Neurology Practice Questions

Q: A patient presents with the CT finding shown in the image. Which one of the following signs is this finding most likely to produce?

Hemiplegia. ***Hemiplegia*** - CT shows a lesion in the **internal capsule**, which contains the **corticospinal tract** responsible for motor control. - Damage to this area causes **pure motor hemiplegia** without sensory or cognitive deficits. *Uniocular blindness* - Requires damage to the **optic nerve** or **central retinal artery**, not the internal capsule. - Would present as **monocular vision loss** with an **afferent pupillary defect**. *Alexia without agraphia* - Results from lesions in the **left occipital lobe** and **splenium of corpus callosum**. - Patients can write but cannot read, requiring **disconnection** between visual and language areas. *Hemiballismus* - Caused by lesions in the **subthalamic nucleus** (body of Luys), not the internal capsule. - Presents as **violent, flinging movements** of the contralateral limbs due to **basal ganglia dysfunction**.

Q: Which of the following conditions has the least chance of causing seizures?

HIV encephalopathy. **Explanation:** The correct answer is **HIV encephalopathy**. In the context of NEET-PG, it is crucial to distinguish between conditions that are "intrinsically epileptogenic" and those that are primarily "degenerative or white-matter involving." [1] **1. Why HIV Encephalopathy is the correct answer:** HIV Encephalopathy (also known as AIDS Dementia Complex) primarily affects the **subcortical white matter** and deep gray matter nuclei. Seizures are typically a manifestation of **cortical** irritation. While patients with HIV can certainly have seizures, they are usually due to secondary opportunistic infections (like Toxoplasmosis or Cryptococcosis) or CNS lymphoma, rather than the direct effect of the HIV virus on the subcortical tissue in encephalopathy. [1] Therefore, it has the lowest intrinsic risk for seizures among the given options. **2. Analysis of incorrect options:** * **Hypoglycemia:** A classic metabolic cause of seizures. Low glucose deprives neurons of energy, leading to membrane instability and massive depolarization. [1] * **Hypocalcemia:** Low ionized calcium lowers the threshold for action potentials by increasing sodium permeability in neuronal membranes, leading to neuromuscular irritability and seizures. [1] * **Neurocysticercosis (NCC):** This is the **most common cause of adult-onset seizures** in developing countries like India. The inflammatory response to the degenerating cyst (scolex) in the cortical parenchyma is highly epileptogenic. **Clinical Pearls for NEET-PG:** * **Most common cause of seizures in HIV patients:** Toxoplasmosis (due to ring-enhancing cortical lesions). * **Metabolic triad of seizures:** Hypoglycemia, Hypocalcemia, and Hyponatremia. [1] * **NCC Staging:** The "Colloidal vesicular" stage is most associated with acute seizures due to the peak inflammatory response.

Q: Which of the following can cause 3rd nerve paralysis?

Midbrain infarct. The **3rd cranial nerve (Oculomotor nerve)** originates from the midbrain at the level of the superior colliculus. Therefore, a **midbrain infarct** (such as Weber’s or Benedikt’s syndrome) directly involves the oculomotor nucleus or its exiting fascicles, leading to ipsilateral 3rd nerve paralysis. [2] **Analysis of Options:** * **A. Posterior Communicating Artery (PCoA) Aneurysm:** While a PCoA aneurysm is a classic cause of "surgical" 3rd nerve palsy (often involving the pupil), it causes compression in the **subarachnoid space**, not within the brainstem itself. In many clinical contexts, this is a correct cause, but in the context of localized neuroanatomy, the midbrain is the primary site of origin. [1] * **B. Tolosa-Hunt Syndrome:** This is an idiopathic granulomatous inflammation of the **cavernous sinus**. While it can cause 3rd nerve palsy, it typically presents as painful ophthalmoplegia involving multiple nerves (III, IV, VI). [1] * **D. Lateral Medullary Lesions (Wallenberg Syndrome):** This affects the medulla, involving nerves IX, X, and XI, along with sympathetic fibers (Horner’s syndrome). It does **not** involve the 3rd nerve, which is located much higher in the brainstem (midbrain). **High-Yield Clinical Pearls for NEET-PG:** * **Rule of Pupil:** Medical causes (e.g., Diabetes) usually spare the pupil because parasympathetic fibers are peripheral. Surgical causes (e.g., PCoA Aneurysm) typically involve the pupil due to external compression. [3] * **Weber’s Syndrome:** Midbrain infarct causing ipsilateral 3rd nerve palsy and contralateral hemiplegia. * **Benedikt’s Syndrome:** Midbrain lesion involving the 3rd nerve and the red nucleus (causing contralateral tremors/ataxia).

