positive HLA-B27 test
E. Excessive lymphoblasts
Explanation: ***Anti-dsDNA antibodies***
- The patient presents with **fatigue, fever, weight loss, lymphadenopathy, oral ulcers**, **arthralgia/arthritis**, and **proteinuria**, along with **anemia, leukopenia, and thrombocytopenia**. This constellation of symptoms is highly suggestive of **Systemic Lupus Erythematosus (SLE)**.
- **Anti-dsDNA antibodies** are highly specific for SLE and are often associated with active disease, particularly **lupus nephritis**, which is indicated by the proteinuria.
*Anti-citrullinated peptide antibodies*
- These antibodies are highly specific for **rheumatoid arthritis (RA)**, a disease primarily affecting joints in a symmetrical pattern.
- While the patient's mother has RA, the patient's systemic symptoms (fever, weight loss, anemia, leukopenia, thrombocytopenia, proteinuria) and oral ulcers are not typical features of RA, especially in a 13-year-old.
*Leukocytoclastic vasculitis with IgA and C3 immune complex deposition*
- This finding is characteristic of **IgA vasculitis (Henoch-Schönlein Purpura)**, which typically presents with a palpable purpuric rash, arthritis, abdominal pain, and renal involvement (hematuria/proteinuria).
- The patient's presentation lacks the characteristic rash and GI symptoms, making this diagnosis less likely.
*Positive HLA-B27 test*
- A positive **HLA-B27** is associated with **spondyloarthropathies** such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis.
- These conditions primarily affect the spine and sacroiliac joints, often with enthesitis, and do not typically present with the multi-systemic features like cytopenias, oral ulcers, and significant proteinuria observed in this patient.
*Excessive lymphoblasts*
- The presence of **excessive lymphoblasts** in the bone marrow or blood is indicative of **acute lymphoblastic leukemia (ALL)**.
- Although ALL can present with fatigue, fever, weight loss, anemia, and thrombocytopenia, it is less commonly associated with oral ulcers, arthritis, and significant proteinuria. Additionally, while the patient has leukopenia (2,000/mm3), the presence of circulating lymphoblasts would be a key distinguishing feature of ALL that is not mentioned in this case.
Question 1155: A 27-year-old Asian woman presents to her primary care physician with joint pain and a headache. She has had intermittent joint and muscle pain for the past several months in the setting of a chronic headache. She states that the pain seems to migrate from joint to joint, and her muscles typically ache making it hard for her to sleep. The patient's past medical history is non-contributory, and she is currently taking ibuprofen for joint pain. Physical exam is notable for an asymmetrical pulse in the upper extremities. The patient has lost 10 pounds since her previous visit 2 months ago. Laboratory values are notable for an elevated C-reactive protein and erythrocyte sedimentation rate. Which of the following is the best next step in management?
A. Methotrexate
B. Recommend exercise and optimize the patient's sleep regimen
C. Prednisone (Correct Answer)
D. Temporal artery biopsy
E. Anti-dsDNA level
Explanation: ***Prednisone***
- The patient's presentation with **migratory joint pain**, headache, **asymmetrical pulses**, and elevated inflammatory markers (CRP, ESR) in a young Asian woman suggests **Takayasu arteritis**.
- **Corticosteroids** like prednisone are the cornerstone of initial treatment for active Takayasu arteritis to suppress inflammation and prevent further vascular damage.
*Methotrexate*
- **Methotrexate** is an immunosuppressant often used in conjunction with corticosteroids or as a steroid-sparing agent in rheumatic conditions.
- However, it's not the initial monotherapy of choice for active, severe vasculitis requiring rapid inflammation control.
*Recommend exercise and optimize the patient's sleep regimen*
- While exercise and sleep are important for overall well-being, they do not address the underlying **severe inflammatory vasculitis** and are not an appropriate primary intervention for Takayasu arteritis.
- Delaying proper medical treatment can lead to irreversible vascular damage.
*Temporal artery biopsy*
- A **temporal artery biopsy** is the diagnostic gold standard for **Giant Cell Arteritis (GCA)**, which typically affects older individuals (>50 years).
- The patient's age (27 years) and other clinical features are more consistent with Takayasu arteritis, which affects larger arteries and often presents at a younger age.
*Anti-dsDNA level*
- An **anti-dsDNA level** is a specific marker for **Systemic Lupus Erythematosus (SLE)**.
- While SLE can cause joint pain and headaches, the presence of **asymmetrical pulses** and the demographic (young Asian woman) are more indicative of Takayasu arteritis, not SLE.
