Internal Medicine
6 questionsWhat is the primary cause of Waterhouse-Friderichsen 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?
Subclavian steal syndrome is
Isolated painful third nerve palsy is a feature of aneurysms of:
In Wilson's disease, copper deposition primarily occurs in which part of the brain?
Genitourinary complication of ulcerative colitis
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 801: What is the primary cause of Waterhouse-Friderichsen syndrome?
- A. Adrenal hemorrhage post malignancy
- B. Adrenal hemorrhage after meningococcal infection (Correct Answer)
- C. Adrenal hemorrhage after corticosteroid withdrawal
- D. Congenital adrenal deficiency
Explanation: ***Adrenal hemorrhage after meningococcal infection*** - **Waterhouse-Friderichsen syndrome** is characterized by **massive, bilateral adrenal hemorrhage**, leading to acute adrenal insufficiency [1]. - It is most commonly associated with overwhelming **meningococcal sepsis**, particularly due to *Neisseria meningitidis* [1]. *Adrenal hemorrhage post malignancy* - While malignancies can cause adrenal hemorrhage, it is not the primary cause of **Waterhouse-Friderichsen syndrome**. - This syndrome is specifically linked to severe **bacterial sepsis**, not typically cancer-related adrenal bleeding [1]. *Congenital adrenal deficiency* - **Congenital adrenal hyperplasia (CAH)** involves genetic defects affecting cortisol synthesis, leading to chronic adrenal insufficiency. - It does not involve acute **adrenal hemorrhage** as seen in Waterhouse-Friderichsen syndrome. *Adrenal hemorrhage after corticosteroid withdrawal* - Abrupt withdrawal of corticosteroids can precipitate an **adrenal crisis** due to suppression of the hypothalamic-pituitary-adrenal (HPA) axis [2]. - However, it does not typically cause the characteristic **massive adrenal hemorrhage** seen in Waterhouse-Friderichsen syndrome [2].
Question 802: 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 803: 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 804: Isolated painful third nerve palsy is a feature of aneurysms of:
- A. Aneurysm of the posterior communicating artery (Correct Answer)
- B. Aneurysm of the anterior communicating artery
- C. Aneurysm of the vertebrobasillary artery
- D. Aneurysm of the ophthalmic artery
Explanation: ***Aneurysm of the posterior communicating artery*** - An aneurysm of the **posterior communicating artery (PCOM)** can compress the ipsilateral **oculomotor nerve (CN III)** as it exits the brainstem. - This compression typically affects the **superficial parasympathetic fibers** first, leading to a **dilated pupil** (mydriasis) along with ophthalmoplegia and ptosis, making the third nerve palsy "painful" and "isolated" without other focal neurological deficits. *Aneurysm of the anterior communicating artery* - Aneurysms of the **anterior communicating artery (ACoM)** are more commonly associated with **subarachnoid hemorrhage** and can cause **visual field defects** or **frontal lobe dysfunction**, but generally not isolated CN III palsy. - While rupture can lead to various neurological deficits, isolated painful third nerve palsy due to ACoM aneurysm is atypical. *Aneurysm of the vertebrobasillary artery* - Aneurysms in the **vertebrobasillar system** typically present with symptoms related to **brainstem compression** or ischemia, such as cranial nerve palsies beyond the third nerve, ataxia, or motor/sensory deficits. - Isolated third nerve palsy is an uncommon presentation for vertebrobasilar aneurysms compared to PCOM aneurysms. *Aneurysm of the ophthalmic artery* - **Ophthalmic artery aneurysms** are usually **intraorbital** and can cause **visual loss** due to direct compression of the **optic nerve (CN II)** or orbital structures. - They are less likely to cause isolated painful third nerve palsy, as the third nerve's course is generally not directly compromised by ophthalmic artery aneurysms.
Question 805: In Wilson's disease, copper deposition primarily occurs in which part of the brain?
