NEET-PG 2012 - Internal Medicine Practice Questions

Q: In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Ascending aorta. ***Ascending aorta*** - The **ascending aorta** is the most common site for aortic aneurysm and dissection in Marfan syndrome due to cystic medial degeneration weakening the vessel wall [1]. - This predisposition is linked to defects in the **fibrillin-1 gene (FBN1)**, severely impacting the structural integrity of the arterial media primarily in the ascending aorta [1]. *Descending aorta* - While possible, **descending aortic** involvement is less common than ascending aortic involvement in Marfan syndrome [2]. - Aneurysms here are more frequently associated with atherosclerosis or other connective tissue disorders. *Abdominal aorta* - **Abdominal aortic aneurysms** are relatively rare in Marfan syndrome and are more typically seen in older patients with atherosclerosis [3]. - The disease primarily affects the elastic tissue content, which is most abundant in the proximal aorta. *Arch of aorta* - Aortic arch aneurysms can occur, but they are still less frequent than those in the **ascending aorta** as the primary initial site of dilation and dissection in Marfan syndrome. - Arch involvement often represents an extension of a more proximal ascending aortic pathology.

Q: In which of the following conditions is hypomagnesemia not typically observed?

Diabetes mellitus. Diabetes mellitus - While hypomagnesemia can occur in poorly controlled diabetes due to osmotic diuresis, it is not a typical or defining feature of the condition itself in the same way as other options. - Many individuals with controlled diabetes may have normal magnesium levels, and it's often associated with complications rather than the primary disease process. Diarrhea - Chronic or severe diarrhea leads to significant gastrointestinal losses of electrolytes, including magnesium. - This is a common cause of hypomagnesemia, as the body loses fluids and minerals before they can be absorbed. Gitelman syndrome - This is a renal tubular disorder characterized by a defect in the thiazide-sensitive Na-Cl cotransporter in the distal convoluted tubule. - It leads to hypomagnesemia (due to increased renal excretion) and hypokalemia, along with metabolic alkalosis. Bartter syndrome - This syndrome involves a defect in the Na-K-2Cl cotransporter in the thick ascending limb of the loop of Henle. - It results in significant renal wasting of magnesium [1], leading to hypomagnesemia, along with hypokalemia and metabolic alkalosis.

Q: Tuberculosis of the spine; what is the most common site affected?

Dorsolumbar. ***94ed055d-c7da-4d18-a2fd-52720dfe8b6e*** - The **dorsolumbar (thoracolumbar)** region is the most common site of **spinal tuberculosis (Pott's disease)** [1] due to its high vascularity, facilitating hematogenous spread. - **Spinal tuberculosis** typically affects the vertebral bodies, leading to their destruction, kyphosis (angular deformity), and potentially neurological deficits [1]. *aebdfe6c-98dc-4073-892f-bb24d047bab4* - The **sacral** region can be affected by **tuberculosis**, but it is considerably less common than the thoracolumbar region. - Involvement of the sacrum is often associated with **direct extension** from adjacent structures, such as the sacroiliac joint, rather than primary vertebral involvement. *15c1feef-e3ca-496f-a180-127d52b77bfa* - **Cervical spine tuberculosis** is relatively rare, accounting for a small percentage of all spinal tuberculosis cases. - While possible, it presents with specific challenges due to the proximity of vital neurological and vascular structures. *d05d4d13-bb83-4f26-aa2d-c9c0203d299c* - The **lumbosacral region** (L5-S1) can be involved in **tuberculosis**, but it is less frequently affected than the thoracolumbar region. - While the lumbar spine is a common site, the entire lumbosacral region as a single entity is not the most common spot for spinal TB.

Q: Antibodies most commonly seen in drug induced lupus are:

Antihistone Antibodies. ***Antihistone Antibodies*** - **Antihistone antibodies** are the most common laboratory finding, present in 95% of patients with **drug-induced lupus erythematosus (DIL)**. - This type of lupus is often triggered by medications such as **procainamide**, **hydralazine**, and **isoniazid**. *Anti ds DNA Antibodies* - **Anti-double-stranded DNA (dsDNA) antibodies** are highly specific for **systemic lupus erythematosus (SLE)**, particularly severe cases, but are rarely seen in DIL. - High titers of anti-dsDNA often correlate with **lupus nephritis** and disease activity. *Anti Sm Antibodies* - **Anti-Sm antibodies** are highly specific for **SLE**, sometimes associated with neuropsychiatric manifestations, but are rarely identified in drug-induced lupus. - Their presence helps to confirm the diagnosis of SLE but not DIL. *Anti-Ro Antibodies* - **Anti-Ro (SSA) antibodies** are most commonly associated with **Sjögren's syndrome** and **neonatal lupus**, and can be seen in a subset of SLE patients, especially those with photosensitivity. - While they can be present in some forms of SLE, they are not the hallmark autoantibody for drug-induced lupus.

