Among the following, most reliable test for screening of diabetes mellitus?
Tabes dorsalis is seen in -
What condition is caused by the intake of exogenous steroids?
HIV post exposure prophylaxis should be started within?
What is the most common cause of ophthalmoplegia in adults?
A 45-year-old patient presents with progressive dyspnea, orthopnea, and bilateral pedal edema. On examination, there is elevated JVP, S3 gallop, and hepatomegaly. What is the most likely underlying pathophysiology?
Madarosis is seen in ?
Ataxia, nystagmus, and ophthalmoplegia are seen in which of the following conditions?
What is the primary electrolyte found in Oral Rehydration Salts (ORS) at a concentration of 75 mEq/L?
Which visual disturbance is commonly associated with Vitamin B12 deficiency?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 31: Among the following, most reliable test for screening of diabetes mellitus?
- A. Urine sugar
- B. Random sugar
- C. Fasting sugar (Correct Answer)
- D. Glucose tolerance test
Explanation: ***Fasting sugar*** - A **fasting plasma glucose** (FPG) test is the most common and reliable initial test for screening for **diabetes mellitus** because it measures blood glucose after an overnight fast (typically 8-12 hours), providing a baseline level unaffected by recent food intake [1]. - A fasting glucose level of **≥ 126 mg/dL** (7.0 mmol/L) on two separate occasions is diagnostic of diabetes, making it an excellent screening tool for identifying individuals with impaired glucose metabolism [1]. *Random sugar* - A random plasma glucose test can be used to diagnose diabetes if the level is **≥ 200 mg/dL** (11.1 mmol/L) in a symptomatic individual, but it is less reliable for screening asymptomatic individuals due to its variability depending on recent food intake [1]. - Because it can be measured at any time of day without regard to the last meal, it has a **lower sensitivity** for detecting early stages of diabetes compared to fasting glucose. *Glucose tolerance test* - An **oral glucose tolerance test** (OGTT) is highly sensitive and specific for diagnosing diabetes and impaired glucose tolerance, but it is more cumbersome and time-consuming, involving multiple blood draws over two hours after consuming a sugary drink. - While it is a definitive diagnostic test, its complexity makes it **less practical for routine screening** in large populations compared to simpler tests like fasting plasma glucose. *Urine sugar* - The presence of glucose in urine (glycosuria) indicates that blood glucose levels have exceeded the **renal threshold** (typically around 180 mg/dL), meaning the kidneys are unable to reabsorb all the glucose. - This is a **less sensitive and specific** method for screening, as it only becomes positive once blood glucose is significantly elevated, and it does not detect milder forms of impaired glucose metabolism or early diabetes.
Question 32: Tabes dorsalis is seen in -
- A. Tertiary syphilis (Correct Answer)
- B. Primary syphilis
- C. Latent syphilis
- D. Secondary syphilis
Explanation: ***Tertiary syphilis*** - **Tabes dorsalis** is a neurological manifestation of **tertiary syphilis**, characterized by demyelination and degeneration of the posterior columns of the spinal cord [1]. - This leads to symptoms such as **ataxia**, **loss of proprioception**, **lightning pains**, and **Argyll-Robertson pupils**. *Primary syphilis* - Characterized by the presence of a **chancre**, a painless ulcer, at the site of infection [1]. - This stage typically occurs 3-90 days after exposure and is not associated with neurological complications of tabes dorsalis. *Latent syphilis* - This is a period during which there are **no clinical signs or symptoms** of syphilis, although the infection persists. - It can be early or late, but it is not the stage where overt neurological complications like tabes dorsalis arise [1]. *Secondary syphilis* - This stage typically presents with a **generalized mucocutaneous rash**, **lymphadenopathy**, and **condylomata lata** [1]. - While it can involve various organ systems, it does not typically include the severe neurological degeneration seen in tabes dorsalis.
Question 33: What condition is caused by the intake of exogenous steroids?
- A. Addison's disease
- B. Cushing's syndrome (Correct Answer)
- C. Pheochromocytoma
- D. Conn's syndrome
Explanation: ***Cushing's syndrome*** - **Exogenous steroid intake** is the most common cause of Cushing's syndrome, leading to symptoms associated with **excess cortisol** [1]. - This occurs because the steroids mimic the effects of **cortisol**, suppressing the body's natural production and leading to its characteristic signs and symptoms [2]. *Addison's disease* - This condition is characterized by **adrenal insufficiency**, meaning the adrenal glands produce too little **cortisol** and often **aldosterone**. - It is typically caused by autoimmune destruction of the adrenal glands, not by exogenous steroid intake. *Pheochromocytoma* - This is a rare tumor of the **adrenal medulla** that causes the overproduction of **catecholamines** (epinephrine and norepinephrine). - Symptoms include sudden, severe episodes of hypertension, palpitations, and sweating, unrelated to steroid intake. *Conn's syndrome* - Also known as **primary hyperaldosteronism**, this condition involves the overproduction of **aldosterone** by the adrenal glands. - It typically results in hypertension and hypokalemia and is not directly caused by exogenous steroid administration.
