QBDOTW: A 43-year-old Female with Involuntary Facial Movement
Welcome to MedSmarter’s USMLE Style Question Break Down of the Week. For those preparing for the USMLE Step 1, this week we break down a high-yield Neurology question. As mentioned previously, you always want to begin with reading the last sentence of the vignette first to get a good understanding of what the question is asking for.
Question Break Down of the Week:
A 43-year-old female comes to the physician because of the gradual onset of involuntary facial and extremity movements, increasing mood swings, and difficulty with her memory. She says that her mother displayed similar symptoms when she was in her 50s. Which of the following changes would most likely be seen in the brain of this patient?
A) Accumulation of neuritic plaques
B) Copper accumulation in the basal ganglia
C) Gliosis of the caudate nucleus
D) Loss of pigmentation in substantia nigra
E) Scattered plaques of demyelination
The correct answer choice is C: This patient is suffering from the onset of Huntington’s disease. Huntington’s disease is classically characterized by choreiform movements, dystonia, altered behavior, and dementia. Its inheritance is an autosomal dominant disease involving multiple abnormal CAG triplet repeats on chromosome 4p and demonstrates anticipation (increasing disease severity and earlier age of onset with each generation). The caudate and putamen are mainly affected, altering the indirect pathway of the basal ganglia, which results in loss of motor inhibition. Gliosis in these areas results in hyperkinesia.
Did you think the answer was different?
Did you think that the correct answer choice was other than C? You can view this video for a deeper discussion of why A, B, D, and E were not the correct answer choices.
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