Neuropathology — MCQs

A 42-year-old immunosuppressed male presents with rapidly progressing neurologic symptoms including mental deterioration, visual loss, abnormal speech, and ataxia. Radiographic studies demonstrate multifocal lesions in the white matter without mass effect. A stereotactic brain biopsy reveals areas of demyelination. Which histologic feature is most likely to be present in this patient?

Q78Easy

Mutation in which of the following chromosomes is associated with meningioma?

Q79Medium

Which of the following conditions is associated with brain tumors?

Q80Easy

Enamel-like superstructure is seen in which CNS lesion?

Neuropathology Indian Medical PG Practice Questions and MCQs

Question 71: Neurodegeneration with iron accumulation in basal ganglia is typically seen in which condition?

A. Hallervorden-Spatz disease (Correct Answer)
B. Hemochromatosis
C. Wilson's disease
D. Cystic fibrosis

Explanation: **Explanation:** **1. Why Hallervorden-Spatz Disease is Correct:** Hallervorden-Spatz disease, now more commonly known as **Pantothenate Kinase-Associated Neurodegeneration (PKAN)**, is a rare autosomal recessive neurodegenerative disorder caused by mutations in the *PANK2* gene. This defect leads to an abnormal accumulation of **iron** in the brain, specifically within the **globus pallidus** and **substantia nigra pars reticulata**. On T2-weighted MRI, this iron deposition creates a pathognomonic sign known as the **"Eye of the Tiger" sign** (a central area of hyperintensity surrounded by a rim of hypointensity). **2. Why the Other Options are Incorrect:** * **Hemochromatosis:** This is a systemic iron overload disorder. While iron accumulates in the liver, heart, and endocrine organs, it typically **spares the brain** due to the blood-brain barrier. * **Wilson’s Disease:** This is a disorder of **copper** metabolism, not iron. While it involves the basal ganglia (specifically the putamen), the primary pathology is copper toxicity leading to gliosis and cavitation. * **Cystic Fibrosis:** This is a multi-system disorder affecting chloride channels (CFTR gene), primarily impacting the lungs and pancreas. It has no association with iron accumulation in the basal ganglia. **3. NEET-PG High-Yield Pearls:** * **MRI Finding:** Look for the "Eye of the Tiger" sign in clinical vignettes. * **Genetics:** Autosomal Recessive; *PANK2* gene mutation on Chromosome 20p. * **Histology:** Presence of **Spheroid bodies** (swollen axonal terminals) and iron-containing pigment (neuromelanin and lipofuscin). * **Clinical Presentation:** Extrapyramidal symptoms like dystonia, parkinsonism, and choreoathetosis, usually beginning in childhood.

Question 72: What is the most common primary brain tumor in adults?

A. Astrocytoma (Correct Answer)
B. Oligodendroglioma
C. Ependymoma
D. Medulloblastoma

Explanation: **Explanation:** **Astrocytoma** is the correct answer because it represents the most common group of primary intracranial neoplasms in adults [1]. Specifically, **Glioblastoma (GBM)**, which is a Grade IV astrocytoma, is the most frequent and aggressive primary malignant brain tumor in the adult population [1], [2]. Astrocytomas originate from astrocytes, the star-shaped glial cells that support neuronal function. **Analysis of Options:** * **B. Oligodendroglioma:** These are less common than astrocytomas. They typically present in middle-aged adults (30–50 years) and are characterized histologically by a "fried-egg" appearance and "chicken-wire" vascularity. * **C. Ependymoma:** While these can occur in adults (often in the spinal cord), they are much more common in children, typically arising in the fourth ventricle. * **D. Medulloblastoma:** This is a highly malignant Grade IV tumor, but it is primarily a **pediatric tumor** (the most common malignant brain tumor in children), occurring in the cerebellum [1]. It is rare in adults. **High-Yield Clinical Pearls for NEET-PG:** * **Most common brain tumor in adults (overall):** Metastatic tumors (Lung > Breast > Melanoma). * **Most common primary brain tumor in adults:** Astrocytoma (specifically Glioblastoma) [1]. * **Most common benign brain tumor in adults:** Meningioma (often associated with Psammoma bodies). * **Glioblastoma Marker:** GFAP (Glial Fibrillary Acidic Protein) positive. * **Radiology:** Glioblastoma typically shows a "butterfly glioma" pattern crossing the corpus callosum with ring enhancement on MRI [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 725-726. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1308-1310.

