A 68-year-old man is brought to the emergency department because of right-sided weakness for 2 hours. He has hypertension, dyslipidemia, and type 2 diabetes. Current medications include hydrochlorothiazide, metoprolol, amlodipine, pravastatin, and metformin. His pulse is 87/min and blood pressure is 164/98 mm Hg. Neurological examination shows right-sided weakness, facial droop, and hyperreflexia. Sensation is intact. Which of the following is the most likely cause of these findings?
Q842
A 42-year-old woman comes to the physician because of 2 episodes of loss of consciousness over the past week. She recovered immediately and was not confused following the episodes. During the past 5 months, she has also had increased shortness of breath and palpitations. She has been unable to carry out her daily activities. She also reports some chest tightness that resolves with rest. She has no history of serious illness and takes no medications. She immigrated with her family from India 10 years ago. Her temperature is 37.3°C (99.1°F), pulse is 115/min and irregular, and blood pressure is 108/70 mm Hg. Examination shows jugular venous distention and pitting edema below the knees. Bilateral crackles are heard at the lung bases. Cardiac examination shows an accentuated and split S2. There is an opening snap followed by a low-pitched diastolic murmur in the fifth left intercostal space at the midclavicular line. An ECG shows atrial fibrillation and right axis deviation. Which of the following is the most likely underlying mechanism of these findings?
Q843
A 21-year-old woman comes to the physician because of a 1-day history of right leg pain. The pain is worse while walking and improves when resting. Eight months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued two months ago. Her mother had systemic lupus erythematosus. On examination, her right calf is diffusely erythematous, swollen, and tender. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the right popliteal vein is not compressible. Laboratory studies show an elevated serum level of D-dimer and insensitivity to activated protein C. Further evaluation of this patient is most likely to show which of the following?
Q844
A 33-year-old woman comes to the physician because of a 6-month history of worsening shortness of breath and fatigue. Her paternal uncle had similar symptoms and died of respiratory failure at 45 years of age. The lungs are clear to auscultation. Pulmonary function testing shows an FVC of 84%, an FEV1/FVC ratio of 92%, and a normal diffusion capacity. An ECG shows a QRS axis greater than +90 degrees. Genetic analysis shows an inactivating mutation in the bone morphogenetic protein receptor type II (BMPR2) gene. Which of the following is the most likely cause of this patient's symptoms?
Q845
A 33-year-old woman presents to her primary care physician for non-bloody nipple discharge. She states that it has been going on for the past month and that it sometimes soils her shirt. The patient drinks 2 to 3 alcoholic beverages per day and smokes 1 pack of cigarettes per day. She is currently seeking mental health treatment with an outpatient psychiatrist after a recent hospitalization for auditory hallucinations. Her psychiatrist prescribed her a medication that she can not recall. Otherwise, she complains of headaches that occur frequently. Her temperature is 98.6°F (37.0°C), blood pressure is 137/68 mmHg, pulse is 70/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for bilateral galactorrhea that can be expressed with palpation. Which of the following is the best next step in management?
Q846
A 25-year-old woman presents to her primary care physician with 3 weeks of palpitations and shortness of breath while exercising. She says that these symptoms have been limiting her ability to play recreational sports with her friends. Her past medical history is significant for pharyngitis treated with antibiotics and her family history reveals a grandfather who needed aortic valve replacements early due to an anatomic abnormality. She admits to illicit drug use in college, but says that she stopped using drugs 4 years ago. Physical exam reveals a clicking sound best heard at the apex. This sound occurs between S1 and S2 and is followed by a flow murmur. Which of the following is most likely associated with the cause of this patient's disorder?
Q847
A 30-year-old African American woman comes to the physician because of fatigue and muscle weakness for the past 5 weeks. During this period, she has had recurrent headaches and palpitations. She has hypertension and major depressive disorder. She works as a nurse at a local hospital. She has smoked about 6–8 cigarettes daily for the past 10 years and drinks 1–2 glasses of wine on weekends. Current medications include enalapril, metoprolol, and fluoxetine. She is 168 cm (5 ft 6 in) tall and weighs 60 kg (132 lb); BMI is 21.3 kg/m2. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 155/85 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. The abdomen is soft and nontender; bowel sounds are normal. Her skin is dry and there is no edema in the lower extremities. Laboratory studies show:
Hemoglobin 13.3 g/dL
Serum
Na+ 146 mEq/L
Cl- 105 mEq/L
K+ 3.0 mEq/L
HCO3- 30 mEq/L
Urea nitrogen 10 mg/dL
Glucose 95 mg/dL
Creatinine 0.8 mg/dL
Urine
Blood negative
Glucose negative
Protein negative
RBC 0–1/hpf
WBC none
Which of the following is the most likely diagnosis in this patient?
