A 65-year-old man presents to the emergency department for a loss of vision. He was outside gardening when he suddenly lost vision in his right eye. He then immediately called emergency medical services, but by the time they arrived, the episode had resolved. Currently, he states that he feels fine. The patient has a past medical history of diabetes and hypertension. His current medications include lisinopril, atorvastatin, metformin, and insulin. His temperature is 99.5°F (37.5°C), blood pressure is 140/95 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 98% on room air. Cardiac exam is notable for a systolic murmur along the right sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Neurological exam reveals cranial nerves II-XII as grossly intact with 5/5 strength and normal sensation in the upper and lower extremities. The patient has a negative Romberg's maneuver, and his gait is stable. A CT scan of the head demonstrates mild cerebral atrophy but no other findings. Which of the following is the next best step in management?
Q122
A 45-year-old male presents to the hospital complaining of frequent headaches and a decreased libido. During the physical exam, the patient also states that he has recently been experiencing vision problems. The patient is suffering from what type of adenoma?
Q123
A 62-year-old man presents for evaluation of an adrenal nodule, which was accidentally discovered while performing a computerized tomography (CT) scan of the abdomen for recurrent abdominal pain. The CT was negative except for a 3 cm low-density, well-circumscribed nodule in the left adrenal gland. He reports weight gain of 12 kg (26.4 lb) over the past 3 years. He has type 2 diabetes mellitus and hypertension, which have been difficult to control with medications. Which of the following is the best initial test for this patient?
Q124
A 49-year-old man presents to a physician with the complaint of pain in the thigh after walking. He says that he is an office clerk with a sedentary lifestyle and usually drives to his office. On 2 occasions last month he had to walk to his office, which is less than a quarter of a mile from his home. On both occasions, soon after walking, he experienced pain in the right thigh which subsided spontaneously within a few minutes. His past medical history is negative for hypertension, hypercholesterolemia, or ischemic heart disease. He is a non-smoker and non-alcoholic. His father has ischemic heart disease. His physical examination is within normal limits, and the peripheral pulses are palpable in all extremities. His detailed diagnostic evaluation, including magnetic resonance angiogram (MRA) and exercise treadmill ankle-brachial index (ABI) testing, suggests a diagnosis of peripheral vascular disease due to atherosclerosis of the right iliac artery. Which of the following is the best initial treatment option?
Q125
A 50-year-old female is evaluated by her physician for recent weight gain. Physical examination is notable for truncal obesity, wasting of her distal musculature and moon facies. In addition she complains of abnormal stretch marks that surround her abdomen. The physician suspects pituitary adenoma. Which of the following high-dose dexamethasone suppression test findings and baseline ACTH findings would support his view?
Q126
A 25-year-old man presents to the emergency department with back pain. He states that it started yesterday and has been gradually getting worse. He states that the pain is worsened with moving and lifting and is relieved with rest and ibuprofen. He has a past medical history of smoking and IV drug abuse and states he last used IV drugs 2 days ago. He thinks his symptoms may be related to lifting a heavy box. His temperature is 99.3°F (37.4°C), blood pressure is 122/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for focal back pain lateral to the patient’s spine on the left. There is no midline tenderness and the rest of the patient’s exam is unremarkable. There are scars in the antecubital fossae bilaterally. Laboratory values including a C-reactive protein are unremarkable. Which of the following is the most likely diagnosis?
Q127
A 34-year-old female presents to her primary care physician complaining of fatigue. Over the last three months she has experienced decreased energy and gained 7 pounds. Review of systems is negative for symptoms of depression but is positive for constipation, myalgias, and cold intolerance. Physical exam is notable for delayed deep tendon reflex relaxation. Vital signs are as follows: T 37.1 C, HR 61, BP 132/88, RR 16, and SpO2 100%. Which of the following is the best initial screening test for this patient?
Q128
A 63-year-old woman with a previous diagnosis of rheumatoid arthritis and Sjogren syndrome was referred for a second opinion. She has had a known chronic idiopathic pericardial effusion for about a year and has dealt with intermittent chest pain ever since. She underwent 2 diagnostic pericardiocenteses, but the fluid returned each time. She also has used empiric anti-inflammatory therapies with NSAIDs and colchicine without significant changes in the size of the pericardial effusion. The etiological testing was negative. At this visit, she is still complaining of pain in her chest but has no evidence of distended neck veins. An ECG shows sinus rhythm with low QRS voltages. What will be the procedure of choice that would be both therapeutic and diagnostic?