Question 73: Rupture of Berry aneurysm causes which type of hemorrhage?

A. Extradural hemorrhage
B. Subdural hemorrhage
C. Subarachnoid hemorrhage (Correct Answer)
D. Intracerebral hemorrhage

Explanation: **Explanation:** **Subarachnoid Hemorrhage (SAH)** is the classic presentation of a ruptured **Berry (Saccular) aneurysm** [1]. These aneurysms typically develop at the bifurcations of arteries within the **Circle of Willis**, located in the subarachnoid space [3]. When they rupture, blood extravasates directly into the cerebrospinal fluid (CSF) pathways between the arachnoid and pia mater [2]. **Analysis of Options:** * **Extradural Hemorrhage (EDH):** Usually results from trauma causing rupture of the **middle meningeal artery**. It is characterized by a biconvex (lens-shaped) hematoma on CT and a "lucid interval" clinically. * **Subdural Hemorrhage (SDH):** Caused by the tearing of **bridging veins** crossing from the cortex to the dural sinuses. It typically presents as a crescent-shaped hematoma, often in elderly patients or following minor trauma. * **Intracerebral Hemorrhage (ICH):** Most commonly caused by **systemic hypertension**, leading to the rupture of Charcot-Bouchard aneurysms in the small penetrating arteries (e.g., lenticulostriate arteries) of the basal ganglia. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Junction of the **Anterior Communicating Artery (ACoA)** and Anterior Cerebral Artery [3]. * **Clinical Presentation:** Sudden onset of the **"worst headache of my life"** (Thunderclap headache) and nuchal rigidity [1]. * **Associated Conditions:** Autosomal Dominant Polycystic Kidney Disease (ADPKD), Ehlers-Danlos syndrome, and Coarctation of the Aorta [1]. * **Diagnosis:** Non-contrast CT is the initial investigation; if negative but suspicion is high, **Lumbar Puncture** showing xanthochromia (yellowish CSF due to bilirubin) is diagnostic. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 705-706. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1272-1273. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, p. 1272.

Question 74: Which of the following statements is FALSE regarding Krabbe's disease?

A. Extensive involvement of deep white matter
B. Involvement of cerebellar white matter
C. Hyperdensity on T2 MRI image (Correct Answer)
D. Basal ganglia calcification in CT scan

Explanation: **Explanation:** Krabbe’s disease (Globoid Cell Leukodystrophy) is an autosomal recessive lysosomal storage disorder caused by a deficiency of the enzyme **Galactocerebrosidase (GALC)**. This leads to the accumulation of psychosine, which is toxic to oligodendrocytes, resulting in severe demyelination [1]. **Why Option C is False:** In Krabbe’s disease, there is a profound loss of myelin (demyelination) and reactive gliosis in the white matter [1]. On MRI, demyelinated areas contain increased water content, which characteristically appears as **T2-hyperintensity** (bright) and T1-hypointensity (dark). Therefore, "hyperdensity" (a CT term) or "hypointensity on T2" would be incorrect descriptors for the typical presentation. **Analysis of Other Options:** * **Options A & B:** Krabbe’s disease is a classic leukodystrophy characterized by **extensive involvement of deep white matter**, including the cerebral hemispheres, cerebellar white matter, and brainstem. It typically spares the subcortical U-fibers initially. * **Option D:** While not present in every case, **thalamic and basal ganglia calcifications** or hyperdensities are recognized features on CT scans in infants with Krabbe’s disease, helping differentiate it from other leukodystrophies. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic Feature:** Presence of **Globoid cells** (multinucleated macrophages containing undigested galactosylceramide) in the white matter [1]. * **Enzyme Deficiency:** Galactocerebrosidase (GALC); Gene: *GALC* on chromosome 14. * **Clinical Presentation:** Irritability, severe developmental delay, spasticity, and optic atrophy (infantile form is most common). * **Peripheral Nerves:** Unlike many other leukodystrophies, Krabbe’s also involves the peripheral nervous system (segmental demyelination). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1304-1305.

Question 75: What is the most common type of pathological change seen in Rabies?

