NEET-PG 2015 - Internal Medicine Practice Questions

Q: Which of the following sites is responsible for the amnestic defect in Wernicke's Korsakoff syndrome:

Thalamus. ***Thalamus*** - Damage to the **medial dorsal nucleus of the thalamus** is a key pathological finding in Wernicke's Korsakoff syndrome, directly contributing to the severe **anterograde and retrograde amnesia** [1]. - The thalamus plays a crucial role in memory consolidation and retrieval, acting as a relay station for information processing between cortical and subcortical structures. *Mammillary body* - While **mammillary body damage** is characteristic of Wernicke-Korsakoff syndrome, it is primarily associated with the **acute Wernicke encephalopathy phase** and contributes to the overall amnesia through its connections with the thalamus and hippocampus, rather than being the sole site for the amnestic defect [1]. - The mammillary bodies are part of the **Papez circuit**, which is important for episodic memory, but their lesion alone doesn't fully explain the complete amnestic syndrome. *Hippocampus* - The **hippocampus** is critical for the formation of new memories, and its damage typically causes **anterograde amnesia**, as seen in conditions like temporal lobe epilepsy or anoxia. - While memory is affected, direct **hippocampal lesions are not the primary pathology** in Wernicke-Korsakoff syndrome; the memory impairment arises from damage to structures *connected* to the hippocampus, such as the thalamus and mammillary bodies. *Periventricular Grey matter* - The **periventricular grey matter** is involved in various autonomic functions and pain modulation, not directly in memory formation or retrieval. - While lesions in this area can occur in Wernicke-Korsakoff syndrome, they are not considered the primary cause of the **amnestic defect**.

Q: Which of the following is the most common initial presenting feature of multiple sclerosis:

Optic Neuritis. ***Optic Neuritis*** - **Optic neuritis** is a very common initial symptom of multiple sclerosis, occurring in 20-25% of patients. - It presents with **unilateral vision loss** (often painful), blurred vision, and a central scotoma, reflecting inflammation and demyelination of the optic nerve [1]. *Cerebellar Ataxia* - While **cerebellar ataxia** (impaired coordination, balance, speech) can occur in MS, it is less common as an initial presenting symptom. - It often develops later in the disease course due to demyelination in the **cerebellum** or its connections [1]. *Internuclear ophthalmoplegia* - **Internuclear ophthalmoplegia (INO)** is a specific eye movement disorder common in MS but rarely the very first symptom [1]. - It results from a lesion in the **medial longitudinal fasciculus (MLF)**, causing impaired adduction of one eye during conjugate gaze with nystagmus in the abducting eye. *Diplopia* - **Diplopia** (double vision) can be an early symptom of MS, but it is less frequent as the very first presentation compared to optic neuritis [1]. - It typically arises from lesions affecting the **cranial nerves** controlling eye movements (III, IV, VI) or their brainstem nuclei.

Q: What are the expected neurological manifestations in a patient with complete absence of the corpus callosum?

Severe developmental delays. ***Severe developmental delays*** - Complete agenesis of the corpus callosum often results in **significant neurological impairments** due to the disruption of interhemispheric communication essential for coordinated brain function. - This typically manifests as **intellectual disability**, **developmental delays** in motor and speech skills, and difficulties with complex cognitive tasks. *Mild cognitive impairment* - While some individuals with partial agenesis or isolated cases might present with mild cognitive issues, **complete absence** usually leads to more profound deficits. - Mild impairment would not fully capture the extensive neurological challenges associated with a total lack of such a critical brain structure. *Seizures* - Seizures can occur in patients with corpus callosum agenesis, but they are not the **most encompassing** or universally expected neurological manifestation. - Seizures are often part of a broader syndrome of developmental abnormalities rather than the primary expected outcome of the agenesis itself. *No significant neurological deficits* - The corpus callosum is vital for **integrating information** between the cerebral hemispheres, affecting a wide range of sensory, motor, and cognitive functions. - Therefore, its complete absence almost invariably leads to notable neurological deficits, making a lack of significant issues highly unlikely.

Q: What is the first symptom of Parkinson's disease?