Q: In which condition is paradoxical splitting of the second heart sound observed?

Left Bundle Branch Block (LBBB). ***Left Bundle Branch Block (LBBB)*** - In LBBB, the **left ventricle** depolarizes and contracts *after* the right ventricle, causing the **aortic valve (A2)** to close *after* the **pulmonic valve (P2)** [1]. - During inspiration, right ventricular ejection time is prolonged, which further delays P2. However, in LBBB, A2 is already delayed, and the inspiratory delay of P2 can bring P2 closer to A2, or even cause them to merge, making the splitting *less wide* or *disappear* on inspiration, which is paradoxical. *Right Bundle Branch Block (RBBB)* - RBBB causes a **delay in right ventricular depolarization**, leading to a **delayed P2** (pulmonic valve closure). - This typically results in **wide and fixed splitting of S2**, where the splitting persists during expiration and widens further with inspiration, which is not paradoxical. *Ventricular Septal Defect (VSD)* - A VSD can cause a **loud holosystolic murmur** and may lead to increased pulmonary blood flow. - While it can affect the timing of heart sounds, it does not typically cause paradoxical splitting of S2. *Atrial Septal Defect (ASD)* - An ASD causes a **left-to-right shunt**, leading to chronic volume overload of the right ventricle and increased pulmonary blood flow. - This often results in a **widely fixed splitting of S2**, where the split between A2 and P2 is constant regardless of respiration, which is different from paradoxical splitting.

Q: Which of the following is a characteristic feature of myasthenia gravis?

Presence of antibodies against acetylcholine receptors. ***Presence of antibodies against acetylcholine receptors*** - **Myasthenia gravis** is an **autoimmune disorder** characterized by the production of **antibodies against acetylcholine receptors** at the neuromuscular junction [1]. - These antibodies block, alter, or destroy the acetylcholine receptors, leading to impaired nerve-to-muscle communication and **muscle weakness** [2]. *Decreased levels of myosin in muscle fibers* - Myosin is a **motor protein** crucial for muscle contraction, and its decreased levels are not a primary feature of myasthenia gravis, but rather other **myopathies** or muscle wasting conditions. - The disease mechanism in myasthenia gravis is primarily at the **neuromuscular junction**, not within the muscle fibers themselves. *Absence of troponin C in muscle fibers* - **Troponin C** is a component of the troponin complex essential for **calcium-mediated muscle contraction**, found inside muscle fibers. - Its absence would lead to severe and widespread muscle dysfunction, unlike the specific and fluctuating weakness seen in **myasthenia gravis**. *Increased transmission at the myoneural junction* - Myasthenia gravis is characterized by **decreased** or **impaired transmission** at the myoneural (neuromuscular) junction due to the destruction or blockade of acetylcholine receptors [2]. - Increased transmission would lead to **muscle hyperactivity** or spasms, which is contrary to the **fatigable weakness** observed in myasthenia gravis.

Q: What is the most common presentation for IgA nephropathy?

Repeated gross hematuria. ***Repeated gross hematuria*** - The hallmark of **IgA nephropathy** is recurrent episodes of **gross hematuria**, particularly following **respiratory infections** [1]. - It is often associated with **renal impairment** but can present initially with **visible blood** in the urine [1]. *Nephritic syndrome* - While IgA nephropathy can lead to nephritic features, it does not commonly present primarily as **nephritic syndrome**, which includes hypertension and edema. - Nephritic syndrome is characterized by significant **proteinuria** and acute renal failure, rather than the classic presentation of hematuria [2]. *Microscopic hematuria* - Although **microscopic hematuria** can occur in IgA nephropathy, it is not the most common and noticeable presentation; **gross hematuria** is more characteristic [1]. - Microscopic hematuria lacks the acute visual symptoms seen in cases proving the diagnosis. *Nephritic syndrome* - This option is a repetition of and does not provide any additional unique characteristics specific to **IgA nephropathy**. - It shares the same clinical features discussed previously and is thus not representative of the most common presentation.

Q: What is the preferred test for confirming H. pylori eradication?

Urease breath test. ***Urease breath test*** - The **urea breath test** is highly sensitive and specific for detecting active *H. pylori* infection and its eradication by measuring radioactive or non-radioactive labeled carbon dioxide released from metabolizing urea. - It is a non-invasive test preferred after treatment to confirm eradication, as it directly detects bacterial urease activity. *Culture* - **Culture** requires an invasive endoscopic biopsy, is expensive, and takes several days to yield results; therefore, it is not the preferred method for routine eradication confirmation. - While it offers the advantage of **antibiotic susceptibility testing**, its invasiveness and turnaround time make it less practical for post-treatment assessment. *Serological test* - **Serological tests** (blood tests for antibodies) remain positive for **H. pylori antibodies** for extended periods even after successful eradication, rendering them unsuitable for confirming eradication. - These tests primarily indicate past exposure rather than current, active infection. *Biopsy urease test* - A **biopsy urease test** involves an invasive endoscopy to obtain a tissue sample, which is then tested for urease activity. - Although useful for initial diagnosis, its invasiveness makes it less preferred for confirming eradication compared to the non-invasive breath test.

