NEET-PG 2013 Practice Questions

Q: Which of the following is not commonly used for local infiltration anesthesia?

Dibucaine. ***Dibucaine*** - **Dibucaine** is a local anesthetic with a long duration of action but is rarely used for local infiltration due to its **high toxicity**. - Its narrow therapeutic index makes it less safe for common use compared to other available local anesthetics. *Lidocaine* - **Lidocaine** is one of the most widely used local anesthetics for **local infiltration** due to its rapid onset and intermediate duration of action. - It is effective for a variety of minor surgical procedures and dental interventions. *Ropivacaine* - **Ropivacaine** is an amide-type local anesthetic commonly used for **local infiltration** and regional anesthesia due to its good safety profile and differential block. - It produces less motor block and has a lower potential for cardiotoxicity compared to bupivacaine. *Bupivacaine* - **Bupivacaine** is frequently used for **local infiltration** and regional anesthesia, especially when a longer duration of action is desired. - It is known for its prolonged sensory block but has a higher risk of **cardiac toxicity** compared to lidocaine.

Q: Which drug is most commonly associated with causing fixed drug eruptions?

Sulfonamide. ***Sulfonamide*** - **Sulfonamides**, particularly **sulfamethoxazole-trimethoprim**, are frequently implicated in causing fixed drug eruptions. - A fixed drug eruption characteristically recurs at the **same cutaneous site** each time the offending drug is administered. *Aminoglycoside* - **Aminoglycosides** are broad-spectrum antibiotics known for potential **ototoxicity** and **nephrotoxicity**. - While they can cause various adverse reactions, fixed drug eruptions are **not a common association** with this drug class. *Erythromycin* - **Erythromycin** is a macrolide antibiotic primarily associated with **gastrointestinal side effects**, such as nausea and abdominal cramping. - Although drug eruptions can occur, fixed drug eruptions are **not typically linked** to erythromycin. *None of the options* - This option is incorrect because **sulfonamides** are well-documented causes of fixed drug eruptions. - Therefore, there is a specific drug class listed that is strongly associated with this condition.

Q: What is the most likely diagnosis for a 15 mm hyperpigmented lesion on the shoulder that is enlarging and has hair growing from it?

Becker nevus. ***Correct: Becker nevus*** This diagnosis is supported by the description of a **hyperpigmented lesion** that is **enlarging** and has **hair growing from it**, typically appearing during adolescence or young adulthood. **Becker nevus** often presents as an **irregular, hyperpigmented patch**, usually on the shoulder or upper trunk, and is characteristically associated with **hypertrichosis** (increased terminal hair growth). The combination of location (shoulder), enlargement, and hair growth in a 15 mm lesion is classic for Becker nevus. *Incorrect: Melanocytic nevus* While **melanocytic nevi** are hyperpigmented, they typically do not continue to **enlarge significantly** after childhood and generally do not develop new onset **hypertrichosis** as a primary feature. The size (15 mm) and progressive growth combined with hair development are more characteristic of a Becker nevus than a common melanocytic nevus. *Incorrect: Sebaceous nevus* **Sebaceous nevi** are typically **yellow-orange to tan, waxy plaques**, often on the scalp or face, with a cobblestone or papillomatous texture. They are not primarily characterized by **hyperpigmentation** and terminal hair growth, but rather by sebaceous gland proliferation. *Incorrect: Comedo nevus* A **comedo nevus** presents as a linear or unilateral group of **dilated follicular openings** filled with keratinous material, resembling blackheads. It is not characterized by diffuse **hyperpigmentation** or the increased terminal hair growth described in this case.

Q: A young sexually active female presents with intense pruritus and watery discharge. What is the most likely causative organism?

