Pseudomembranous colitis, all are true except:
Waterhouse-Friderichsen syndrome is seen in:
Most common site for hydatid cyst
Which of the following is NOT a symptom of mild dehydration?
Which of the following is NOT a characteristic feature of systemic sclerosis?
Subclavian steal syndrome is
What are the key characteristics of Evans syndrome?
A 25 year old female presents with generalized restriction of eye movement in all direction, intermittent ptosis, proximal muscle weakness and fatigability.Which is the MOST useful test in making the diagnosis?
Which of the following is NOT a feature of Cushing's triad?
Which of the following is a feature of tumor lysis syndrome?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 51: Pseudomembranous colitis, all are true except:
- A. Blood in stools is a common feature (Correct Answer)
- B. Toxin A is responsible for clinical manifestation
- C. Summit lesions are early histopathological findings
- D. Toxin B is responsible for clinical manifestation
Explanation: ***Blood in stools is a common feature*** - While diarrhea is a hallmark of **pseudomembranous colitis**, **bloody stools** are uncommon and, if present, suggest severe disease or an alternative diagnosis [1]. - The typical presentation involves **watery diarrhea**, abdominal cramps, and fever, not usually overt bleeding [1]. *Toxin A is responsible for clinical manifestation* - **Toxin A (TcdA)** is one of the primary exotoxins produced by *Clostridioides difficile* and contributes significantly to the **inflammation** and fluid secretion seen in pseudomembranous colitis. - It acts as an **enterotoxin**, causing fluid secretion and mucosal damage in the colon [1]. *Summit lesions are early histopathological findings* - **Summit lesions**, also known as "summit pseudomembranes" or **"volcano lesions"**, refer to characteristic histological findings where inflammatory exudates effuse from the tips of damaged crypts. - These are typical early findings in pseudomembranous colitis, demonstrating the focal nature of the **mucosal injury**. *Toxin B is responsible for clinical manifestation* - **Toxin B (TcdB)** is another key exotoxin produced by *Clostridioides difficile*, and it is considered even more **cytotoxic** than Toxin A [1]. - It causes significant **cell damage** and **apoptosis**, playing a crucial role in the development of the pseudomembranes and clinical symptoms [1].
Question 52: Waterhouse-Friderichsen syndrome is seen in:
- A. Neisseria meningitidis (Correct Answer)
- B. Yersinia
- C. Pseudomonas
- D. Pneumococci
Explanation: ***Neisseria meningitidis*** - **Waterhouse-Friderichsen syndrome** is a severe complication of **meningococcal sepsis**, predominantly caused by *Neisseria meningitidis* [1]. - It is characterized by **adrenal gland hemorrhage**, leading to acute adrenal insufficiency, hemorrhagic skin rash, and shock [1]. *Pseudomonas* - While *Pseudomonas aeruginosa* can cause severe infections, including sepsis, it is **not typically associated** with Waterhouse-Friderichsen syndrome. - *Pseudomonas* infections often lead to **ecthyma gangrenosum** in immunocompromised patients, a different dermatological manifestation. *Yersinia* - *Yersinia* species can cause various infections, such as **yersiniosis** (gastroenteritis) and **plague** (*Yersinia pestis*). - These infections do not commonly present with the distinct features of **adrenal hemorrhage** and **fulminant sepsis** seen in Waterhouse-Friderichsen syndrome. *Pneumococci* - *Streptococcus pneumoniae* (**pneumococci**) is a common cause of **meningitis** and **sepsis**, especially in children and the elderly. - Although it can lead to severe bloodstream infections, it is **rarely specifically linked** to the adrenal hemorrhage syndrome known as Waterhouse-Friderichsen syndrome.
Question 53: Most common site for hydatid cyst
- A. Lung
- B. Liver (Correct Answer)
- C. Brain
- D. Kidney
Explanation: ***Liver*** - The **liver** is the most common site for hydatid cysts, accounting for approximately **60-70%** of cases [1]. - It often leads to **biliary obstruction** and liver dysfunction, highlighting its impact on the organ. *Kidney* - Hydatid cysts in the **kidney** are rare and account for a small percentage of cases (around **2-5%**). - Symptoms are often nonspecific, including **flank pain** or hematuria, which are not primary concerns. *Brain* - While the **brain** can be affected, it is not a common site; CNS involvement occurs in only **1-2%** of hydatid disease cases. - Symptoms are related to increased intracranial pressure or focal neurological deficits, not typical for hydatid cysts. *Lung* - The **lung** is another site for hydatid cysts but accounts for about **10-20%** of cases. - Presentation may include **cough** and chest pain, making it less common compared to liver involvement.
Question 54: Which of the following is NOT a symptom of mild dehydration?
