Cerebrovascular disease and trauma Flashcards
What are the two different types of oedema that occur in the brain?
- Vasogenic - due to disruption of the blood brain barrier
- Cytogenic 2nd due to cellular injury (e..g hypoxia/ischaemia
Explain the normal flow of CSF in the brian
- Produced by coroid plexus
- into Lateral ventricle
- Into 3rd ventrile
- Through aqueduct into 4th ventricle
- absorbtion in subarachnoid space –> drain into superior saggital sinus
What is a non-communicating hydrocephalus?
What site is most cmommonly affected?
involves obstruction of flow of CSF
most commonly in aqueduct
What are the normal ranges of ICP in an adult?
7-15 mmHg
What different types of herniation can occur due to increased ICP?
- Subfalcine herniation
- Transterntorial herniation
- Tonsillar herniation
What is subfalcine herniation?
Herniation of singular cortex beneath the falx
(midline fold of the dura) - usually due ICP above/in level of falx
What is a Transtentorial/uncal herniation?
hernation of medial temporal lobe
under tentorium (horizonal dura mater between parietal
lobes and cerebellum)
What is a Tonsillar herniation
herniation of cerebellum through
foramen magnum. This compresses the brainstem leading to cardiorespiratory arrest and death (risk if doing a LP if ↑ ICP)
What is the definition of stroke vs TIA?
Both: rapid onset, signs and/or focal symptomns due to vascular difunction
Stroke: lasting >24h or leading to death
TIA <24h (usually only minutes)
What is the likelihood of a stroke once someone had a TIA?
1/3 of people with TIA have a significant infarct within 5 years of episode
What is the most common cause of intraparenchymal haemorrhoage?
In what terratory does it usually occur?
> 50% are due to Hypertension
Most common in the basal ganglia
What is an lacunar infarct?
Small strokes (both haemorrhoagic or ischamemic, usually haemorrhoagic)
usually asymptomatic, can be seen on Brain imaging
What are characteristics of Arteriousvenous malformation?
Developmental malformation in vasculature leading to high-pressure abnormalities
Usually present in young people <50, mean age 30) presenting with massive bleeding –> high morbidity afterwards
What is a cavernous angioma?
Slow-flow venous malformation (well-defined) within the brain
Usually initially asymptomatic, can become symptomatic >50 with recurrent, low pressure bleeds
(presents with headache, seizure, focal deficits, haemorrage)
What is the most common cause of a SAH?
Sub-arachnoid haemorrhage
85% due to rupture of Berry aneurism (risk of rupture when 6-10mm)
fWhat is the most common sites for SAH to occur?
80 % - internal carotid artery bifurcation, 20% occur within the vertebro-basilar circulation
Picture: most common site of Berry aneurisms
What is a typical CT findings of a SAH?
hyperattenuation around Circle of Willis (blood in Sub-arachnoid space)
What is the most common cause of Stroke?
What are the risk factors?
70-80% due to ischaemia
Mostly due to ifarction —> atherosclerosis
What vascular territory is most commonly affected by cerebral infarction?
Most common site of stroke: MCA
What ist a typical presentation of a MCA Stroke?
- contralateral weakness and sensory loss of face and arm
- cortical sensory loss
- may have contralateral homonymous hemianopia or quadrantanopia
- if dominant (usually left) hemisphere: aphasia
- if non-dominant (usually right) hemisphere: neglect
- eye deviation towards the side of the lesion and away from the weak side
What is a typical presentation of an ACA stroke?
- Contralateral leg paresis
- sensory loss
- cognitive deficits (e.g. apathy, confusion, and
poor judgment)
What is a typical presentatio of a PCA stroke?
- contralateral hemianopia or quadrantanopia
- midbrain findings: CN III and IV palsy/pupillary changes, hemiparesis
- thalamic findings: sensory loss, amnesia, decreased level of consciousness
- if bilateral: cortical blindness or prosopagnosia
What is the most common cause of extradural haemorrhage?
What is the clinical presentation
Skull fracture from TRAUMA
–> Most common site - ruptured middle meningeal artery
Rapid arterial bleed, lucid interval then LoC
● BUZZWORD – “lemon” shape
What is Battle’s sign?
What does it indicate?
haemorrhage on mastoid process –> indicates base of skull fracture
What is a contusion?
Contusion = Bruise on brain
(most commonly in inferior surface of the brain)
What is diffuse axonal injury?
What are the most common sittes and potential long-term consequences?
Tearinf of axons of nerve cells (due to tensile force at time of injory)
Commonest cause of coma-post brain injory if there is no bleed
midline structures like Corpus Callosum, rostral
brainstem and septum pellucidum affected → Vegetative state, post traumatic dementia
What is communicating hydrocephalus?
What are some causes?
Reduced absorption of CSF into sinus veins
a. E.g. in meningitis the meninges can become fibrous and this reduces absorption
