Neurology Practice Questions

Q: Which of the following is NOT a sign of raised intracranial pressure in a 7-month-old infant?

Papilledema. In infants, the clinical presentation of raised intracranial pressure (ICP) differs significantly from that of older children and adults due to the presence of open cranial sutures and a patent anterior fontanelle. **Why Papilledema is the Correct Answer:** Papilledema (swelling of the optic disc) is rarely seen in infants under the age of 1 year, even with significantly raised ICP. This is because the **open sutures and fontanelles** act as a "safety valve," allowing the skull to expand and accommodate the increased pressure. This decompression prevents the pressure from being transmitted directly to the optic nerve sheath. Therefore, the absence of papilledema does **not** rule out raised ICP in an infant. **Explanation of Incorrect Options:** * **Bulging Fontanelle:** This is the most reliable clinical sign of raised ICP in an infant. When the intracranial volume increases, the non-ossified anterior fontanelle becomes tense and protrudes. * **Increase in Head Size:** Since the cranial sutures are not yet fused, increased pressure leads to "macrocephaly" or a rapid increase in head circumference (crossing percentiles on a growth chart) as the bones are pushed apart. * **Increasing Irritability:** This is a common non-specific behavioral sign of raised ICP. It may be accompanied by a high-pitched cry, poor feeding, or projectile vomiting. **NEET-PG High-Yield Pearls:** * **Macewen’s Sign (Cracked-pot sign):** Percussion of the skull in an infant with raised ICP/hydrocephalus yields a resonant sound due to separated sutures. * **Sunset Sign:** Downward deviation of the eyes (sclera visible above the iris) is a late sign of raised ICP in infants. * **Cushing’s Triad:** Hypertension, bradycardia, and irregular respirations (a late sign of impending herniation).

Q: A 6-year-old child, weighing 20 kg, with a known seizure disorder and already on Valproate 200 mg twice daily, presents with breakthrough seizures to the pediatric casualty. The seizures were aborted with Inj. Lorazepam. What should be the next medication administered to this child?

Sodium Valproate. **Explanation:** The core principle in managing breakthrough seizures in a child already on an Anti-Epileptic Drug (AED) is to **optimize the dose of the current medication** before switching or adding a new class, provided the current drug is appropriate for the seizure type. **Why Sodium Valproate is correct:** The child is currently receiving 400 mg/day (20 mg/kg/day) of Valproate. The standard therapeutic range for Valproate in pediatrics is **20–40 mg/kg/day**. Since the child is at the lower end of the therapeutic window and experiencing breakthrough seizures, the immediate next step is to administer an intravenous loading dose of Sodium Valproate (usually 15–20 mg/kg) to rapidly achieve therapeutic levels and prevent recurrence. **Why other options are incorrect:** * **Phenytoin:** It is a potent hepatic enzyme inducer. Adding it to Valproate complicates metabolism and increases the risk of drug-drug interactions and toxicity. It is generally avoided if Valproate can be optimized. * **Phenobarbitone:** While effective, it causes significant sedation and respiratory depression, especially when used after benzodiazepines (Lorazepam). It is typically reserved for refractory cases or neonatal seizures. * **Levetiracetam:** Although a safe add-on, the priority is to maximize the primary drug (Valproate) that has already been chosen for this patient's specific epilepsy syndrome. **Clinical Pearls for NEET-PG:** * **Valproate Loading Dose:** 20–40 mg/kg IV over 5–10 minutes. * **Drug of Choice:** Valproate is the drug of choice for generalized tonic-clonic seizures (GTCS) and myoclonic seizures in children. * **Status Epilepticus Protocol:** If seizures persist after two doses of benzodiazepines, the next step is a long-acting AED (Fosphenytoin, Valproate, or Levetiracetam). In a patient already on Valproate, Valproate is the preferred choice.

Q: What is the earliest symptom of Tay-Sachs disease?

