Investigation of choice in pheochromocytoma is:
Which of the following is a characteristic of Yellow-nail syndrome?
Which of the following medications is not typically used in the treatment of malignant malaria?
What is the most common complication of a large Patent Ductus Arteriosus (PDA)?
Tuberculosis of the spine; what is the most common site affected?
Oculoorogenital ulcers are associated with which of the following conditions?
Which of the following conditions is most commonly associated with resorption of the distal phalanx?
Which of the following statements about lepromatous leprosy is true?
In an EMG/NCV study, which radiculopathy is most closely associated with the H. reflex?
Hereditary angioneurotic edema is due to?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 51: Investigation of choice in pheochromocytoma is:
- A. CT scan
- B. Urinary catecholamines (Correct Answer)
- C. MIBG scan
- D. MRI Scan
Explanation: ***Urinary catecholamines*** - Measurement of **24-hour urinary fractionated metanephrines and catecholamines** is the initial **biochemical test of choice**. - These biochemical tests are preferred over plasma levels due to the **episodic release** of hormones from a pheochromocytoma, which can lead to high false-negative rates in single plasma measurements. *CT scan* - While a **CT scan** is a crucial **imaging modality** for localizing a pheochromocytoma once the biochemical diagnosis is established [1], it is not the *initial* diagnostic investigation. - Imaging should be performed only after **biochemical confirmation** to avoid unnecessary investigations of incidental adrenal masses [1]. *MIBG scan* - An **MIBG scan** (metaiodobenzylguanidine scan) is a **functional imaging study** used primarily for **localizing metastatic pheochromocytomas** [1] or for cases where CT/MRI is equivocal. - It is not the initial investigation but rather a **secondary imaging test** [1]. *MRI Scan* - **MRI** is an alternative **imaging modality** to CT for localizing pheochromocytomas [1], especially in pregnant women or when radiation exposure is a concern. - Like CT, it serves as a **localization tool** after biochemical confirmation, not the diagnostic test itself.
Question 52: Which of the following is a characteristic of Yellow-nail syndrome?
- A. Knee joint effusion and lymphedema, associated with discolored nails
- B. Pericardial effusion and lymphedema, associated with discolored nails
- C. Pleural effusion and lymphedema, associated with discolored nails (Correct Answer)
- D. Peritoneal effusion and lymphedema, associated with discolored nails
Explanation: ***Pleural effusion and lymphedema, associated with discolored nails*** - Yellow-nail syndrome is characterized by the triad of **yellow, thickened, slow-growing nails**, **lymphedema**, and **pleural effusions**. - **Pleural effusions** are the most common respiratory manifestation, often chronic and recurrent. *Knee joint effusion and lymphedema, associated with discolored nails* - While **lymphedema** is a feature of Yellow-nail syndrome, **knee joint effusion** is not a primary or defining characteristic of the syndrome. - Joint effusions can occur in various conditions, but Yellow-nail syndrome is specifically associated with serous effusions in cavities like the pleura. *Pericardial effusion and lymphedema, associated with discolored nails* - **Pericardial effusion** is a rare manifestation of Yellow-nail syndrome, not a defining characteristic. - The classic triad includes **pleural effusions**, not pericardial. *Per peritoneal effusion and lymphedema, associated with discolored nails* - **Peritoneal effusion** (ascites) is another rare manifestation of Yellow-nail syndrome, not typically included in its core diagnostic criteria. - The syndrome is predominantly associated with effusions in the **pleural space**.
Question 53: Which of the following medications is not typically used in the treatment of malignant malaria?
- A. Doxycycline
- B. Artesunate
- C. Quinine
- D. Quinolone (Correct Answer)
Explanation: ***Quinolone*** - **Quinolone** antibiotics, while broad-spectrum, are not typically used as primary antimalarial agents due to limited efficacy against *Plasmodium falciparum* and potential for resistance. - Their use in malaria treatment is generally restricted to specific co-infections rather than direct antimalarial efficacy. *Quinine* - **Quinine** has been a cornerstone of severe malaria treatment for many years, especially in regions with limited access to newer artemisinin derivatives. - It works by interfering with the parasite's ability to detoxify heme, thus killing the parasites. *Doxycycline* - **Doxycycline** is an effective antimalarial, particularly as a prophylactic agent and in combination therapy for uncomplicated malaria or as an alternative for severe malaria when other agents are contraindicated. - It inhibits **protein synthesis** in the parasite. *Artesunate* - **Artesunate** is the recommended first-line treatment for severe malaria due to its rapid action and potent parasiticidal effects. - It is an **artemisinin derivative** that produces free radicals toxic to the parasite.
Question 54: What is the most common complication of a large Patent Ductus Arteriosus (PDA)?