Q129
An 81-year-old man comes to the emergency department because of left-sided visual loss that started 1 hour ago. He describes initially seeing jagged edges, which was followed by abrupt, complete loss of central vision in the left eye. He has hypertension and type 2 diabetes mellitus. Blood pressure is 145/89 mm Hg. Neurologic examination shows no abnormalities. A photograph of the fundoscopic findings is shown. Which of the following tests is most likely to confirm this patient's underlying condition?
Q130
A 68-year-old woman is brought to the physician by her husband for the evaluation of confusion and memory deficits for the last month. During this period, she has also had mild weakness in her left leg. She has hypertension and hyperlipidemia. Her current medications include enalapril and atorvastatin. She has smoked two packs of cigarettes daily for the last 45 years. She drinks a glass of wine every day. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 135/85 mm Hg. She is oriented only to person. She recalls 2 out of 3 objects immediately and none after 5 minutes. The patient is unable to lift her eyebrows or to smile. Muscle strength is decreased in the left lower extremity. A T2-weighted MRI scan of the head shows several hyperintense round lesions in the frontal and temporal lobe at the border of the gray and white matter. Which of the following is the most likely diagnosis?
Cardiology US Medical PG Practice Questions and MCQs
Question 121: A 65-year-old man presents to the emergency department for a loss of vision. He was outside gardening when he suddenly lost vision in his right eye. He then immediately called emergency medical services, but by the time they arrived, the episode had resolved. Currently, he states that he feels fine. The patient has a past medical history of diabetes and hypertension. His current medications include lisinopril, atorvastatin, metformin, and insulin. His temperature is 99.5°F (37.5°C), blood pressure is 140/95 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 98% on room air. Cardiac exam is notable for a systolic murmur along the right sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Neurological exam reveals cranial nerves II-XII as grossly intact with 5/5 strength and normal sensation in the upper and lower extremities. The patient has a negative Romberg's maneuver, and his gait is stable. A CT scan of the head demonstrates mild cerebral atrophy but no other findings. Which of the following is the next best step in management?
A. No further management necessary
B. Tissue plasminogen activator
C. Ultrasound of the neck (Correct Answer)
D. MRI
E. Heparin bridge to warfarin
Explanation: ***Ultrasound of the neck***
- The patient experienced a **transient monocular vision loss (amaurosis fugax)**, which is a common symptom of **carotid artery stenosis**, often due to an **embolus from an atherosclerotic plaque**.
- The presence of a **systolic murmur radiating to the carotids**, along with a history of **diabetes and hypertension**, further increases suspicion for **carotid atherosclerosis**, making an ultrasound of the neck (carotid duplex) the appropriate next step to assess the degree of stenosis.
*No further management necessary*
- Ignoring this episode would be **negligent** given the patient's risk factors and the transient nature of the symptoms, which suggest a **transient ischemic attack (TIA)**.
- TIAs are **warning signs** for future stroke, and identifying the cause is crucial for **stroke prevention**.
*Tissue plasminogen activator*
- **tPA is indicated for acute ischemic stroke** within a specific time window, typically 3-4.5 hours from symptom onset, and when there is persistent neurological deficit.
- The patient's symptoms have **already resolved**, and there is **no ongoing stroke**, making tPA inappropriate.
*MRI*
- While an **MRI of the brain is more sensitive than CT** for detecting acute ischemic changes and TIAs, the primary concern here is the **source of the embolus** affecting the eye, which is likely the carotid artery.
- An MRI might be pursued later if the carotid workup is inconclusive or to further characterize cerebral findings, but **carotid imaging takes precedence** given the presentation.
*Heparin bridge to warfarin*
- This is a treatment for conditions like **atrial fibrillation** or **deep vein thrombosis** to prevent clot formation and is a form of **anticoagulation**.
- While some patients with embolic TIA might require anticoagulation, the **initial step is to identify the source** of the embolus, which in this case is highly suspected to be carotid stenosis, treatable with **antiplatelet agents** or **surgery/stenting**, rather than immediate anticoagulation.