Q848
A 45-year-old man is rushed to the emergency department by his wife after complaining of sudden onset excruciating headache that started about an hour ago. On further questioning, the patient's wife gives a prior history of flank pain, hematuria, and hypertension in the patient, and she recalls that similar symptoms were present in his uncle. On examination, his GCS is 12/15. When his hip and knee are flexed, he resists subsequent extension of the knee. When the neck is passively flexed, there is severe neck stiffness and the patient's hips and knees flex involuntarily. During the examination, he lapses into unconsciousness. Which of the following mechanisms best explains what led to this patient's presentation?
Q849
A 44-year-old woman presents to the outpatient clinic for the evaluation of amenorrhea which she noted roughly 4 months ago. Her monthly cycles up to that point were normal. Initially, she thought that it was related to early menopause; however, she has also noticed that she has a small amount of milk coming from her breasts as well. She denies any nausea, vomiting, or weight gain but has noticed that she has lost sight in the lateral fields of vision to the left and right. Her vital signs are unremarkable. Physical examination confirms bitemporal hemianopsia. What test is likely to reveal her diagnosis?
Q850
A 47-year-old woman presents with blurry vision for the past 2 weeks. She says that symptoms onset gradually and have progressively worsened. She works as a secretary in a law firm, and now her vision is hampering her work. Past medical history is significant for psoriasis, diagnosed 7 years ago, managed with topical corticosteroids. Her blood pressure is 120/60 mm Hg, respiratory rate is 17/min, and pulse is 70/min. Her BMI is 28 kg/m2. Physical examination is unremarkable. Laboratory findings are significant for the following:
RBC count 4.4 x 1012/L
WBC count 5.0 x 109/L
Hematocrit 44%
Fasting plasma glucose 250 mg/dL
Hemoglobin A1C 7.8%
Which of the following would be the most likely cause of death in this patient?
Cardiology US Medical PG Practice Questions and MCQs
Question 841: A 68-year-old man is brought to the emergency department because of right-sided weakness for 2 hours. He has hypertension, dyslipidemia, and type 2 diabetes. Current medications include hydrochlorothiazide, metoprolol, amlodipine, pravastatin, and metformin. His pulse is 87/min and blood pressure is 164/98 mm Hg. Neurological examination shows right-sided weakness, facial droop, and hyperreflexia. Sensation is intact. Which of the following is the most likely cause of these findings?
A. Lipohyalinosis of penetrating vessels (Correct Answer)
B. Dissection of the vertebral artery
C. Stenosis of the internal carotid artery
D. Rupture of an intracranial aneurysm
E. Embolism from the left atrium
Explanation: ***Lipohyalinosis of penetrating vessels***
- This patient presents with an acute onset of **hemiparesis**, **facial droop**, and hyperreflexia, without cortical signs like cortical sensory loss or aphasia, which is characteristic of a **lacunar stroke**.
- **Lipohyalinosis** is the most common cause of lacunar infarcts, resulting from chronic hypertension and diabetes affecting small penetrating arteries in the brain.
*Dissection of the vertebral artery*
- Vertebral artery dissection typically presents with **posterior circulation symptoms** such as vertigo, ataxia, brainstem dysfunction, and often includes severe headache or neck pain.
- The presented symptoms of pure motor hemiparesis are more indicative of an anterior circulation event involving deeper structures.
*Stenosis of the internal carotid artery*
- Significant **internal carotid artery stenosis** typically causes larger territorial infarcts by reducing blood flow or via artery-to-artery embolism to the middle cerebral artery territory.
- This would result in symptoms like **aphasia**, **cortical sensory deficits**, or **homonymous hemianopia**, which are not present here.
*Rupture of an intracranial aneurysm*
- A ruptured intracranial aneurysm usually causes a **subarachnoid hemorrhage**, leading to a sudden, severe headache ("thunderclap headache"), meningismus, and altered consciousness.
- While focal neurological deficits can occur, the primary presentation is distinct from the patient's symptoms of a gradual onset of pure motor deficit.