Tremors. ***Tremors*** - A resting **tremor**, often starting unilaterally in a hand or foot, is frequently the **initial motor symptom** of Parkinson's disease [1]. - This tremor is typically **slow**, rhythmic, and may involve a "pill-rolling" motion of the fingers [1]. *Postural instability* - **Postural instability** tends to be a later symptom, emerging as the disease progresses and affecting balance and gait [2]. - It is not usually the **presenting complaint** in the early stages of Parkinson's disease [2]. *Rigidity* - **Rigidity**, characterized by increased muscle tone and resistance to passive movement, often develops after tremors or bradykinesia [1]. - It can manifest as **cogwheel** or **lead-pipe rigidity** and contributes to the stooped posture and reduced arm swing observed in Parkinson's patients [1]. *Bradykinesia* - **Bradykinesia** (slowness of movement) is a core motor symptom, often described as difficulty initiating or continuing movements [1]. - While present early, **tremors** are often the first symptom noticed by the patient or their family, making bradykinesia a close second in sequence [1].

Q: Which of the following metal ions is associated with secondary Parkinsonisms?

Manganese (Mn). ***Manganese (Mn)*** - Chronic exposure to high levels of **manganese** can lead to **manganism**, a neurological disorder characterized by **Parkinsonian-like symptoms**, including bradykinesia, rigidity, and gait disturbances [1]. - This is due to manganese accumulation in the **basal ganglia**, particularly the **globus pallidus**, affecting dopaminergic pathways. *Magnesium (Mg)* - **Magnesium** is an essential mineral vital for numerous bodily functions, including nerve and muscle function. - While imbalances can cause neurological issues (e.g., tremors with hypomagnesemia), it is not directly associated with **secondary parkinsonism**. *Selenium (Se)* - **Selenium** is a trace element with antioxidant properties, important for thyroid hormone metabolism and immune function. - Both deficiency and toxicity can cause various health problems, but it is not known to cause **secondary parkinsonism**. *Molybdenum (Mo)* - **Molybdenum** is an essential trace element that functions as a cofactor for several enzymes. - No known association exists between molybdenum exposure, deficiency, or toxicity and the development of **secondary parkinsonism**.

Q: Isaac syndrome is characterized by -

Peripheral nerve hyperexcitability. Isaac syndrome is characterized by - ***Peripheral nerve hyperexcitability*** - Isaac syndrome, also known as **neuromyotonia** or **Isaacs' syndrome**, is fundamentally characterized by symptoms arising from **peripheral nerve hyperexcitability**. [1] - This hyperexcitability leads to continuous muscle fiber activity even at rest, manifesting as **muscle stiffness, cramps, myokymia, and fasciculations**. *Opsoclonus syndrome* - This syndrome is characterized by **rapid, irregular, chaotic eye movements** (**opsoclonus**) and often associated with **myoclonus (rapid muscle jerks)** and **ataxia (impaired coordination)**. - While it can be paraneoplastic, it involves the **central nervous system**, specifically the brainstem and cerebellum, not primarily peripheral nerve hyperexcitability. *Encephalitis* - **Encephalitis** is an inflammation of the **brain parenchyma**, typically caused by viral infections. - Its clinical presentation includes fever, headache, altered mental status, and seizures, which are distinct from the primary neuromuscular symptoms of Isaac syndrome. *Limbic encephalitis syndrome* - **Limbic encephalitis** is a form of encephalitis specifically affecting the **limbic system** of the brain, leading to symptoms like **memory loss, seizures, and psychiatric disturbances**. - This condition involves **central nervous system inflammation** and does not directly cause the peripheral nerve hyperexcitability seen in Isaac syndrome.

Q: Most common acute complication of dialysis is

Hypotension. ***Hypotension*** - **Intradialytic hypotension** is the most common acute complication, occurring in 15-30% of dialysis sessions. - It is often caused by rapid removal of fluid (ultrafiltration), leading to a significant drop in blood pressure [1]. *Bleeding* - While bleeding can occur due to **anticoagulation** used during dialysis or as a complication of vascular access, it is less common than hypotension. - It is not considered the most frequent acute complication of the dialysis procedure itself. *Dementia* - **Dementia** is a chronic neurological condition that is not an acute complication directly attributable to a single dialysis session. - It can be a long-term comorbidity in patients with end-stage renal disease (ESRD), but not an immediate side effect. *Muscle cramps* - **Muscle cramps** are a relatively common acute complication during or immediately after dialysis, affecting about 5-20% of patients. - However, their frequency is generally lower than that of intradialytic hypotension [1].

Q: What is the most common cause of death in patients with advanced cancer?