A. Meningitis
B. Cranial arteritis
C. Ventriculitis
D. Brain stem encephalitis (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Brain stem encephalitis** **Pathophysiology:** Rabies is caused by a neurotropic RNA virus (Lyssavirus) that travels via retrograde axonal transport from the site of inoculation to the Central Nervous System (CNS) [1]. Once it reaches the brain, it causes a severe, diffuse **encephalitis**. While the virus affects various regions, the most profound pathological changes and viral concentrations are typically found in the **brain stem**, hippocampus (Ammon’s horn), and cerebellum [1]. The involvement of the brain stem is clinically significant as it leads to the characteristic dysfunction of cranial nerves, causing hydrophobia (laryngeal spasms) and autonomic instability. **Analysis of Incorrect Options:** * **A. Meningitis:** Rabies is primarily a parenchymal disease (encephalitis) rather than an inflammation of the leptomeninges [1]. While mild meningeal irritation can occur, it is not the hallmark change. * **B. Cranial arteritis:** This refers to inflammation of the blood vessels. Rabies does not typically cause vasculitis or arteritis; it is a direct viral invasion of neurons. * **C. Ventriculitis:** This involves inflammation of the ventricular lining (ependyma), usually seen in bacterial or fungal infections. It is not a feature of Rabies. **NEET-PG High-Yield Pearls:** * **Negri Bodies:** The pathognomonic finding. These are eosinophilic, intracytoplasmic inclusions found most commonly in **Pyramidal cells of the Hippocampus** and **Purkinje cells of the Cerebellum** [1]. * **Babes Nodes:** Microglial nodules formed around degenerating neurons (neuronophagia). * **Incubation Period:** Highly variable, depending on the distance between the bite site and the CNS. * **Clinical Forms:** "Furious" (encephalitic) is the most common (80%), followed by "Dumb" (paralytic). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1279-1280.

Question 76: What is a watershed infarct in the brain?

A. Occurs in the proximal portion of main arteries
B. Occurs in the central portion of main arteries
C. Occurs in the terminal portion of main arteries (Correct Answer)
D. None of the above

Explanation: **Explanation:** A **watershed infarct** (also known as a border-zone infarct) occurs at the most distal territories of the brain's blood supply [1]. These areas are located at the **terminal portions** of the major cerebral arteries (e.g., where the distal branches of the Anterior and Middle Cerebral Arteries meet) [1]. 1. **Why Option C is correct:** These terminal zones are the most vulnerable to systemic hypotension or reduced cardiac output [1]. Because they are at the very end of the arterial "irrigation" system, they have the lowest perfusion pressure [1]. When blood pressure drops significantly, these "end-of-the-line" areas are the first to suffer from ischemia, leading to infarction. 2. **Why Options A and B are incorrect:** The proximal and central portions of main arteries (like the stem of the MCA) are closer to the high-pressure source. In states of global hypotension, these areas maintain perfusion longer than the distal terminals. Infarcts here are typically caused by local thrombosis or embolism rather than "watershed" physiology [2]. **NEET-PG High-Yield Pearls:** * **Commonest Site:** The border zone between the **Anterior Cerebral Artery (ACA) and Middle Cerebral Artery (MCA)** is the most frequently involved [1]. * **Clinical Presentation:** Often presents as "Man-in-a-barrel" syndrome (proximal muscle weakness of the arms and legs with sparing of the face and distal extremities). * **Morphology:** On imaging or gross pathology, these appear as wedge-shaped infarcts. * **Vulnerable Cells:** The **Pyramidal cells of the Hippocampus (Sommer sector/CA1)** and **Purkinje cells of the Cerebellum** are the most sensitive to the global hypoxia that often precedes watershed territory damage [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 150-151. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1266-1268.

Question 77: A 42-year-old immunosuppressed male presents with rapidly progressing neurologic symptoms including mental deterioration, visual loss, abnormal speech, and ataxia. Radiographic studies demonstrate multifocal lesions in the white matter without mass effect. A stereotactic brain biopsy reveals areas of demyelination. Which histologic feature is most likely to be present in this patient?