Q: Lateral medullary syndrome (Wallenberg syndrome) is characterized by all features EXCEPT:

Horner's syndrome is rare. **Explanation:** Lateral Medullary Syndrome (Wallenberg Syndrome) is a classic brainstem stroke typically caused by occlusion of the **Posterior Inferior Cerebellar Artery (PICA)** or the vertebral artery. **Why Option D is the correct answer:** In Wallenberg syndrome, **Horner’s syndrome is a common and characteristic feature**, not rare [1]. It occurs due to the involvement of the **descending sympathetic tract** located in the lateral medulla [1]. It presents with ipsilateral ptosis, miosis, and anhidrosis. Therefore, stating it is "rare" is clinically incorrect, making it the right choice for an "EXCEPT" question. **Analysis of other options:** * **A. Giddiness:** This is a hallmark symptom caused by involvement of the **vestibular nuclei** and their connections, leading to vertigo, nausea, and nystagmus [2]. * **B. Dysphagia:** This occurs due to damage to the **Nucleus Ambiguus** (affecting CN IX and X), which leads to paralysis of the palatal and pharyngeal muscles, causing dysphagia, dysarthria, and a diminished gag reflex [3]. * **C. Crossed hemianaesthesia:** This is a classic finding [1]. It refers to **ipsilateral** loss of pain and temperature on the face (due to the **Spinal Trigeminal Nucleus**) and **contralateral** loss of pain and temperature on the body (due to the **Lateral Spinothalamic Tract**) [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for PICA Syndrome:** "DANVAH" (Dysarthria/Dysphagia, Ataxia, Nystagmus, Vertigo, Anaesthesia (crossed), Horner’s). * **Key Distinction:** Wallenberg syndrome **spares the Motor system** (Corticospinal tract) and the **Medial Lemniscus** (fine touch/proprioception), as these are located medially. * **Most common cause:** Vertebral artery occlusion is actually more frequent than isolated PICA occlusion.

Q: Which of the following is not useful for the diagnosis of myasthenia gravis?

Voltage-gated calcium channel antibodies. ### Explanation **Myasthenia Gravis (MG)** is an autoimmune disorder of the neuromuscular junction (NMJ) characterized by muscle weakness and fatigability. The diagnosis relies on demonstrating the presence of specific autoantibodies or physiological responses at the postsynaptic membrane. **Why Voltage-gated calcium channel (VGCC) antibodies is the correct answer:** VGCC antibodies are the hallmark of **Lambert-Eaton Myasthenic Syndrome (LEMS)**, not Myasthenia Gravis [1]. In LEMS, antibodies attack the *presynaptic* calcium channels, preventing the release of acetylcholine [3]. In contrast, MG is a *postsynaptic* disorder [2]. **Analysis of other options:** * **AChR antibodies:** These are the most specific markers for MG, found in approximately 85% of patients with generalized MG and 50% with ocular MG. * **Muscle-specific kinase (MuSK) antibodies:** These are found in about 30–40% of patients who are "seronegative" for AChR antibodies. * **Edrophonium (Tensilon) test:** This is a pharmacological test using a short-acting acetylcholinesterase inhibitor. A rapid, transient improvement in muscle strength (e.g., resolution of ptosis) is diagnostic of MG [1]. --- ### High-Yield Clinical Pearls for NEET-PG: * **Most Sensitive Test:** Single-fiber Electromyography (SFEMG) showing increased "jitter." * **Initial Screening Test:** AChR antibody titer (highly specific). * **Bedside Test:** Ice pack test (improvement of ptosis due to cold inhibiting acetylcholinesterase). * **Associated Pathology:** Thymoma (found in 10–15% of MG patients); a CT chest is mandatory in all newly diagnosed cases [1]. * **Treatment of Choice:** Pyridostigmine (first-line) and Thymectomy (indicated in most patients aged 15–60) [1].

Q: A 35-year-old patient presents with numbness over the neck. On examination, decreased pain and temperature sensation is found in the distribution of C4 and C5 dermatomes. Scalp sensation, cranial nerve function, and limb examination are normal. Bladder and bowel sphincter control are normal. What is the diagnosis?

