Nervous Damage 2 Flashcards
what are the 4 causes of ischaemic stroke?
atherothrombotic cerebrovascular disease, cryptogenic so no cause, lacunar
what is atherothrombotic cerebrovascular disease?
blockage of the blood supply to the brain
what is lacunar cause of ischaemic stroke?
small vessel disease
what are the 2 types of haemorrhagic stroke?
intercerebral or subarachnoid
how is anatomical Protection of the brain caused?
by the circle of Willis
what are the 4 vessels that supply circle of willis?
left and right internal carotid and left and right vertebral
what arteries come out of the circle of willis?
anterior, middle and posterior cerebral arteries
what is the function of the arteries coming out of circle of willis?
supply distinct areas of the brain
where is supplied by the middle cerebral arteries?
lateral regions of the brain
what are the modifiable risks of strokes?
smoking, diabetes, high blood pressure, obesity, arrhythmia, drug abuse, alcohol abuse
what are the non-modifiable risk factors of strokes?
age, genetics, race, prior strokes, gender
how does a intracerebral haemorrhage begin?
vessel rupture leads to extravasation of blood into the brain parenchyma
how does a intracerebral haemorrhage grow?
the initial haemotoma causes an increase in local pressure and rupture of other vessels
how might intracerebral haemorrhages be more likely to happen?
coagulation disorders causes a higher bleed and higher blood pressure may mean re-bleeding may occur
how does a subarachnoid haemorrhage occur?
rupture of saccular anaeuryms in the vessels that supply the brain
where do subarachnoid haemorrhages usually occur?
in the circle of willis where bifurcations of major arteries are located
what is a flaw in the circle of willis?
high number of junctions and so likely to form aneurysms
what is grade I of intracranial aneurysms?
asymptomatic or a minimal headache
what is grade II of intacranial aneurysm?
headache and moderate neck rigidity
what is grade III of intracranial haemorrhage?
drowsiness, confusion, mild focal deficit
what is grade IV intracranial haemorrhage?
stupor, moderate to severe hemi paresis, early decerebrate rigidity
what is grade V of intracranial haemorrhage?
deep coma, decerebrate rigidity
how are haemorrhagic strokes diagnosed?
thunderclap headaches, xanthochromic lumbar, star pattern on CT scan
how can aneurysms be treated?
prevented bursting by clipping aneurysm or using an endovascular coil to prevent blood clotting
what types of strokes are most common?
ischaemic stroke
what makes ischameia so damaging to the brain?
high vascular supply, high cellular activities, cell type variations
at what time does blood deprivation to the brain become permanent?
4 minutes
what is the ischaemic core?
area most affected by ischaemic event such as low oxygen, low ATP and glucose and low pH
what area of the brain is less affected by ischaemia?
penumbra
what is the left hemisphere responsible for?
mathematical and scientific functions
what is the right hemisphere responsible for?
more artistic and creative functions
what kind of stress can happen in the brain?
oxidative, mechanical or metabolic
how can higher levels of calcium be caused by stress?
stress can reduce the concentration of ion pumps, cause membrane damage and release calcium stores from mitochondria
what damaging effects happen due to increased calcium?
activate unwanted enzymes, disruption to cytoskeleton, cell dysfunction or apoptosis and membrane blobbing
what is an ischaemic cascade?
lack of blood flow causes ischaemia, impacts pre and post synaptic cells, causes decreased energy of cells and eventually neurones death
what things can cause epilepsy?
electrolyte imbalance, fever, hypoglycaemia, hypoxia, brain tumours, brain injury
what is grand Mal?
tonic-clonal seizures
what is petit mal?
absence seizures with a brief change in consciousness
what things can trigger seizures?
infections, trauma, drugs, electrolyte imbalance, tumours or strokes, fevers
what are the key features of epilepsy diagnosis?
that a normal EEG or an abnormal EEG is not sufficient for diagnosis
what are the dangers of seizures?
chance of injury and brain cells can die
what is excitotioxicity?
brain cell death during a seizure
how does excitotoxicity occur?
seizures release glutamate, activation of glutamate NDMA receptors, the double gating system is opened, magnesium ion block is removed and calcium enters mediating neuronal damage
what things effect treatment of epilepsy?
pre-existing conditions, dosage and monitoring and type of syndrome
