Neurology: Parkinson disease pathology: practice question

A General Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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General Medicine · Neurology: Parkinson disease pathology

Sample item

A 65-year-old man has a 4 to 6 Hz pill-rolling resting tremor, bradykinesia and cogwheel rigidity. What is the underlying pathology?

ALoss of GABAergic medium spiny neurons in the striatumBLoss of dopaminergic neurons in the substantia nigra pars compacta with Lewy bodiesCLoss of Purkinje cells in the cerebellumDLoss of cholinergic neurons in the nucleus basalis of Meynert

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Loss of dopaminergic neurons in the substantia nigra pars compacta with Lewy bodies

Parkinson disease results from degeneration of dopaminergic neurons of the pars compacta, with intracellular alpha-synuclein inclusions called Lewy bodies. The resulting dopamine deficit reduces the direct pathway output of the basal ganglia. Treatment replaces dopamine with levodopa or agonists.

Option by option

A. Loss of GABAergic medium spiny neurons in the striatum
Striatal GABAergic neuron loss is the pathology of Huntington disease.
B. Loss of dopaminergic neurons in the substantia nigra pars compacta with Lewy bodies (correct)
Correct. Nigral dopaminergic loss with Lewy bodies defines Parkinson disease.
C. Loss of Purkinje cells in the cerebellum
Purkinje cell loss causes cerebellar ataxia.
D. Loss of cholinergic neurons in the nucleus basalis of Meynert
Loss of nucleus basalis cholinergic neurons occurs in Alzheimer disease.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is B, Loss of dopaminergic neurons in the substantia nigra pars compacta with Lewy bodies. Parkinson disease results from degeneration of dopaminergic neurons of the pars compacta, with intracellular alpha-synuclein inclusions called Lewy bodies.

Why is "Loss of GABAergic medium spiny neurons in the striatum" not the answer?

Striatal GABAergic neuron loss is the pathology of Huntington disease.

Why is "Loss of Purkinje cells in the cerebellum" not the answer?

Purkinje cell loss causes cerebellar ataxia.

Why is "Loss of cholinergic neurons in the nucleus basalis of Meynert" not the answer?

Loss of nucleus basalis cholinergic neurons occurs in Alzheimer disease.

What concept does this question test?

It tests Neurology: Parkinson disease pathology in General Medicine. The resulting dopamine deficit reduces the direct pathway output of the basal ganglia. Treatment replaces dopamine with levodopa or agonists.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neurology: Parkinson disease pathology?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.