Which diseases are fatal brain disorders that are caused by the prion protein?

RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Medical & Surgical Nursing

Easy

Appeared in: RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Explanation

Creutzfeldt-Jakob disease (CJD) is a fatal, degenerative brain disorder caused by prions.
Prions are abnormal, misfolded forms of the cellular prion protein (PrPC) that become infectious.
These prions (PrPSc) cause a chain reaction, inducing normal proteins to misfold, leading to exponential accumulation in the brain.
This process results in characteristic spongiform (sponge-like) changes, neuronal death, and rapidly progressive dementia.

Option A: Pick's Disease is a type of frontotemporal dementia, but it is caused by the abnormal accumulation of tau proteins (known as Pick bodies), not prion proteins.
Option B: Mad Cow Disease, or Bovine Spongiform Encephalopathy (BSE), is a prion disease, but it primarily affects cattle. The question asks for a human disease, and CJD is the specific human prion disease listed.
Option D: Lewy Body Disease (or Dementia with Lewy Bodies) is caused by abnormal deposits of a protein called alpha-synuclein, which form Lewy bodies in the brain.

Visual 1: Diagram - A flowchart showing the conversion of a normal prion protein (PrPC) into the abnormal, disease-causing form (PrPSc), illustrating the chain-reaction mechanism.
Visual 2: Microscopic Image - A micrograph of brain tissue from a CJD patient showing spongiform changes (vacuoles), neuronal loss, and gliosis, contrasted with healthy brain tissue.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Neurodegenerative Disorders as background academic context rather than a clinical decision trigger.
Prion diseases like CJD are unique because they can be sporadic, inherited, or acquired through infection, making diagnosis and public health surveillance critical.
Due to the risk of iatrogenic transmission (e.g., through contaminated surgical instruments), special, stringent sterilization procedures are required for equipment used on patients with suspected CJD.
What if? If a patient presents with rapidly progressive dementia and myoclonus, a nurse should anticipate diagnostic tests like EEG (looking for periodic sharp wave complexes), brain MRI (for characteristic signal changes), and CSF analysis for 14-3-3 protein, and prioritize safety measures due to ataxia and cognitive decline.

How to Approach the Question

First, identify the key term in the question: 'prion protein'. This is the central concept you need to match with the options.
Evaluate each option based on its known pathological cause.
Recall or determine that Pick's Disease is a 'tauopathy' (caused by tau protein) and Lewy Body Disease is a 'synucleinopathy' (caused by alpha-synuclein protein). Eliminate these options.
Differentiate between Mad Cow Disease and Creutzfeldt-Jakob disease. Recognize that both are prion diseases, but Mad Cow Disease (BSE) refers to the illness in cattle, while CJD is the primary human form.
Select Creutzfeldt-Jakob disease as the most appropriate answer for a fatal human brain disorder caused by prions from the given choices.

Concept Tested & Keywords

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