*Embolism from the left atrium*
- An embolism from the left atrium (e.g., due to atrial fibrillation) typically causes a **cortical infarct** involving a larger vascular territory, such as the middle cerebral artery.
- This would result in symptoms like **aphasia**, **neglect**, or **cortical sensory deficits**, which are absent in this presentation of pure motor hemiparesis.
Question 842: A 42-year-old woman comes to the physician because of 2 episodes of loss of consciousness over the past week. She recovered immediately and was not confused following the episodes. During the past 5 months, she has also had increased shortness of breath and palpitations. She has been unable to carry out her daily activities. She also reports some chest tightness that resolves with rest. She has no history of serious illness and takes no medications. She immigrated with her family from India 10 years ago. Her temperature is 37.3°C (99.1°F), pulse is 115/min and irregular, and blood pressure is 108/70 mm Hg. Examination shows jugular venous distention and pitting edema below the knees. Bilateral crackles are heard at the lung bases. Cardiac examination shows an accentuated and split S2. There is an opening snap followed by a low-pitched diastolic murmur in the fifth left intercostal space at the midclavicular line. An ECG shows atrial fibrillation and right axis deviation. Which of the following is the most likely underlying mechanism of these findings?
A. Increased left ventricular end diastolic pressure
B. Increased left to right shunting
C. Increased systemic arterial resistance
D. Increased left atrial pressure (Correct Answer)
E. Decreased left ventricular contractility
Explanation: ***Increased left atrial pressure***
- The patient's symptoms (dyspnea, palpitations, chest tightness, volume overload signs like JVD, edema, crackles) and cardiac findings (**accentuated S2, opening snap, diastolic murmur**) are highly suggestive of **mitral stenosis**.
- **Mitral stenosis** causes obstruction of blood flow from the left atrium to the left ventricle, leading to a significant increase in **left atrial pressure** to maintain cardiac output, which can then cause atrial fibrillation and pulmonary hypertension.
*Increased left ventricular end diastolic pressure*
- This is typically seen in conditions like **aortic stenosis**, **aortic regurgitation**, or **decompensated heart failure** where the left ventricle is distended or failing.
- The patient's presentation with an **opening snap** and **diastolic murmur** points away from primary left ventricular pathology causing elevated LVEDP, and more towards a valvular issue upstream.
*Increased left to right shunting*
- This typically occurs in **septal defects** (e.g., VSD, ASD, PDA) and would lead to symptoms of pulmonary hypertension and right heart strain, but the specific murmur and opening snap are not characteristic of a shunt.
- While it can cause right ventricular hypertrophy and pulmonary hypertension, the classic auscultatory findings are distinct from those described here.
*Increased systemic arterial resistance*
- This is characteristic of **hypertension** or conditions causing systemic vasoconstriction, which primarily affect afterload on the left ventricle.
- While it can lead to left ventricular hypertrophy over time, it does not explain the specific findings of an **opening snap** and **diastolic murmur**, or the symptoms of pulmonary congestion in this context.
*Decreased left ventricular contractility*
- This would lead to **systolic heart failure** with reduced ejection fraction, causing symptoms like fatigue and dyspnea, and often a **S3 gallop** with a systolic murmur if mitral regurgitation develops.
- However, it does not explain the specific auscultatory findings of an **opening snap** and **diastolic murmur** that are pathognomonic for mitral stenosis.
Question 843: A 21-year-old woman comes to the physician because of a 1-day history of right leg pain. The pain is worse while walking and improves when resting. Eight months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued two months ago. Her mother had systemic lupus erythematosus. On examination, her right calf is diffusely erythematous, swollen, and tender. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the right popliteal vein is not compressible. Laboratory studies show an elevated serum level of D-dimer and insensitivity to activated protein C. Further evaluation of this patient is most likely to show which of the following?
A. Deficiency of protein C
B. Protein S deficiency
C. Elevated coagulation factor VIII levels
D. Mutation of coagulation factor V (Correct Answer)
E. Mutation of prothrombin
Explanation: ***Mutation of coagulation factor V***
- The patient's history of **recurrent DVT/PE** at a young age, family history of autoimmune disease (mother's SLE), and laboratory finding of **insensitivity to activated protein C** strongly point towards **Factor V Leiden mutation**.
