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
What is the pars compacta?
the smaller region of the substantia niagra containing dopamine-producing neurons
What is the pars reticula?
the larger region of the substantia niagra which helps regulate movement by inhibiting unwanted movement
What are the symptoms of PD?
- dyskenisa
- bradykinesia
- muscle rigidity
- postural instability and impaired balance
What is dyskinesia?
involuntary, abnormal movements that can affect any part of the body
What is bradykinesia?
- slowness in initiating movements
- reduced speed of movements
- decreased dexterity
- facial masking
- hypophonia
- freezing
What are the signs of hypokinetic dysarthria?
- brasylalia (slow speech)
- monotone speech
- reduced stress/loudness
- imprecise articulation
- difficulty initiating speech
- reduced breath support
- reduced facial expressions
What are some other symptoms of PD?
- cognitive changes
- constipation
- sleep problems
- depression
- anosmia
- hallucinations
What is the epidemiology of MND?
- 2/100,000 worldwide
- lifetime risk 1/300
- 1.6:1 male:female
- more likely in people over 50
- mean disease duration is 2.5 years
- 5000 people UK
What is MND?
a group of diseases which affect the nerve cells in the brain and spinal cord that control muscle movement
How does MND affect someone over time?
nerve cells waste away and die, leading to muscle weakness, stiffness, difficult speaking/swallowing/breathing
Which cranial nerves can be affected by MND?
V, VII, IX, X, XI, XII
What are the types of MND?
- amyptrophic lateral sclerosis (ALS)
- primary lateral sclerosis (PLS)
- progressive bulbar palsy (PBP)
- progressive muscular atrophy (PMA)
- spinal muscular atrophy (SMA)
What is amyotrophic lateral sclerosis (ALS)
most common type of MND (90%) affecting lower and upper motor neurons
What is primary lateral sclerosis (PLS)
type of MND affecting upper motor neurons
What is progressive bulbar palsy (PBP)?
Type of MND affecting lower motor neurons in the brainstem which control muscle sin swallowing and speaking
What is progressive muscular atrophy (PMA)?
type of MND affecting lower motor neurons in limbs
What is spinal muscular atrophy (SMA)?
genetic disorder affecting lower motor neurons in spinal cord
What are the main symptoms of MND?
- muscle weakness and wasting
- motor speech difficulties
- EDS difficulties
What are other symptoms of MND?
- muscle cramps and twitches
- stiffness and rigidity
- balance problems and falls
- respiratory problems
- fatigue
- some cognitive changes
What are the motor speech difficulties in ALS?
generally mixed dysarthria
What are the motor speech difficulties in PBP?
generally mixed dysarthria
What are the motor speech difficulties in PLS?
spastic dysarthria
What are the motor speech difficulties in PMA?
flaccid dysarthria
What are the motor speech difficulties in SMA?
flaccid dysarthria