Trichomonas vaginalis. ***Trichomonas vaginalis*** - **Trichomoniasis** commonly presents with **intense vulvovaginal pruritus**, a **frothy, greenish-yellow discharge**, and sometimes a **strawberry cervix**. - It is a **sexually transmitted infection (STI)** caused by a flagellated protozoan. *Candida vaginitis* - Typically causes severe **pruritus**, **dysuria**, and a **thick, white, curd-like discharge**, often without the watery characteristic. - Known as a **yeast infection**, it is caused by an overgrowth of *Candida* species. *Gardnerella vaginalis* - Associated with **bacterial vaginosis**, which presents with a **thin, grayish-white discharge** and a **fishy odor**, especially after intercourse, but usually less intense pruritus. - It's characterized by an imbalance of vaginal flora rather than being a true STI in the same sense as trichomoniasis. *Chlamydia trachomatis* - Often causes **asymptomatic infections** or symptoms such as **mucopurulent discharge**, **dysuria**, or **post-coital bleeding**, but usually **not intense pruritus** or watery discharge. - It is a **bacterial STI** known for causing cervicitis and pelvic inflammatory disease.

Q: What is the age range associated with the concrete operational stage in Piaget's theory of cognitive development?

7-11 years. ***7-11 years*** - This age range aligns with Piaget's **concrete operational stage**, during which children develop **logical thinking** about concrete events. - They begin to understand **conservation**, classification, and seriation. *2-6 years* - This range corresponds to the **preoperational stage**, characterized by **egocentrism** and reliance on intuition rather than logical reasoning. - Children in this stage have not yet mastered the concept of conservation. *5-10 years* - While it partially overlaps, this range is not the precise and commonly accepted period for the **concrete operational stage** in Piaget's theory. - The upper limit of 10 years excludes the latter portion of this cognitive stage. *10-15 years* - This age range predominantly represents the **formal operational stage**, where adolescents develop the ability for **abstract thought**, hypothetical reasoning, and systematic problem-solving. - This thinking is more advanced than the concrete operations.

Q: What is the investigation of choice for whole body imaging in metastatic breast cancer?

CT Scan. ***CT Scan (Correct answer for NEET 2013)*** - **Contrast-enhanced CT scan** was the standard imaging modality for **whole-body staging** in metastatic breast cancer at the time of this exam (2013). - CT offers **excellent spatial resolution** for detecting metastases in **bone, lung, liver, and lymph nodes**. - It is widely available, relatively quick, and provides comprehensive anatomical information. - **Modern Update:** While CT was the standard in 2013, **PET-CT (FDG-PET/CT) is now considered the gold standard** for whole-body staging in metastatic breast cancer due to its combined metabolic and anatomical imaging capabilities. However, PET-CT was not among the options in this historical question. *Magnetic Resonance Imaging* - **MRI** is highly sensitive for specific sites, particularly for **brain metastases** and **bone metastases (especially spine and bone marrow)**. - **Whole-body MRI** protocols are emerging but require longer acquisition times and specialized equipment. - Not ideal as a single first-line modality for comprehensive whole-body staging compared to CT (or modern PET-CT). *Angiography* - **Angiography** is an invasive vascular imaging procedure used to visualize **arterial blood flow**. - It has **no role in routine metastatic screening or staging** of breast cancer. - Reserved for specific indications like preoperative vascular mapping or interventional procedures. *Venography* - **Venography** specifically visualizes **venous structures** and is used to detect venous thrombosis or venous obstructions. - It is **not applicable** for detecting solid organ metastases, bone lesions, or lymph node involvement in cancer staging.

