medicine beginner 10 sample questions

Neurology MCQ Practice Test

Nervous system disorder management

Q1. A patient on carbamazepine develops diplopia and ataxia, and the serum drug level is above the therapeutic range. The most likely cause is:

Explanation: Carbamazepine (like phenytoin) causes diplopia, ataxia, and nystagmus when levels exceed the therapeutic range — classic cerebellar toxicity, often from accumulation or interactions. It is not a GABA-transaminase or cholinesterase inhibitor.

Q2. A patient with a history of recurrent Migraines with aura is found to have a discrepancy in the visual field between the two eyes. Which of the following conditions is the cornerstone of the pathophysiology?

Explanation: The patient's symptoms and visual field discrepancy are suggestive of a condition known as Familial Hemiplegic Migraine. This condition is closely linked to mutations in the CACNA1A gene, which codes for a subunit of the P/Q-type voltage-gated calcium channel. Alterations in the cerebral vasculature, specifically the blood vessels of the brain, play a critical role in the pathophysiology of this condition.

Q3. A 30-year-old patient with a history of traumatic brain injury presents with persistent vegetative state. Which of the following medications is most likely to be used to manage their associated spasticity?

Explanation: Baclofen is a GABA receptor agonist that is commonly used to manage spasticity in patients with spinal cord injuries or traumatic brain injuries. It can be administered intrathecally via a lumbar puncture, which is a common treatment for patients with severe spasticity who have not responded to oral medications.

Q4. A 35-year-old woman with a history of recurrent seizures is found to have a heterozygous mutation in the SCN1A gene. Which of the following medications is most likely to be effective in controlling her seizures?

Explanation: Rufinamide is a medication that is specifically approved for the treatment of seizures associated with Dravet syndrome, a condition caused by mutations in the SCN1A gene. It works by stabilizing inactivated sodium channels, which is particularly beneficial in this patient population.

Q5. A 45-year-old patient with a history of multiple sclerosis presents with worsening dysarthria and dysphagia. Which of the following is the most likely cause of this patient's symptoms?

Explanation: The patient's worsening dysarthria and dysphagia, in the context of multiple sclerosis, suggest a secondary cause of these symptoms. Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the John Cunningham virus (JCV). It is a known complication of multiple sclerosis and can present with progressive neurological decline, including dysarthria and dysphagia. The other options are less likely, as they typically present with different clinical features and are not directly related to multiple sclerosis or are very rare.

Q6. A 35-year-old woman with a history of recurrent generalized tonic-clonic seizures, treated with carbamazepine, presents with a 2-week history of increasing fatigue, weakness, and a 4.5 kg weight gain. Laboratory findings show a mild anemia of chronic disease, elevated liver enzymes, and a serum sodium level of 130 mEq/L. Which of the following is the most likely cause of her hyponatremia?

Explanation: Carbamazepine can cause hyponatremia by stimulating the release of vasopressin, leading to water retention and subsequent hyponatremia. This is due to its effect on the hypothalamus, leading to SIADH.

Q7. A 35-year-old patient with a history of recurrent generalized tonic-clonic seizures is started on a new antiepileptic medication. After 2 weeks, the patient presents with diplopia, ataxia, and confusion. Laboratory tests reveal an increase in the patient's INR. Which of the following medications is most likely responsible for this patient's presentation?

Explanation: Phenytoin is known to induce the cytochrome P450 enzyme system, leading to increased metabolism of vitamin K-dependent clotting factors and thus a higher INR. Additionally, phenytoin can cause cerebellar dysfunction, leading to ataxia and confusion, and can also cause blurred vision and diplopia due to its effects on the cerebellum and visual pathways.

Q8. A 45-year-old patient with a history of multiple sclerosis presents with worsening spasticity and increased muscle tone in the lower extremities. Which of the following medications, used in combination with baclofen, is most likely to be beneficial in this patient?

Explanation: Rimabotulinumtoxin B can be used in combination with baclofen to reduce muscle tone and spasticity in patients with multiple sclerosis. Dalfampridine is used to enhance nerve conduction, tizanidine is a muscle relaxant that can be used to manage spasticity, but it is not used in combination with baclofen. Gabapentin is used to manage neuropathic pain, but it is not specifically indicated for spasticity in multiple sclerosis.

Q9. A 35-year-old patient with a history of recurrent episodes of peripheral neuropathy is diagnosed with a rare genetic disorder. The patient's symptoms are exacerbated by a specific medication used to treat another condition. Which of the following medications is most likely to be the culprit?

Explanation: Methotrexate is known to cause or exacerbate peripheral neuropathy in some patients, particularly those with a history of recurrent episodes. This is due to its toxic effects on the nerves, leading to demyelination and axonal damage. The patient's genetic disorder may predispose them to this adverse effect, making methotrexate a likely culprit.

Q10. A 35-year-old patient with a history of recurrent hemiplegic migraines is found to have a mutation in the CACNA1A gene. Which of the following is the most likely mechanism by which this mutation contributes to the development of hemiplegic migraines?

Explanation: The CACNA1A gene encodes the alpha 1A subunit of the P/Q-type calcium channel. Mutations in this gene have been shown to increase the permeability of the calcium channel to sodium ions, leading to an influx of sodium ions and subsequent neuronal hyperexcitability, which is thought to contribute to the development of hemiplegic migraines.

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Neurology MCQ Practice Test | Mind Hustle