Dementia Flashcards
What are the risk factors for dementia ?
Increased age
Cardiovascular disease
Infections
Lifestyle factors - smoking, obesity
Neaurological diseases
Trauma head injuries
Environmental toxins
Hormonal
Non-modifiable risk factors for dementia. ?
Age, sex, gender
Ethnicity
Genetics cognitive impairment in childhood
Modifiable risks for dementia ?
Obesity
Cardiovascular disease
Smoking and alcohol use
Traumatic brain injury (TBI)
Infection
What is dementia ?
Brain disorder that effects the thinking, behaviour and ability of a person to preform tasks and brain functions
What’s the most common type of dementia ?
Alzheimer’s disease (40-70%)
What are Tau proteins ?
These proteins are found within the brain and they stabilise microtubules, abundant in the neurons of the nervous system and are less common everywhere else
What happens when astrocytes are impaired ?
If they become impaired and become injured then they trigger/exacerbate changes in Tau and amyloid-beta (AB) pathologies
What does loss of astrocyte function and deficit in Tau probations lead to ?
The formation of amyloid and neurofibrillary tangles (NFTs) as well as neuronal dysfunction
What cells medicate neuroinflammation ?
Medicated by activated microglial cells which are a source of Cytokines
Describe and explain the inflammatory process with effects towards Alzheimer’s disease ?
Neuroinflammation activated cytokines
Disturbances in cerebral glucose metabolism also effects AD
Increase in circulating Interleukins and tumour necrosis factor-alpha (A) buildup
C-reactive protein and interleukins-6 can predict congnative decline
Microglia circulate the brain looking for infection or inflammation caused by toxic proteins that might damage neurons
The result: more and more damaged neurons which can lead to the onset of AD
What are Cytokines and what role do they play ?
They are key compound in the brains inflammatory response.
They are triggered by pro-inflammatory and anti inflammatory events, stimulated by injury, ischaemia and beta-amyloid toxicity.
Cytokines (interleukin 1) and tumour necrosis cause ongoing inflammatory responses, such as the amyloid cascade.
Inflammatory process also increases the presence of vascular injury, hypertension, atherosclerosis and high blood cholesterol.
Presence of Chromic inflammatory cells (Neutrophils, T cells CD4 and CD8 positive T cells and Macrophages) all within the walls of the blood vessels in the brain
What are Beta-Amyloid plaques and what role do they play ?
Amyloid beta proteins (APP) are proteins found in the cell membrane at the synapse of the neuron - regulate synapse formation
In AD the abnormal process of APP results in the formation of beta-amyloid which is toxic, they come from larger proteins found in the fatty membrane o surrounding nerve cells.
Beta-amyloid is “sticky” and clumps together to form plaques, the abnormal clusters of proteins buildup between nerve cels and block the cel to cell signalling at synapses.
They also activate the immune system cells (microbial) trigger inflammation and destroy the synapse.
What two types of neurotransmitters are affected in AD ?
Subcortical - Acetylcholine, noradrenaline, serotonin
Cortical - somatostatin, glutamate
What is the role of Acetylcholine ?
Plays a crucial role in information processing and memory
In AD the brain shows …
Loss of cholinergic neurons in the basal forebrain, decreased acetylcholine levels and a decrease in the acetylcholine synthesising enzyme choline acetyltransferse (CHAT) in the cerebral cortex