Question 122: A 45-year-old male presents to the hospital complaining of frequent headaches and a decreased libido. During the physical exam, the patient also states that he has recently been experiencing vision problems. The patient is suffering from what type of adenoma?
A. Lactotroph (Correct Answer)
B. Somatotroph
C. Thyrotroph
D. Gonadotroph
E. Corticotroph
Explanation: ***Lactotroph***
- A **lactotroph adenoma**, or **prolactinoma**, is the most common type of pituitary adenoma.
- In males, it presents with symptoms such as **hypogonadism** (decreased libido, erectile dysfunction), **headaches**, and **visual field defects** due to compression of the optic chiasm.
*Somatotroph*
- A **somatotroph adenoma** secretes excessive **growth hormone**, leading to **acromegaly** in adults (e.g., increased hand/foot size, facial changes) or gigantism in children.
- Headache and vision problems can occur due to tumor mass effect, but decreased libido is not a primary symptom.
*Thyrotroph*
- A **thyrotroph adenoma** secretes excessive **TSH**, resulting in **hyperthyroidism** (e.g., weight loss, palpitations, heat intolerance).
- While large tumors can cause headaches and visual disturbances, the primary endocrine symptoms are related to thyroid hormone excess.
*Gonadotroph*
- **Gonadotroph adenomas** secrete FSH and LH, but they are often **non-functional** or only mildly active, with hormonal effects being variable.
- When symptomatic, they may present with mass effects like headaches and visual problems, but marked hypogonadism or galactorrhea are less common than with prolactinomas.
*Corticotroph*
- A **corticotroph adenoma** secretes excessive **ACTH**, leading to **Cushing's disease** (e.g., central obesity, moon facies, striae, hypertension).
- While mass effects like headaches can occur, the primary clinical features are those of hypercortisolism, not decreased libido.
Question 123: A 62-year-old man presents for evaluation of an adrenal nodule, which was accidentally discovered while performing a computerized tomography (CT) scan of the abdomen for recurrent abdominal pain. The CT was negative except for a 3 cm low-density, well-circumscribed nodule in the left adrenal gland. He reports weight gain of 12 kg (26.4 lb) over the past 3 years. He has type 2 diabetes mellitus and hypertension, which have been difficult to control with medications. Which of the following is the best initial test for this patient?
A. 1 mg overnight dexamethasone suppression test (Correct Answer)
B. ACTH stimulation test
C. CT of the chest, abdomen and pelvis
D. Inferior petrosal sampling
E. Pituitary magnetic resonance imaging (MRI)
Explanation: ***1 mg overnight dexamethasone suppression test***
- The patient presents with an adrenal incidentaloma and clinical features suggestive of **Cushing's syndrome**, including uncontrolled hypertension and type 2 diabetes, and weight gain.
- The **1 mg overnight dexamethasone suppression test** is the screening test of choice to evaluate for **cortisol overproduction** in patients suspected of having Cushing's syndrome.
*ACTH stimulation test*
- The **ACTH stimulation test** is used to evaluate for **adrenal insufficiency**, not adrenal hyperfunction.
- It assesses the adrenal gland's ability to produce cortisol in response to exogenous ACTH.
*CT of the chest, abdomen and pelvis*
- A CT scan of the abdomen has already identified the adrenal nodule; a repeat or extended scan for localization of the adrenal nodule itself is unnecessary as an initial diagnostic step for hormonal activity.
- While imaging is used to characterize the nodule for malignant potential, the primary concern here given the clinical context is hormonal activity.
*Inferior petrosal sampling*
- **Inferior petrosal sinus sampling (IPSS)** is a specialized and invasive test used to differentiate between **Cushing's disease** (pituitary ACTH-secreting tumor) and ectopic ACTH secretion or primary adrenal disease after biochemical tests confirm ACTH-dependent Cushing's syndrome.
- This is an advanced diagnostic step, not an initial screening test.
*Pituitary magnetic resonance imaging (MRI)*
- A **pituitary MRI** is performed to identify a pituitary adenoma in patients with confirmed **ACTH-dependent Cushing's syndrome**, typically after initial biochemical screening tests and possibly IPSS.
- It is not an initial test for patients with an adrenal incidentaloma and suspected cortisol excess.
