Cerebral Pathology Flashcards
Two types of cerebral oedema
Vasogenic - disruption of the BBB
Cytotoxic - due to cellular damage (hypoxia/ischaemia) - usually due to end astrocyte end feet damage
What is water transporting channel in the brain
AQP4
What radiological appearance is characteristic of cerebral oedema?
Loss of gyri on CT scan
Describe CSF passage through brain
Produced in the choroid plexus - into the lateral ventricles and through the interventricular foramina - through the cerebral aqueduct into the 4th ventricle - down into spinal canal
Most leaves 4th V into the subarachnoid space where drains via arachnoid granulations into superior saggital sinus and back into blood stream
Two types of hydrocephalus
Communicating - due to obstruction of outflow of CSF via arachnoid granulations (?infection - meningitis)
Non-communicating - due to obstruction (usually in cerebral aqueduct)
Normal ICP range
7-15mmHg
Three sites for brain herniation
Subfalcine - frontal lobe gets pushed below the falx cerebri
Uncal - median temporal lobe is pushed down through the opening of the tentorium cerebelli
Tonsilar - herniation of the cerebellar tonsils through the foramen magnum
Stroke definition
clinical syndrome of rapidly developing symptoms of focal or global loss of cerebral function lasting >24hr of no other origin other than vascular
Diseases encompassed by stroke
Cerebral infarction
Intracerebral haemorrhage
Intraventricular haemorrhage
SAH
Diseases excluded by stroke
Sub-dural haemorrhage
Epidural haemorrhage
Infarction due to infection/tumour
Ix for stroke
Urgent non-contrast CT (?haemorrhagic)
Ix for vascular risk - BP/FBC/ESR/glucose/CXR/ECG + carotid doppler
Sx of TIA
Symptoms resolve <24hrs
Amarosis fugax
Carotid bruits
What is non-traumatic intraparenchymal haemorrhage
Haemorrhage of small vessels into brain parenchyma
HTN = big RF (in 50% of cases)
Where to intraparenchymal haemorrhages occur most frequently
Basal ganglia
What is AV malformations
Where blood flows quickly from an artery to a vein without going through the normal capillary network
Can occur anywhere in brain - usually occur under high pressure so result in massive bleeds
How are AV malformations treated
Surgery
Embolisation
Radiosurgery
What are cavernous angiomas
Collection of well defined malformative vessels - closely packed with no parenchyma in between them
Appearance of cavernous angiomas on CT
Target shape (unlike AV malformations)
Cause of SAH
Rupture of berry aneurysm (higher risk in Ehlers-Danlos syndrome)
Where are berry aneurysms commonly found
80% at carotid bifurcation
20% in vertebro-basilar circulation
Which artery most commonly affected by embolic stroke
MCA
Describe ACA stroke
Contralateral hemiparesis legs>arms
Change in personality (apathy, confusion, poor judgement)
Describe MCA stroke
Contralateral hemiparesis arms>legs Ataxia Aphasia Apraxia Contralateral homonymous hemianopia or quadrantopia
Describe PCA stroke
Contralateral hemianopia and quadrantopia
Amnesia + LOC
prosopagnosia