Exaggerated startle response. ### Explanation **Tay-Sachs Disease (TSD)** is an autosomal recessive lysosomal storage disorder caused by a deficiency of the enzyme **Hexosaminidase A**. This leads to the toxic accumulation of **GM2 gangliosides** within the lysosomes of neurons, resulting in progressive neurodegeneration. **Why "Exaggerated Startle Response" is correct:** The earliest clinical sign of Tay-Sachs disease, typically appearing between **3 to 6 months of age**, is an exaggerated startle response (hyperacusis) to loud noises. This occurs due to early neuronal irritability and dysfunction in the central nervous system before gross motor regression or blindness (amaurosis) becomes apparent. **Why the other options are incorrect:** * **B. Bone deformation:** This is characteristic of **Gaucher disease** (Erlenmeyer flask deformity) or **Hurler syndrome** (dysostosis multiplex), but not Tay-Sachs. * **C. Hepatomegaly:** A crucial diagnostic differentiator is that Tay-Sachs has **no hepatosplenomegaly**. Its presence would instead suggest **Niemann-Pick disease** (Sphingomyelinase deficiency) or Gaucher disease. * **D. Excessive bleeding:** This is not a feature of sphingolipidoses; it is typically associated with platelet disorders or coagulation factor deficiencies. **High-Yield Clinical Pearls for NEET-PG:** * **Cherry-red spot on macula:** A classic finding in both Tay-Sachs and Niemann-Pick. * **Enzyme Deficiency:** Hexosaminidase **A** (Tay-S**A**chs). * **Accumulated Substance:** GM2 Ganglioside. * **Histology:** "Onion-skin" appearance of lysosomes. * **Key Differentiator:** Tay-Sachs = No Hepatosplenomegaly; Niemann-Pick = Hepatosplenomegaly present.

Q: A six-year-old girl presents with brief, irregular contractions in her feet. These symptoms are suspected to be a result of an untreated streptococcal infection. What is the most likely diagnosis?

Sydenham chorea. **Explanation:** The correct answer is **Sydenham chorea (D)**. This condition is a major clinical manifestation of **Acute Rheumatic Fever (ARF)**, occurring due to molecular mimicry where antibodies against Group A Beta-hemolytic Streptococcus (GABHS) cross-react with the basal ganglia (specifically the caudate and putamen). **Why Sydenham Chorea is correct:** It typically presents in children (ages 5–15) weeks to months after a streptococcal pharyngeal infection. The clinical hallmark is "chorea"—brief, purposeless, irregular, involuntary movements—often accompanied by muscular hypotonia and emotional lability. **Analysis of Incorrect Options:** * **A. Chorea gravidarum:** This refers to chorea occurring during pregnancy. While it is often a recurrence of Sydenham chorea triggered by hormonal changes, it is not the primary diagnosis for a six-year-old child. * **B. Chorea major:** This is an archaic term sometimes used for Huntington’s disease or severe chorea, but it is not a standard clinical diagnosis in the context of post-streptococcal sequelae. * **C. Ballism:** This involves large-amplitude, violent, flinging movements of the proximal limbs, usually unilateral (hemiballismus) and typically caused by a lesion in the subthalamic nucleus, not streptococcal infection. **Clinical Pearls for NEET-PG:** * **Jones Criteria:** Sydenham chorea is a **Major Criterion** for the diagnosis of ARF. * **Latent Period:** It has the longest latent period of all ARF features (up to 6 months). * **Clinical Signs:** Look for the **"Milkmaid’s grip"** (irregular contractions of hand muscles), **"Jack-in-the-box tongue"** (inability to protrude the tongue steadily), and **"Pronator sign."** * **Treatment:** Usually self-limiting; however, bed rest and penicillin prophylaxis are essential to prevent rheumatic heart disease. Severe cases may require valproate or carbamazepine.