Question 124: A 49-year-old man presents to a physician with the complaint of pain in the thigh after walking. He says that he is an office clerk with a sedentary lifestyle and usually drives to his office. On 2 occasions last month he had to walk to his office, which is less than a quarter of a mile from his home. On both occasions, soon after walking, he experienced pain in the right thigh which subsided spontaneously within a few minutes. His past medical history is negative for hypertension, hypercholesterolemia, or ischemic heart disease. He is a non-smoker and non-alcoholic. His father has ischemic heart disease. His physical examination is within normal limits, and the peripheral pulses are palpable in all extremities. His detailed diagnostic evaluation, including magnetic resonance angiogram (MRA) and exercise treadmill ankle-brachial index (ABI) testing, suggests a diagnosis of peripheral vascular disease due to atherosclerosis of the right iliac artery. Which of the following is the best initial treatment option?
A. Percutaneous angioplasty with stenting
B. Exercise therapy (Correct Answer)
C. Pentoxifylline
D. Mediterranean diet
E. A combination of aspirin and clopidogrel
Explanation: ***Exercise therapy***
- **Supervised exercise programs** are the cornerstone of initial treatment for patients with claudication and PAD, demonstrating significant improvement in walking distance and quality of life.
- It helps in developing **collateral circulation**, improving endothelial function, and increasing pain-free walking distance.
*Percutaneous angioplasty with stenting*
- While effective for revascularization, this is typically reserved for patients with **severe claudication** that significantly impacts daily life and is refractory to conservative management.
- It carries risks such as **restenosis** and potential complications from the procedure itself.
*Pentoxifylline*
- This medication is a **xanthine derivative** that can improve blood flow by increasing erythrocyte flexibility and reducing blood viscosity.
- Its efficacy in improving walking distance in PAD is **modest at best**, and it is generally less effective than supervised exercise.
*Mediterranean diet*
- A healthy diet, such as the Mediterranean diet, is crucial for **overall cardiovascular risk reduction** in PAD patients by managing risk factors like hypercholesterolemia.
- However, it is a **preventive and supportive measure** rather than an initial treatment for alleviating claudication symptoms.
*A combination of aspirin and clopidogrel*
- **Antiplatelet therapy** (e.g., aspirin, clopidogrel) is essential for reducing the risk of cardiovascular events in PAD patients, but it **does not directly improve claudication symptoms**.
- Dual antiplatelet therapy is often reserved for post-procedure management or in higher-risk patients, not as an initial treatment for claudication itself.
Question 125: A 50-year-old female is evaluated by her physician for recent weight gain. Physical examination is notable for truncal obesity, wasting of her distal musculature and moon facies. In addition she complains of abnormal stretch marks that surround her abdomen. The physician suspects pituitary adenoma. Which of the following high-dose dexamethasone suppression test findings and baseline ACTH findings would support his view?
A. Cortisol suppression, normal baseline ACTH
B. Elevation of cortisol above pre-test levels, high baseline ACTH
C. No cortisol suppression, low baseline ACTH
D. No cortisol suppression, high baseline ACTH
E. Cortisol suppression, high baseline ACTH (Correct Answer)
Explanation: **Cortisol suppression, high baseline ACTH**
- A **pituitary adenoma** (Cushing's disease) causes **excessive ACTH production**, leading to high baseline ACTH levels and **cortisol overproduction**.
- In the high-dose dexamethasone suppression test, the large dose of synthetic glucocorticoid can **suppress ACTH secretion** from the adenoma, leading to a reduction in cortisol levels.
*Cortisol suppression, normal baseline ACTH*
- This pattern generally suggests **exogenous glucocorticoid use** as the cause of Cushing's syndrome, where the adrenal axis is suppressed.
- A **pituitary adenoma** would typically cause **elevated ACTH**, not normal levels, before suppression.
*Elevation of cortisol above pre-test levels, high baseline ACTH*
- Elevation of cortisol above pre-test levels is not expected in any form of Cushing's syndrome with a dexamethasone suppression test.
- While a high baseline ACTH is consistent with an ACTH-dependent cause, the **lack of suppression and increase** is unusual.
*No cortisol suppression, low baseline ACTH*
- This pattern is characteristic of **ACTH-independent Cushing's syndrome**, such as an **adrenal tumor**.
