PANRE Neurology 3

Question 1

A 45-year-old with HIV presents with focal seizures and a ring-enhancing lesion on MRI. The most likely diagnosis is:

Accepted Answer

Toxoplasma encephalitis

Answer

In HIV-positive patients, a ring-enhancing brain lesion most commonly represents Toxoplasma gondii encephalitis, especially when CD4 count is below 100 cells/µL.

Question 2

Which feature best differentiates migraine with aura from a TIA?

Accepted Answer

Positive phenomena that march across the visual field

Answer

Migraine aura features positive phenomena (e.g., scintillating scotoma that spreads) and evolves slowly over minutes, while TIA causes negative, abrupt deficits.

Question 3

A patient with myasthenia gravis undergoes elective surgery. Which medication should be avoided perioperatively due to risk of cholinergic crisis if combined with pyridostigmine?

Accepted Answer

Succinylcholine

Answer

Succinylcholine is a depolarizing neuromuscular blocker metabolized by acetylcholinesterase; pyridostigmine inhibits this enzyme, leading to prolonged paralysis or crisis.

Question 4

A 30-year-old presents with bilateral leg weakness, ascending numbness, and loss of deep tendon reflexes following a GI infection 2 weeks ago. CSF shows elevated protein with normal cell count. Diagnosis?

Accepted Answer

Guillain-Barré syndrome

Answer

Guillain-Barré syndrome is a post-infectious ascending demyelinating polyneuropathy characterized by albuminocytologic dissociation (high protein, normal cells) in the CSF.

Question 5

Which antiepileptic drug is contraindicated in pregnancy due to highest risk of neural tube defects?

Accepted Answer

Valproate

Answer

Valproate inhibits folate metabolism and is associated with a 1–2% risk of neural tube defects and multiple other congenital abnormalities, making it contraindicated in pregnancy when possible.

PANRE Test Practice Test

PANRE Test Practice Test

PANRE Neurology 3