Hi - Cerebrovascular Disease / Trauma Flashcards
Define stroke
> 24hours
- focal/global loss of cerebral function
- inadequate vascular perfusion
Most common site for cerebral thrombosis
- Carotid bifurcation
- Basilar artery
Most common site for cerebral embolus
Middle cerebral artery
Typical site of embolism in TIA?
ophthalmic branch of internal carotid
Ix in TIA to attempt to confirm Dx?
Carotid USS
Initial management of TIA
Aspirin + dipyridamole +/- carotid endarterectomy
If <3h since stroke, what is the management
thrombolytics + aspirin +/- dipyridamole
Cause of global cerebral ischemia
Failure of systemic circulation eg HF
3 non-traumatic forms of cerebral haemorrhage?
- Intraparenchymal haemorrhage
- Subarachnoid haemorrhage
- Arteriovenous malformations
Main RF for intraparenchymal haemorrhage
Hypertension
Most common site of intraparenchymal haemorrhage
Basal Ganglia
RFs for subarachnoid haemorrhage
PCKD
Ehlers Danlos
Aortic Coarctation
Most common cause + site of subarachnoid haemorrhage
Rupture of berry aneurysm
80% Carotid bifurcation, 20% vertebro-basillar circulation
Tx of subarachnoid haemorrhage from rupture berry aneurysms?
coil - stops blood flow through weak vessel area
what is coup
where impact occurs
what is contracoup
opposite side to where impact occurred
Contusion - tends to affect which lobes?
Frontal and temporal
2 main types of cerebral oedema & definitions
- Vasogenic (disruption of BBB)
- Cytotoxic (2ndary to cellular injury eg hypoxia)
How does cerebral oedema resolve itself? i.e. where does the fluid go - state 3 ways
1) into blood via AQP4 in foot processes
2) into subarachnoid CSF
3) into ventricles
Normal CSF flow in the brain
Choroid plexus –> lateral vent –> 3rd vent –> 4th vent –> spinal cord OR subarach space
2 types of hydrocephalus
1) Communicating (problem with CSF resorption into venous sinuses)
2) Non-communicating (obstruction to CSF flow)
What is a cavernous angioma
Collection of large weak capillaries with no parenchyma between them, making a cavity
Average age of presentation of a cavernous angioma? how do they present?
> 50yo with headache/haemorrhage/focal neuro Sx
apperance of cerebral oedema at post mortem
swollen brain with no visible sulci, enlarged gyri
arachnoid tight over parenchyma
Tx of hydrocephalus in neonates
Catheterise ventricle to drain CSF
Normal ICP
7-15mmHg
Where does the brain herniate when raised ICP (3)
Subfalcine - under falx cerebri between superior cortex
Transtentorial / uncal - medial temporal lobe goes into posterior fossa
Tonsillar - brainstem through foramen magnem
What is an AVM
Blood passes quikcly from artery to vein through engorged capillaries. Decreases perfusion to tissue around it
How do AVMs present
2-5th decade
Haemorrhage - massive bleeding due to high pressure
Seizure, headache, focal neuro signs
How does presentation of AVM and cavernous angioma differ?
AVM is high pressure so massive quick bleed, CA is low pressure so slow / recurrent bleeds
What diameter of berry anueyrsm is a risk?
6-10mm
Causes of infarct stroke
cerebral atherosclerosis is main one
HTN
Smoking
DM
Where do stroke emboli vs thrombus come from?
Emboli from MCA branches
Thrombus from carotid bifurcation
Contrast histology of infarct vs haemorrhagic stroke
Infarct - tissue necrosis, permenant, no recovery
Haemorrhage - fewer macrophages, limited tissue damage with some recovery
Prognoses of TBI
19% vegetative
31% good recovery
2 types of TBI
Missle and non missle
Signs of skull base fracture
Ottorrhoea / rhinorrhoea - CSF through ear/nose
Battle’s sign - haematoma below ear
What is diffuse axonal injury
Tearing of axons due to shear/tensile forces that occur at moment of injury
What brain area is vulnerable to diffuse axonal injury
Midline structures eg corpus callosum
