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NORCET 10 Mains
Medical & Surgical Nursing
Easy

Which neurotransmitter is primarily deficient in Parkinson’s disease?

Appeared in: NORCET 10 Mains

Explanation

  • Parkinson's disease is fundamentally a disorder of the dopaminergic system.
  • It is characterized by the death of dopamine-producing neurons in a specific brain area called the substantia nigra.
  • This loss leads to a profound deficiency of dopamine, which is a neurotransmitter essential for coordinating smooth, controlled muscle movements.
  • The lack of dopamine directly results in the primary motor symptoms of Parkinson's, including resting tremors, muscle rigidity, and bradykinesia (slowness of movement).
  • Therapeutic strategies, such as the use of Levodopa (a dopamine precursor) and dopamine agonists, are designed to counteract this specific deficiency.

Why Other Options Were Wrong

  • Option B: Acetylcholine is not deficient in Parkinson's disease. Instead, the loss of dopamine creates a relative imbalance, making the excitatory effects of acetylcholine more pronounced.
  • Option C: While serotonin levels can be reduced in Parkinson's disease, this is considered a secondary issue and not the primary cause of the core motor symptoms.
  • Option D: GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter, and its function within the brain's motor circuits is altered as a downstream effect of dopamine loss, but it is not the primary deficient neurotransmitter.

Related Visual

A simplified comparison of a healthy brain and a Parkinsons brain, showing the substantia nigra and the reduced release of dopamine in the striatum in the Parkinsons brain.
Clinical Relevance
  • Nursing practice connection: Knowing Pathophysiology of Parkinson's Disease: Neurotransmitter Deficiency helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
  • A nurse's primary role involves assessing for the cardinal signs of Parkinson's (tremor, rigidity, bradykinesia, postural instability), which are direct results of dopamine deficiency.
  • Understanding that dopamine is deficient explains the mechanism of action for primary Parkinson's medications like Levodopa/Carbidopa, which nurses frequently administer. The goal is to replenish dopamine.
  • The concept of the dopamine-acetylcholine imbalance is critical. Nurses monitor for side effects of anticholinergic drugs (used to reduce acetylcholine's effect), such as dry mouth, blurred vision, and confusion.
How to Approach the Question
  • First, identify the key terms in the question: 'primarily deficient,' 'neurotransmitter,' and 'Parkinson’s disease.'
  • The word 'primarily' is a crucial qualifier, indicating you need to find the main or most important neurotransmitter involved.
  • Recall the fundamental pathophysiology of Parkinson's disease. The core of the disease is the loss of specific neurons.
  • Connect the loss of these neurons to the neurotransmitter they produce. The neurons lost are in the substantia nigra, and they produce dopamine.
  • Evaluate the options based on this core fact. Dopamine is directly deficient. The other neurotransmitters are involved in secondary or indirect ways.
  • Select the option that represents the foundational cause of the motor symptoms, which is dopamine.
Concept Tested & Keywords
  • Concept Tested: Pathophysiology of Parkinson's Disease: Neurotransmitter Deficiency
  • Stem keywords: neurotransmitter, deficient, Parkinson’s disease
  • Lead-in keywords: primarily

Question ID

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Reference Book

E6 Robert Boland, Marcia L. Verduin - Kaplan and Sadock's Comprehensive Text of Psychiatry-Wolters Kluwer Health (2024) (pp 1-16525 of 16525) p. 10088-10090

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