Question 1156: A 49-year-old woman presents to her primary care physician for a routine health maintenance examination. She says that she is currently feeling well and has not noticed any acute changes in her health. She exercises 3 times a week and has tried to increase the amount of fruits and vegetables in her diet. She has smoked approximately 1 pack of cigarettes every 2 days for the last 20 years. Her last pap smear was performed 2 years ago, which was unremarkable. Her past medical history includes hypertension and type II diabetes. Her mother was diagnosed with breast cancer at 62 years of age. The patient is 5 ft 5 in (165.1 cm), weighs 185 lbs (84 kg), and has a BMI of 30.8 kg/m^2. Her blood pressure is 155/98 mmHg, pulse is 90/min, and respirations are 18/min. Physical examination is unremarkable. Lipid studies demonstrate an LDL cholesterol of 130 mg/dL and an HDL cholesterol of 42 mg/dL. Which of the following is the best next step in management?
A. Colonoscopy
B. Pap smear
C. Mammogram
D. Chest radiography
E. Statin therapy (Correct Answer)
Explanation: ***Statin therapy***
- This patient has multiple **cardiovascular risk factors**, including a BMI of 30.8 kg/m^2 (obesity), hypertension, type II diabetes, and a history of smoking, placing her at high risk for **atherosclerotic cardiovascular disease (ASCVD)**.
- Her **LDL cholesterol of 130 mg/dL** is elevated in the context of these risk factors, warranting **statin therapy** to reduce her ASCVD risk.
*Colonoscopy*
- **Routine colorectal cancer screening** with colonoscopy typically begins at age **45-50 for average-risk individuals**, or earlier for those with specific risk factors like a strong family history of early-onset colorectal cancer.
- While this patient is 49, there is nothing in her history to suggest the need for urgent colonoscopy over managing her significant cardiovascular risks.
*Pap smear*
- The patient's last **Pap smear was 2 years ago and unremarkable**. Guidelines for cervical cancer screening generally recommend a Pap smear every **3 years for women aged 21-65 years** with normal results.
- This recommendation suggests she is not yet due for another routine Pap smear.
*Mammogram*
- **Routine mammography screening** for breast cancer typically begins at age **40-50 for average-risk women**, depending on specific guideline recommendations (e.g., annually from 40, or biennially from 50).
- While her mother had breast cancer at 62, this is not considered "early-onset" and does not necessarily warrant immediate mammography over other pressing health concerns, although it should be considered.
*Chest radiography*
- **Routine chest radiography** is generally **not recommended for asymptomatic adults**, even in smokers, for general health maintenance.
- It is typically reserved for evaluating specific respiratory symptoms, abnormal physical exam findings, or occupational exposures.
Question 1157: A 28-year-old woman presents with severe vertigo. She also reports multiple episodes of vomiting and difficulty walking. The vertigo is continuous, not related to the position, and not associated with tinnitus or hearing disturbances. She has a past history of acute vision loss in her right eye that resolved spontaneously several years ago. She also experienced left-sided body numbness 3 years ago that also resolved rapidly. She only recently purchased health insurance and could not fully evaluate the cause of her previous symptoms at the time they presented. The patient is afebrile and her vital signs are within normal limits. On physical examination, she is alert and oriented. An ophthalmic exam reveals horizontal strabismus. There is no facial asymmetry and her tongue is central on the protrusion. Gag and cough reflexes are intact. Muscle strength is 5/5 bilaterally. She has difficulty maintaining her balance while walking and is unable to perform repetitive alternating movements with her hands. Which of the following is the best course of treatment for this patient’s condition?
A. Acyclovir
B. Azathioprine
C. Plasma exchange
D. High doses of glucose
E. High-dose corticosteroids (Correct Answer)
Explanation: ***High-doses of corticosteroids***
- The patient presents with a **neurological deficit**, specifically **vertigo**, in the context of a history of **disseminated neurological symptoms** (vision loss, numbness) that resolved spontaneously at different times. This clinical picture is highly suggestive of a **multiple sclerosis (MS) flare**.
- **High-dose corticosteroids** (e.g., intravenous methylprednisolone) are the mainstay treatment for acute MS exacerbations to reduce inflammation and speed recovery.
*Acyclovir*
- **Acyclovir** is an antiviral medication used to treat viral infections, especially **herpes simplex virus** or **varicella-zoster virus**.
- There is no evidence of a viral infection causing the patient's symptoms; MS is an **autoimmune demyelinating disease**, not a viral one.
*Azathioprine*
- **Azathioprine** is an **immunomodulatory drug** used as a disease-modifying therapy in MS to prevent relapses in the long term.
- It is not used for the **acute treatment of an MS exacerbation** due to its slow onset of action.
