Lecture 16 - Dementia Flashcards
What is atherosclerosis?
Accumulation of damage due to parasitic/ .ovsl neoplastic evolution of arterial lining cells, which cause atheromas which then cause blockages —> mini strokes
What is an atheroma?
Yellowish plaque that grows from the lining of the artery. Contains damaged lining cells and white blood cells. Can also be cholesterol crystals which then calcify and harder blocking off blood vessels.
What are Lewy bodies?
Abnormal microscopic protein deposits found inside nerve cells
How do patients with Lewy body dementia present normally?
Fluctuating better and worse periods of psychotic symptoms such as hallucinations and persecutory delusions . With the addition of Parkinson’s symptoms e.g. Frozen movement.
What is the pathology of Parkinson’s/ what happens in the brain?
Loss of neurons in the substantial Nigra which is in the basal ganglia, which is important for fine motor control.
The area starts off pale and gradually turns black over your lifetime.
What is the likely explanation for this loss of neurons?
It’s an inevitable side effect of the dopamine system providing chemicals necessary for drive and motivation. It this system as a shy product also produces toxins that destroys cells.
Using this theory of cell death due to the dopamine toxin by product…what assumption can you make about why Lewy body dementia comes about?
It’s a side effect of being adaptive, we need to be driven and motivated , it just so happens that there is a cost to that. However, natural selection hasn’t adapted against it because it happens so late in life that most of your reproducing has already happened . Plus in old age, there is multi system failure do if your substantial Nigra doesn’t kill you some other organ will.
Is it likely that damage to the substantia Nigra only happens during old age?
No it’s not, because there are some early onset cases. So it might be that it’s happening all through your life and it just so happens that the process is accelerated in some people.
What might help fight against the onset of Lewy bodys dementia?
Knoll suggests small doses of selegiline from early adult life. Selegiline inhibits the breakdown of dopamine therefore enhancing its effects for longer, with less toxins needed to be made.
Why might dementia seem like a new disease of modern society? / appeared quite recently ?
What conclusion can we draw about why it’s come about?
It is only in recent modern society that life has been prolonged so much.
It’s a maladaptation of a necessary process in younger life that increases reproductive success
What are some of the causes of dementia?
Vascular or multi infarct dementia is caused by:
- many small minor strikes that are due to blocked blood vessels, leads to damage and death of many different bits of the brain.
- atherosclerosis