An intramedullary tumor. ### Explanation The clinical presentation of **dissociated sensory loss** (loss of pain and temperature with preserved touch/proprioception) in a specific dermatomal distribution (C4–C5) is the hallmark of a **central cord syndrome**, most commonly caused by an **intramedullary tumor** (e.g., ependymoma) or syringomyelia [1]. **Why Intramedullary Tumor is correct:** The spinothalamic tract fibers, which carry pain and temperature, decussate in the **anterior white commissure** of the spinal cord. A lesion expanding from the center of the cord (intramedullary) first compresses these crossing fibers at the level of the lesion. This results in a "suspended sensory loss" or "cape-like" distribution. Because the lesion is central, the peripherally located sacral fibers and long tracts (motor and dorsal columns) are initially spared, explaining the normal limb examination and bladder/bowel control. **Why other options are incorrect:** * **Amyotrophic Lateral Sclerosis (ALS):** This is a pure motor neuron disease involving both upper and lower motor neurons. It does **not** present with sensory loss. * **Neurosyphilis (Tabes Dorsalis):** This involves the **dorsal columns**. It would present with loss of vibration and proprioception (sensory ataxia) rather than pain and temperature loss. * **AIDP (Guillain-Barré Syndrome):** This is a peripheral demyelinating process typically presenting with ascending symmetrical paralysis and areflexia, not a localized dermatomal sensory dissociation. **NEET-PG High-Yield Pearls:** * **Dissociated Sensory Loss:** Loss of pain/temp + Preserved touch/vibration = Central Cord Lesion. * **Sacral Sparing:** A key feature of intramedullary lesions because sacral fibers are located most peripherally in the spinothalamic tract. * **Most common intramedullary tumor in adults:** Ependymoma. * **Most common intramedullary tumor in children:** Astrocytoma.

Q: A 68-year-old man presents with delirium secondary to a urinary tract infection. Following successful treatment of the infection, his mental status improved, but he exhibits persistent disorientation, impaired short-term memory, difficulty naming objects, and poor concentration. His family reports an 8-month history of gradual cognitive decline. He is now unable to manage finances and has a history of getting lost twice while driving. Post-discharge, he has urinary incontinence and an unsteady gait requiring assistance. Which disorder most likely accounts for this patient's dementia?

Normal pressure hydrocephalus. **Explanation:** The clinical presentation highlights the classic triad of **Normal Pressure Hydrocephalus (NPH)**, often remembered by the mnemonic **"Wet, Wobbly, and Wacky."** 1. **Wacky (Cognitive Decline):** The patient has an 8-month history of gradual cognitive impairment (disorientation, memory loss, and executive dysfunction like inability to manage finances). 2. **Wobbly (Gait Disturbance):** He exhibits an unsteady gait requiring assistance. In NPH, this is typically a "magnetic gait" (short steps, feet appearing stuck to the floor). 3. **Wet (Urinary Incontinence):** The development of incontinence post-infection indicates a persistent neurological issue rather than just the acute UTI. **Why the other options are incorrect:** * **Creutzfeldt-Jakob Disease (CJD):** Characterized by *rapidly* progressive dementia (weeks to months) and myoclonus. An 8-month gradual decline is too slow for typical CJD. * **Huntington Disease:** Presents with choreiform movements and psychiatric symptoms, usually in younger patients (30s–40s), with a strong autosomal dominant family history. * **Parkinson Disease:** While it features gait issues, the primary symptoms are resting tremor, rigidity, and bradykinesia. Dementia in PD typically occurs many years *after* the onset of motor symptoms. **NEET-PG High-Yield Pearls:** * **Pathophysiology:** NPH is caused by impaired CSF resorption at the arachnoid villi, leading to ventricular enlargement with *normal* opening pressure on lumbar puncture. * **Diagnosis:** MRI shows ventriculomegaly out of proportion to sulcal atrophy (Evans Index >0.3). * **Treatment:** It is a **reversible cause of dementia**. The "Miller Fisher Test" (large volume lumbar puncture) is used to see if symptoms improve; definitive treatment is a **Ventriculoperitoneal (VP) shunt**.

Q: A 12-year-old boy presents with a history of progressively increasing difficulty in walking and frequent falls. Physical examination reveals an ataxic gait and nystagmus. All deep tendon reflexes are absent, and the plantar response is extensor. What is the most likely diagnosis?