Q: All of the following are causes of hypotonia in a 2-year-old child, except:

Cerebral palsy. **Explanation:** The core concept in pediatric hypotonia is distinguishing between **Lower Motor Neuron (LMN)** and **Upper Motor Neuron (UMN)** lesions. **Why Cerebral Palsy (CP) is the correct answer:** Cerebral Palsy is a non-progressive UMN disorder caused by an insult to the developing brain. While children with CP may present with transient "floppiness" in early infancy (the hypotonic phase), by age 2, the condition typically evolves into **spasticity** (hypertonia) and hyperreflexia. Therefore, in a 2-year-old, CP is characterized by increased muscle tone rather than persistent hypotonia. **Analysis of Incorrect Options:** * **Trisomy 21 (Down Syndrome):** This is a classic cause of **central (syndromic) hypotonia**. The hypotonia is persistent and associated with joint hyperlaxity and developmental delay. * **Spinal Muscular Atrophy (SMA):** This is an **LMN disorder** involving the anterior horn cells. It presents with profound, progressive hypotonia, "frog-leg" positioning, and absent deep tendon reflexes. * **Congenital Muscular Dystrophy (CMD):** This is a **myopathic cause** of hypotonia. It presents at birth or early childhood with muscle weakness, hypotonia, and often contractures. **Clinical Pearls for NEET-PG:** * **The "Floppy Infant" Rule:** Most cases of neonatal hypotonia are **Central** (80%), but if the infant is alert with severe weakness, suspect **Peripheral** causes (like SMA). * **Evolution of Tone:** CP is the most common cause of "changing tone"—starting as hypotonia and evolving into spasticity. * **Gower’s Sign:** While associated with Duchenne, it can be seen in various muscular dystrophies. * **SMA Type 1 (Werdnig-Hoffmann):** Most common genetic cause of death in infants; look for tongue fasciculations.

Q: What is the most common cause of fatal ventriculomegaly?

Aqueductal Stenosis. **Explanation:** **Aqueductal Stenosis** is the most common cause of congenital obstructive (non-communicating) hydrocephalus, accounting for approximately 33% of cases. It involves a narrowing of the Aqueduct of Sylvius, which connects the third and fourth ventricles. This obstruction leads to significant **ventriculomegaly** (enlargement of the lateral and third ventricles) and is the leading cause of fetal/neonatal macrocephaly requiring surgical intervention. **Analysis of Options:** * **Arnold Chiari Malformation - II (Option B):** While this is the most common cause of hydrocephalus associated with **myelomeningocele**, it is less frequent as an isolated cause of fetal ventriculomegaly compared to aqueductal stenosis. * **Arnold Chiari Malformation - I (Option A):** This typically presents in adolescence or adulthood with cerebellar symptoms (downbeat nystagmus, ataxia) and is rarely a cause of significant fetal ventriculomegaly. * **Dandy Walker Malformation (Option D):** This involves cystic dilation of the fourth ventricle and cerebellar hypoplasia. While it causes hydrocephalus, its incidence is lower than that of aqueductal stenosis. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** "Setting sun" sign (downward gaze), bulging fontanelle, and rapidly increasing head circumference. * **X-ray finding:** "Copper beaten skull" (Luckenschadel skull) due to chronic increased intracranial pressure. * **Associated Infections:** Congenital **Toxoplasmosis** is a classic infectious cause of aqueductal stenosis due to periaqueductal inflammation/scarring. * **Genetic Link:** X-linked hydrocephalus (L1CAM mutation) is the most common inherited form, specifically causing aqueductal stenosis.

Q: Which of the following types of cerebral palsy is most common in low-birth weight infants?

Spastic diplegia. **Explanation:** **Spastic diplegia** is the most common form of cerebral palsy (CP) observed in low-birth-weight (LBW) and preterm infants. The underlying pathophysiology is **Periventricular Leukomalacia (PVL)**. In preterm infants, the watershed area near the lateral ventricles is highly susceptible to ischemia and oxidative stress. This area contains the descending pyramidal tracts; specifically, the fibers subserving the lower extremities are located closest to the ventricles. Damage here results in spasticity that affects the legs more significantly than the arms. **Analysis of Incorrect Options:** * **Spastic Quadriplegia:** This is the most severe form and is typically associated with global hypoxic-ischemic encephalopathy (HIE), severe brain malformations, or multicystic encephalomalacia. It involves all four limbs and is often seen in term infants with severe perinatal asphyxia. * **Choreoathetoid (Dyskinetic) CP:** This type is classically associated with **bilirubin encephalopathy (Kernicterus)** or profound asphyxia affecting the basal ganglia. It is less common now due to effective management of neonatal jaundice. * **Hemiplegia:** This usually results from focal vascular insults, such as a neonatal stroke (middle cerebral artery territory), and is more commonly seen in term infants rather than as a direct consequence of LBW/prematurity. **High-Yield Clinical Pearls for NEET-PG:** * **Most common overall type of CP:** Spastic CP (specifically Spastic Diplegia in preterms). * **Scissor Gait:** A classic clinical sign of spastic diplegia due to increased tone in hip adductors. * **Imaging of choice:** MRI Brain is the gold standard for evaluating the extent of brain injury in CP. * **Key Risk Factor:** Prematurity is the single most important risk factor for the development of CP.

