Sheet 5 Flashcards
What are the classic features of neurodegenerative diseases?
1) Progressive and slow loss of neurons
2) Typically affects groups of neurons with functional interconnections
3) Different diseases involve different neural systems = different symptoms
4) The histologic hallmark for ALL diseases is the accumulation of protein aggregates
5) Same protein may aggregate in different diseases, but at different distributions
6) Proteins resist degradation, accumulate within the cells, elicit inflammatory response, and are toxic to neurons = neurons will die while proteins will stay and spread from one cell to another
What are the causes of protein accumulation?
1) Mutations that alter protein conformation as the protein is misfolded and resistant to cleavage
2) Mutations disrupting the processing and clearance of proteins
3) Subtle imbalance between protein synthesis and clearance (genetic or environmental factors)
What happens if the neurodegenerative disease involves the cortex?
Causes dementia, which is a collection of cognitive abnormalities (memory, behaviour and language).
What are examples of neurodegenerative diseases involving the cortex?
1) Alzheimer disease (AD)
2) Frontotemporal dementia (FTD)
3) Pick disease (subtype of FTD)
What happens if the neurodegenerative disease involves the basal ganglia?
Causes movement disorders
What are examples of neurodegenerative diseases involving the basal ganglia?
1) Parkinson disease: causes hypokinesia
2) Huntington disease: causes hyperkinesia
Parkinson disease causes __(hyperkinesia/hypokinesia), while Huntington disease causes __ (hyperkinesia/hypokinesia).
Hypokinesia; hyperkinesia
What happens if the neurodegenerative disease involves the cerebellum?
Causes ataxia because cerebellum is the coordinator of balance
What are examples of neurodegenerative diseases involving the cerebellum?
Spinocerebellar ataxia
What happens if the neurodegenerative disease involves the motor system?
Causes difficulty swallowing and respiration with muscle weakness
What are examples of neurodegenerative diseases involving the motor system?
Amyotrophic lateral sclerosis
Can neurodegenerative diseases be communicable?
No, there is no evidence of person-to-person transmission
What are the common features of neurodegenerative diseases?
1) Protein aggregates can seed the development of more aggregates
2) Protein aggregates can spread from one neuron to another in Prion-like pattern
3) Activation of the innate immune system
What is dementia?
The development of memory impairment and other cognitive deficits severe enough to decrease the person’s capacity to function at his previous level despite normal level of consciousness.
What is the difference between dementia and mild cognitive impairment?
The cognitive deficit must affect the person’s performance in his daily life activities to be called dementia
What are the cognitive changes of dementia?
1) Memory loss, which is usually noticed by someone else
2) Difficulty communicating or finding words
3) Difficulty reasoning or problem-solving (solving math problem for example)
4) Difficulty handling complex tasks (Many tasks at the same time)
5) Difficulty with planning and organizing
6) Difficulty with coordination and motor functions later (can’t wear his boots)
7) Confusion and disorientation
What are the psychological changes of dementia?
1) Personality changes
2) Depression
3) Anxiety
4) Inappropriate behavior
5) Paranoia
6) Agitation
7) Hallucinations
What are the complications of dementia?
1) Inadequate nutrition
2) Pneumonia
3) Inability to perform self-care tasks
4) Personal safety challenges
5) Death due to infections from aspiration of food (pneumonia)
What is the most common cause of dementia in older adults?
Alzheimer disease (AD)
Describe the incidence of Alzheimer disease (AD).
Increases with age (47% in those over 84 years).
What are some characteristics of Alzheimer disease (AD)?
1) Most cases are sporadic
2) 5-10% are familial (onset before 50)
3) Gradual onset
4) Impaired higher intellectual functions as recognition is weak, memory
impairment and altered mood and behavior.
5) Severe cortical dysfunction occurs late in this disease (disorientation, aphasia, profound disability, mute, and immobile)
6) Death usually due to infections (pneumonia)
What are the phases of Alzheimer disease (AD)?
1) Asymptomatic phase: Proteins start to aggregate
but the patient doesn’t show
2) Predementia phase: Early symptoms related to memory starts to appear, cognitive domains in the brain are not affected that much
3) Dementia phase: Decline in at least one cognitive skill that impairs daily functioning and independence.
What is the most commonly recognized symptom of Alzheimer Disease (AD)?
Inability to acquire new memories and difficulty in recalling recently observed facts.
What are the symptoms of advancing Alzheimer Disease (AD)?
1) Confusion
2) Irritability and aggression
3) Mood swings
4) Language breakdown
5) Long term memory loss
6) A gradual loss of bodily functions
7) Death
How does Alzheimer Disease (AD) occur?
Accumulation of two proteins: αβ amyloid and Tau in the form of plaques outside the cell and neurofibrillary tangles inside the cell = neuronal dysfunction, death, and inflammation.