- This mutation makes **Factor V resistant to inactivation** by activated protein C, leading to a hypercoagulable state and increased risk of venous thromboembolism.
*Deficiency of protein C*
- While it also causes **insensitivity to activated protein C** and a hypercoagulable state, a true deficiency of protein C would lead to quantitative reduction, not primarily functional insensitivity.
- Protein C deficiency can cause **severe thrombotic events**, but the given lab finding of "insensitivity to activated protein C" points more directly to a defect in Factor V.
*Protein S deficiency*
- **Protein S** acts as a cofactor for activated protein C, so its deficiency would also impair the anticoagulant pathway and could lead to thrombosis.
- However, **Protein S deficiency** does not directly cause "insensitivity to activated protein C" as the primary defect; rather, it reduces the effectiveness of activated protein C.
*Elevated coagulation factor VIII levels*
- **High levels of Factor VIII** are a risk factor for VTE, but this condition would not lead to **insensitivity to activated protein C**.
- While it contributes to a hypercoagulable state, it's a distinct mechanism not indicated by the specific lab finding mentioned.
*Mutation of prothrombin*
- **Prothrombin G20210A mutation** (mutation of prothrombin) leads to increased prothrombin levels and increased thrombin generation, predisposing to thrombosis.
- However, this mutation would not result in **insensitivity to activated protein C**, which is the key laboratory finding in this patient.
Question 844: A 33-year-old woman comes to the physician because of a 6-month history of worsening shortness of breath and fatigue. Her paternal uncle had similar symptoms and died of respiratory failure at 45 years of age. The lungs are clear to auscultation. Pulmonary function testing shows an FVC of 84%, an FEV1/FVC ratio of 92%, and a normal diffusion capacity. An ECG shows a QRS axis greater than +90 degrees. Genetic analysis shows an inactivating mutation in the bone morphogenetic protein receptor type II (BMPR2) gene. Which of the following is the most likely cause of this patient's symptoms?
A. Thickening of the interventricular septum
B. Fibrosis of the pulmonary parenchyma
C. Chronic intravascular hemolysis
D. Elevated left atrial pressure
E. Elevated pulmonary arterial pressure (Correct Answer)
Explanation: ***Elevated pulmonary arterial pressure***
- The patient's symptoms (dyspnea, fatigue), family history of early respiratory failure, and the presence of an inactivating mutation in **BMPR2** are highly suggestive of **heritable pulmonary arterial hypertension (PAH)**.
- **PAH** is characterized by elevated pressures in the pulmonary arteries, leading to right ventricular strain, which is reflected by the **ECG finding of a QRS axis greater than +90 degrees** (right axis deviation).
- The **normal diffusion capacity** helps distinguish PAH from parenchymal lung diseases, and the **FEV1/FVC ratio of 92%** (elevated) with relatively preserved FVC is consistent with the restrictive physiology sometimes seen in PAH.
*Thickening of the interventricular septum*
- While septal thickening can occur in some cardiac conditions, it is not the primary cause of symptoms in the context of heritable PAH, nor is it directly indicated by the given pulmonary function tests or ECG.
- **Hypertrophic cardiomyopathy** can cause septal thickening, but it typically presents with different cardiac pathologies and is not associated with BMPR2 mutations.
*Fibrosis of the pulmonary parenchyma*
- This would cause a **restrictive lung disease** with a **reduced FVC** and **reduced diffusion capacity** due to impaired gas exchange across thickened alveolar-capillary membranes.
- The patient's **normal diffusion capacity** specifically rules out significant pulmonary fibrosis or other interstitial lung diseases.
*Chronic intravascular hemolysis*
- This condition would typically present with **anemia**, **jaundice**, **elevated LDH**, and possibly **splenomegaly**, none of which are mentioned.
- It is not associated with the BMPR2 genetic mutation or the specific PFT and ECG findings in this case.
*Elevated left atrial pressure*
- Elevated left atrial pressure (e.g., due to **left-sided heart failure** or mitral stenosis) can cause pulmonary congestion and dyspnea, but would typically lead to **pulmonary edema** with crackles on auscultation and **reduced diffusion capacity** due to fluid in the alveoli.
- The patient's clear lung auscultation and normal diffusion capacity make elevated left atrial pressure unlikely.