- A. Eisenmenger syndrome
- B. Congestive Heart Failure (CHF) (Correct Answer)
- C. Infective endocarditis
- D. None of the options
Explanation: ***Congestive Heart Failure (CHF)*** - A large PDA results in a significant **left-to-right shunt**, increasing pulmonary blood flow and leading to **pulmonary overcirculation**. [1] - This increased workload on the heart, particularly the left atrium and ventricle, can lead to **ventricular dysfunction** and ultimately CHF. [1] *Eisenmenger syndrome* - While a severe complication of an untreated large PDA, it represents a **late stage** where the left-to-right shunt has reversed due to **pulmonary hypertension**. [1] - It is not the *most common* initial complication, as CHF often develops earlier in the disease progression. *Infective endocarditis* - This is a potential long-term complication of a PDA, especially if untreated, due to the **turbulent blood flow** across the ductus. - However, it is less common than CHF, which results directly from the hemodynamic burden imposed by a large shunt. *None of the options* - This option is incorrect because **Congestive Heart Failure** is indeed a very common and significant complication of a large Patent Ductus Arteriosus.
Question 55: Tuberculosis of the spine; what is the most common site affected?
- A. Sacral
- B. Dorsolumbar (Correct Answer)
- C. Lumbosacral
- D. Cervical
Explanation: ***94ed055d-c7da-4d18-a2fd-52720dfe8b6e*** - The **dorsolumbar (thoracolumbar)** region is the most common site of **spinal tuberculosis (Pott's disease)** [1] due to its high vascularity, facilitating hematogenous spread. - **Spinal tuberculosis** typically affects the vertebral bodies, leading to their destruction, kyphosis (angular deformity), and potentially neurological deficits [1]. *aebdfe6c-98dc-4073-892f-bb24d047bab4* - The **sacral** region can be affected by **tuberculosis**, but it is considerably less common than the thoracolumbar region. - Involvement of the sacrum is often associated with **direct extension** from adjacent structures, such as the sacroiliac joint, rather than primary vertebral involvement. *15c1feef-e3ca-496f-a180-127d52b77bfa* - **Cervical spine tuberculosis** is relatively rare, accounting for a small percentage of all spinal tuberculosis cases. - While possible, it presents with specific challenges due to the proximity of vital neurological and vascular structures. *d05d4d13-bb83-4f26-aa2d-c9c0203d299c* - The **lumbosacral region** (L5-S1) can be involved in **tuberculosis**, but it is less frequently affected than the thoracolumbar region. - While the lumbar spine is a common site, the entire lumbosacral region as a single entity is not the most common spot for spinal TB.
Question 56: Oculoorogenital ulcers are associated with which of the following conditions?
- A. Lichen planus
- B. Behcet's disease (Correct Answer)
- C. Systemic lupus erythematosus (SLE)
- D. Psoriasis
Explanation: ***Behcet's disease*** - This condition is characterized by **recurrent oral and genital ulcers**, along with **ocular inflammation** (e.g., uveitis), perfectly matching the "Oculoorogenital ulcers" description. - It is a **chronic, relapsing inflammatory disease** of unknown etiology involving vasculitis affecting various organ systems. *Lichen planus* - This is a chronic inflammatory condition affecting the **skin, hair, nails, and mucous membranes**. - While it can cause oral lesions, it typically presents as **purple, polygonal, pruritic papules** on the skin and does not cause genital ulcers or significant ocular involvement like Behcet's. *Systemic lupus erythematosus (SLE)* - SLE is a **systemic autoimmune disease** with diverse manifestations, including skin rashes, arthritis, and internal organ involvement. - Oral ulcers can occur, but **genital ulcers and severe ocular inflammation** as a prominent triad are not typical diagnostic features of SLE. *Psoriasis* - This is a common **chronic inflammatory skin disease** characterized by well-demarcated erythematous plaques with silvery scales. - Psoriasis primarily affects the skin and joints, and **does not typically present with oral, genital, or ocular ulcers** as described.
Question 57: Which of the following conditions is most commonly associated with resorption of the distal phalanx?
- A. Scleroderma (Correct Answer)
- B. Hyperparathyroidism
- C. Reiter's syndrome
- D. Osteitis deformans (Paget's disease)
Explanation: ***Scleroderma*** - **Scleroderma** (systemic sclerosis) can cause characteristic changes in the distal phalanges, specifically **acro-osteolysis**, leading to resorption of the **distal tufts** [1]. - This is often associated with **Raynaud's phenomenon**, **digital ischemia**, and **calcinosis**, leading to severe circulatory compromise in the digits [1]. *Hyperparathyroidism* - **Primary hyperparathyroidism** causes bone resorption due to increased parathyroid hormone, primarily affecting the **subperiosteal bone** (especially in the radial aspect of the middle phalanges), leading to a "lace-like" appearance on X-ray. - While it causes bone resorption, **distal phalanx tuft resorption** is not its most common or prominent skeletal feature compared to scleroderma. *Reiter's syndrome* - **Reiter's syndrome** (now known as reactive arthritis) is an inflammatory arthropathy usually involving large joints of the lower extremities in an **asymmetric** pattern. - It does not typically cause **resorption of the distal phalanx**; instead, it's associated with enthesitis, dactylitis, and periostitis. *Osteitis deformans (Paget's disease)* - **Paget's disease** is characterized by abnormal bone remodeling, leading to enlarged, deformed bones that are prone to fracture, predominantly affecting the **pelvis, spine, skull, and long bones**. - It causes areas of localized bone destruction and excessive bone formation, but **distal phalanx resorption** is not a feature of this condition.
