Which neurotransmitter is deficient in Parkinson's disease?

NORCET 9 Mains - 2025

Medical Surgical Nursing

Easy

Appeared in: NORCET 9 Mains - 2025

Explanation

Parkinson's disease is a neurodegenerative disorder caused by the progressive loss of dopamine-producing neurons in a specific area of the brain called the substantia nigra.
Dopamine is a crucial neurotransmitter for controlling smooth, purposeful movement. Its deficiency disrupts the balance of signals in the basal ganglia.
This loss of dopamine leads to the characteristic motor symptoms of Parkinson's: resting tremor, rigidity, bradykinesia (slowness of movement), and postural instability.
Dopaminergic dysfunction is a well-established hallmark of Parkinson's disease, and treatment focuses on replenishing or mimicking the action of dopamine.

Option B: While serotonin levels can be reduced and contribute to non-motor symptoms like depression and anxiety in Parkinson's, it is not the primary neurotransmitter responsible for the core motor deficits.
Option C: In Parkinson's, acetylcholine is not deficient. Instead, the loss of dopamine creates a relative excess of acetylcholine activity, which contributes to symptoms like tremor.
Option D: GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system. While it is involved in the complex circuitry of the basal ganglia that is disrupted in Parkinson's, a deficiency of GABA itself is not the underlying cause of the disease.

Visual 1: Diagram: Comparison of a healthy brain and a Parkinson's brain, highlighting the degeneration of the substantia nigra and the resulting decrease in dopamine.
Visual 2: Flowchart: Illustrating the chemical imbalance in Parkinson's, showing how decreased dopamine leads to a relative increase in acetylcholine, causing motor symptoms.

Clinical Relevance

Nursing practice connection: Knowing Pathophysiology of Parkinson's Disease: Neurotransmitter Imbalance helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the dopamine deficit is fundamental to nursing care, as the primary treatment involves dopamine replacement therapy (e.g., Levodopa/Carbidopa).
Nurses must monitor for the 'on-off' phenomenon and dyskinesias, which are side effects of long-term dopamine replacement therapy, and educate patients on managing these fluctuations.
What if? If a patient with Parkinson's develops severe confusion and hallucinations, the nurse should consider that this could be a side effect of dopamine agonist medication and report it, as the dosage may need adjustment.

How to Approach the Question

First, identify the key terms in the question: 'Parkinson's disease' and 'deficient neurotransmitter'.
This is a factual recall question that requires knowledge of the pathophysiology of a specific neurological disorder.
Recall the primary cause of Parkinson's motor symptoms. The disease is classically defined by the loss of dopamine-producing cells.
Evaluate the options based on this core fact. Dopamine is the only option that represents the primary deficiency.
Consider the roles of the other neurotransmitters to confirm the answer. The loss of dopamine leads to a relative excess of acetylcholine, not a deficiency.

Concept Tested & Keywords

Concept Tested: Pathophysiology of Parkinson's Disease: Neurotransmitter Imbalance
Stem keywords: neurotransmitter, deficient, Parkinson's disease
Lead-in keywords: Which
Negative lead-in flag: false

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