Neurodegenerative Disorders Flashcards
What are neurodegenerative diseases?
Neurodegenerative disorders tend to be due to the loss of neurones
They are progressive and irreversible diseases
Give some examples of neurodegenerative disorders?
Alzheimer’s disease
Multiple sclerosis
Parkinson’s disease
Huntington’s disease
What is Alzheimer’s disease?
Disease of aging
Memory loss
Dementia
The cost of dementia in the UK is £17 billion / year
What are some symptoms of alzheimer’s?
Early - Short term memory; Disorientation - time then place; Difficulty with words, names, numbers; Clumsiness and Visuospatial orientation (gets lost)
Later - Loss of social skills; psychosis + paranoia/hallucinations/delusions and bradykinesia/rigidity
Latest - Mutism, Incontinence and Bedridden
What is the pathology of alzheimer’s?
- Loss of nerve cells = atrophy of the brain
○ The gyrus are smaller and the sulcus widen
○ The ventricles (fluid-filled spaces) of the brain become larger
○ The hippocampus is atrophied the most and some areas of language in the frontal cortex - Build up of amyloid plaques - mainly extracellular, aggregations of amyloid alpha and beta proteins
- Increase in neurofibrillary tangles - this is a hyper-phosphorylated tau protein
○ Leads to transport issues within the cell = neurone death
The neuronal loss/shrinkage - it is mainly focused around synapses and particularly cholinergic pathways
What is the epidemiology of Alzheimer’s?
Affects about 12 million worldwide.
500,000+ in the UK
£14 billion spent in care and treatment.
Risk doubles every five years after 65
As we have an aging population the number of suffers will double in the next 20 years
What is some treatment of Alzheimer’s?
We give acetylcholinesterase in order to break down acetylcholine into choline and acetic acid
It may slow progression and may improve cognition
What is Multiple Sclerosis?
Causes changes in sensory and motor systems
This leads to muscle weakness, lack of balance and issues with swallowing/vision/fatigue etc…
There are different forms of progression, as some as gradual and others have rapid intermediate attacks
What is the cause of multiple sclerosis?
The lateral ventricles become very large due to loss of neuronal tissue
It is an autoimmune disorder - antibodies degrade the myelin sheath (the oligodendrocytes)
This is more common in women
What is Parkinson’s disease?
Extrapyramidal disorder
Loss of movement
Increased muscle tone - involuntary tremor
There is a difficulty in voluntary movements
Therefore an akinetic disorder
What are some symptoms of Parkinson’s disease?
Tremor, Rigidity, Speech, Micrographia, Akinesia and Postural changes
What is the pathology of Parkinson’s disease?
Diminished substantia nigra in the midbrain
The substantia nigra contains neuromelanin, and as the nerve cells die off the dark band of this region fades
The pathways that come from the substantia nigra become more difficult to complete - this is involved in dopamine motor pathways
They are supposed to initiate muscle control
What is Huntington’s disease?
Inherited disorder
Autosomal dominant
Polyglutamine repeat
○ Until 36 repeats you don’t develop the disease
○ After 36 repeats = Huntington’s disease
The more you have, the earlier the onset and the worse it is
What are some symptoms of Huntington’s disease?
- The dementia side - Irritability, moodiness and antisocial behaviour
- The motor symptoms - fidgeting, restlessness, leading to gross choreiform movements (large expansive movements that they have no control over)
What is the pathology of Huntington’s disease?
Loss of neurones - in the cerebral cortex and the corpus striatum
This effects the GABAergic and cholinergic neurones