- In this case, the adrenal glands are autonomously producing cortisol, and the high cortisol suppresses pituitary ACTH release.
*No cortisol suppression, high baseline ACTH*
- This finding is typical of an **ectopic ACTH-producing tumor** (e.g., small cell lung cancer).
- These tumors often produce a large amount of ACTH that is **not suppressed** by even high doses of dexamethasone.
Question 126: A 25-year-old man presents to the emergency department with back pain. He states that it started yesterday and has been gradually getting worse. He states that the pain is worsened with moving and lifting and is relieved with rest and ibuprofen. He has a past medical history of smoking and IV drug abuse and states he last used IV drugs 2 days ago. He thinks his symptoms may be related to lifting a heavy box. His temperature is 99.3°F (37.4°C), blood pressure is 122/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for focal back pain lateral to the patient’s spine on the left. There is no midline tenderness and the rest of the patient’s exam is unremarkable. There are scars in the antecubital fossae bilaterally. Laboratory values including a C-reactive protein are unremarkable. Which of the following is the most likely diagnosis?
A. Epidural hematoma
B. Epidural abscess
C. Compression fracture
D. Herniated nucleus pulposus
E. Muscle strain (Correct Answer)
Explanation: ***Muscle strain***
- The patient's presentation with **sudden onset back pain** worsened by movement/lifting and relieved by rest/NSAIDs, along with focal tenderness lateral to the spine, is classic for a **muscle strain**.
- The absence of fever, neurologic deficits, and unremarkable lab values (including CRP) makes more serious conditions less likely, even with a history of IV drug use.
*Epidural hematoma*
- An **epidural hematoma** would typically present with more acute, severe pain, often following trauma or in patients on anticoagulants.
- Neurological deficits, such as **radiculopathy** or **myelopathy**, would be expected, which are not described here.
*Epidural abscess*
- An **epidural abscess** is highly suspected in a patient with a history of **IV drug abuse** and back pain; however, it typically presents with **fever**, elevated inflammatory markers (e.g., **CRP**, ESR), and possibly neurological compromise, which are absent here.
- The patient's normal temperature and CRP significantly reduce the likelihood of an active infection.
*Compression fracture*
- A **compression fracture** usually occurs in older patients with **osteoporosis** or following significant trauma in younger individuals.
- While pain can be worsened by movement, the focal, non-midline tenderness and lack of a significant traumatic event make this less likely.
*Herniated nucleus pulposus*
- A **herniated nucleus pulposus** would typically present with **radicular pain** (shooting pain down the leg), numbness, or weakness in a dermatomal or myotomal distribution.
- The patient's pain is described as focal back pain lateral to the spine, with no mention of radicular symptoms.
Question 127: A 34-year-old female presents to her primary care physician complaining of fatigue. Over the last three months she has experienced decreased energy and gained 7 pounds. Review of systems is negative for symptoms of depression but is positive for constipation, myalgias, and cold intolerance. Physical exam is notable for delayed deep tendon reflex relaxation. Vital signs are as follows: T 37.1 C, HR 61, BP 132/88, RR 16, and SpO2 100%. Which of the following is the best initial screening test for this patient?
A. Serum TSH (Correct Answer)
B. Morning cortisol and plasma ACTH
C. Serum Free T4
D. Level of anti-thyroid peroxidase (TPO) antibodies
E. Hemoglobin and hematocrit
Explanation: ***Serum TSH***
- The patient presents with classic symptoms of **hypothyroidism**, including fatigue, weight gain, constipation, myalgias, and cold intolerance, along with a delayed relaxation of deep tendon reflexes and bradycardia (HR 61), making **TSH** the best initial screening test.
- An elevated TSH level is the most **sensitive** and **specific** indicator of primary hypothyroidism, as the pituitary gland increases TSH production in response to low thyroid hormone levels.
*Morning cortisol and plasma ACTH*
- These tests are used to evaluate **adrenal insufficiency** (Addison's disease), which can cause fatigue and weight loss, but not typically weight gain, constipation, or cold intolerance.
- The constellation of symptoms is more indicative of thyroid dysfunction rather than adrenal pathology.