Q: On imaging, diffuse axonal injury is characterized by -

Multiple small petechial hemorrhages. ***Multiple small petechial hemorrhages*** - Diffuse axonal injury (DAI) is characterized on imaging by numerous **small petechial hemorrhages** at the **gray-white matter junction**, **corpus callosum**, and **brainstem**. - These microhemorrhages are the **hallmark imaging finding** and are best visualized on MRI (GRE/SWI sequences), though they can be seen on CT as small hyperdensities. - This is the **most specific** and characteristic finding that defines DAI. *Patchy ill-defined low density lesion mixed with small hyperdensities of petechial hemorrhage* - While this description can be seen in DAI (combining edema with microhemorrhages), it is **less specific** and could represent other entities. - This mixed pattern is more commonly associated with **contusions** where there is more prominent parenchymal injury with larger areas of edema and hemorrhage. - DAI classically shows predominantly **small punctate hemorrhages** rather than larger patchy low-density lesions. *Crescentic extra-axial hematoma* - A crescentic extra-axial collection describes a **subdural hematoma**, which is an entirely separate entity from DAI. - Subdural hematomas are located between the dura and arachnoid membranes, whereas DAI involves direct **axonal shearing injury** within brain parenchyma. *White matter lucencies* - This is a **non-specific finding** that can occur in many conditions including ischemia, demyelination, and chronic small vessel disease. - While DAI can cause white matter edema leading to lucencies, this does not capture the **characteristic petechial hemorrhages** that define the condition on imaging.

Q: What is the CT scan finding in a carotid cavernous sinus fistula?

Enlarged superior ophthalmic vein. ***Enlarged superior ophthalmic vein*** * A carotid cavernous sinus fistula (CCSF) causes **high-pressure arterial blood** to shunt into the **venous system** of the cavernous sinus. * This increased pressure leads to retrograde flow and congestion in the draining veins, most notably the **superior ophthalmic vein**, causing its dilation. *Enlarged inferior ophthalmic vein* * While the inferior ophthalmic vein can also be involved in some cases of CCSF, the **superior ophthalmic vein** is typically more prominent and consistently affected due to its primary drainage pathway. * The inferior ophthalmic vein is less frequently the primary or most notable imaging finding compared to the superior ophthalmic vein. *Enlarged superior ophthalmic artery* * A CCSF involves an abnormal connection between the **carotid artery** (an artery) and the **cavernous sinus** (a venous structure), leading to venous, not arterial, dilation. * Arteries in the orbital region, like the superior ophthalmic artery, would not typically enlarge as a direct result of increased venous pressure in the cavernous sinus. *Enlarged inferior ophthalmic artery* * Similar to the superior ophthalmic artery, the inferior ophthalmic artery is an **arterial structure** and would not enlarge due to a high-flow arteriovenous shunt within the cavernous sinus. * The pathological changes in CCSF are primarily observed in the **venous drainage pathways**.

Q: What is the echogenic lesion size criterion for chronic pancreatitis?

> 3 mm. ***> 3 mm*** - An echogenic lesion **greater than 3 mm** in size is a diagnostic criterion for **chronic pancreatitis** when observed on ultrasound imaging. - This represents one of the **major features** in ultrasound diagnosis of chronic pancreatitis, particularly when echogenic foci demonstrate acoustic shadowing (suggesting calcifications). - This criterion is part of established diagnostic frameworks and helps differentiate pathological calcifications from minor, non-specific findings. *> 4 mm* - While a **4 mm threshold** would indicate significant findings, the established diagnostic criterion for chronic pancreatitis uses **> 3 mm** as the cutoff. - Using a higher threshold would reduce sensitivity for detecting chronic pancreatitis. *> 2 mm* - A lesion larger than **2 mm** is generally considered below the established diagnostic threshold for **chronic pancreatitis**. - This size may represent early changes or incidental findings that are not yet definitive for diagnosis. *> 1 mm* - A lesion **greater than 1 mm** is too small to be a definitive criterion for **chronic pancreatitis** and could represent minor, non-pathological findings. - Such small echogenic foci lack sufficient specificity for diagnosing chronic pancreatic disease.