- A. Basal ganglia (Correct Answer)
- B. Cerebellum
- C. Pons
- D. Medulla
Explanation: ***Basal ganglia*** - The **basal ganglia**, particularly the **putamen** and **globus pallidus**, are the most common sites for copper deposition in the brain in Wilson's disease [1]. - This deposition leads to **neurological symptoms** such as dystonia [2], tremor, and dysarthria. *Pons* - While copper can accumulate in various brain regions, the **pons** is not a primary or characteristic site of significant copper deposition. - Neurological symptoms associated with pontine damage are not typical presenting features of Wilson's disease. *Cerebellum* - The **cerebellum** can show some copper accumulation in advanced stages, but it is not the primary site. - Cerebellar signs like **ataxia** can occur in Wilson's disease, but usually secondary to more widespread pathology rather than primary cerebellar copper deposition. *Medulla* - The **medulla oblongata** is generally spared from significant copper deposition in Wilson's disease. - Involvement of the medulla would typically manifest with severe autonomic or brainstem dysfunction, which is not a hallmark of early Wilson's disease.
Question 806: Genitourinary complication of ulcerative colitis
- A. Urinary calculi (Correct Answer)
- B. Pyelonephritis
- C. Urethritis
- D. Cystitis
Explanation: ***Urinary calculi*** - Patients with ulcerative colitis are at an increased risk of developing **urinary calculi** due to several factors, including chronic dehydration, malabsorption of fats leading to increased oxalate absorption (enteric hyperoxaluria), and altered urine composition. - The inflammatory process and potential for surgical interventions (e.g., colectomy with ileostomy) can further predispose individuals to kidney stone formation. *Cystitis* - While cystitis (bladder inflammation) can occur in the general population, it is not considered a specific or significantly elevated genitourinary complication directly linked to the pathogenesis of ulcerative colitis itself. - It results primarily from bacterial infection, and there is no direct evidence suggesting UC patients have a higher intrinsic risk compared to the general population. *Pyelonephritis* - Pyelonephritis (kidney infection) is not a direct or common complication of ulcerative colitis. - It is typically caused by bacterial ascent from the lower urinary tract and is not specifically promoted by the inflammatory processes or metabolic changes associated with UC. *Urethritis* - Urethritis (inflammation of the urethra) is primarily associated with sexually transmitted infections or irritation and is not a recognized genitourinary complication directly caused by ulcerative colitis. - There is no increased incidence of urethritis in UC patients compared to the general population.
Pathology
1 questionsWhat is a watershed infarct in the brain?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 801: What is a watershed infarct in the brain?
- A. Occurs in the border zones between major arteries (Correct Answer)
- B. Occurs in the areas supplied by only one artery
- C. Occurs in the terminal portion of main arteries
- D. Occurs only in areas with complete arterial occlusion
Explanation: ***Occurs in the border zones between major arteries*** - A **watershed infarct** or **border zone infarct** arises in areas where the **perfusion** from two different arterial territories meets [1]. - These areas are particularly vulnerable to ischemia during periods of **systemic hypoperfusion**, as blood flow is lowest at the "watershed" of these overlapping supply zones [1]. *Occurs in the areas supplied by only one artery* - Infarcts in areas supplied by only one artery are typically seen in **lacunar strokes**, affecting **deep penetrating arteries** and not necessarily watershed areas [2]. - These are often due to occlusion of a single, small perforating artery, leading to a **discrete, localized lesion**. *Occurs only in areas with complete arterial occlusion* - Watershed infarcts result from **systemic hypoperfusion** rather than complete arterial occlusion [1]. - They occur when global reduction in cerebral blood flow affects the **most vulnerable border zones**, even without complete vessel occlusion. - Complete arterial occlusions typically cause **territorial infarcts** in the distribution of that specific artery. *Occurs in the terminal portion of main arteries* - Infarcts in the terminal portions of main arteries are more consistent with **embolic or thrombotic events** directly occluding that specific artery. - A watershed infarct is distinct as it results from a **global reduction in cerebral blood flow**, affecting the *most distal* and *least well-perfused regions*. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 150-151. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1266-1268.