Question 845: A 33-year-old woman presents to her primary care physician for non-bloody nipple discharge. She states that it has been going on for the past month and that it sometimes soils her shirt. The patient drinks 2 to 3 alcoholic beverages per day and smokes 1 pack of cigarettes per day. She is currently seeking mental health treatment with an outpatient psychiatrist after a recent hospitalization for auditory hallucinations. Her psychiatrist prescribed her a medication that she can not recall. Otherwise, she complains of headaches that occur frequently. Her temperature is 98.6°F (37.0°C), blood pressure is 137/68 mmHg, pulse is 70/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for bilateral galactorrhea that can be expressed with palpation. Which of the following is the best next step in management?
A. Ultrasound and biopsy
B. Mammography
C. Serum prolactin level (Correct Answer)
D. CT scan of the head
E. Discontinuation of current psychiatric medications
Explanation: ***Serum prolactin level***
- The patient presents with **bilateral, non-bloody nipple discharge (galactorrhea)**, which is strongly suggestive of **hyperprolactinemia**. Given her psychiatric history and recent change in medication, a drug-induced cause (e.g., antipsychotics) is highly probable, making a serum prolactin level the most appropriate initial diagnostic step.
- Elevated prolactin can be caused by various factors, including **prolactinomas**, **hypothyroidism**, and **medications** (especially antipsychotics that block dopamine D2 receptors), and measuring this level helps differentiate between these causes and guides further management.
*Ultrasound and biopsy*
- This approach is typically indicated for suspicious **breast masses** or **unilateral, bloody nipple discharge** to rule out malignancy.
- The patient's symptoms are characteristic of galactorrhea, not a suspicious breast lesion requiring imaging and biopsy at this stage.
*Mammography*
- Mammography is primarily used for **breast cancer screening** or to investigate suspicious **breast lumps** or **bloody nipple discharge** in older women.
- Given the patient's age (33) and the bilateral, non-bloody nature of the discharge, mammography is not the initial investigation of choice for galactorrhea.
*CT scan of the head*
- A CT scan of the head (or MRI) would be indicated if the **serum prolactin level is significantly elevated** and suggests a **pituitary adenoma** (prolactinoma), or if other neurological symptoms point to an intracranial pathology.
- It is premature to order head imaging before confirming hyperprolactinemia, as the cause could be medication-related and not require imaging.
*Discontinuation of current psychiatric medications*
- While psychiatric medications, particularly **antipsychotics**, can cause hyperprolactinemia, discontinuing them should not be the *first* step without confirming the diagnosis and ruling out other serious causes.
- Abrupt discontinuation of psychiatric medication can lead to relapse of mental health symptoms and is usually done under strict medical supervision after a clear diagnosis.
Question 846: A 25-year-old woman presents to her primary care physician with 3 weeks of palpitations and shortness of breath while exercising. She says that these symptoms have been limiting her ability to play recreational sports with her friends. Her past medical history is significant for pharyngitis treated with antibiotics and her family history reveals a grandfather who needed aortic valve replacements early due to an anatomic abnormality. She admits to illicit drug use in college, but says that she stopped using drugs 4 years ago. Physical exam reveals a clicking sound best heard at the apex. This sound occurs between S1 and S2 and is followed by a flow murmur. Which of the following is most likely associated with the cause of this patient's disorder?
A. Increased valvular dermatan sulfate (Correct Answer)
B. Intravenous drug abuse
C. Mutation in cardiac contractile proteins
D. Infection with Streptococcus pyogenes
E. Bicuspid aortic valve
Explanation: ***Increased valvular dermatan sulfate***
- The patient presents with classic signs of **mitral valve prolapse (MVP)**: a **mid-systolic click** followed by a **systolic murmur**. MVP is characterized by **myxomatous degeneration** of the mitral valve, leading to redundant and thickened leaflets.
- This myxomatous degeneration is associated with an accumulation of **dermatan sulfate** and other proteoglycans within the valve tissue, leading to weakened collagen and elastic fibers.
*Intravenous drug abuse*
- While intravenous drug abuse can cause valvular disease, it typically leads to **infective endocarditis**, often affecting the **tricuspid valve** in the right heart.
- This patient's signs and symptoms, particularly the mid-systolic click and the timing of the murmur, are not consistent with intravenous drug abuse-related endocarditis.
*Mutation in cardiac contractile proteins*
- Mutations in cardiac contractile proteins are characteristic of **hypertrophic cardiomyopathy (HCM)**, which presents with symptoms like shortness of breath and palpitations due to outflow tract obstruction.