Question 58: Which of the following statements about lepromatous leprosy is true?
- A. Thickened peripheral nerves are a common feature.
- B. Erythema nodosum leprosum occurs in less than 50% of cases.
- C. The lepromin test is usually negative or weakly positive.
- D. Lepromatous leprosy typically presents with multiple cutaneous lesions. (Correct Answer)
Explanation: ***Lepromatous leprosy typically presents with multiple cutaneous lesions.*** - Lepromatous leprosy is characterized by **widespread skin involvement**, often manifesting as numerous, symmetrically distributed nodules, plaques, and macules [1]. - The high bacterial load in lepromatous leprosy leads to extensive skin infiltration due to the host's ineffective cellular immune response. *Thickened peripheral nerves are a common feature.* - While nerve thickening can occur in lepromatous leprosy, it is a **more prominent and early feature** of **tuberculoid leprosy** due to a more robust granulomatous inflammatory response within the nerve [2]. - In lepromatous leprosy, nerve damage is often more diffuse and less demarcated, leading to **insidious nerve loss** rather than clearly palpable thickening. *Erythema nodosum leprosum occurs in less than 50% of cases.* - **Erythema nodosum leprosum (ENL)** is a common type 2 leprosy reaction associated with lepromatous leprosy, estimated to occur in **approximately 30-50% of untreated patients** [1]. - It results from an immune complex deposition and is triggered by changes in bacillary load or drug therapy, and it is observed within the stated percentage range. *The lepromin test is usually negative or weakly positive.* - The lepromin test assesses **cell-mediated immunity** to *Mycobacterium leprae* antigens. - In lepromatous leprosy patients, there is a **deficient cell-mediated immune response**, making the lepromin test typically **negative**, indicating anergy.
Question 59: In an EMG/NCV study, which radiculopathy is most closely associated with the H. reflex?
- A. S1 radiculopathy (Correct Answer)
- B. L3 radiculopathy
- C. L4 radiculopathy
- D. L5 radiculopathy
Explanation: ***S1 radiculopathy*** - The **H-reflex (Hoffmann reflex)** primarily assesses the integrity of the **S1 nerve root** and the **tibial nerve** pathway. - A diminished or absent H-reflex is a sensitive indicator of **S1 radiculopathy**, often correlating with **Achilles reflex loss** [1]. *L3 radiculopathy* - **L3 radiculopathy** typically affects the **quadriceps muscle** and the **patellar reflex** [1]. - The H-reflex is not a primary diagnostic tool for isolated L3 nerve root involvement. *L4 radiculopathy* - **L4 radiculopathy** usually presents with weakness in **tibialis anterior** and altered sensation over the medial leg/foot [1]. - While it can sometimes impact the patellar reflex, the H-reflex is not the most direct or specific measure for L4 involvement. *L5 radiculopathy* - **L5 radiculopathy** often leads to weakness in **foot dorsiflexion** and **toe extension**, with sensory loss over the dorsum of the foot [1]. - It does not directly involve the reflex arc assessed by the H-reflex.
Question 60: Hereditary angioneurotic edema is due to?
- A. Deficiency of C1 inhibitor (Correct Answer)
- B. Deficiency of NADPH oxidase
- C. Deficiency of MPO
- D. Deficiency of properdin
Explanation: ***Deficiency of C1 inhibitor*** - **Hereditary angioedema (HAE)** is caused by a genetic deficiency or dysfunction of the **C1 esterase inhibitor (C1-INH)** protein. - C1-INH normally regulates the **complement system**, kinin system (mediating **bradykinin** release), and coagulation pathways, and its deficiency leads to uncontrolled activation and excessive bradykinin production, causing angioedema. *Deficiency of NADPH oxidase* - A deficiency in **NADPH oxidase** is associated with **Chronic Granulomatous Disease (CGD)**, a primary immunodeficiency characterized by recurrent bacterial and fungal infections due to impaired phagocytic oxidative burst. - It does not cause angioedema, which involves fluid extravasation rather than impaired microbial killing. *Deficiency of MPO* - **Myeloperoxidase (MPO) deficiency** typically leads to mild to moderate impairment in the killing of certain microorganisms by phagocytes but is often asymptomatic or causes only recurrent candidal infections. - It is not linked to the pathogenesis of angioedema, which involves dysregulation of vasoactive peptides. *Deficiency of properdin* - A deficiency in **properdin** affects the **alternative pathway of the complement system**, increasing susceptibility to **Neisseria infections**. - While properdin is part of the complement system, its deficiency does not directly lead to the uncontrolled production of bradykinin, which is the primary mediator in angioedema due to C1-INH deficiency.