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: Distal renal tubular acidosis is associated with:

Calcium stones. ***Calcium stones*** - Distal renal tubular acidosis (Type 1 RTA) causes metabolic acidosis due to impaired distal tubular **hydrogen ion secretion**. - This leads to **increased urinary calcium excretion** (hypercalciuria) and decreased urinary citrate, creating an environment favorable for the formation of **calcium phosphate renal stones**. *Oxalate stones* - While oxalate is a component of some calcium stones (calcium oxalate), **primary hyperoxaluria** or dietary excess of oxalate are the main causes, not directly distal RTA. - Distal RTA specifically promotes **calcium phosphate stone formation** due to pH changes and hypercalciuria. *Hypocitraturia* - **Hypocitraturia** is indeed a feature of distal RTA as the kidney attempts to excrete acid by reabsorbing citrate, making the urine less inhibitory to stone formation. - However, the most direct and common clinically observed consequence in stone formation is the development of **calcium stones**, as hypocitraturia combined with hypercalciuria facilitates their formation. *Uric acid stones* - **Uric acid stones** typically form in persistently **acidic urine** and are associated with conditions like gout or myeloproliferative disorders. - While distal RTA results in systemic acidosis, the urine pH in distal RTA is typically **alkaline or inappropriately neutral**, which does not favor uric acid stone formation.

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: Anomic aphasia is due to defect in

Temporal occipital lobe. ***Temporal occipital lobe*** - Anomic aphasia, characterized by difficulty recalling **words or names (anomia)**, is most commonly associated with lesions in the **left temporo-occipital region**. - This area is crucial for **semantic processing** and word retrieval. *Left inferior parietal lobe* - Damage to the left inferior parietal lobe is more commonly associated with **conduction aphasia**, characterized by impaired repetition despite fluent speech and good comprehension. - It is also involved in aspects of **reading (alexia)** and **writing (agraphia)**. *Left temporal lobe* - While portions of the left temporal lobe (especially Wernicke's area) are critical for language comprehension, damage primarily to this area typically results in **Wernicke's aphasia**, where speech is fluent but meaningless, and comprehension is severely impaired. - Anomia can be a feature of Wernicke's aphasia, but the primary deficit is comprehension. *Cerebellum* - The cerebellum plays a significant role in **motor control**, balance, and coordination, but it is not directly involved in the **generation or comprehension of language** in the same way as cortical areas. - Damage to the cerebellum might lead to **dysarthria** (speech motor difficulties), but not typical aphasia.

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: The most classical symptom of VIPOMA is:

Secretory diarrhea. The original text cannot be accurately enriched with the provided references to because none of the source materials directly address the pathophysiology or clinical presentation of VIPoma. The available references focus on general gastroenteropancreatic neuroendocrine tumors (NETs) , radiation-induced intestinal damage , arsenic poisoning , gastrointestinal bleeding , and the physiology of taste , but they do not provide the specific confirmation needed for the 'classical symptom' of VIPoma (secretory diarrhea).

Q: Which of the following is a characteristic feature of primary Sjogren's syndrome?

Enlargement of salivary glands. ***Enlargement of salivary glands*** - **Sjögren's syndrome** is characterized by chronic inflammation of **exocrine glands**, leading to swelling and dysfunction, most notably in the **parotid** and **submandibular glands**. - This glandular enlargement often presents as recurrent or persistent **bilateral swelling** of the major salivary glands. *Can occur in children* - While possible, Sjögren's syndrome is predominantly a disease of **adults**, with incidence peaking in individuals between **40 and 60 years old**. - **Juvenile Sjögren's syndrome** is rare and typically presents with more variable symptoms, making it less of a characteristic feature of the primary disease in the general population. *Increased complement C4 is associated with thymoma* - **Increased complement C4** levels are generally not associated with Sjögren's syndrome; instead, **hypocomplementemia** (low C4) can be seen in some patients, indicating immune complex activity. - **Thymoma** is primarily linked to **myasthenia gravis** and other paraneoplastic syndromes, not a direct or characteristic association with Sjögren's syndrome or C4 levels in this context. *Can be associated with rheumatoid arthritis* - Sjögren's syndrome can be classified as **primary** (occurring alone) or **secondary** (occurring in conjunction with another autoimmune disease). - Its association with **rheumatoid arthritis** defines **secondary Sjögren's syndrome**, meaning it's not a characteristic feature of the *primary* form of the disease itself.