*Serum Free T4*
- While **Free T4** directly measures the active thyroid hormone, it is usually ordered *after* an abnormal TSH level is found.
- TSH is a more sensitive initial screen for primary hypothyroidism, as small changes in T4 can cause large inverse changes in TSH.
*Level of anti-thyroid peroxidase (TPO) antibodies*
- **Anti-TPO antibodies** are indicative of **Hashimoto's thyroiditis**, an autoimmune cause of hypothyroidism, but they are not the initial screening test for thyroid function itself.
- TSH should first be evaluated to determine if there is indeed thyroid dysfunction.
*Hemoglobin and hematocrit*
- These tests are used to screen for **anemia**, which can cause fatigue. However, the other distinct symptoms like cold intolerance, constipation, weight gain, and delayed deep tendon reflex relaxation are not characteristic of anemia.
- While anemia can coexist with hypothyroidism, it is not the primary screening test for the patient's presented symptoms.
Question 128: A 63-year-old woman with a previous diagnosis of rheumatoid arthritis and Sjogren syndrome was referred for a second opinion. She has had a known chronic idiopathic pericardial effusion for about a year and has dealt with intermittent chest pain ever since. She underwent 2 diagnostic pericardiocenteses, but the fluid returned each time. She also has used empiric anti-inflammatory therapies with NSAIDs and colchicine without significant changes in the size of the pericardial effusion. The etiological testing was negative. At this visit, she is still complaining of pain in her chest but has no evidence of distended neck veins. An ECG shows sinus rhythm with low QRS voltages. What will be the procedure of choice that would be both therapeutic and diagnostic?
A. Pericardial window (Correct Answer)
B. Pericardiectomy
C. Pericardiodesis
D. Non-surgical management
E. Repeated pericardiocentesis
Explanation: ***Pericardial window***
- A **pericardial window** allows continuous drainage of pericardial fluid into the pleural space or peritoneum, preventing reaccumulation and providing symptomatic relief for **recurrent pericardial effusions**.
- It also enables **biopsy of the pericardium**, offering a diagnostic opportunity in cases where previous fluid analysis was inconclusive, which is crucial given the patient's autoimmune history and persistent effusion.
*Pericardiectomy*
- **Pericardiectomy** involves surgical removal of part or all of the pericardium and is typically reserved for **constrictive pericarditis** or highly refractory recurrent effusions with significant hemodynamic compromise.
- While it offers a definitive solution, it is a more invasive procedure than a pericardial window and might be excessive given the absence of overt **constrictive physiology** (e.g., no jugular venous distention indicating tamponade).
*Pericardiodesis*
- **Pericardiodesis** involves instilling an irritant (e.g., talc, tetracycline) into the pericardial space to induce inflammation and adhesion between the pericardial layers, aiming to prevent fluid reaccumulation.
- This procedure is primarily used in cases of **malignant pericardial effusions** and is less suitable for chronic idiopathic or inflammatory effusions, especially if the underlying cause is not definitively ruled out.
*Non-surgical management*
- **Non-surgical management** with NSAIDs and colchicine has already been attempted in this patient without success, indicating its ineffectiveness for this chronic, recurrent effusion.
- Given the persistent symptoms and effusion despite medical therapy and previous drainage attempts, further non-surgical approaches alone are unlikely to be sufficient or diagnostic.
*Repeated pericardiocentesis*
- While pericardiocentesis provides temporary relief, the history explicitly states the fluid **returned each time**, making repeated procedures ineffective for long-term management and prevention of recurrence.
- Repeated pericardiocentesis does not offer a definitive diagnostic yield beyond initial fluid analysis, nor does it address the underlying issue of recurrent fluid accumulation.
Question 129: An 81-year-old man comes to the emergency department because of left-sided visual loss that started 1 hour ago. He describes initially seeing jagged edges, which was followed by abrupt, complete loss of central vision in the left eye. He has hypertension and type 2 diabetes mellitus. Blood pressure is 145/89 mm Hg. Neurologic examination shows no abnormalities. A photograph of the fundoscopic findings is shown. Which of the following tests is most likely to confirm this patient's underlying condition?