Question 1

Which of the following is NOT a sign of raised intracranial pressure in a 7-month-old infant?

Accepted Answer

Papilledema

Answer

Bulging fontanelle

Answer

Increase in head size

Answer

Increasing irritability

Question 2

A 1-week-old infant is noted to be at the seventy-fifth percentile for size and head circumference. One month later, the infant is still at the seventy-fifth percentile for size, but the head circumference has increased to the ninety-fifth percentile. The infant's anterior fontanelle is tense, and the skull sutures are open. An MRI of the brain with intravenous contrast shows greatly dilated lateral and third ventricles, an aqueduct of Sylvius that cannot be easily visualized, and a small fourth ventricle. There are no lesions within the subarachnoid space or cerebral parenchyma. What is the most likely diagnosis?

Accepted Answer

Noncommunicating hydrocephalus

Answer

Communicating hydrocephalus

Answer

Normal-pressure hydrocephalus

Answer

Arnold-Chiari malformation with herniation of the cerebellum into the foramen magnum

Question 3

A 7-year-old boy has progressive difficulty in climbing stairs, walks with a waddling gait, and also has calf muscle hypertrophy. What is the most likely diagnosis?

Accepted Answer

Becker's Muscular Dystrophy

Answer

Duchenne Muscular Dystrophy (DMD)

Answer

Myositis

Answer

Dermatomyositis

Question 4

A 6-year-old child, weighing 20 kg, with a known seizure disorder and already on Valproate 200 mg twice daily, presents with breakthrough seizures to the pediatric casualty. The seizures were aborted with Inj. Lorazepam. What should be the next medication administered to this child?

Accepted Answer

Sodium Valproate

Answer

Phenobarbitone

Answer

Phenytoin

Answer

Levetiracetam

Question 5

What is the earliest symptom of Tay-Sachs disease?

Accepted Answer

Exaggerated startle response

Answer

Bone deformation

Answer

Hepatomegaly

Answer

Excessive bleeding

Question 6

A six-year-old girl presents with brief, irregular contractions in her feet. These symptoms are suspected to be a result of an untreated streptococcal infection. What is the most likely diagnosis?

Accepted Answer

Sydenham chorea

Answer

Chorea gravidarum

Answer

Chorea major

Answer

Ballism

Question 7

All of the following are causes of hypotonia in a 2-year-old child, except:

Accepted Answer

Cerebral palsy

Answer

Trisomy 21

Answer

Spinal muscular atrophy

Answer

Congenital muscular dystrophy

Question 8

What is the most common cause of fatal ventriculomegaly?

Accepted Answer

Aqueductal Stenosis

Answer

Arnold Chiari Malformation - I

Answer

Arnold Chiari Malformation - II

Answer

Dandy Walker Malformation

Question 9

Which feature differentiates hydranencephaly from hydrocephalus?

Accepted Answer

Cerebral cortex is deficient or hypoplastic in hydranencephaly.

Answer

Hydranencephaly is static while hydrocephalus continues to increase in size.

Answer

Hydranencephaly does not cause an increase in head size.

Answer

All of the above.

Question 10

Which of the following types of cerebral palsy is most common in low-birth weight infants?

Accepted Answer

Spastic diplegia

Answer

Spastic quadriplegia

Answer

Choreoathetoid cerebral palsy

Answer

Hemiplegia

Neurology — MCQs

Neurology — MCQs

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