- A. Thirst
- B. Restlessness
- C. Dry tongue
- D. Normal BP (Correct Answer)
Explanation: ***Normal BP*** - In **mild dehydration**, the body's compensatory mechanisms, such as increased heart rate and vasoconstriction, typically manage to maintain a **normal blood pressure**. [1] - A significant drop in **blood pressure** (hypotension) is usually indicative of **moderate to severe dehydration**, where these compensatory mechanisms begin to fail. [2] *Thirst* - **Thirst** is one of the **earliest and most reliable** indicators of dehydration, as the body signals a need for fluid intake. [3] - It arises in response to increased plasma osmolality and decreased blood volume, both occurring even in **mild dehydration**. [3] *Restlessness* - **Restlessness** can be an early sign of discomfort and altered mental status associated with **mild dehydration**, particularly in infants and young children. - As the body struggles to maintain fluid balance, individuals may experience irritability and general unease. *Dry tongue* - A **dry tongue** and **dry sticky mucous membranes** are common signs of mild to moderate dehydration. - This symptom results from reduced salivary production due to decreased fluid volume in the body.
Question 55: Which of the following is NOT a characteristic feature of systemic sclerosis?
- A. Calcinosis cutis
- B. Digital ulcers
- C. Acroosteolysis
- D. Gottron's papules (Correct Answer)
Explanation: ***Gottron's papules*** - **Gottron's papules** are pathognomonic for **dermatomyositis**, not systemic sclerosis. They are red, scaling papules found over the extensor surfaces of the metacarpophalangeal (MCP) and interphalangeal (IP) joints. - While both systemic sclerosis and dermatomyositis are connective tissue diseases, their distinct cutaneous manifestations aid in differentiation. *Acroosteolysis* - **Acroosteolysis** refers to the resorption of the distal phalanges, a common feature in systemic sclerosis, particularly in severe cases. - This symptom contributes to the characteristic digital abnormalities seen in the disease. *Calcinosis cutis* - **Calcinosis cutis** is the deposition of calcium in the skin and subcutaneous tissues, often seen in subsets of systemic sclerosis, especially the CREST syndrome. - It can manifest as firm, white-yellow nodules or plaques and contribute to skin breakdown. *Digital ulcers* - **Digital ulcers** are a frequent and debilitating complication of systemic sclerosis, resulting from severe **vasculopathy** [1] and **ischemia** [1]. - They are often painful and can lead to significant tissue loss and infection.
Question 56: Subclavian steal syndrome is
- A. Reversal of blood flow in the ipsilateral vertebral artery (Correct Answer)
- B. Reversal of blood flow in the contralateral carotid artery
- C. Reversal of blood flow in the contralateral vertebral artery
- D. B/L reversal of blood flow in vertebral arteries
Explanation: ***Reversal of blood flow in the ipsilateral vertebral artery*** - Subclavian steal syndrome occurs due to a **proximal stenosis** or **occlusion of the subclavian artery**. - This causes blood to be "stolen" from the **ipsilateral vertebral artery**, flowing retrograde to supply the arm and thereby reducing blood flow to the brainstem. *Reversal of blood flow in the contralateral carotid artery* - The carotid arteries supply blood to the brain directly and are typically not directly involved in thesteal phenomenon in this specific syndrome. - Reversal of flow in the carotid artery would indicate a much more severe and different pathology, not characteristic of subclavian steal. *Reversal of blood flow in the contralateral vertebral artery* - The steal phenomenon specifically involves the vertebral artery on the **same side (ipsilateral)** as the subclavian artery obstruction. - The contralateral vertebral artery would typically continue to supply blood to the brain without a reversed flow in this syndrome. *B/L reversal of blood flow in vertebral arteries* - Subclavian steal syndrome is generally a **unilateral phenomenon**, affecting the vertebral artery ipsilateral to the subclavian artery stenosis. - Bilateral reversal would imply bilateral subclavian artery obstruction or other severe cerebrovascular disease, which is not the definition of subclavian steal syndrome itself.
Question 57: What are the key characteristics of Evans syndrome?
- A. Autoimmune hemolytic anemia and immune thrombocytopenia (Correct Answer)
- B. Low lymphocyte and red blood cell counts
- C. High platelet and lymphocyte counts
- D. A reduction in all blood cell types
Explanation: ***Autoimmune hemolytic anemia and immune thrombocytopenia*** - **Evans syndrome** is defined by the simultaneous or sequential occurrence of **autoimmune hemolytic anemia (AIHA)** and **immune thrombocytopenia (ITP)** [1], [2]. - Both conditions involve the immune system mistakenly attacking and destroying **red blood cells** and **platelets**, respectively [1], [2]. *Low lymphocyte and red blood cell counts* - While **red blood cell counts** are low in Evans syndrome due to AIHA, **lymphocyte counts** are not a defining characteristic; they can vary. - This option does not fully capture the dual autoimmune destruction of red blood cells and platelets specific to Evans syndrome. *High platelet and lymphocyte counts* - **Platelet counts** are **low** in Evans syndrome due to ITP, not high. - **Lymphocyte counts** are not characteristically high; a high count might suggest other conditions like leukemias or lymphomas. *A reduction in all blood cell types* - A reduction in all (red blood cells, white blood cells, and platelets) is known as **pancytopenia**, which is not the defining feature of Evans syndrome. - Evans syndrome specifically involves the destruction of **red blood cells** and **platelets**, but not necessarily all white blood cell types.
