Virology USMLE Step 1 Practice Question
A 58-year-old man presents with rapidly progressive dementia, ataxia, and myoclonus over three months. Vital signs show BP 128/82, HR 88, RR 16, temp 37.2°C, SpO2 98%. Electroencephalography demonstrates periodic sharp wave complexes. Brain MRI reveals cortical atrophy with T2 hyperintensities in basal ganglia. Cerebrospinal fluid protein is elevated at 95 mg/dL with negative bacterial culture. Brain biopsy shows spongiform change without inflammatory infiltrates. Which of the following best describes the pathogenesis of this disease?
Answer choices
- AProtozoal invasion of basal ganglia neurons
- BImmune complex deposition in cerebral vessels
- CLatent infection with a double stranded DNA virus
- DMisfolded protein inducing conformational change in normal host proteinsCorrect answer
- EAutoantibody binding to postsynaptic acetylcholine receptors
- FReactivation of a latent neurotropic RNA virus
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