NEET-PG 2015 Practice Questions

Q: Which of the following is the only clinically available depolarizing muscle relaxant?

Suxamethonium. ***Suxamethonium*** - **Suxamethonium** (also known as succinylcholine) is currently the **only depolarizing neuromuscular blocker** available for clinical use. - It works by mimicking acetylcholine, binding to and activating nicotinic acetylcholine receptors at the **neuromuscular junction**, causing initial muscle fasciculations followed by relaxation. *Decamethonium* - **Decamethonium** is a depolarizing neuromuscular blocker but is **no longer clinically available** due to its prolonged action and side effects. - It also acts by opening nicotinic acetylcholine receptor channels, leading to depolarization and muscle paralysis. *Mivacurium* - **Mivacurium** is a **nondepolarizing neuromuscular blocker**, meaning it acts as a competitive antagonist at the acetylcholine receptor. - It is known for its **short duration of action** due to rapid hydrolysis by plasma cholinesterases but is not depolarizing. *None of the options* - This option is incorrect because suxamethonium is indeed a clinically available depolarizing muscle relaxant. - The question specifically asks for the *only* clinically available one, which suxamethonium fulfills.

Q: Which drug is not considered a mood stabilizer?

Imipramine. ***Imipramine*** - Imipramine is a **tricyclic antidepressant (TCA)**, primarily used to treat depression, not to stabilize mood in bipolar disorder. - TCAs can sometimes induce **mania** or hypomania in individuals with bipolar disorder, thus they are generally not used as monotherapy for mood stabilization. *Lithium* - **Lithium** is considered the gold standard and one of the oldest and most effective **mood stabilizers** for bipolar disorder. - It works by modulating **neurotransmitter systems** and second messenger pathways in the brain. *Lamotrigine* - **Lamotrigine** is an **anticonvulsant** medication that is also recognized as an effective **mood stabilizer**, particularly for preventing depressive episodes in bipolar disorder. - Its mechanism involves stabilizing neuronal membranes by blocking **voltage-gated sodium channels**. *Carbamazepine* - **Carbamazepine** is an **anticonvulsant** medication often used as a **mood stabilizer** for the treatment of acute manic and mixed episodes in bipolar disorder. - It works by reducing the excitability of nerve impulses through blocking **voltage-sensitive sodium channels**.

Q: What is the most common cause of delirium?

Infection. ***Infection*** - **Infections**, particularly urinary tract infections (UTIs) or pneumonia, are a very common and often reversible cause of **delirium**, especially in elderly or immunocompromised patients [1]. - The systemic inflammatory response to infection can lead to neuroinflammation and direct effects on brain function, manifesting as acute changes in attention and cognition. *Liver failure* - While **liver failure** can cause **hepatic encephalopathy**, which presents with altered mental status, it typically has a more gradual onset and a different neurochemical profile than acute delirium caused by infection. - Hepatic encephalopathy is characterized by abnormal ammonia metabolism and often includes motor signs like **asterixis**, which are not universally present in delirium from infection. *Belladonna poisoning* - **Belladonna poisoning** (due to **anticholinergic toxicity**) can cause **delirium**, along with a constellation of symptoms like dilated pupils, dry mouth, and tachycardia. - However, it is a specific toxicological cause and not as broad or commonly encountered as infection as a general cause of new-onset delirium in hospitalized or elderly populations. *None of the options* - This option is incorrect because **infection** is indeed a very common and recognized cause of delirium [1].

Q: Increased dopamine levels are associated with which of the following conditions?

Schizophrenia. ***Schizophrenia*** - The **dopamine hypothesis of schizophrenia** is the most well-established association with increased dopamine levels, particularly in the **mesolimbic pathway**, which contributes to positive symptoms such as **hallucinations** and **delusions**. - Antipsychotic medications, which are **dopamine D2 receptor antagonists**, effectively reduce these positive symptoms by blocking dopamine activity. - This is the **classic and primary answer** when considering increased dopamine levels in psychiatry. *Depression* - Depression is primarily associated with **decreased levels of monoamines**, including **serotonin**, **norepinephrine**, and **dopamine**. - Treatments for depression often aim to increase these neurotransmitter levels, not related to dopamine excess. *Mania* - Mania, a hallmark of **bipolar disorder**, is associated with **increased dopamine activity** along with elevated **norepinephrine** and **serotonin** levels. - While mania does involve dopamine elevation, **schizophrenia** remains the **primary and most established** condition associated with the dopamine hypothesis in psychiatric literature. - The distinction is that schizophrenia's pathophysiology is more centrally and specifically linked to dopamine dysregulation. *Delirium* - Delirium is a state of **acute brain failure** characterized by a fluctuating course and disturbances in attention and cognition. - While neurotransmitter imbalances, including dopamine, **acetylcholine deficiency**, and GABA alterations, can contribute to delirium, it is not primarily defined by increased dopamine as the main pathophysiological mechanism.

