CVD & trauma Flashcards
what are the main types of cerebral oedema?
Vasogenic – disruption of the blood brain barrier
Cytotoxic – secondary to cellular injury e.g. hypoxia/ischaemia
what are 3 ways that cerebral oedema can form?
Cytotoxic;
fluid leaves vasculature, though aquaporin 4 - AQP4, into astrocyte foot process.
Hydrocephalic;
Fluid leaves ventricle, past epdenyma cells, through aqp4 then past astrocytes.
Vasogenic;
when the integrity of the BBB is disturbed this is the oedema that results. out of vasculature
what are 3 ways that cerebral oedema can be removed?
From cells / astrocytes Into bloodstream
Into subarachnoid space
Into cerebral ventricles
all mediated via AQP4
what is the biggest venus sinus in brain and what is its course?
Sagittal sinus
Runs along the midline
describe the function of the ventricular system in the brain?
the choroid plexus is located in the lateral ventricle and makes CSF
CSF makes its way down to the 4th ventricle, where it can go down the spine OR
passes through a foramen to go into the subarachnoid space
once it flows to top of head, csf is resorbed into venus sinuses/ system through arachnoid granulations
csf is then recycled
what are the forms of hydrocephalus?
Non-communicating -
involves obstruction of flow of CSF
Communicating -
involves no obstruction but problems with reabsorption of CSF into venous sinuses
what is the Consequence of raised ICP?
herniation of brain structures where space is available
what are the forms of herniation in the brain?
Subfalcine herniatiion – supra tentorial herniation
Transtentorial herniation -
aka uncal herniation - medial temporal lobe
Tonsillar herniation - doesn’t involve cortex – this is cerebellum herniating through - CONING
what is the timing in the definition of stroke?
with symptoms lasting more than 24 hours or leading to death, with no apparent cause other than that of vascular origin
difference between TIA and stroke?
Most TIAs last less than five minutes; the average is about a minute. Unlike a stroke, when a TIA is over, there is usually no permanent injury to the brain
aetiology of TIA?
TIA is caused by a clot; the blockage is temporary
PROGNOSIS of a TIA?
1/3 of those with TIA get significant infarct within 5 years
a 55 y/o man with a hx of essential hypertension but is known to be non-compliant with medication is brought into AnE by family with severe headache, vomiting.
You suspect CNS pathology and perform some neurological exams and discover focal neurological signs.
During the test he rapidly losses of consciousness.
You are the F1 on duty. what is going on with him?
Likely a Non-traumatic intra-parenchymal haemorrhage
rupture of a small intraparenchymal vessel
Hypertension > 50% of bleeds
Most common in basal ganglia
how would an Arteriovenous malformation present?
prognosis? Rx? aetiology?
haemorrhage, seizures, headache, focal neurological deficits
Treatment: surgery, embolization, radiosurgery
Prognosis; rupture -> poor prognosis
Aetiology - congenital !
which cns tumour presents as:
Present with headache, seizures, focal deficits, haemorrhage Low pressure – recurrent bleeds
Cavernous angioma
which cns tumour is described as;
composed of closely packed vessels with no parenchyma interposed between vascular spaces”
Cavernous angioma
what causes Sub-arachnoid haemorrhage?
Rupture of a berry aneurysm
where does Rupture of a berry aneurysm occur most?
80 % - internal carotid artery bifurcation,
20% occur within the vertebro-basilar circulation
how does Sub-arachnoid haemorrhage present?
Present with sudden onset of severe headache, vomiting, loss of consciousness
how might a berry aneurysm be treated?
endovascular treatment - coils
reduces blood flow hence risk of bursting
70-80% of strokes are caused by ___?
Infarcts -
and cerebral atherosclerosis most common cause of infarcts
what is the prognosis of haemorrhagic vs ischaemic strokes?
Infarct: Tissue necrosis (stains) Rarely haemorrhagic Permanent damage in the affected area No recovery
Haemorrhage: Bleeding Dissection of parenchyma Fewer macrophages Limited tissue damage (periphery) Partial recovery
what is the particular risk with head fractures?
Infection risk – associated with fractures
what is a Contusion?
Brain in collision with skull
Surface “bruising”
If pia mater torn then becomes laceration
in traumatic brain injuries, what is the commonest cause of coma in the absence of bleeding?
Diffuse axonal injury
axonal injury mainly affects which structures?
Midline structures particularly affected e.g. corpus callosum, rostral brainstem and septum pellucidum
what is otorrhea / rhinorrhea
csf leaking out of ear / nose
straw coloured fluid. following fissure fractures
acceleration / deceleration injury can lead to what?
contusion
due to rebound. sometimes called coup/contrecoup
what protein is implicated in CTE - chronic traumatic encephalopathy?
Tau protein