- However, HCM does not typically manifest with a **mid-systolic click** and a flow murmur originating from a prolapsing valve.
*Infection with *Streptococcus pyogenes**
- **Rheumatic fever**, caused by *Streptococcus pyogenes*, can lead to valvular damage, particularly to the **mitral valve (rheumatic mitral stenosis)**. However, this typically manifests as a **diastolic murmur** and is associated with a history of recurrent strep throat with inadequate treatment.
- The patient's pharyngitis was treated with antibiotics, and the physical exam findings are not typical for chronic rheumatic heart disease.
*Bicuspid aortic valve*
- A **bicuspid aortic valve** is a congenital anomaly that can cause **aortic stenosis** or **aortic regurgitation**, leading to distinct murmurs (e.g., crescendo-decrescendo systolic ejection murmur for stenosis).
- The patient's grandfather had an aortic valve abnormality, but her current findings of a **mid-systolic click** and a murmur after S1 point specifically to **mitral valve prolapse**, not bicuspid aortic valve disease.
Question 847: A 30-year-old African American woman comes to the physician because of fatigue and muscle weakness for the past 5 weeks. During this period, she has had recurrent headaches and palpitations. She has hypertension and major depressive disorder. She works as a nurse at a local hospital. She has smoked about 6–8 cigarettes daily for the past 10 years and drinks 1–2 glasses of wine on weekends. Current medications include enalapril, metoprolol, and fluoxetine. She is 168 cm (5 ft 6 in) tall and weighs 60 kg (132 lb); BMI is 21.3 kg/m2. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 155/85 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. The abdomen is soft and nontender; bowel sounds are normal. Her skin is dry and there is no edema in the lower extremities. Laboratory studies show:
Hemoglobin 13.3 g/dL
Serum
Na+ 146 mEq/L
Cl- 105 mEq/L
K+ 3.0 mEq/L
HCO3- 30 mEq/L
Urea nitrogen 10 mg/dL
Glucose 95 mg/dL
Creatinine 0.8 mg/dL
Urine
Blood negative
Glucose negative
Protein negative
RBC 0–1/hpf
WBC none
Which of the following is the most likely diagnosis in this patient?
A. Cushing syndrome
B. Aldosteronoma (Correct Answer)
C. Laxative abuse
D. Pheochromocytoma
E. Renal artery stenosis
Explanation: ***Aldosteronoma***
- This patient presents with **hypertension**, **muscle weakness**, fatigue, **hypokalemia** (K+ 3.0 mEq/L), and **metabolic alkalosis** (HCO3- 30 mEq/L), which are classic signs of **primary hyperaldosteronism**.
- **Aldosteronomas** are a common cause of primary hyperaldosteronism due to autonomous aldosterone production, leading to sodium retention, potassium excretion, and subsequent hypertension and hypokalemia.
*Cushing syndrome*
- While Cushing syndrome can cause hypertension and muscle weakness, it typically presents with features like **central obesity**, **moon facies**, **buffalo hump**, **striae**, and **hyperglycemia**, which are not described in this patient.
- Although it can cause hypokalemia, the overall clinical picture is more suggestive of primary hyperaldosteronism given the constellation of symptoms.
*Laxative abuse*
- Laxative abuse can cause hypokalemia and metabolic alkalosis, but it typically presents with **diarrhea**, **abdominal pain**, and potentially features of **dehydration**, which are absent here.
- Chronic laxative abuse would not typically be the primary cause of sustained hypertension in this context without other tell-tale signs.
*Pheochromocytoma*
- **Pheochromocytoma** causes episodic or sustained hypertension, often accompanied by **palpitations**, **headaches**, and **sweating** due to excessive catecholamine release.
- However, it does not typically cause hypokalemia or metabolic alkalosis unless there is co-secretion of other hormones, making it less likely than aldosteronoma with the presented lab abnormalities.
*Renal artery stenosis*
- **Renal artery stenosis** can cause hypertension and sometimes hypokalemia due to increased renin secretion, leading to secondary hyperaldosteronism.
- However, the primary cause would be renal ischemia, and the hyperaldosteronism would be reactive, whereas in this case, the hypokalemia and metabolic alkalosis strongly point towards autonomous aldosterone production.