Q: What does the term 'jamais vu' refer to?

The feeling of strangeness in a familiar situation. ***The feeling of strangeness in a familiar situation*** - **Jamais vu** describes the opposite of déjà vu; it is the experience of encountering something familiar—a person, place, or word—but feeling that it is **unfamiliar or strange**. - This phenomenon can sometimes be a symptom associated with certain neurological conditions like **temporal lobe epilepsy**. *A thought that feels familiar but is actually new* - This describes a sensation closer to **cryptomnesia** or a "false familiarity," where a new idea is mistakenly believed to be an original thought. - Jamais vu specifically relates to the **perception of external reality** or recognition of known entities, not the familiarity of internal thoughts. *A situation that feels familiar but is actually new* - This is the definition of **déjà vu**, not jamais vu. Déjà vu involves experiencing a new event or situation as if it has happened before. - **Déjà vu** translates to "already seen," directly contrasting with the "never seen" sensation of jamais vu. *An illusion where one feels they have heard something before* - This is a specific type of **déjà vu** known as **déjà entendu** ("already heard"). - Jamais vu involves the *loss of familiarity* with something known, rather than the *false familiarity* with something new.

Q: On CT scan, gastric volvulus typically shows which of the following findings?

Enlarged twisted stomach. ***Enlarged twisted stomach*** - In gastric volvulus, the stomach **twists on its mesentery**, leading to outflow obstruction and subsequent **gastric distension** or enlargement. - CT scans typically show a **dilated stomach** that appears abnormally oriented or twisted, often with a characteristic **"whirl sign"** of the gastric outlet. *Normal twisted stomach* - A normal-sized stomach that is twisted is unlikely to cause the significant obstruction and symptoms associated with gastric volvulus. - The definition of volvulus implies a degree of internal organ torsion that would typically lead to **obstruction** and changes in organ size. *Shortened twisted stomach* - Gastric volvulus does not cause the stomach to shorten; rather, it leads to **distension** due to obstruction of gastric emptying. - Shortening of the stomach is not a characteristic feature of gastric volvulus. *None of the options* - This option is incorrect because the finding of an **enlarged twisted stomach** is a hallmark of gastric volvulus on imaging. - CT scans play a crucial role in identifying the **degree of distension** and the characteristic twisting pattern in this condition.

Q: Epidural hematoma on CT scan shows which of the following?

Biconvex hyperdense lesion. ***Biconvex hyperdense lesion*** - An epidural hematoma is characterized by a **biconvex** (lens-shaped) collection of blood between the dura mater and the skull. - Since it is an acute hemorrhage, the blood appears **hyperdense** (bright white) on a CT scan. *Crescent-shaped hyperdense lesion* - A **crescent shape** is characteristic of an **acute subdural hematoma**, not an epidural hematoma. - While acute subdural hematomas are also hyperdense, their crescent shape (following the contour of the brain) distinguishes them from the biconvex epidural hematomas. - Epidural hematomas are limited by suture lines and appear lens-shaped, while subdural hematomas can cross suture lines. *Biconcave hypodense lesion* - A **biconcave** shape is not a standard description in neuroradiology and does not represent epidural hematoma. - **Hypodense** would indicate an older lesion or other pathology, not acute hemorrhage. *Ring-enhancing hypodense lesion* - **Ring-enhancing lesions** are typically associated with abscesses, glioblastoma, or metastatic tumors, not an acute hematoma. - A **hypodense** (darker) center with enhancement would indicate an abscess or necrotic tumor, not a fresh extravasation of blood.

Q: Tigroid pattern on MRI is seen in -

Metachromatic leukodystrophy. ***Metachromatic leukodystrophy*** - The **tigroid pattern** on MRI, characterized by **perivascular sparing** within demyelinated white matter, is highly characteristic of metachromatic leukodystrophy. - This pattern results from the accumulation of **sulfatides** in oligodendrocytes and macrophages, leading to central demyelination with spared U-fibers and white matter adjacent to vessels. *Wilson's disease* - Wilson's disease involves **copper accumulation** and typically presents with abnormalities in the **basal ganglia**, thalami, and brainstem. - While it causes neurodegeneration, it does not produce a characteristic tigroid demyelination pattern. *Parkinsonism* - Parkinsonism refers to a group of neurological disorders characterized by motor symptoms like **bradykinesia, rigidity, tremor, and postural instability**. - MRI findings in Parkinsonism often show **nigral degeneration** but do not typically involve a tigroid pattern of leukodystrophy. *GB syndrome* - **Guillain-Barré syndrome (GBS)** is an acute autoimmune peripheral neuropathy affecting the **peripheral nerves and nerve roots**. - It does not involve central nervous system demyelination or display a tigroid pattern on brain MRI.

Q: Which of the following X-ray findings is associated with Chilaiditi syndrome?

