Dementia Flashcards
Function of the occipital lobe?
Visual cortex and visual processing
Function of the temporal lobe
Language
Recognition of faces and objects
Emotional response eg stranger vs close family member
Memory
Functions of the frontal lobe?
Motor cortex
Personality
Motor expression of speech (Broca’s)
Functions of the parietal lobe?
Sensation Perception Two-point discrimination Joint position sense Fine touch Temperature
Right - spacial layout of world, awareness of self and relationship to the environment
Left - reading, writing, arithmetic, abstraction, word finding, metaphors, orchestration of skilled movement
What is homonymous hemianopia a sign of?
Damage to occipital lobe on one side
What is loss of macula vision a sign of? What can cause it?
Stroke affecting the occipital pole
What is visual anosognosia?
Where there has been damage to the occipital lobes on both sides causing cortical blindness, however people deny that they are blind.
What is dementia?
The progressive decline of cognitive function, usually affecting the cortex as a whole.
What deteriorates in dementia?
Memory Intellect Behaviour Personality Speech
What is dementia due to?
Death of neurones in the cortex
What are the different types of dementia?
Alzheimer’s
Lewy body dementia
Vascular dementia
Fronto-temporal lobe dementia
What happens in vascular dementia?
Multiple infarcts occur throughout the cortex, causing neuronal death in tiny areas
Symptoms of vascular dementia?
Rigidity of thinking
Apathy
Personality change
Treatment of vascular dementia?
Manage vascular risk factors
What is neurodegenerative dementia caused by?
Accumulation of abnormal proteins that cannot be cleared leading to neuronal cell death
What is the most common type of dementia?
Alzheimer’s
How does Alzheimer’s present?
Progressive memory loss Various aphasias Apraxia Agnosia Behavioural changes eg aggression, agitation, wandering Depression
What are the neurofibrillary tangles that develop in Alzheimer’s?
Intracellular twisted filaments of Tau protein
It normally binds to and stabilises microtubules in the cells but in AD, they become hyperphosphorylated and very stable, producing neurofibrillary tangles
What are the senile plaques that develop in Alzheimer’s?
Foci of enlarged axons, synaptic terminals, and dendrites, with amyloid deposition in the vessels in the centre of the plaque
How do the amyloid proteins form in Alzheimer’s?
As a result of up-regulation of amyloid precursor protein and mutation to the enzymes that would normally breakdown the amyloid proteins
Other than amyloid proteins and senile plaques, what else can happen in Alzheimer’s?
Atrophy of cholinergic fibres running from the hippocampus to the cerebral cortex
Initially there is a reduction in cholinergic transmission, and later a reduction in the synthesis of ACh
What is seen on an MRI in Alzheimer’s?
Atrophy of the brain tissue, especially the frontal and temporal cortex
Enlargement of ventricles to compensate
Exaggerated gyri and sulci
Bilateral atrophy of hippocampus
What is Lewy body demetia characterised by?
Fluctuation in cognition from day to day - especially attention and alertness
Memory loss may not occur in early stages
Visual hallucintations
Delusions and paranoia
REM sleep behaviour disorder
Later resembles AD with movement difficulties, problems with speech and swallowing, challenging behaviour
More rapid onset than Alzheimer’s
What is seen at autopsy in Lewy body dementia?
Cortical lewy bodies