Q: What is the first symptom of leprosy?

Decreased pain. Decreased pain - Leprosy primarily targets Schwann cells in peripheral nerves, leading to sensory loss [1]. - The sensation of pain is typically affected earliest, often presenting as areas of numbness [1]. Decreased vibration & position sense - These sensations are typically carried by larger myelinated fibers, which tend to be affected later in the disease progression of leprosy. - While eventually involved, they are not usually the first symptom of sensory loss. Decreased temperature - Temperature sensation is also an early modality affected in leprosy, as it's carried by small, unmyelinated or thinly myelinated fibers [1]. - However, pain is often cited as the very first sensory loss, even preceding temperature changes in some cases. Decreased light touch - Light touch sensation is generally an early loss, similar to pain and temperature, due to damage to nerve fibers in the skin. - But, when distinguishing the absolute first symptom, pain perception often shows impairment even before light touch in affected areas.

Q: Migraine is due to

Cortical spreading depression. ***Cortical spreading depression*** - The current understanding is that **cortical spreading depression (CSD)** is the initiating event in migraine with aura, characterized by a wave of neuronal and glial depolarization that spreads across the cerebral cortex, leading to a temporary shutdown of neuronal activity [1]. - CSD is thought to activate the **trigeminal nerve**, subsequently causing the release of inflammatory neuropeptides and contributing to the pain phase [1]. *Dilatation of cranial blood vessels* - While **vasodilation of intracranial and extracranial blood vessels** does occur during the headache phase of migraine, it is now considered a *consequence* of the initial neurological events rather than the primary cause [1]. - This vasodilation contributes to the throbbing sensation of migraine pain but does not explain the aura or the initiation of the attack. *Constriction of cranial blood vessels* - **Vasoconstriction** was previously thought to be the cause of the migraine aura, but this theory has largely been disproven. - While some temporary constriction may precede CSD, it is not the primary mechanism behind the migraine attack. *Inflammation of the meninges* - While **neurogenic inflammation** of the meninges, involving the release of inflammatory mediators like **calcitonin gene-related peptide (CGRP)**, does play a role in sensitizing the trigeminal system and contributing to migraine pain, it is a downstream effect. - It is not the initial trigger for a migraine attack but rather part of the pain pathway activated by events like CSD.

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

Distal renal tubular acidosis is associated with:

Accepted Answer

Calcium stones

Answer

Hypocitraturia

Answer

Oxalate stones

Answer

Uric acid stones

Question 3

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 4

Anomic aphasia is due to defect in

Accepted Answer

Temporal occipital lobe

Answer

Left inferior parietal lobe

Answer

Left temporal lobe

Answer

Cerebellum

Question 5

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 6

All the following are true about multiple myeloma except for which of the following?

Accepted Answer

Chromosomal translocation t(8;14), commonly seen in Burkitt's lymphoma

Answer

Hypercalcemia

Answer

Presence of Bence-Jones proteins in urine

Answer

Osteolytic bone disease

Question 7

The most classical symptom of VIPOMA is:

Accepted Answer

Secretory diarrhea

Answer

Gall stones

Answer

Steatorrhea

Answer

Flushing

Question 8

Which of the following is a characteristic feature of primary Sjogren's syndrome?

Accepted Answer

Enlargement of salivary glands

Answer

Can occur in children

Answer

Increased complement C4 is associated with thymoma

Answer

Can be associated with rheumatoid arthritis

Question 9

What is the first symptom of leprosy?

Accepted Answer

Decreased pain

Answer

Decreased vibration & position sense

Answer

Decreased temperature

Answer

Decreased light touch

Question 10

Migraine is due to

Accepted Answer

Cortical spreading depression

Answer

Dilatation of cranial blood vessels

Answer

Constriction of cranial blood vessels

Answer

Inflammation of the meninges

NEET-PG 2012 — Internal Medicine