A. CD4+ T-cell count
B. Carotid artery duplex ultrasonography (Correct Answer)
C. Glycated hemoglobin concentration
D. Erythrocyte sedimentation rate
E. Tonometry
Explanation: ***Carotid artery duplex ultrasonography***
- The patient's presentation with sudden, painless, complete **visual loss** preceded by **amaurosis fugax** (jagged edges) along with fundoscopic findings of a **cherry-red spot** and **retinal whitening** strongly suggests a central retinal artery occlusion (CRAO).
- CRAO is often caused by an **embolus** originating from the **carotid arteries** or the heart, making carotid artery duplex ultrasonography essential to identify the source and guide management.
*CD4+ T-cell count*
- This test is primarily used to assess the immune status in individuals with **HIV infection** and is not relevant to acute monocular vision loss.
- There are no clinical signs or symptoms presented that would suggest an increased risk of immunocompromise or opportunistic infection affecting the retina.
*Glycated hemoglobin concentration*
- While the patient has **type 2 diabetes mellitus**, his acute visual loss is not characteristic of diabetic retinopathy, which usually causes progressive vision changes due to microvascular damage, not sudden, complete loss of central vision associated with a cherry-red spot.
- While important for managing his diabetes, this test would not confirm the acute underlying cause of his abrupt visual loss.
*Erythrocyte sedimentation rate*
- An elevated ESR is a marker of **inflammation** and could be indicative of conditions like **giant cell arteritis** (GCA), which can cause monocular vision loss.
- However, GCA typically presents with headache, jaw claudication, and scalp tenderness, none of which are reported, and the fundoscopic findings of CRAO are not the primary feature of GCA-related vision loss.
*Tonometry*
- Tonometry measures **intraocular pressure** and is used to screen for and monitor **glaucoma**.
- While glaucoma can cause visual field defects, it does not typically present with acute, complete monocular vision loss as described, nor is it associated with a cherry-red spot on fundoscopic examination.
Question 130: A 68-year-old woman is brought to the physician by her husband for the evaluation of confusion and memory deficits for the last month. During this period, she has also had mild weakness in her left leg. She has hypertension and hyperlipidemia. Her current medications include enalapril and atorvastatin. She has smoked two packs of cigarettes daily for the last 45 years. She drinks a glass of wine every day. Her temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 135/85 mm Hg. She is oriented only to person. She recalls 2 out of 3 objects immediately and none after 5 minutes. The patient is unable to lift her eyebrows or to smile. Muscle strength is decreased in the left lower extremity. A T2-weighted MRI scan of the head shows several hyperintense round lesions in the frontal and temporal lobe at the border of the gray and white matter. Which of the following is the most likely diagnosis?
A. Multiple sclerosis
B. Lung cancer (Correct Answer)
C. Progressive multifocal leukoencephalopathy
D. Glioblastoma multiforme
E. Colorectal cancer
Explanation: **Lung cancer**
- The patient's extensive smoking history of **45 pack-years** significantly increases her risk for lung cancer, which commonly metastasizes to the brain.
- The MRI findings of **multiple hyperintense round lesions** at the gray-white matter junction are highly suggestive of **brain metastases**, a frequent complication of lung cancer.
*Multiple sclerosis*
- While MS can cause **demyelinating plaques** that appear as hyperintense lesions on MRI, it typically presents with **neurological symptoms that are relapsing-remitting** and tends to affect younger patients.
- The patient's age and the **progressive nature** of her symptoms, along with significant risk factors for malignancy, make MS less likely.
*Progressive multifocal leukoencephalopathy (PML)*
- PML is a rare opportunistic infection caused by the **JC virus** that primarily affects immunocompromised individuals.
- There is no indication of **immunocompromise** in this patient, and the MRI lesions of PML are typically **asymmetric white matter lesions** that do not enhance, which differs from the likely metastatic pattern described.
*Glioblastoma multiforme*
- Glioblastoma is a **primary brain tumor** that often presents as a single, large, irregularly enhancing mass on MRI, sometimes with necrosis and surrounding edema.
- The presence of **multiple, round hyperintense lesions** points away from a primary glioblastoma and towards metastatic disease.
*Colorectal cancer*
- While colorectal cancer can metastasize to the brain, the patient's strong smoking history makes **lung cancer** a much more probable primary source for brain metastases.
- There are no clinical symptoms or risk factors specifically pointing towards **gastrointestinal malignancy** in this case.
