Neuropathy of dementia Flashcards
what is the function of the post central gyrus
Perception and integration of sensory stimuli- parietal lobe
what is the function of the pre central gyrus
motor planning strategic thinking-frontal lobe
what is the function of the limbic system,
Arousal, emotion, motivation, attention and memory (hippocampus)
what is the function of the hippocampus
newly learned response.
what is the function of the basal ganglia
fine-tuning of movement
what is the function of the thalamus
sends info to cortex so you know what is happening, it sorts out the information.
define neurodegenerative disorders
neurones die
How can neurodegenrative disease be classified
anatomical
etiologically
proteinopathy- Tau, ubiquin and alpha synuclein.
neurones in which lobes degenerate in alzheimer’s
temporal, frontal and parietal
which genes or genetic disorders increase
Apo E (E4) APP -chromosome 21 trisomy down syndrome increase the risk of early onset dementia Prenesillin
what proteins are involved in neurodegenerative diseases
B amyloid
Tau
A-synclein
Ubiquitin
define amyloid proteins
Insoluble, fibrous protein aggregate- sharing specific structural traits- toxic and adhesive
pathogenesis of b amyloid plaques
arise from 18 inappropriately folded versions of polypeptides present in the body.
misfolded structures alter their proper configuration so they erroneously interact with each other forming insoluble fibrils.
what is the function of Tau
stabilise microtubules in neurones
microtubules (provide a path for neurotransmitter and cell bodies to be transferred along)
how many isoforms of Tau are there
six
amyloid defects are strongly linked with defects in what other proteins
Tau
what causes increased levels of amyloid
mitochondrial dysfunction (overactive neurone)
how does amyloid affect the function of Tau
it inter tangles within the Tau as it accumulates as a plaque.
what types of dementia is A synucelin seen in
parkinsons and dementia
Lewy body.
what is ubiquitin
Small regulatory protein, found in almost all cells of eukaryotic organisms
what is the function of ubiquitin
Direct proteins to compartment in the cells, including proteasome, which destroy and recycle protein and it can attach to proteins and label them for destruction.
what are the main pathological causes of dementia
oxidative free radicals
excitotoxicity- glutamine stimulation
apoptosis
cytokines-inflammation
genetic factors- single or multiple mutations
Ageing- age related decline in efficiency of metabolic processes
which proteins accumulate intracellularly in dementia and which accumulate extracellularly
Intracellularly- Tau, a synuclein, polygltmine and ubiquitin.
Extracellulary- amyloid.
what is the brain weight
1200-1400
what are the main macroscopic findings in a brain with dementia
brain atrophy atrophy in white matter atrophy in the deep white matter ventricular dilation Atrophy of brainstem of cerebellum pale substania niagra
what are the main microscopic findings in a brain with dementia
neurone loss from the hippocampus, cerebral cortex and SN and LC.
Microvacuolatin in the cerebral neocortex neurones just vanish leaving spaces.
readied white matter
wide perivascular spaces in white matter.
Abnormal proteins- amyloid plaques- Tau neurofibrillary tangles, a synuclein, Lewy body, ubiquitinn.
which part of the brain does Alzheimer’s spread from
hippocampus
what are the common macroscopic findings of Alzheimer’s
Thalamus is thinned and smaller Thin corpus callosum Brain weight 900-1200 ventricular dilatation Atrophy of gryi and widening sulci
what are the BRAAK stages
used to classify the degree of pathology in Alzheimer’s.
what is the definition of a BRAAK stage 1 or 2
neurofibrillary tangle involvement is confined mainly to the transentorhinal region (parahippocompus) of the brain,
what is the definition of a BRAAK stage 3 or 4
involvement of limbic regions such as the hippocampus.
what is the definition of a BRAAK stage 5 or 6
extensive isocortical (majority of the cerebral cortex) involvement.
what are the microscopic findings in alzhiemer’s
Loss of neurones but overall structure is normal.
Atrophy of amygdala.
B Amyloid plaques- attach to the wall of blood vessels
Cytoplasmic process become tangled in the B amyloid plaques.
Neuritic plaques with prominent amyloid cores
Perivascular plaques- Around blood vessels.
Diffuse plaques
Neuropil threads and neurofibrillary tangles (NFT)-entangling of microfilaments.
what are the macroscopic changes in dementia with Lewy body
Pale substania niagra and locus creels lost- Pale because if neurones die then no neuromelanins, which give SN it, colour can be formed.
Atrophy of amygdala, cingulate gyrus, temporal and parietal lobes
what are the microscopic changes in dementia with Lewy body
Neuronal loss
Accumulation of a synuclein and +ve bodies in the neurones of the substania Niagara, amygdala and then cortex.
what is binswanger disease and what is it associated with
Multi infarct dementia- blood vessels.
infarct in white matter
vascular dementia.
In what form of dementia do you get pick bodies
fronto-temoral dementia.
what proteins are pick bodies made from
ubiquitin and Tau
