Which visual disturbance is commonly associated with Vitamin B12 deficiency?
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)?
In axillary nerve paralysis, which of the following statements is false?
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 statements about lepromatous leprosy is true?
In an EMG/NCV study, which radiculopathy is most closely associated with the H. reflex?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 41: 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**.
Question 42: 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 43: 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 44: 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 45: 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 46: In axillary nerve paralysis, which of the following statements is false?
- A. Extension of shoulder with arm abducted to 90 degrees is impossible (Correct Answer)
- B. Deltoid muscle is wasted
- C. Small area of numbness is present over the shoulder region
- D. Patient cannot initiate abduction
Explanation: Extension of shoulder with arm abducted to 90 degrees is impossible - The **axillary nerve** primarily innervates the **deltoid** and **teres minor muscles**. [2] - While axillary nerve paralysis would affect abduction and external rotation, the ability to *extend* the shoulder from an abducted position is mainly a function of muscles like the **posterior deltoid** (also innervated by axillary nerve to varying degrees) and latissimus dorsi, and its impossibility is not a definitive and exclusive sign of axillary nerve paralysis, as other muscles contribute to extension. *Deltoid muscle is wasted* - The **deltoid muscle** is the principal muscle supplied by the **axillary nerve**. [2] - Paralysis leads to **denervation atrophy**, causing visible wasting and weakness of the deltoid. [1] *Small area of numbness is present over the shoulder region* - The **axillary nerve** gives rise to the **upper lateral cutaneous nerve of the arm**. - Damage to the nerve results in sensory loss in a small, circumscribed area over the **deltoid insertion**. [2] *Patient cannot initiate abduction* - The **deltoid muscle**, innervated by the **axillary nerve**, is the primary abductor of the arm after the initial 0-15 degrees (supraspinatus). [2] - Paralysis of the deltoid significantly impairs or prevents the initiation and execution of **shoulder abduction**.
Question 47: 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 48: 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 49: 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 50: 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.