Friedreich's Ataxia. ### Explanation The clinical presentation of a young patient with progressive ataxia, nystagmus, absent deep tendon reflexes (DTRs), and extensor plantar response (Babinski sign) is classic for **Friedreich’s Ataxia (FRDA)**. **Why Friedreich’s Ataxia is correct:** FRDA is an autosomal recessive trinucleotide repeat (GAA) disorder affecting the *FXN* gene (frataxin). The pathology involves the degeneration of: 1. **Posterior Columns:** Loss of vibration and position sense. 2. **Spinocerebellar Tracts:** Leading to gait and limb ataxia. 3. **Corticospinal Tracts:** Resulting in upper motor neuron signs (extensor plantar response). 4. **Dorsal Root Ganglia:** Leading to the loss of DTRs (lower motor neuron component). The combination of **absent DTRs (LMN sign) + extensor plantar (UMN sign)** is a high-yield clinical hallmark of FRDA. **Why other options are incorrect:** * **Subacute Combined Degeneration (SCD):** Caused by Vitamin B12 deficiency. While it involves posterior columns and corticospinal tracts, it typically presents in adults and is associated with megaloblastic anemia, not primary cerebellar signs like nystagmus. * **Becker’s Muscular Dystrophy:** An X-linked recessive disorder characterized by proximal muscle weakness and pseudohypertrophy of calves. It does not present with ataxia or UMN signs. * **Tabes Dorsalis:** A late manifestation of neurosyphilis. It involves the posterior columns (sensory ataxia and absent DTRs) and presents with Argyll Robertson pupils, but it does not typically cause nystagmus or extensor plantar responses. **NEET-PG High-Yield Pearls:** * **Most common** hereditary ataxia. * **Genetic defect:** GAA repeat on Chromosome 9. * **Associated features:** Hypertrophic cardiomyopathy (most common cause of death), Diabetes Mellitus, and skeletal deformities (Kyphoscoliosis, Pes Cavus). * **Key Triad:** Progressive ataxia + Absent DTRs + Extensor Plantar.

Question 1

A patient presents with the CT finding shown in the image. Which one of the following signs is this finding most likely to produce?

Accepted Answer

Hemiplegia

Answer

Uniocular blindness

Answer

Alexia without agraphia

Answer

Hemiballismus

Question 2

Which of the following conditions has the least chance of causing seizures?

Accepted Answer

HIV encephalopathy

Answer

Hypoglycemia

Answer

Hypocalcemia

Answer

Neurocysticercosis

Question 3

Unilateral stepping gait is seen in all except?

Accepted Answer

Distal polyneuropathy

Answer

L5 radiculopathy

Answer

Sciatic neuropathy

Answer

Peroneal neuropathy

Question 4

Which of the following can cause 3rd nerve paralysis?

Accepted Answer

Midbrain infarct

Answer

Posterior communicating artery (PCA) aneurysm

Answer

Tolosa-Hunt syndrome

Answer

Lateral medullary lesions

Question 5

Lateral medullary syndrome (Wallenberg syndrome) is characterized by all features EXCEPT:

Accepted Answer

Horner's syndrome is rare

Answer

Giddiness

Answer

Dysphagia

Answer

Crossed hemianaesthesia

Question 6

Which of the following is not useful for the diagnosis of myasthenia gravis?

Accepted Answer

Voltage-gated calcium channel antibodies

Answer

AChR antibodies

Answer

Muscle-specific kinase antibodies

Answer

Edrophonium test

Question 7

A 35-year-old patient presents with numbness over the neck. On examination, decreased pain and temperature sensation is found in the distribution of C4 and C5 dermatomes. Scalp sensation, cranial nerve function, and limb examination are normal. Bladder and bowel sphincter control are normal. What is the diagnosis?

Accepted Answer

An intramedullary tumor

Answer

Amyotrophic lateral sclerosis

Answer

Neurosyphilis

Answer

Acute inflammatory demyelinating polyneuropathy (AIDP)

Question 8

A 68-year-old man presents with delirium secondary to a urinary tract infection. Following successful treatment of the infection, his mental status improved, but he exhibits persistent disorientation, impaired short-term memory, difficulty naming objects, and poor concentration. His family reports an 8-month history of gradual cognitive decline. He is now unable to manage finances and has a history of getting lost twice while driving. Post-discharge, he has urinary incontinence and an unsteady gait requiring assistance. Which disorder most likely accounts for this patient's dementia?

Accepted Answer

Normal pressure hydrocephalus

Answer

Creutzfeldt-Jakob disease

Answer

Huntington disease

Answer

Parkinson disease

Question 9

A 12-year-old boy presents with a history of progressively increasing difficulty in walking and frequent falls. Physical examination reveals an ataxic gait and nystagmus. All deep tendon reflexes are absent, and the plantar response is extensor. What is the most likely diagnosis?

Accepted Answer

Friedreich's Ataxia

Answer

Subacute Combined Degeneration of Cord

Answer

Becker's Muscular Dystrophy

Answer

Tabes Dorsalis

Question 10

In Bell's palsy, in which part of the face is a neurological lesion typically seen?

Accepted Answer

Upper and lower parts of one half of the face

Answer

Upper part of the face

Answer

Lower part of one half of the face

Answer

Upper and lower parts of the opposite side of the face

Neurology — MCQs

Neurology — MCQs

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