DAT, Parkinson's, MND Flashcards
What is the DSM5 criteria for DAT?
- evidence of significant cognitive decline from a previous level of performance in one or more cognitive domains
- cognitive deficits interfere with independence in everyday activities
- cognitive deficits do not occur exclusively in the context of delirium
- cognitive deficits are not better explained by another mental disorder
What causes DAT symptoms?
neurons in the brain becoming damaged or dying
What are the tow main changes that occur in DAT?
- amyloid beta plaques develop outside the neurons
- tau neurofibrillary tangles develop within the neurons
What is amyloid beta?
- naturally occurring peptide fragment cleaved from larger amyloid precursor protein
- is associated with normal cognition and the health of the hippocampus
What happens to amyloid beta in DAT?
plaques develop when peptide cut by incorrect enzyme
Where are tau proteins found?
- in axons
- can occur in dendrites, nucleus, plasma, membrane, synapses
What do tau proteins do?
provide support and maintain the stability of microtubules
What happens to tau protein in DAT?
there is a fold in the proteins, and they break away and accumulate, causing tangles to develop
What is the amyloid cascade hypothesis?
- amyloid beta fragments begin to clump, forming plaques
- plaques disrupt normal functioning of tau, making it fold and creating tangles
- plaques and tangles cause chronic inflammation in brain which interferes with blood flow
- communication between neurons is disrupted, causing death of neurons = cognitive decline and dementia
How can DAT impact communication?
- WFD
- topic maintenance
- comprehension difficulties
- episodic memory difficulties
- frustration and withdrawal
What is the epidemiology of PD?
- 153000 people in UK
- more common in males
- 18000 people a year
What are the main risk factors for PD?
- age - 60 is normal onset
- genetics - increased risk if close family member, but many do not have family history of condition
- gender
- environmental factors - exposure to certain chemicals and toxins
What is PD?
A progressive neurodegenerative disorder characterised by:
1. loss of dopaminergic neurons in substantia niagra
2. development of lewy bodies and lewy neurites
What are Lewy bodies and neurites composed of?
predominantly alpha-synuclein
What is the substantia niagra?
a midbrain dopaminergic nucleus with a critical role in modulating motor movement and reward functions as part of the basal ganglia circuitry
What are the areas within the substantia niagra?
- pars compacta
- pars reticula