Q: Which of the following is NOT a common pathogen causing pneumonia in COPD patients?

Legionella spp. ***Legionella spp*** - While *Legionella* can cause pneumonia, it is **not a common pathogen** specifically in COPD exacerbations or community-acquired pneumonia in these patients [1]. - *Legionella* pneumonia often presents with **extrapulmonary symptoms** like diarrhea and hyponatremia and is typically associated with contaminated water sources [1]. *Haemophilus influenzae* - This is a very common pathogen causing both **acute exacerbations of COPD (AECOPD)** and pneumonia in patients with underlying COPD [1]. - COPD patients often have **impaired mucociliary clearance** and altered airway microbiology, making them susceptible to *H. influenzae* colonization and infection [1]. *Pseudomonas aeruginosa* - *Pseudomonas aeruginosa* is an important pathogen in **severe COPD exacerbations**, especially in patients with frequent exacerbations, bronchiectasis, or prior antibiotic use. - Its presence often indicates a **more severe disease course** and requires specific antibiotic coverage. *Klebsiella pneumoniae* - *Klebsiella pneumoniae* is a significant cause of **pneumonia in immunocompromised individuals**, including those with COPD, diabetes, or alcoholism. - It often leads to **severe, necrotizing pneumonia**, particularly in the upper lobes, and can cause abscess formation.

Q: Which of the following is a characteristic of Wilson's disease?

Increased copper in liver. ***Increased copper in liver*** - Wilson's disease is characterized by **accumulation of copper** in liver tissues due to defective copper transport [1]. - This excess leads to **hepatocellular damage**, resulting in liver dysfunction and potential cirrhosis [1]. *Decreased copper excretion in urine* - In Wilson's disease, there is actually **decreased excretion of copper**, which results in accumulation in the liver [1]. - **Urine copper levels** are typically low to normal in early stages because the liver fails to excrete excess copper effectively. *Autosomal dominant* - Wilson's disease is inherited in an **autosomal recessive** pattern, not dominant. - It is caused by mutations in the gene responsible for copper transport (ATP7B) [1]. *Increased serum ceruloplasmin* - Serum ceruloplasmin levels are often **decreased** in Wilson's disease due to impaired copper incorporation into this protein [1]. - Low ceruloplasmin is a key laboratory finding, contrasting the assertion of this option.

Question 1

In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Accepted Answer

Ascending aorta

Answer

Descending aorta

Answer

Abdominal aorta

Answer

Arch of aorta

Question 2

In which of the following conditions is hypomagnesemia not typically observed?

Accepted Answer

Diabetes mellitus

Answer

Diarrhea

Answer

Gitelman syndrome

Answer

Bartter syndrome

Question 3

Tuberculosis of the spine; what is the most common site affected?

Accepted Answer

Dorsolumbar

Answer

Sacral

Answer

Lumbosacral

Answer

Cervical

Question 4

Antibodies most commonly seen in drug induced lupus are:

Accepted Answer

Antihistone Antibodies

Answer

Anti ds DNA Antibodies

Answer

Anti Sm Antibodies

Answer

Anti-Ro Antibodies

Question 5

In which condition is paradoxical splitting of the second heart sound observed?

Accepted Answer

Left Bundle Branch Block (LBBB)

Answer

Right Bundle Branch Block (RBBB)

Answer

Ventricular Septal Defect (VSD)

Answer

Atrial Septal Defect (ASD)

Question 6

Which of the following is a characteristic feature of myasthenia gravis?

Accepted Answer

Presence of antibodies against acetylcholine receptors

Answer

Decreased levels of myosin in muscle fibers

Answer

Absence of troponin C in muscle fibers

Answer

Increased transmission at the myoneural junction

Question 7

What is the most common presentation for IgA nephropathy?

Accepted Answer

Repeated gross hematuria

Answer

Nephritic syndrome

Answer

Nephrotic syndrome

Answer

Microscopic hematuria

Question 8

What is the preferred test for confirming H. pylori eradication?

Accepted Answer

Urease breath test

Answer

Culture

Answer

Serological test

Answer

Biopsy urease test

Question 9

Which of the following is NOT a common pathogen causing pneumonia in COPD patients?

Accepted Answer

Legionella spp

Answer

Klebsiella pneumoniae

Answer

Pseudomonas aeruginosa

Answer

Haemophilus influenzae

Question 10

Which of the following is a characteristic of Wilson's disease?

Accepted Answer

Increased copper in liver

Answer

Autosomal dominant

Answer

Increased serum ceruloplasmin

Answer

Decreased copper excretion in urine

NEET-PG 2012 — Internal Medicine