Question 34: HIV post exposure prophylaxis should be started within?
- A. 1-2 hrs
- B. 14 hrs
- C. 18 hrs
- D. 72 hrs (Correct Answer)
Explanation: ***72 hrs*** - **Post-exposure prophylaxis (PEP)** aims to prevent HIV infection after potential exposure and should ideally be initiated as soon as possible, but no later than **72 hours** after exposure [1]. - Starting PEP within this window significantly increases its effectiveness in preventing HIV seroconversion. *1-2 hrs* - While initiating PEP as soon as possible is crucial, stating it must be within **1-2 hours** can be misleading as the window of effectiveness extends beyond this. - This timeframe might be an ideal, but not the absolute crucial limit for efficacy. *14 hrs* - This timeframe is **too restrictive** for the recommended window for PEP initiation. - Missing the opportunity within **14 hours** does not negate the effectiveness of PEP if started within the broader 72-hour window. *18 hrs* - Similar to **14 hours**, **18 hours** is an unnecessarily strict limit for PEP initiation. - Guidelines universally support starting PEP up to **72 hours** post-exposure for optimal benefit [1].
Question 35: What is the most common cause of ophthalmoplegia in adults?
- A. Cranial nerve palsy (Correct Answer)
- B. Myasthenia gravis
- C. Diabetes mellitus
- D. Trauma
Explanation: ***Cranial nerve palsy*** - **Cranial nerve palsies**, particularly those affecting cranial nerves III, IV, or VI, are the most frequent causes of isolated ophthalmoplegia in adults [1]. - They can result from various etiologies like **ischemia**, **compression**, or **inflammation**, directly impairing the nerves responsible for eye movement [1]. *Myasthenia gravis* - While it frequently causes **ocular symptoms** (ptosis and diplopia), it typically presents with **fluctuating weakness** that worsens with sustained effort [1]. - It's a neuromuscular junction disorder, not a primary cranial nerve issue, and often affects other muscle groups beyond the eyes. *Diabetes mellitus* - **Diabetic ophthalmoplegia** is a specific type of cranial nerve palsy (often CN III or VI) caused by microvascular ischemia. - While common in diabetics, it is a *cause* of cranial nerve palsy, not the overarching most common cause of ophthalmoplegia itself. *Trauma* - **Trauma** can certainly cause ophthalmoplegia, often due to direct damage to **extraocular muscles**, **orbital fractures**, or **cranial nerve injury**. - However, in the general adult population, non-traumatic cranial nerve palsies are more frequently encountered as the cause of ophthalmoplegia.
Question 36: A 45-year-old patient presents with progressive dyspnea, orthopnea, and bilateral pedal edema. On examination, there is elevated JVP, S3 gallop, and hepatomegaly. What is the most likely underlying pathophysiology?
- A. DALEY
- B. HALE (Correct Answer)
- C. OALY
- D. None of the options
Explanation: ***HALE*** - This acronym stands for **Heart-failure Associated Lung Edema**. The symptoms of **progressive dyspnea**, **orthopnea**, **bilateral pedal edema**, **elevated JVP**, **S3 gallop**, and **hepatomegaly** are classic signs of **congestive heart failure** leading to fluid overload and pulmonary congestion [1]. - The pathophysiology involves the heart's inability to pump blood effectively, causing a buildup of pressure in the pulmonary and systemic circulations, leading to the observed symptoms [1]. *DALEY* - This is not a recognized acronym in medical pathophysiology. The symptoms presented are strongly indicative of a specific cardiovascular condition. - There is no clinical scenario where "DALEY" would accurately describe the underlying pathophysiology of dyspnea, edema, and heart failure signs. *OALY* - This is not a recognized acronym in medical pathophysiology. The presented clinical picture requires a well-established and specific pathophysiological explanation. - Using an unrecognized term would not provide an accurate or helpful description of the patient's condition. *None of the options* - The acronym HALE (Heart-failure Associated Lung Edema) accurately captures the core pathophysiology evident from the patient's symptoms and signs. - Given the strong clinical presentation of congestive heart failure with pulmonary and systemic congestion, one of the provided options *does* accurately describe the situation.
Question 37: Madarosis is seen in ?