Pseudopneumoperitoneum. ***Pseudopneumoperitoneum*** - Chilaiditi syndrome is characterized by the **interposition of a loop of colon (usually transverse colon) or, less commonly, small intestine** between the liver and the right hemidiaphragm. - This anatomical variation can mimic **free air under the diaphragm** on an X-ray, leading to the misdiagnosis of pneumoperitoneum. *Pseudopneumothorax* - This term describes the appearance of **air in the pleural space** that is not actually present, which is not associated with Chilaiditi syndrome. - While Chilaiditi syndrome involves misinterpretation of air, it specifically relates to the **abdominal cavity**, not the thoracic cavity. *Pneumothorax* - A **true pneumothorax** is the presence of air in the pleural cavity causing partial or complete lung collapse, which is a significant medical emergency. - It is distinct from Chilaiditi syndrome, which involves **abdominal content displacement** mimicking abdominal free air. *Hydropneumothorax* - This condition involves the presence of both **fluid and air in the pleural cavity**. - It is a pathology of the thoracic cavity and has **no direct association** with the abdominal interposition of bowel loops seen in Chilaiditi syndrome.

Q: A patient presents with abdominal pain. On physical examination there was abdominal guarding and tenderness. A plain erect chest X-ray reveals air under diaphragm. Probable diagnosis is

Perforated abdominal viscus. ***Perforated abdominal viscus*** - The presence of **abdominal guarding** and **tenderness** indicates peritoneal irritation, while **air under the diaphragm** on an erect chest X-ray (**pneumoperitoneum**) is a classic sign of a perforated hollow abdominal organ. - This combination strongly suggests a **perforated abdominal viscus**, such as a **perforated peptic ulcer** or perforated diverticulitis, leading to the leakage of air and intestinal contents into the peritoneal cavity. *Acute myocardial infarction* - Acute myocardial infarction primarily presents with **chest pain**, radiation to the arm/jaw, and shortness of breath, not typically severe abdominal pain with guarding. - While it can cause some epigastric discomfort, it would not explain the **pneumoperitoneum** seen on the chest X-ray. *Aortic dissection* - Aortic dissection typically causes **sudden, severe tearing chest or back pain**, often radiating to the back. - There is no direct link between aortic dissection and **air under the diaphragm** unless there's a co-existing, unrelated issue, which is not suggested by the primary symptoms. *None of the options* - Given the clear clinical and radiological findings of **pneumoperitoneum** and **peritoneal signs**, a perforated abdominal viscus is the most fitting diagnosis among the choices provided. - This option is incorrect as there is a highly probable diagnosis among the given choices.

Question 1

Which of the following is the only clinically available depolarizing muscle relaxant?

Accepted Answer

Suxamethonium

Answer

Decamethonium

Answer

Mivacurium

Answer

None of the options

Question 2

Which drug is not considered a mood stabilizer?

Accepted Answer

Imipramine

Answer

Lithium

Answer

Lamotrigine

Answer

Carbamazepine

Question 3

What is the most common cause of delirium?

Accepted Answer

Infection

Answer

Liver failure

Answer

Belladonna poisoning

Answer

None of the options

Question 4

Increased dopamine levels are associated with which of the following conditions?

Accepted Answer

Schizophrenia

Answer

Depression

Answer

Mania

Answer

Delirium

Question 5

What does the term 'jamais vu' refer to?

Accepted Answer

The feeling of strangeness in a familiar situation

Answer

A thought that feels familiar but is actually new

Answer

A situation that feels familiar but is actually new

Answer

An illusion where one feels they have heard something before

Question 6

On CT scan, gastric volvulus typically shows which of the following findings?

Accepted Answer

Enlarged twisted stomach

Answer

Normal twisted stomach

Answer

Shortened twisted stomach

Answer

None of the options

Question 7

Epidural hematoma on CT scan shows which of the following?

Accepted Answer

Biconvex hyperdense lesion

Answer

Crescent-shaped hyperdense lesion

Answer

Biconcave hypodense lesion

Answer

Ring-enhancing hypodense lesion

Question 8

Tigroid pattern on MRI is seen in -

Accepted Answer

Metachromatic leukodystrophy

Answer

Wilson's disease

Answer

Parkinsonism

Answer

GB syndrome

Question 9

Which of the following X-ray findings is associated with Chilaiditi syndrome?

Accepted Answer

Pseudopneumoperitoneum

Answer

Pseudopneumothorax

Answer

Pneumothorax

Answer

Hydropneumothorax

Question 10

A patient presents with abdominal pain. On physical examination there was abdominal guarding and tenderness. A plain erect chest X-ray reveals air under diaphragm. Probable diagnosis is

Accepted Answer

Perforated abdominal viscus

Answer

Acute myocardial infarction

Answer

Aortic dissection

Answer

None of the options

NEET-PG 2015

Pharmacology

Psychiatry

Radiology

Surgery