NEET-PG 2012 - Internal Medicine Practice Questions

Q: What is the most common cause of ophthalmoplegia in adults?

Cranial nerve palsy. ***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.

Q: Which visual disturbance is commonly associated with Vitamin B12 deficiency?

Centrocaecal scotoma. 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**.

Q: Ataxia, nystagmus, and ophthalmoplegia are seen in which of the following conditions?

Wernicke encephalopathy. ***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.

Q: Meningitis with rash is seen in -

Neisseria meningitidis. **Neisseria meningitidis** - **Meningococcal meningitis** is classically associated with an acute onset of fever, headache, stiff neck, and a characteristic **petechial or purpuric rash** [1]. - The rash is due to widespread **vasculitis** and disseminated intravascular coagulation (DIC) caused by the bacteria. *H. influenzae* - While *H. influenzae* type b (Hib) was a major cause of bacterial meningitis before vaccination, it typically does not cause a *rash*. - Meningitis caused by *H. influenzae* presents with fever, headache, stiff neck, and altered mental status without dermatological manifestations. *Strepto. agalactiae* - *Streptococcus agalactiae* (Group B Strep) is a common cause of meningitis in **neonates** and infants. - It usually presents with non-specific symptoms like fever, lethargy, and poor feeding, and a rash is not a typical feature of GBS meningitis. *Pneumococcus* - *Streptococcus pneumoniae* (Pneumococcus) is another leading cause of bacterial meningitis in adults and children [1]. - Symptoms include fever, headache, stiff neck, and altered mental status, but a cutaneous rash is not characteristic of pneumococcal meningitis [1].

Q: In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Ascending aorta. ***Ascending aorta*** - The **ascending aorta** is the most common site for aortic aneurysm and dissection in Marfan syndrome due to cystic medial degeneration weakening the vessel wall [1]. - This predisposition is linked to defects in the **fibrillin-1 gene (FBN1)**, severely impacting the structural integrity of the arterial media primarily in the ascending aorta [1]. *Descending aorta* - While possible, **descending aortic** involvement is less common than ascending aortic involvement in Marfan syndrome [2]. - Aneurysms here are more frequently associated with atherosclerosis or other connective tissue disorders. *Abdominal aorta* - **Abdominal aortic aneurysms** are relatively rare in Marfan syndrome and are more typically seen in older patients with atherosclerosis [3]. - The disease primarily affects the elastic tissue content, which is most abundant in the proximal aorta. *Arch of aorta* - Aortic arch aneurysms can occur, but they are still less frequent than those in the **ascending aorta** as the primary initial site of dilation and dissection in Marfan syndrome. - Arch involvement often represents an extension of a more proximal ascending aortic pathology.

Q: Which of the following is a characteristic of Wilson's disease?

Increased copper in liver. ***Increased copper in liver*** - Wilson's disease is characterized by **accumulation of copper** in liver tissues due to defective copper transport [1]. - This excess leads to **hepatocellular damage**, resulting in liver dysfunction and potential cirrhosis [1]. *Decreased copper excretion in urine* - In Wilson's disease, there is actually **decreased excretion of copper**, which results in accumulation in the liver [1]. - **Urine copper levels** are typically low to normal in early stages because the liver fails to excrete excess copper effectively. *Autosomal dominant* - Wilson's disease is inherited in an **autosomal recessive** pattern, not dominant. - It is caused by mutations in the gene responsible for copper transport (ATP7B) [1]. *Increased serum ceruloplasmin* - Serum ceruloplasmin levels are often **decreased** in Wilson's disease due to impaired copper incorporation into this protein [1]. - Low ceruloplasmin is a key laboratory finding, contrasting the assertion of this option.

Q: In which condition is paradoxical splitting of the second heart sound observed?

Left Bundle Branch Block (LBBB). ***Left Bundle Branch Block (LBBB)*** - In LBBB, the **left ventricle** depolarizes and contracts *after* the right ventricle, causing the **aortic valve (A2)** to close *after* the **pulmonic valve (P2)** [1]. - During inspiration, right ventricular ejection time is prolonged, which further delays P2. However, in LBBB, A2 is already delayed, and the inspiratory delay of P2 can bring P2 closer to A2, or even cause them to merge, making the splitting *less wide* or *disappear* on inspiration, which is paradoxical. *Right Bundle Branch Block (RBBB)* - RBBB causes a **delay in right ventricular depolarization**, leading to a **delayed P2** (pulmonic valve closure). - This typically results in **wide and fixed splitting of S2**, where the splitting persists during expiration and widens further with inspiration, which is not paradoxical. *Ventricular Septal Defect (VSD)* - A VSD can cause a **loud holosystolic murmur** and may lead to increased pulmonary blood flow. - While it can affect the timing of heart sounds, it does not typically cause paradoxical splitting of S2. *Atrial Septal Defect (ASD)* - An ASD causes a **left-to-right shunt**, leading to chronic volume overload of the right ventricle and increased pulmonary blood flow. - This often results in a **widely fixed splitting of S2**, where the split between A2 and P2 is constant regardless of respiration, which is different from paradoxical splitting.

Q: Which of the following is a characteristic feature of Crohn's disease?