Question 848: A 45-year-old man is rushed to the emergency department by his wife after complaining of sudden onset excruciating headache that started about an hour ago. On further questioning, the patient's wife gives a prior history of flank pain, hematuria, and hypertension in the patient, and she recalls that similar symptoms were present in his uncle. On examination, his GCS is 12/15. When his hip and knee are flexed, he resists subsequent extension of the knee. When the neck is passively flexed, there is severe neck stiffness and the patient's hips and knees flex involuntarily. During the examination, he lapses into unconsciousness. Which of the following mechanisms best explains what led to this patient's presentation?
A. Uremic encephalopathy from chronic renal disease
B. Meningeal irritation from a space occupying lesion
C. Increased wall tension within an aneurysm (Correct Answer)
D. Embolic occlusion of a cerebral vessel
E. Intracerebral hemorrhage due to vascular malformations
Explanation: ***Increased wall tension within an aneurysm***
- The sudden onset of an **excruciating headache** ("thunderclap headache") followed by rapid deterioration of consciousness (lapsing into unconsciousness) is highly suggestive of a **subarachnoid hemorrhage (SAH)**.
- The patient's history of **flank pain, hematuria, hypertension**, and a **family history** of similar symptoms (uncle) point towards **autosomal dominant polycystic kidney disease (ADPKD)**, which is strongly associated with an increased risk of **cerebral aneurysms** and SAH. The neurological signs (**GCS 12/15**, resistance to knee extension with hip flexion (positive Kernig's sign: resistance to knee extension when hip is flexed), and flexion of hips and knees with neck flexion (positive Brudzinski's sign: active flexion of the neck causes involuntary flexion of hips and knees)) indicate **meningeal irritation** due to blood in the subarachnoid space and further support the diagnosis of SAH, likely from a ruptured aneurysm.
*Uremic encephalopathy from chronic renal disease*
- While the patient has signs suggestive of ADPKD, which can lead to chronic renal disease and uremic encephalopathy, the acute presentation of a **thunderclap headache** and rapid neurological decline is not typical of uremic encephalopathy, which usually has a more protracted and fluctuating course.
- Uremic encephalopathy primarily results from the accumulation of **uremic toxins**, leading to altered mental status, asterixis, and seizures, but typically without the dramatic acute onset and meningeal signs seen here.
*Meningeal irritation from a space occupying lesion*
- Meningeal irritation can be caused by a space-occupying lesion if it bleeds or causes significant mass effect and inflammation, but the **sudden, excruciating headache** (thunderclap headache) followed by rapid neurological deterioration is not the primary presentation for most space-occupying lesions.
- A space-occupying lesion would typically cause focal neurological deficits, seizures, or a more gradual onset of headache, rather than the abrupt, severe global headache and signs of meningeal irritation observed.
*Embolic occlusion of a cerebral vessel*
- **Embolic occlusion** typically causes an **ischemic stroke**, presenting with sudden focal neurological deficits such as hemiparesis, aphasia, or visual field loss, usually without severe headache as the primary symptom.
- While a severe headache can occur in some ischemic strokes, it is not typically described as an "excruciating thunderclap" headache, and meningeal signs like Kernig's and Brudzinski's are absent unless there is hemorrhagic transformation.
*Intracerebral hemorrhage due to vascular malformations*
- Intracerebral hemorrhage (ICH) can cause a sudden severe headache and neurological deterioration, but it typically presents with **focal neurological deficits** corresponding to the area of hemorrhage.
- While there may be some degree of meningeal irritation if the hemorrhage extends to the ventricles or subarachnoid space, the strong association with **ADPKD** and cerebral aneurysms makes SAH leading to meningeal irritation a more likely and specific explanation for this presentation.
Question 849: A 44-year-old woman presents to the outpatient clinic for the evaluation of amenorrhea which she noted roughly 4 months ago. Her monthly cycles up to that point were normal. Initially, she thought that it was related to early menopause; however, she has also noticed that she has a small amount of milk coming from her breasts as well. She denies any nausea, vomiting, or weight gain but has noticed that she has lost sight in the lateral fields of vision to the left and right. Her vital signs are unremarkable. Physical examination confirms bitemporal hemianopsia. What test is likely to reveal her diagnosis?
