Neurodegeneration Flashcards
what is neurodegeneration?
why is this a problem?
what is the biggest risk factor for most common neurodegenerative diseases?
progressive loss of neurones beyond that of the normal ageing process
neurones cannot be replaced
age
when does neurodegeneration occur?
neurodegenerative diseases e.g. Alzheimer’s
cancer
trauma (head/spine injury)
viral diseases
vascular/circulatory disorders
developmental disorders
what are the 3 examples of neurodegeneration-associated vascular and circulatory disorders?
ischemia/infarction
transient ischemic attacks
haemorrhage
what are the various causes of stroke?
atherosclerosis
= narrowing of vessels
thrombosis
= damages vessels
embolism
= a blockage e.g. plaque/air bubble
vasospasm
= abnormal contractions cause vessel rupture
hypertensive vasculopathy
2 types of stroke
ischemic
- clot blocks blood flow to brain
= deprives neurones from nutrients + O2 etc
haemorrhagic
- bleeding occurs inside/around brain tissue
= can cause destruction of neurones
what is venous infarction?
what does it result from?
risk factors?
a haemorrhagic stroke form
venous sinus thrombosis
no. of states that result in hyper viscosity or increased coagulability
topography of focal ischemia
focus = area where neurones begin to die via necrosis
flow gradient:
densely ischemia region surrounded by areas of less severe CBF (cerebral blood flow) reduction
how can necrotic cells at a focus affect surrounding cells?
what is this called and what does it lead to?
cells break open and release contents
-> e.g. release glutamate
-> glutamate toxicity
= kills other cells
ischemia penumbra
- an area of reduced perfusion sufficient to cause reversible clinical deficits
= can be reversed by quick intervention
what is an infective disease that causes neurodegeneration?
what are the different forms?
meningitis
bacterial
tuberculous
fungal
viral
inflammation of the coating of the brain containing the meninges
- > can damage blood supply
- > damages brain
what is poliomyelitis caused by?
what can it lead to?
poliovirus (RNA virus)
3% of cases enter the CNS
1% of cases this leads to focal loss of motor neurones in the spinal cord
what neuroscience findings have been discovered from polio?
study of spinal motor neurone loss + comparison to resulting loss of muscle control
-> mapping of motor neurone foci in the spinal cord to innervated muscle
what makes neurodegenerative diseases special?
often unknown cause
no cure
progressive
sporadic +/or inherited forms
often age dependent
types of neurodegenerative diseases
dementia
- Alzheimer’s = most common
- Prion = rare
movement disorders
- Parkinson’s
= loss of dopaminergic cells
- Huntingtons
Motor neurone disease
- ALS
- MS
loss of upper + lower motor neurones
what are Amyloidogenic diseases?
examples
neurodegenerative diseases where there’s deposition of an abnormal amyloidogenic protein isoform
Alzheimer’s disease
Parkinson’s disease
Prion disease
what are amyloidogenic proteins?
those that form fibrillar aggregates with beta-sheet configurations