Sinus & fistula. ***Sinus & fistula*** - **Transmural inflammation**, a hallmark of Crohn's disease, can extend through the bowel wall, leading to the formation of **sinus tracts** and **fistulae** (abnormal connections between organs or to the skin). [1] - These complications include enteroenteric, enterovesical, and perianal fistulae, which are highly characteristic of Crohn's. [1] *Continuous involvement* - Crohn's disease is characterized by **skip lesions**, meaning there are healthy segments of bowel interspersed with diseased segments, not continuous involvement. [1] - **Ulcerative colitis** typically presents with continuous inflammation, starting from the rectum and extending proximally. [1] *Mesenteric lymphadenitis* - While mesenteric lymph nodes can be involved in Crohn's disease due to inflammation, **mesenteric lymphadenitis** is more commonly associated with infectious etiologies or other inflammatory conditions, and not a primary defining characteristic. - It refers to inflammation of lymph nodes in the mesentery, which can cause abdominal pain but does not specifically differentiate Crohn's from other conditions. *Crypt abscesses* - **Crypt abscesses** are a characteristic histological feature of **ulcerative colitis**, where neutrophils infiltrate the glandular crypts. [1] - While they can occasionally be seen in Crohn's, they are much more common and prominent in ulcerative colitis and are not a defining feature of Crohn's.

Q: Migraine is due to

Cortical spreading depression. ***Cortical spreading depression*** - The current understanding is that **cortical spreading depression (CSD)** is the initiating event in migraine with aura, characterized by a wave of neuronal and glial depolarization that spreads across the cerebral cortex, leading to a temporary shutdown of neuronal activity [1]. - CSD is thought to activate the **trigeminal nerve**, subsequently causing the release of inflammatory neuropeptides and contributing to the pain phase [1]. *Dilatation of cranial blood vessels* - While **vasodilation of intracranial and extracranial blood vessels** does occur during the headache phase of migraine, it is now considered a *consequence* of the initial neurological events rather than the primary cause [1]. - This vasodilation contributes to the throbbing sensation of migraine pain but does not explain the aura or the initiation of the attack. *Constriction of cranial blood vessels* - **Vasoconstriction** was previously thought to be the cause of the migraine aura, but this theory has largely been disproven. - While some temporary constriction may precede CSD, it is not the primary mechanism behind the migraine attack. *Inflammation of the meninges* - While **neurogenic inflammation** of the meninges, involving the release of inflammatory mediators like **calcitonin gene-related peptide (CGRP)**, does play a role in sensitizing the trigeminal system and contributing to migraine pain, it is a downstream effect. - It is not the initial trigger for a migraine attack but rather part of the pain pathway activated by events like CSD.

Question 1

What is the most common cause of ophthalmoplegia in adults?

Accepted Answer

Cranial nerve palsy

Answer

Myasthenia gravis

Answer

Diabetes mellitus

Answer

Trauma

Question 2

Which visual disturbance is commonly associated with Vitamin B12 deficiency?

Accepted Answer

Centrocaecal scotoma

Answer

Binasal hemianopia

Answer

Constriction of peripheral vision

Answer

Bitemporal hemianopia

Question 3

Ataxia, nystagmus, and ophthalmoplegia are seen in which of the following conditions?

Accepted Answer

Wernicke encephalopathy

Answer

3rd nerve palsy

Answer

Myasthenia gravis

Answer

Chronic progressive external ophthalmoplegia

Question 4

Meningitis with rash is seen in -

Accepted Answer

Neisseria meningitidis

Answer

H. influenzae

Answer

Strepto. agalactae

Answer

Pneumococcus

Question 5

In Marfan's syndrome, Aortic aneurysm occurs most commonly in:

Accepted Answer

Ascending aorta

Answer

Descending aorta

Answer

Abdominal aorta

Answer

Arch of aorta

Question 6

What is a feature of short bowel syndrome?

Accepted Answer

Malabsorption leading to diarrhea, dehydration, and malnutrition.

Answer

Hypergastrinemia & high gastric secretion is seen

Answer

Diarrhea, dehydration and malnutrition

Answer

Chronic TPN dependence

Question 7

Which of the following is a characteristic of Wilson's disease?

Accepted Answer

Increased copper in liver

Answer

Autosomal dominant

Answer

Increased serum ceruloplasmin

Answer

Decreased copper excretion in urine

Question 8

In which condition is paradoxical splitting of the second heart sound observed?

Accepted Answer

Left Bundle Branch Block (LBBB)

Answer

Right Bundle Branch Block (RBBB)

Answer

Ventricular Septal Defect (VSD)

Answer

Atrial Septal Defect (ASD)

Question 9

Which of the following is a characteristic feature of Crohn's disease?

Accepted Answer

Sinus & fistula

Answer

Mesenteric lymphadenitis

Answer

Continuous involvement

Answer

Crypt abscesses

Question 10

Migraine is due to

Accepted Answer

Cortical spreading depression

Answer

Dilatation of cranial blood vessels

Answer

Constriction of cranial blood vessels

Answer

Inflammation of the meninges

NEET-PG 2012 — Internal Medicine