dementia and alzheimers disease Flashcards
Dementia is
a chronic and persistent disease with behaviour and intellectual derrangements due to a brain disorder
features:
- memory problems
- personality changes
- disorientation
- impaired reasoning
- condition deteriorates with time
Delirium
an acute disorder with mental derangements that accompanies a organic brain disease
features:
- impaired consciousness
- cognitive changes
- delusions
- disorientation
- hallucination
deliriums are treatable, and can be metabolic or drug induced
Can dementia present with delirium?
Yes
What does the DSM-V classify dementia as?
a Neurocognitive Disorder, alongside amnesia
features:
- there is a cognitive decline detected by observation and by appropriate assessment tools
- independence and daily living is impaired
- does not occur in the context of delirium
- there is no underlying mental health disorder
What are the different types of dementia?
Cortical Dementias - Alzheimers - Picks Disease - Frontotemporal dementia - CJD - Diffuse Lewy Body Subcortical Dementias - Huntington's - Parkinson's (not true dementias but appear in later stages of the disease) Mixed Dementias - vascular dementia (from many TIAs, or CVAs) - HIV related dementia
Which of all dementias is most commonly seen?
Alzheimer’s disease 50-60%
Risk of dementia in society
Risk doubles every 5 years from the age of 60
Alzheimer’s disease
characterised by a gradual onset of cognitive decline
- most diagnosed are aged 85 years or older
- characterised by three phases: early middle and late
- progression from early stage to late stage is approx 5-10 years
- early stage is characterised by short term memory loss, with long term memory loss intact
What are the risk factors for Alzheimers disease (AD)
- Down’s syndrome
- history of head trauma
- some genetics links
- Females > Males
Imaging of AD patients
- brain atrophy
- enlarged ventricles
- widening of the sulci
What are characteristic histopathological findings in Alzheimer’s disease
- neurofibrillary tangles
intracellular tau protein aggregates on microfilament tubules
- amyloid senile plaques
extracellular beta-amyloid fragments
- diffuse neuronal loss
from the toxic effects of plaques, and tangles
These features are found in the brains of AD patients. These findings confirm the diagnosis, which is clinically made prior to autopsy.
What are the gross pathological findings of AD?
hippocampus - site of early pathology (memory)
cortex:
- tangles, atrophy in layer V
- plaques in layers II, III and V
occipital and primary motor sensory cortices are affected very late in the disease
Hypotheses of AD aetiology
- cholinergic hypothesis
lack of choline acetyltransferase enzyme - beta amyloid
- genetics
early onset alzheimers disease
- homozygotes for the e4 allele (ApoE gene) are at an 8 fold increased risk than homozygotes of e3
- Downs syndrome - chromosome 21 - site of amyloid precursor protein
Protective risk factors for AD
- smoking (? early mortality from Ca)
- use of anti-inflammatories
- HRT
- statins
- high educational attainment
- ApoE e3 allele
Neuropsychological performace of a AD patient
- rapid forgetfullness - repetition shows no benefit
- have poor attention - attention shifts
- visuospatial deficits
- working memory impaired
- procedural memory and language intact
