Neurodegenerative diseases Flashcards Preview

Mechanisms of human disease > Neurodegenerative diseases > Flashcards

Flashcards in Neurodegenerative diseases Deck (24):

Which brain cells are susceptible to chronic diseases?

The astrocytes, neurons and microglia.


What is the most common chronic disease of the CNS?

Dementia related diseases. There are many different types because dementia can occur in different parts of the brain and as such will have differing symptoms. There are about 100 diseases known to cause dementia.


What is AID's related dementia or ADC?

Aids related dementia is the an umbrella term for a collection of neurodegenerative diseases caused by the HIV infection. It is believed that the HIV virus travels to the brain and infects the activated immune cells there, like the macrophages and microglia cells, causing them to produce neurotoxins that kill the neurons. ADC tends to be more prevalent in HIV/AIDS sufferers in their advanced stages that are not taking medication for the disease.


What is alcohol induced dementia?

The alcohol induced dementia is occurs in chronic, excessive alcoholics and is said to be associated with the vitamin deficiencies in the brain that lead to damaged neurons. Alcohol is known to alter the absorption and use of the B-vitamin thiamine and as such, deprives the brain of it. Thiamine is important in detoxifiying the brain.


What is traumatic brain injury or TBI?

Traumatic brain injury occurs as a result of excessive, physical external force being applied to the brain. The shearing, tearing and stretching forces can result in the physical damage to the brain structures (e.g gyri). It can occur to anyone at any age. Sports people who may have multiple TBI's are very vulnerable to developing chronic encephalopathy.


What is chronic traumatic encephalopathy?

Chronic traumatic encephalopathy, is basically the nasty consequence of many TBI's. There are many abnormalities in the important cells and structures of the brain that result in the inflammation of the brain. Amyloid deposition can also occur. The symptoms include mood, personality, cognitive and behavioural changes.


What is Alzheimer's disease?

Alzheimer's disease has two types, sporodic and familial meaning that one occurs just randomly and the other occurs because of a genetic mutation. The spodoric cases form the 90% majority. It is basically the gradual degeneration of the brain and starts first with short-term memory loss and leads to such substantial long-term loss that death eventually incurs.


What is the biochemical process that causes Alzheimer disease?

As brain cells die, the substance of the brain shrinks.
Abnormal material builds up as “tangles” in the centre of the brain cells and “plaques” outside the brain cells, disrupting messages within the brain, damaging connections between brain cells. But overall, the mechanism for Alzheimer disease is not fully understood.


How is Alzheimers disease diagnosed?

The biomarkers for Alzheimers in the blood is the presence of the chemical PIB, which is said to come from the Amyloid-beta plaques in the neurons. Brain scans can also indicate the presence of plaques and shrinkage of the brain associated with significant death of the neurons.


What is the relationship between Alzheimer disease and Down's syndrome?

Sufferer's of Down syndrome all have 3 copies of chromosome 21, and chromosome 21 is known to encode the Amyloid precursor protein, which forms the amyloid-beta plaques in the neurons. This is why Down's syndrome sufferers that live to the age of 40 will all have Alzheimer disease, because of the overexpression of the Amyloid precursor protein associated with the presence of 3 chromosome 21's.


What is fronto-temporal lobar degeneration?

This is the name given to dementia that occurs in either the frontal or temporal lobes of the brain. The frontal lobe is associated with cognition and thought, whilst the temporal lobe is associated with sensory integration and perception. Thus the symptoms that are experienced as a result of FTLD can vary.


What is Pick's disease?

Pick's disease is one type of FTLD disease. It is basically degeneration in the frontal and sometimes temporal lobes.


What is the cause of Fronto-temporal lobar degeneration?

FTLD is caused by a mutation to the tau protein gene on chromosome 17. The pathological features of FTLD include tufted astrocytes, pick bodies, neuritic plaque and overall atrophy of the frontal and temporal lobes.


What is vascular dementia?

it is the umbrella term for dementia caused by disrupted blood flow to the brain. There is multi-infarct dementia, in which a series of mini-strokes in the brain cause neuronal damage. SImilarly, there is Binswanger disease, which is vascular disruption to the deep, white matter of the brain caused by high-blood pressure and thickening of the arteries.


What are amyloid congophilic angiopathy and cerebral amyloid angiopathy?

ACA and CAA are two diseases in which the deposition of amyloid plaques in the cerebral blood vessels results in neuonal ischaemia and hypoxia, leading to acute neuronal injury. These diseases seem more prevalent in the icelandish and English races.


What is Tau, or neurofibrillar tangles (NFT) ?

Tau is a microtubule associated protein that with normal aging, become phosphorylated and turn into neurofibrillar tangles. The problem is that these NFT structures decrease the integrity of the neurons, causing neuronal death. They are formed mainly in the hippocampus and the cortex.


What is Parkinson's disease?

Parkinson's disease involves the formation of Lewy bodies and neurites inside the neurons of the substantia nigra. These neurons in the substantia nigra are important for transmitting dopamine in that region. The Lewy bodies interfere with these neurons and kill them, causing decreased functioning of the substantia nigra. This results in the decreased dopamine levels in the striatum of the brain. The symptoms are rigid muscles, tremors and bradykinesia (slowness in the execution of muscle movement).


Can Lewy bodies occur in other parts of the brain?

Yes, they can. They can still cause neurological diseases there too.


What are the risk factors for Parkinsons's disease?

Age, being male, race, life experience, and more importantly environmental exposure to herbicides, pesticides, metals, well water, farming, rural residence, wood and steel factories.


What is multiple system atrophy?

Multiple system atrophy is a rare combination of Parkinson's disease and other neurological degenerative diseases. It affects the cerebellum, brain stem and basal ganglia.


What is Creutzfeldt-Jakob disease?

It is a rapidly progressive degeneration of the brain that results in dementia. It is caused by coming into contact with prion infected material, and is found in humans and animals. The deposition of the prion protein in the brain causes the degeneration.


What is Amyotrophic lateral sclorosis?

It is the degeneration of the ventral horn neurons that control motor movement by the muscles.


What is huntington's disease?

The Huntington gene has a CAG trinucleotide repeat encoding a polyglutamine region of the protein. More repeats is associated with increasing age onset of HD. It causes so much degeneration of the brain that 25-30% of brain matter is lost from all over the brain.


What are spinocerebellar ataxias?

It is basically atrophy of the cerebellum, caused by the presence of the SCA gene. There are about 30 different types and each type corresponds to a different age of onset of the disease.