Block 6: Week 3: Dementia

how many people globally are affected by dementia?

approximately 50 million

how many people develop dementia each year?

around 9.9 million each year

2019 vs 2040 for dementia in UK

2019 around 885,000 older people (>65) with dementia in UK.

By 2040, around 1.6 million (set to double).

what are the general clinical features of dementia?

begins with forgetfulness of recent events and day to day mistakes…

new information becomes harder to retain and anxiety/depression may occur early.

finishes with disorientation in time, then place, then finally person.

what memory is typically preserved in dementia?

semantic memory, implicit memory

what memory typically declines in dementia?

processing speed, working memory, episodic memory.

what are types of dementia?

Alzheimer’s (50-75%).

Vascular (20-30%).

Lewy Body (10-25%).

Frontotemporal (10-15%).

what cognitive dysfunction occurs in Alzheimer’s?

Cognitive dysfunction includes memory loss, language difficulties and executive
dysfunction

what non-cognitive dysfunction occurs in Alzheimer’s?

Non-cognitive dysfunctions include psychiatric symptoms and behavioural
disturbances, depression, hallucinations, delusion and agitation

compare the mild, moderate and severe symptoms of Alzheimer’s?

Mild – wondering and getting lost, repeating questions.
Moderate – problems recognising friends and family, impulsive behaviour.
Severe – expressive and receptive aphasia.

what is the prodromal phase of Alzheimer’s?

where cognitive deficits are detectable before fully symptomatic

how is Alzheimer’s neuropathologically characterised?

accumulation of intraneuronal and extracellular protein aggregates,

progressive synapse loss and neurodegeneration.

what are neurofibillary tangles?

abnormal accumulations of the protein tau, forming twisted threads inside neurons:

paired helical filaments of microtubule, amyloid plaques aggregate.

ALZHEIMERS

what is the role of microtubules?

transport things across cell (these are affected in Alzherimer’s - essential cell process reduced).

what does a loss of normal tau function mean for the cell? (Alzheimer’s)

reduced normal cellular functions of neurons:
- maintenance of appropriate morphology.

- axonal transport.

- synaptic dysfunction.

- neurodegeneration.

how does the amyloid cascade relate to Alzheimer’s?

accumulation of amyloid beta plaques act as a pathological trigger for amyloid cascade,

includes neuritic injury and formation of neurofibrillary tangles.

what is the treatment for Alzheimer’s?

mediation to slow down progression:

ACh inhibitors, e.g donezipil

NMDA antagonist, e.g memantine.

what are risk factors for vascular dementia?

hypertension, high cholesterol, diabetes mellitus, coronary heart disease, peripheral
artery disease

what are symptoms of vascular dementia?

o Forgetting current or past events, misplacing items
o Trouble following instructions or learning new information
o Poor judgment
o Impaired motor function

what are treatments of vascular dementia?

no medication - only support can be provided.

what causes vascular dementia?

Ischemic changes to the brain
o Disrupted blood flow to the brain – i.e. blot clots, insults, traumatic injuries…
o Sudden onset and stepwise deterioration.

what causes dementia with Lewy bodies?

Lewy bodies (α-synuclein protein aggregates in neurons).
- When in cortex, dementia can result.

what are symptoms of dementia with Lewy bodies?

similar to Alzheimer’s:

• More likely to have initial or early symptoms of sleep disturbances, visual hallucinations.

• And slowness, gait imbalance or other parkinsonian movement features.

what are treatments of dementia with Lewy bodies?

ACh inhibitors,

memantine (NMDA antiagonist).

antipsychotics.

what are symptoms of frontotemporal lobar degeneration?

Early ones include marked changes in personality and behaviour and/or difficulty with
producing or comprehending language.
Memory is typically spared in the early stages of disease.

what is the most common variant of frontotemporal lobar degeneration?

behavioural variant (50% of cases).

personality changes, apathy, progressive decline in socially appropriate behaviour, judgement, self-control.

what is mixed dementia?

Different causes of dementia are associated with distinct symptom patterns and brain abnormalities.

most commonly Alzheimer’s combined with vasuclar dementia,

then Alzheimer’s with Lewy bodies.