02-09-2006, 07:55 AM
A 55-year-old man is brought to his physician's office with a 3-month history of progressive mental
deterioration in the form of memory loss, mood changes, and errors in judgment. His gait is
unsteady, and he requires assistance to prevent falling. He has no history of seizures, head
trauma, or incontinence. Computed tomography (CT) scan and lumbar puncture are unremarkable.
Physical examination reveals hypertonicity of all extremities, bilateral equivocal plantar
response, ataxic gait, and myoclonic jerks in the lower extremities. What is the mechanism by
which this infectious agent causes its pathology?
A. Amyloid deposition
B. Autoimmune destruction
C. Chronic inflammation
D. Embolization and infarction
E. Toxin production
deterioration in the form of memory loss, mood changes, and errors in judgment. His gait is
unsteady, and he requires assistance to prevent falling. He has no history of seizures, head
trauma, or incontinence. Computed tomography (CT) scan and lumbar puncture are unremarkable.
Physical examination reveals hypertonicity of all extremities, bilateral equivocal plantar
response, ataxic gait, and myoclonic jerks in the lower extremities. What is the mechanism by
which this infectious agent causes its pathology?
A. Amyloid deposition
B. Autoimmune destruction
C. Chronic inflammation
D. Embolization and infarction
E. Toxin production