Infection. ***Infection*** - **Immunosuppression** from cancer itself and its treatments (e.g., chemotherapy, radiation) significantly increases susceptibility to infections. - Many patients with advanced cancer die from **sepsis** or opportunistic infections due to their weakened immune systems [1]. *Bleeding* - While bleeding can be a significant complication in advanced cancer (e.g., from tumor erosion, thrombocytopenia), it is less common as a direct cause of death compared to infection. - Life-threatening hemorrhages are typically managed, and other factors often contribute to mortality. *Respiratory failure* - **Respiratory failure** can occur due to **lung metastases**, direct tumor invasion, or complications like pneumonia in advanced cancer patients. - However, the underlying cause of such pneumonia or decline is often infectious or a result of systemic weakness. *Renal failure* - **Renal failure** can be caused by tumor obstruction of the urinary tract, **nephrotoxic chemotherapy**, or paraneoplastic syndromes. - Although serious, it is not the most frequent immediate cause of death in the broad population of advanced cancer patients.

Q: All of the following are true about Gout, except which of the following?

Occurs more in females. ***Occurs more in females*** - **Gout** is more prevalent in **males** than in females, especially before menopause, due to hormonal differences and lifestyle factors. - After menopause, the incidence in females increases but generally remains lower than in males. *Occurs due to accumulation of urate crystals in joint* - **Gout** is precisely characterized by the **deposition of monosodium urate crystals** in joints and surrounding tissues, leading to inflammation [1], [2]. - This accumulation is a direct consequence of **hyperuricemia**, either from overproduction or underexcretion of uric acid [2], [3]. *Can be precipitated by pyrazinamide* - **Pyrazinamide** is an anti-tuberculosis drug known to **inhibit uric acid excretion** by the kidneys. - This leads to **hyperuricemia**, thereby increasing the risk of acute gout attacks. *Birefringent crystals are present in the joint* - Microscopic examination of **synovial fluid** from a gouty joint reveals **needle-shaped, negatively birefringent crystals** of monosodium urate [1], [4]. - This finding is a definitive diagnostic criterion for **gout**.

Question 1

Which of the following sites is responsible for the amnestic defect in Wernicke's Korsakoff syndrome:

Accepted Answer

Thalamus

Answer

Hippocampus

Answer

Mammillary body

Answer

Periventricular Grey matter

Question 2

Which of the following is the most common initial presenting feature of multiple sclerosis:

Accepted Answer

Optic Neuritis

Answer

Cerebellar Ataxia

Answer

Internuclear ophthalmoplegia

Answer

Diplopia

Question 3

What are the expected neurological manifestations in a patient with complete absence of the corpus callosum?

Accepted Answer

Severe developmental delays

Answer

Mild cognitive impairment

Answer

Seizures

Answer

No significant neurological deficits

Question 4

Which of the following is the MOST characteristic feature of Eaton-Lambert syndrome?

Accepted Answer

Repeated electrical stimulation enhances muscle power in it.

Answer

Neostigmine is not effective for this syndrome.

Answer

It is commonly associated with small cell lung cancer.

Answer

It can affect the ocular muscles.

Question 5

What is the first symptom of Parkinson's disease?

Accepted Answer

Tremors

Answer

Rigidity

Answer

Postural instability

Answer

Bradykinesia

Question 6

Which of the following metal ions is associated with secondary Parkinsonisms?

Accepted Answer

Manganese (Mn)

Answer

Magnesium (Mg)

Answer

Selenium (Se)

Answer

Molybdenum (Mo)

Question 7

Isaac syndrome is characterized by -

Accepted Answer

Peripheral nerve hyperexcitability

Answer

Opsoclonus syndrome

Answer

Encephalitis

Answer

Limbic encephalitis syndrome

Question 8

Most common acute complication of dialysis is

Accepted Answer

Hypotension

Answer

Bleeding

Answer

Dementia

Answer

Muscle cramps

Question 9

What is the most common cause of death in patients with advanced cancer?

Accepted Answer

Infection

Answer

Bleeding

Answer

Respiratory failure

Answer

Renal failure

Question 10

All of the following are true about Gout, except which of the following?

Accepted Answer

Occurs more in females

Answer

Can be precipitated by pyrazinamide

Answer

Birefringent crystals are present in the joint

Answer

Occurs due to accumulation of urate crystals in joint

NEET-PG 2015 — Internal Medicine