*Plasma exchange*
- **Plasma exchange (plasmapheresis)** is considered for **severe acute MS attacks** that are refractory to corticosteroid therapy.
- It is a second-line treatment, and high-dose corticosteroids should be tried first.
*High doses of glucose*
- **High doses of glucose** are used to treat conditions like **hypoglycemia** or in specific metabolic disorders.
- This patient's symptoms are neurological and consistent with an inflammatory demyelinating process, for which glucose is not an appropriate treatment.
Question 1158: A 50-year-old woman comes to the physician because of worsening pain and swelling of her left knee. For the past year, she has had pain in her knees and hands bilaterally, but never this severe. During this period, she has also had difficulties moving around for about an hour in the mornings and has been sweating more than usual, especially at night. She has been sexually active with a new partner for the past 4 weeks, and they use condoms inconsistently. She occasionally drinks alcohol. The day before she drank 6 beers because she was celebrating a friend's birthday. Her temperature is 38.5°C (101.3°F), blood pressure is 110/70 mm Hg, and pulse is 92/min. The left knee is erythematous, swollen, and tender; movement is restricted due to pain. There is swelling of the metacarpophalangeal joints and proximal interphalangeal joints bilaterally. Arthrocentesis of the knee with synovial fluid analysis shows a greenish, turbid fluid, a cell count of 68,000 WBC/μL and Gram-negative diplococci. An x-ray of the affected knee is most likely to show which of the following findings?
A. Osteophytes and subchondral cysts
B. Calcifications and osteolysis with moth-eaten appearance
C. Irregularity or fragmentation of the tubercle
D. Calcification of the meniscal and hyaline cartilage
E. Joint space narrowing and bone erosions (Correct Answer)
Explanation: ***Joint space narrowing and bone erosions***
- The patient presents with symptoms and signs consistent with **septic arthritis** due to **Gram-negative diplococci**, likely *N. gonorrhoeae*, superimposed on a history suggestive of **rheumatoid arthritis** (morning stiffness, symmetrical polyarthritis of small joints).
- Both conditions can cause **joint space narrowing** and **bone erosions** on X-ray; septic arthritis causes rapid destruction, while rheumatoid arthritis leads to chronic inflammatory erosion.
*Osteophytes and subchondral cysts*
- These findings are characteristic of **osteoarthritis**, a degenerative joint disease.
- While the patient has chronic joint pain, the acute inflammatory signs (fever, erythema, high WBC count in synovial fluid, Gram-negative diplococci) point away from primary osteoarthritis.
*Calcifications and osteolysis with moth-eaten appearance*
- **Calcifications** in bones or joints can be seen in various conditions, but **osteolysis with a moth-eaten appearance** is more indicative of aggressive bone lesions, such as those caused by **malignancy** or severe osteomyelitis, which is not suggested by the clinical picture.
- The predominant issue here is acute and chronic inflammatory arthritis, not a destructive bone tumor.
*Irregularity or fragmentation of the tubercle*
- This finding, particularly of the tibial tubercle, is commonly associated with conditions like **Osgood-Schlatter disease** in adolescents due to repetitive stress.
- It is not a typical X-ray finding for either septic arthritis or rheumatoid arthritis in an adult knee.
*Calcification of the meniscal and hyaline cartilage*
- This is known as **chondrocalcinosis** and is a hallmark of **calcium pyrophosphate deposition disease (CPPD)**, also known as pseudogout.
- While CPPD can cause acute arthritis, the presence of Gram-negative diplococci and systemic symptoms points to an infectious etiology, and the chronic symmetrical polyarthritis is inconsistent with typical CPPD.
Question 1159: A 74-year-old man presents to the emergency room with abdominal pain. He reports acute onset of left lower quadrant abdominal pain and nausea three hours prior to presentation. The pain is severe, constant, and non-radiating. He has had two maroon-colored bowel movements since the pain started. His past medical history is notable for hypertension, hyperlipidemia, atrial fibrillation, insulin-dependent diabetes mellitus, and rheumatoid arthritis. He takes lisinopril, hydrochlorothiazide, atorvastatin, dabigatran, methotrexate. He has a 60 pack-year smoking history and drinks 1-2 beers per day. He admits to missing some of his medications recently because he was on vacation in Hawaii. His last colonoscopy was 4 years ago which showed diverticular disease in the descending colon and multiple sessile polyps in the sigmoid colon which were removed. His temperature is 100.1°F (37.8°C), blood pressure is 145/85 mmHg, pulse is 100/min, and respirations are 20/min. On exam, he has notable abdominal distention and is exquisitely tender to palpation in all four abdominal quadrants. Bowel sounds are absent. Which of the following is the most likely cause of this patient’s condition?