A. Serum estrogen and progesterone levels
B. Mammogram
C. Serum TSH and free T4
D. Urine pregnancy test
E. MRI brain (Correct Answer)
Explanation: ***MRI brain***
- The combination of **amenorrhea**, **galactorrhea** (milk production), and **bitemporal hemianopsia** is highly suggestive of a **pituitary adenoma**, particularly a **prolactinoma**. An MRI of the brain is the diagnostic imaging test of choice to visualize the pituitary gland and identify such a mass.
- The **bitemporal hemianopsia** indicates compression of the **optic chiasm**, which is classically seen with suprasellar extension of a pituitary tumor.
*Serum estrogen and progesterone levels*
- While these levels might be abnormal in amenorrhea due to various causes, testing them would not directly identify the underlying cause, especially when there are clear signs of a mass effect on the optic chiasm.
- This test is more appropriate for evaluating ovarian function or other hormonal imbalances not associated with mass effects.
*Mammogram*
- A mammogram is used to screen for or diagnose **breast cancer** and evaluate breast lumps.
- Although the patient has galactorrhea, which is breast-related, the presence of amenorrhea and bitemporal hemianopsia points away from primary breast pathology as the root cause.
*Serum TSH and free T4*
- These tests evaluate **thyroid function**. While thyroid dysfunction can cause menstrual irregularities, it typically does not cause galactorrhea or bitemporal hemianopsia.
- Hypothyroidism can cause menstrual irregularities and sometimes galactorrhea, but the bitemporal hemianopsia strongly points to a structural lesion.
*Urine pregnancy test*
- A pregnancy test is a routine initial step in evaluating amenorrhea in women of childbearing age to rule out pregnancy.
- However, the additional symptoms of **galactorrhea** and **bitemporal hemianopsia** are not explained by pregnancy and strongly suggest a more serious underlying condition.
Question 850: A 47-year-old woman presents with blurry vision for the past 2 weeks. She says that symptoms onset gradually and have progressively worsened. She works as a secretary in a law firm, and now her vision is hampering her work. Past medical history is significant for psoriasis, diagnosed 7 years ago, managed with topical corticosteroids. Her blood pressure is 120/60 mm Hg, respiratory rate is 17/min, and pulse is 70/min. Her BMI is 28 kg/m2. Physical examination is unremarkable. Laboratory findings are significant for the following:
RBC count 4.4 x 1012/L
WBC count 5.0 x 109/L
Hematocrit 44%
Fasting plasma glucose 250 mg/dL
Hemoglobin A1C 7.8%
Which of the following would be the most likely cause of death in this patient?
A. Rhinocerebral mucormycosis
B. Coma
C. Peripheral neuropathy
D. Myocardial infarction (Correct Answer)
E. Renal failure
Explanation: ***Myocardial infarction***
- The patient's elevated **fasting plasma glucose** (250 mg/dL) and **HbA1C** (7.8%) indicate **uncontrolled diabetes mellitus**. Her **BMI of 28** kg/m2 points to **overweight/obesity**, another risk factor for cardiovascular disease.
- **Cardiovascular disease**, including **myocardial infarction**, is the leading cause of death in patients with diabetes due to accelerated atherosclerosis.
*Rhinocerebral mucormycosis*
- This is an **opportunistic fungal infection** typically seen in severely immunocompromised patients, particularly those with uncontrolled diabetes and ketoacidosis.
- While diabetes is a risk factor, the patient does not present with characteristic symptoms such as **facial pain**, **black nasal discharge**, or widespread immunosuppression.
*Coma*
- **Diabetic coma** can result from extreme hyperglycemia (**hyperosmolar hyperglycemic state**) or severe hypoglycemia.
- While the patient has hyperglycemia, her blood pressure, respiratory rate, and pulse are stable, and the physical examination is unremarkable, suggesting she is not in immediate danger of diabetic coma.
*Peripheral neuropathy*
- **Diabetic peripheral neuropathy** is a common long-term complication of diabetes, causing symptoms like numbness, tingling, and pain, mainly in the extremities.
- While likely present with long-standing uncontrolled diabetes, it is generally **not a direct cause of death** but rather contributes to morbidity and risk of secondary complications like foot ulcers and infections.
*Renal failure*
- **Diabetic nephropathy** is a major microvascular complication of diabetes leading to **chronic kidney disease** and potentially end-stage renal failure.
- While possible in the long term, there are no specific direct indicators of severe or advanced renal failure in her current presentation such as elevated creatinine or signs of fluid overload; cardiovascular events pose a more immediate and common fatal risk in uncontrolled diabetes.