Radiology
1 questionsHose pipe appearance of intestine is a feature of
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 801: Hose pipe appearance of intestine is a feature of
- A. Malabsorption syndrome
- B. Ulcerative colitis (Correct Answer)
- C. Crohn's disease
- D. Hirschsprung disease
Explanation: ***Crohns disease*** - The **hose pipe appearance** of the intestine on imaging is due to **transmural inflammation** and **strictures**, characteristic of Crohn's disease [1]. - This feature indicates a **narrowed lumen** due to fibrosis, often affecting the small intestine or colon [1]. *Malabsorption syndrome* - This condition is primarily associated with **nutrient absorption issues**, not structural changes in the intestine. - It typically presents with **diarrhea**, **weight loss**, and **malnutrition**, lacking the characteristic imaging findings. *Ulcerative colitis* - Usually presents with **continuous lesions** confined to the colonic mucosa, leading to ulcers and inflammation but not a **hose pipe appearance**. - Symptoms include **bloody diarrhea** and **abdominal pain**, distinctly different from Crohn's disease. *Hirsprung disease* - A congenital condition causing **intestinal obstruction** due to the absence of ganglion cells, leading to **dilated proximal bowel** rather than a hose pipe appearance. - Typically presents in infants with **severe constipation** and **abdominal distension**, unrelated to imaging features seen in Crohn's disease. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 366-367.
Surgery
2 questionsMost common site for anal fissure is
A 55-year-old male presents with a history of dysphagia with vomiting of undigested food throughout the day, weight loss, and appears emaciated and dehydrated. No mass is palpable per abdomen. After appropriate diagnostic workup reveals a benign esophageal stricture, the most appropriate definitive management is:
NEET-PG 2013 - Surgery NEET-PG Practice Questions and MCQs
Question 801: Most common site for anal fissure is
- A. 3 O'clock
- B. 6 O'clock (Correct Answer)
- C. 2 O'clock
- D. 10 O'clock
Explanation: ***6 O'clock*** - The **posterior midline (6 o'clock position)** is the most common site for anal fissures, accounting for approximately **90% of all cases**. - This location is prone to tearing due to relatively **poor blood supply** and increased **mechanical stress** during defecation. - The posterior midline is the least supported part of the anal canal by the external anal sphincter. - **Note**: The **anterior midline (12 o'clock position)** is the second most common site, occurring in **10-25% of women** but rarely in men. *3 O'clock* - The **3 o'clock position (right lateral)** is an infrequent site for anal fissures. - Fissures in this location, especially if *lateral*, may suggest an underlying systemic disease such as **Crohn's disease**, **tuberculosis**, **HIV**, or **malignancy**. - Atypical fissures warrant thorough investigation. *2 O'clock* - The **2 o'clock position (anterior-lateral)** is not typically associated with anal fissures. - Similar to other atypical sites, a fissure here warrants investigation for secondary causes. - Consider inflammatory bowel disease or other pathological conditions. *10 O'clock* - The **10 o'clock position (left lateral)** is also a less common site for anal fissures compared to the posterior midline. - Fissures in lateral positions should raise suspicion for other conditions, such as **inflammatory bowel disease**, **tuberculosis**, **HIV**, or **malignancy**.
Question 802: A 55-year-old male presents with a history of dysphagia with vomiting of undigested food throughout the day, weight loss, and appears emaciated and dehydrated. No mass is palpable per abdomen. After appropriate diagnostic workup reveals a benign esophageal stricture, the most appropriate definitive management is:
- A. IV normal saline
- B. pH monitoring
- C. IV total parenteral nutrition
- D. Endoscopic dilation (Correct Answer)
Explanation: ***Endoscopic dilation (preferred treatment)*** - **Endoscopic dilation** directly addresses the underlying problem of the **benign esophageal stricture** by widening the narrowed esophagus, which is crucial for relieving dysphagia and improving nutritional intake. - Given the patient's severe symptoms like **weight loss**, **emaciation**, and **dehydration**, dilation allows for symptom relief and subsequent rehydration and nutritional support. *IV total parenteral nutrition* - While TPN provides nutrition, it does not resolve the **mechanical obstruction** caused by the stricture and carries risks such as infection and metabolic complications. - It's typically reserved for situations where enteral feeding is not possible or adequate after addressing the obstruction. *IV normal saline* - **IV normal saline** would help address the immediate **dehydration**, but it does not treat the underlying cause of the patient's symptoms (the esophageal stricture). - This is a supportive measure, not the primary management strategy for the stricture itself. *pH monitoring* - **pH monitoring** is used to diagnose and assess gastroesophageal reflux disease (**GERD**), which can sometimes cause strictures. - However, in a patient with a confirmed benign esophageal stricture and severe obstructive symptoms, addressing the stricture mechanically (dilation) takes precedence over diagnostic testing for reflux.