Q: Investigation with least radiation dose in the diagnosis of Meckel's diverticulum is -

Technetium -99m scanning. ***Technetium-99m scanning*** - **Technetium-99m pertechnetate scan** (Meckel's scan) is the **gold standard investigation** for diagnosing Meckel's diverticulum with ectopic gastric mucosa - Among the investigations that can actually **diagnose Meckel's diverticulum**, it has the **lowest radiation dose** (approximately 1-2 mSv) - The radioisotope is specifically taken up by ectopic gastric mucosa, providing both diagnostic utility and relatively low radiation exposure - **Sensitivity: 85-95%** for detecting ectopic gastric mucosa in Meckel's diverticulum - The radiation dose is comparable to a few months of natural background radiation and significantly lower than CT or contrast studies *MRI* - While **MRI uses no ionizing radiation**, it is **not a standard or practical investigation** for diagnosing Meckel's diverticulum - MRI cannot identify ectopic gastric mucosa specifically - It is rarely used in clinical practice for this indication - The question asks about investigation "in the diagnosis" of Meckel's diverticulum, implying a test that is actually used diagnostically *CT* - **Computed Tomography (CT)** delivers a **high radiation dose** (typically 5-10 mSv or more) - While it can identify structural abnormalities, it is not specific for Meckel's diverticulum - Not the first-line investigation for this condition *Contrast radiography* - **Contrast studies** (barium studies) use **moderate ionizing radiation** (3-5 mSv) - Limited utility in diagnosing Meckel's diverticulum as it primarily assesses luminal patency - Cannot identify ectopic gastric mucosa - Lower sensitivity compared to Tc-99m scanning

Question 1

Which of the following is not commonly used for local infiltration anesthesia?

Accepted Answer

Dibucaine

Answer

Lidocaine

Answer

Ropivacaine

Answer

Bupivacaine

Question 2

Which drug is most commonly associated with causing fixed drug eruptions?

Accepted Answer

Sulfonamide

Answer

Aminoglycoside

Answer

Erythromycin

Answer

None of the options

Question 3

What is the most likely diagnosis for a 15 mm hyperpigmented lesion on the shoulder that is enlarging and has hair growing from it?

Accepted Answer

Becker nevus

Answer

Melanocytic nevus

Answer

Sebaceous nevus

Answer

Comedo nevus

Question 4

A young sexually active female presents with intense pruritus and watery discharge. What is the most likely causative organism?

Accepted Answer

Trichomonas vaginalis

Answer

Chlamydia trachomatis

Answer

Candida albicans

Answer

Gardnerella vaginalis

Question 5

What is the age range associated with the concrete operational stage in Piaget's theory of cognitive development?

Accepted Answer

7-11 years

Answer

2-6 years

Answer

5-10 years

Answer

10-15 years

Question 6

What is the investigation of choice for whole body imaging in metastatic breast cancer?

Accepted Answer

CT Scan

Answer

Angiography

Answer

Venography

Answer

Magnetic Resonance Imaging

Question 7

On imaging, diffuse axonal injury is characterized by -

Accepted Answer

Multiple small petechial hemorrhages

Answer

Patchy ill-defined low density lesion mixed with small hyperdensities of petechial hemorrhage

Answer

Crescentic extra-axial hematoma

Answer

White matter lucencies

Question 8

What is the CT scan finding in a carotid cavernous sinus fistula?

Accepted Answer

Enlarged superior ophthalmic vein

Answer

Enlarged inferior ophthalmic vein

Answer

Enlarged superior ophthalmic artery

Answer

Enlarged inferior ophthalmic artery

Question 9

What is the echogenic lesion size criterion for chronic pancreatitis?

Accepted Answer

> 3 mm

Answer

> 2 mm

Answer

> 1 mm

Answer

> 4 mm

Question 10

Investigation with least radiation dose in the diagnosis of Meckel's diverticulum is -

Accepted Answer

Technetium -99m scanning

Answer

MRI

Answer

CT

Answer

Contrast radiography

NEET-PG 2013

Dental

Dermatology

Microbiology

Psychiatry

Radiology