A. Beta-A4 amyloid within blood vessels
B. Prion protein within extracellular plaques
C. Rosenthal fibers within astrocytes
D. Viral particles within oligodendrocytes (Correct Answer)

Explanation: ### Explanation The clinical presentation of rapidly progressive neurologic deficits (mental deterioration, visual loss, ataxia) in an **immunosuppressed** patient, combined with multifocal white matter lesions without mass effect, is classic for **Progressive Multifocal Leukoencephalopathy (PML)** [1]. **1. Why the correct answer is right:** PML is caused by the reactivation of the **JC virus** (a polyomavirus). The virus selectively infects and destroys **oligodendrocytes**, the cells responsible for maintaining myelin in the Central Nervous System [1]. Histologically, this leads to patches of demyelination. The hallmark finding is the presence of **enlarged, "ground-glass" intranuclear viral inclusions** (viral particles) within oligodendrocytes. Bizarre, giant astrocytes are also frequently seen [1]. **2. Why the incorrect options are wrong:** * **Option A (Beta-A4 amyloid):** Characteristic of **Cerebral Amyloid Angiopathy** or Alzheimer’s disease; it presents with lobar hemorrhages or chronic dementia, not acute demyelination. * **Option B (Prion protein):** Seen in **Creutzfeldt-Jakob Disease (CJD)**. While CJD causes rapid dementia, it typically shows "spongiform encephalopathy" (vacuoles in gray matter) rather than white matter demyelination. * **Option C (Rosenthal fibers):** These are thick, eosinophilic protein aggregates found in astrocytes in **Alexander disease** or **Pilocytic Astrocytoma**, not in viral-induced demyelination. **Clinical Pearls for NEET-PG:** * **PML Association:** Highly associated with HIV/AIDS (CD4 <200) and patients on monoclonal antibodies like **Natalizumab** [1]. * **Imaging:** MRI shows T2/FLAIR hyperintensities in the subcortical white matter that **do not enhance** with contrast (distinguishes it from Toxoplasmosis or Lymphoma). * **Diagnosis:** Confirmed by PCR for JC virus DNA in the CSF or brain biopsy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1280-1281.

Question 78: Mutation in which of the following chromosomes is associated with meningioma?

A. Chromosome 1
B. Chromosome 19
C. Chromosome 22 (Correct Answer)
D. Chromosome 9q

Explanation: **Explanation:** **Correct Option: C (Chromosome 22)** Meningiomas are the most common benign intracranial tumors. The most frequent genetic alteration associated with meningioma is the **loss of genetic material on the long arm of chromosome 22 (22q)** [1]. This region houses the **NF2 (Neurofibromatosis type 2) gene**, which encodes the protein **Merlin** (also known as Schwannomin). Merlin acts as a tumor suppressor by regulating cell-to-cell adhesion and contact inhibition. Mutations or deletions of the NF2 gene are found in approximately 50–60% of sporadic meningiomas and are a hallmark of syndromic meningiomas associated with NF2 [1]. **Incorrect Options:** * **Option A (Chromosome 1) & Option B (Chromosome 19):** Co-deletion of **1p and 19q** is the classic molecular signature for **Oligodendrogliomas**. It is a diagnostic and prognostic marker indicating a better response to chemotherapy. * **Option D (Chromosome 9q):** Mutations in the **TSC1 gene** (located on 9q34) are associated with **Tuberous Sclerosis**, which typically presents with Subependymal Giant Cell Astrocytomas (SEGA), not meningiomas. **High-Yield Clinical Pearls for NEET-PG:** * **Histology:** Look for **Psammoma bodies** (laminated calcifications) and **Whorled patterns** of spindle cells [2]. * **Risk Factors:** Prior cranial radiation is a significant risk factor; they are more common in females due to **progesterone receptors** on the tumor cells [2]. * **Classification:** Most are WHO Grade I. However, the **Papillary** and **Rhabdoid** variants are highly aggressive (WHO Grade III). * **Location:** Most commonly found in the parasagittal region, olfactory groove, and sphenoid wing. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1316-1317. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 727-728.

Question 79: Which of the following conditions is associated with brain tumors?