A. Cardiac thromboembolism
B. Splanchnic vasoconstriction
C. Perforated intestinal mucosal herniation (Correct Answer)
D. Paradoxical thromboembolism
E. Duodenal compression
Explanation: ***Perforated intestinal mucosal herniation***
- This patient's presentation with acute abdominal pain, maroon-colored bowel movements, fever, abdominal distention, diffuse tenderness, and absent bowel sounds, in the context of a history of **diverticular disease**, strongly suggests **perforated diverticulitis**. The "intestinal mucosal herniation" refers to a diverticulum, which can perforate.
- The history of **diverticular disease** and involvement of the **left lower quadrant pain** followed by generalized peritonitis and GI bleeding (maroon stools) makes this the most likely diagnosis.
*Cardiac thromboembolism*
- While the patient has **atrial fibrillation** and is on **dabigatran** (which he may have missed), a cardiac thromboembolism would typically lead to **ischemic enteritis** or **mesenteric ischemia**, presenting with severe pain out of proportion to exam findings, but diffuse peritonitis and perforation are less common primary presentations.
- The clinical picture strongly points towards a localized process that progressed to peritonitis rather than a primary embolic event causing perforation directly without prior significant ischemia symptoms.
*Splanchnic vasoconstriction*
- This mechanism is associated with **non-occlusive mesenteric ischemia**, often seen in critically ill patients, those on vasoconstrictors, or with **low cardiac output states**.
- While the patient has risk factors for vascular disease, the acute onset, localized pain progressing to diffuse peritonitis, and history of diverticula make a perforated diverticulum more probable than primary non-occlusive ischemia leading to perforation.
*Paradoxical thromboembolism*
- A paradoxical embolism involves a clot from the venous system bypassing the pulmonary circulation to enter the systemic circulation, typically through a **patent foramen ovale** or **atrial septal defect**.
- There is no clinical evidence in the patient's history to suggest such a defect or a venous thrombosis as the origin of the embolus, making it a less likely mechanism for the presenting symptoms.
*Duodenal compression*
- **Duodenal compression** (e.g., from superior mesenteric artery syndrome) typically causes **proximal bowel obstruction** symptoms like nausea, vomiting, and epigastric pain, often worse postprandially.
- This patient's symptoms of left lower quadrant pain, diffuse peritonitis, and maroon-colored stools are not consistent with duodenal compression.
Question 1160: A 66-year-old man undergoes a coronary artery bypass grafting. Upon regaining consciousness, he reports that he cannot see from either eye and cannot move his arms. Physical examination shows bilaterally equal, reactive pupils. A fundoscopy shows no abnormalities. An MRI of the brain shows wedge-shaped cortical infarcts in both occipital lobes. Which of the following is the most likely cause of this patient's current symptoms?
A. Lipohyalinosis
B. Atherothrombosis
C. Amyloid angiopathy
D. Cardiac embolism
E. Systemic hypotension (Correct Answer)
Explanation: ***Systemic hypotension***
- **Watershed infarcts** secondary to systemic hypotension often occur in areas supplied by the most distal branches of major arteries, such as the regions between the middle and posterior cerebral arteries that supply the **occipital lobes**.
- **Bilateral occipital lobe infarcts** would explain the blindness (**cortical blindness**) despite normal pupillary reflexes and fundoscopy, as the primary visual cortex is affected, while the brainstem pathway for pupillary reflexes is spared.
*Lipohyalinosis*
- This is a process affecting **small, penetrating arteries**, leading to **lacunar infarcts** and is typically associated with chronic hypertension and diabetes.
- It would not typically cause large, wedge-shaped cortical infarcts in multiple arterial territories like the occipital lobes.
*Atherothrombosis*
- This involves the formation of a **thrombus on an atherosclerotic plaque**, commonly in large or medium-sized arteries.
- While it can cause strokes, atherothrombosis is less likely to cause widespread, bilateral watershed infarcts, which are more indicative of a global hypoperfusion event.
*Amyloid angiopathy*
- This condition involves **amyloid deposition in small and medium-sized cerebral arteries**, primarily causing lobar hemorrhages or microinfarcts.
- It is not a common cause of acute, large bilateral occipital lobe infarcts, especially in the context of perioperative complications.
*Cardiac embolism*
- A cardiac embolus would typically cause an **infarct in a single arterial territory**, often affecting unilateral cerebral hemisphere or a single lobe.
- It is less likely to cause **bilateral, symmetrical watershed infarcts**, which are characteristic of global hypoperfusion rather than focal embolic occlusion.