Question 58: A 25 year old female presents with generalized restriction of eye movement in all direction, intermittent ptosis, proximal muscle weakness and fatigability.Which is the MOST useful test in making the diagnosis?
- A. CPK
- B. Edrophonium test (Correct Answer)
- C. EMG
- D. Muscle biopsy
Explanation: ***Edrophonium test*** - The **Edrophonium test** (Tensilon test) is highly useful for diagnosing **myasthenia gravis** due to its rapid onset and short duration of action. - In a patient with suspected myasthenia gravis, such as this one presenting with **generalized restriction of eye movement**, **intermittent ptosis**, and **fatigable proximal muscle weakness**, the administration of edrophonium will lead to a temporary but significant improvement in muscle strength. It works by inhibiting the breakdown of acetylcholine, thereby increasing its availability at the neuromuscular junction [1]. *CPK* - **Creatine phosphokinase (CPK)** levels are typically normal in myasthenia gravis, as it is a disorder of the **neuromuscular junction**, not a primary muscle disease. - Elevated CPK levels usually indicate muscle damage, seen in conditions like **myositis** or **muscular dystrophies**, which are not suggested by the patient's symptoms. *EMG* - **Electromyography (EMG)**, specifically **repetitive nerve stimulation (RNS)** or **single-fiber EMG (SFEMG)**, can show characteristic decremental responses or increased jitter/blocking in myasthenia gravis [2], but it is less direct and often more invasive than the Edrophonium test for initial diagnostic confirmation. - While supportive, it is generally considered a secondary diagnostic tool after a strong clinical suspicion and is not the *most useful* initial test compared to the rapid symptomatic improvement seen with edrophonium. *Muscle biopsy* - A **muscle biopsy** is generally not useful in diagnosing myasthenia gravis as the muscle tissue itself is structurally normal. - This diagnostic tool is reserved for primary **muscle disorders** like muscular dystrophies or inflammatory myopathies, which would show characteristic histological changes.
Question 59: Which of the following is NOT a feature of Cushing's triad?
- A. Hypertension
- B. Bradycardia
- C. Irregular breathing
- D. Hypotension (Correct Answer)
Explanation: ***Hypotension*** - Cushing's triad is an indicator of **increased intracranial pressure (ICP)** and classically presents with **hypertension**, not hypotension. - Hypotension would suggest a different problem, such as **spinal shock** or **hypovolemia**, which are not directly associated with Cushing's triad. *Bradycardia* - **Bradycardia** is a key component of Cushing's triad, resulting from vagal stimulation due to increased intracranial pressure. - This reflex reduces heart rate in an attempt to maintain cerebral perfusion. *Hypertension* - **Hypertension**, specifically a widened pulse pressure, is a cardinal feature of Cushing's triad, caused by systemic vasoconstriction to overcome increased ICP and maintain **cerebral perfusion pressure**. - It is a compensatory mechanism to push blood into the brain. *Irregular breathing* - **Irregular breathing patterns**, such as Cheyne-Stokes respiration or ataxic breathing, are characteristic of Cushing's triad, indicating brainstem compression [1]. - This irregular respiratory effort is due to direct pressure on the **respiratory centers** in the medulla [1].
Question 60: Which of the following is a feature of tumor lysis syndrome?
- A. Metabolic alkalosis (a rise in blood pH)
- B. Hypokalemia (a decrease in blood potassium levels)
- C. Hypocalcemia (a decrease in blood calcium levels) (Correct Answer)
- D. Hypophosphatemia (a decrease in blood phosphate levels)
Explanation: ***Hypocalcemia (a decrease in blood calcium levels)*** - **Hypocalcemia** in tumor lysis syndrome results from the precipitation of calcium with excessive phosphate released from lysed tumor cells. - The elevated phosphate levels bind to calcium, forming **calcium phosphate crystals** that can deposit in tissues, further lowering serum calcium. *Metabolic alkalosis (a rise in blood pH)* - Tumor lysis syndrome typically leads to **metabolic acidosis**, not alkalosis, due to the release of acidic intracellular metabolites like uric acid and phosphate. - The accumulation of these acidic compounds overwhelms the body's buffering systems, decreasing blood pH. *Hypokalemia (a decrease in blood potassium levels)* - Tumor lysis syndrome is characterized by **hyperkalemia**, an increase in blood potassium, as potassium is a major intracellular cation released during cell lysis. - The rapid breakdown of numerous tumor cells dumps vast amounts of intracellular potassium into the bloodstream. *Hypophosphatemia (a decrease in blood phosphate levels)* - Tumor lysis syndrome causes **hyperphosphatemia**, an elevation in blood phosphate levels, because phosphate is abundantly present within tumor cells and is released upon their destruction. - This excessive release of intracellular phosphate is a hallmark biochemical feature of the syndrome.