A. Tuberous sclerosis
B. Von Hippel-Lindau syndrome
C. Neurofibromatosis
D. Sturge-Weber syndrome (Correct Answer)

Explanation: **Explanation:** The correct answer is **Sturge-Weber Syndrome (SWS)**. While SWS is a classic phakomatosis characterized by vascular malformations, it is unique among the listed options because it is **not** typically associated with the development of brain tumors (neoplasms). Instead, it is characterized by a **leptomeningeal angioma** (a vascular malformation), usually involving the pia mater of the occipital and parietal lobes. This leads to cortical atrophy and "tram-track" calcifications rather than neoplastic growth. **Analysis of Options:** * **Neurofibromatosis (Type 1 & 2):** Strongly associated with brain tumors [1]. NF1 is linked to Optic Nerve Gliomas and Astrocytomas; NF2 is famous for the "MISME" mnemonic (Multiple Inherited Schwannomas, Meningiomas, and Ependymomas). * **Tuberous Sclerosis (TSC):** Characterized by **Subependymal Giant Cell Astrocytomas (SEGA)** and cortical tubers (which are hamartomas, but SEGA is a distinct neoplasm) [1],[2]. * **Von Hippel-Lindau (VHL) Syndrome:** Highly associated with **Hemangioblastomas**, particularly in the cerebellum and brainstem [1]. **NEET-PG High-Yield Pearls:** * **Sturge-Weber Syndrome:** Look for the triad of Port-wine stain (Nevus flammeus in V1/V2 distribution), Leptomeningeal angioma, and Glaucoma. It is caused by a somatic mutation in the **GNAQ gene**. * **Radiology:** "Tram-track" calcifications on CT are a classic finding in SWS due to cortical mineralization. * **Rule of Thumb:** Most phakomatoses (NF1, NF2, TSC, VHL) are autosomal dominant and predispose to tumors; SWS is **sporadic** and primarily **vascular/malformative** in nature. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 724-725. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1318-1320.

Question 80: Enamel-like superstructure is seen in which CNS lesion?

A. Craniopharyngioma (Correct Answer)
B. Pituitary tumor
C. Astrocytoma
D. Glioma

Explanation: **Explanation:** The correct answer is **Craniopharyngioma**. Craniopharyngiomas are benign but locally aggressive tumors derived from the remnants of **Rathke’s pouch**. The "enamel-like superstructure" refers to the histological similarity between the **Adamantinomatous** variant of craniopharyngioma and the **adamantinoma/ameloblastoma** of the jaw. Specifically, the Adamantinomatous craniopharyngioma (most common in children) features: 1. **Palisading peripheral epithelium** resembling the enamel organ of developing teeth. 2. **Stellate reticulum**, a loose internal network of cells. 3. **Wet keratin** (lamellar keratin flakes), which often undergoes dystrophic calcification. **Why other options are incorrect:** * **Pituitary tumor:** Most commonly pituitary adenomas, these are composed of uniform sheets of polygonal cells (acidophils, basophils, or chromophobes) without epithelial palisading or keratinization. * **Astrocytoma:** These are glial tumors characterized by fibrillary backgrounds and GFAP positivity [2]. They do not possess epithelial or dental-like structures. * **Glioma:** This is a broad category including astrocytomas, oligodendrogliomas, and ependymomas [1]. None of these exhibit the "enamel-like" architecture seen in craniopharyngiomas. **High-Yield Clinical Pearls for NEET-PG:** * **Bimodal Age Distribution:** Peaks at 5–15 years and >65 years. * **Imaging:** Classically described as a **suprasellar mass** with a "cystic and calcified" appearance (90% show calcification on CT). * **Machinery Oil Fluid:** The cysts often contain dark, cholesterol-rich fluid resembling crankcase or machinery oil. * **Clinical Presentation:** Often presents with **bitemporal hemianopia** (due to optic chiasm compression) and endocrine dysfunction (growth retardation or diabetes insipidus). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1312-1313. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 725-726.

Practice by Chapter

Cellular Pathology of the Nervous System

Practice Questions

Cerebrovascular Diseases

Practice Questions

Trauma to the Central Nervous System

Practice Questions

Infections of the Nervous System

Practice Questions

Demyelinating Diseases

Practice Questions

Neurodegenerative Diseases

Practice Questions

CNS Tumors

Practice Questions

Peripheral Nerve Disorders

Practice Questions

Neuromuscular Junction Diseases

Practice Questions

Congenital and Developmental Disorders

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free