- A. None of the options
- B. Addison's disease
- C. Acromegaly
- D. Hypothyroidism (Correct Answer)
Explanation: ***Hypothyroidism*** - **Madarosis**, specifically the loss of the **outer third of the eyebrows**, is a classic sign of **hypothyroidism** due to decreased thyroid hormone levels affecting hair follicle growth [1]. - Other common symptoms include **fatigue**, **weight gain**, **cold intolerance**, and **dry skin**. *Addison's disease* - This condition involves **adrenal insufficiency**, primarily causing symptoms like **hyperpigmentation**, low blood pressure, and fatigue. - **Hair loss** is generally not a prominent feature, and madarosis is not typically seen. *Acromegaly* - Characterized by excessive **growth hormone** production, leading to enlargement of hands, feet, and facial features. - While it can cause some changes in hair texture, **madarosis** is not a common clinical manifestation. *None of the options* - This option is incorrect because **Hypothyroidism** is a direct cause of madarosis due to its impact on **hair follicle metabolism** [1]. - The other conditions listed do not typically present with this specific type of eyebrow hair loss.
Question 38: Ataxia, nystagmus, and ophthalmoplegia are seen in which of the following conditions?
- A. 3rd nerve palsy
- B. Wernicke encephalopathy (Correct Answer)
- C. Myasthenia gravis
- D. Chronic progressive external ophthalmoplegia
Explanation: ***Wernicke encephalopathy*** - This condition is characterized by the classic triad of **ataxia**, **nystagmus**, and **ophthalmoplegia** (often presenting as external ophthalmoplegia), alongside confusion [2]. - It results from a **thiamine (vitamin B1) deficiency** [2], [3], commonly seen in chronic alcoholics or individuals with severe malnutrition. *Myasthenia gravis* - This is an **autoimmune disorder** affecting the neuromuscular junction, leading to fluctuating muscle weakness that worsens with activity [1]. - While it can cause **ophthalmoplegia** (especially ptosis and diplopia), it does not typically present with ataxia or nystagmus. *3rd nerve palsy* - A **third nerve palsy** specifically affects the oculomotor nerve, causing a constellation of symptoms including ptosis, pupillary dilation, and inability to move the eye up, down, or medially. - While it causes **ophthalmoplegia** affecting one eye, it does not typically cause nystagmus or ataxia. *Chronic progressive external ophthalmoplegia* - This is a mitochondrial disorder characterized by **slowly progressive weakness** of the extraocular muscles, leading to bilateral ptosis and limitation of eye movements. - It causes a specific type of **ophthalmoplegia** but is not typically associated with nystagmus or prominent ataxia.
Question 39: What is the primary electrolyte found in Oral Rehydration Salts (ORS) at a concentration of 75 mEq/L?
- A. Sodium (Correct Answer)
- B. Potassium
- C. Glucose
- D. Chloride
Explanation: ***Sodium*** - The primary electrolyte in **Oral Rehydration Salts (ORS)** is **sodium**, which is crucial for replacing losses due to diarrhea and facilitating water absorption in the intestines [1]. - The standard ORS formulation, recommended by the WHO, contains **75 mEq/L of sodium** to effectively rehydrate individuals with acute watery diarrhea [1]. *Potassium* - While **potassium** is an essential electrolyte found in ORS, its concentration is typically lower than sodium, usually around **20 mEq/L**. - Potassium helps replenish intracellular losses and supports normal cellular function, but it is not the primary electrolyte at the 75 mEq/L concentration. *Glucose* - **Glucose** is a crucial component of ORS, but it is a sugar, not an electrolyte. - Its role is to facilitate the co-transport of **sodium and water** across the intestinal wall, enhancing fluid absorption, but it does not contribute to the electrolyte concentration in mEq/L [1]. *Chloride* - **Chloride** is an electrolyte present in ORS, primarily to balance the charge of **sodium** and prevent hyynatremia. - Its concentration is typically around **65 mEq/L**, making it slightly less concentrated than sodium but still vital for maintaining electrolyte balance.
Question 40: Which visual disturbance is commonly associated with Vitamin B12 deficiency?
- A. Centrocaecal scotoma (Correct Answer)
- B. Binasal hemianopia
- C. Constriction of peripheral vision
- D. Bitemporal hemianopia
Explanation: No relevant citations could be added to the original explanation because the provided references did not specifically address the association between Vitamin B12 deficiency and centrocaecal scotoma. ***Centrocaecal scotoma*** - **Vitamin B12 deficiency** can lead to optic neuropathy, which often manifests as a **centrocaecal scotoma**, affecting central and paracentral vision. - This visual impairment is due to **demyelination of the optic nerve fibers** caused by the deficiency. *Binasal hemianopia* - This type of visual field defect is rare and typically caused by lesions that compress the uncrossed retinal nerve fibers, such as **bilateral internal carotid artery aneurysms** or **bilateral optic nerve disease**. - It does not directly correlate with **Vitamin B12 deficiency**. *Constriction of peripheral vision* - **Peripheral vision loss** is associated with conditions like **glaucoma** or advanced **retinitis pigmentosa**. - It is not a characteristic visual disturbance of **Vitamin B12 deficiency**. *Bitemporal hemianopia* - This visual field defect is commonly caused by compression of the **optic chiasm**, most often due to a **pituitary adenoma**. - It results in loss of vision in the outer half of both visual fields and is not linked to **Vitamin B12 deficiency**.