Cerebral Pathology

Question 1

Two types of cerebral oedema

Answer 1

Vasogenic - disruption of the BBB

Cytotoxic - due to cellular damage (hypoxia/ischaemia) - usually due to end astrocyte end feet damage

Question 2

What is water transporting channel in the brain

Answer 2

AQP4

Question 3

What radiological appearance is characteristic of cerebral oedema?

Answer 3

Loss of gyri on CT scan

Question 4

Describe CSF passage through brain

Answer 4

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

Question 5

Two types of hydrocephalus

Answer 5

Communicating - due to obstruction of outflow of CSF via arachnoid granulations (?infection - meningitis)
Non-communicating - due to obstruction (usually in cerebral aqueduct)

Question 6

Normal ICP range

Answer 6

7-15mmHg

Question 7

Three sites for brain herniation

Answer 7

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

Question 8

Stroke definition

Answer 8

clinical syndrome of rapidly developing symptoms of focal or global loss of cerebral function lasting >24hr of no other origin other than vascular

Question 9

Diseases encompassed by stroke

Answer 9

Cerebral infarction
Intracerebral haemorrhage
Intraventricular haemorrhage
SAH

Question 10

Diseases excluded by stroke

Answer 10

Sub-dural haemorrhage
Epidural haemorrhage
Infarction due to infection/tumour

Question 11

Ix for stroke

Answer 11

Urgent non-contrast CT (?haemorrhagic)

Ix for vascular risk - BP/FBC/ESR/glucose/CXR/ECG + carotid doppler

Question 12

Sx of TIA

Answer 12

Symptoms resolve <24hrs
Amarosis fugax
Carotid bruits

Question 13

What is non-traumatic intraparenchymal haemorrhage

Answer 13

Haemorrhage of small vessels into brain parenchyma

HTN = big RF (in 50% of cases)

Question 14

Where to intraparenchymal haemorrhages occur most frequently

Answer 14

Basal ganglia

Question 15

What is AV malformations

Answer 15

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

Question 16

How are AV malformations treated

Answer 16

Surgery
Embolisation
Radiosurgery

Question 17

What are cavernous angiomas

Answer 17

Collection of well defined malformative vessels - closely packed with no parenchyma in between them

Question 18

Appearance of cavernous angiomas on CT

Answer 18

Target shape (unlike AV malformations)

Question 19

Cause of SAH

Answer 19

Rupture of berry aneurysm (higher risk in Ehlers-Danlos syndrome)

Question 20

Where are berry aneurysms commonly found

Answer 20

80% at carotid bifurcation

20% in vertebro-basilar circulation

Question 21

Which artery most commonly affected by embolic stroke

Answer 21

MCA

Question 22

Describe ACA stroke

Answer 22

Contralateral hemiparesis legs>arms

Change in personality (apathy, confusion, poor judgement)

Question 23

Describe MCA stroke

Answer 23

Contralateral hemiparesis arms>legs
Ataxia
Aphasia
Apraxia
Contralateral homonymous hemianopia or quadrantopia

Question 24

Describe PCA stroke

Answer 24

Contralateral hemianopia and quadrantopia
Amnesia + LOC
prosopagnosia

Question 25

How are TBIs classified

Answer 25

1) Non-missile = acceleration/deceleration (car) or rotational (boxing)
2) Missile (shrapnel/bullets etc)

Question 26

Consequences of basal skull fracture

Answer 26

Battle sign - bruise over mastoid process
Racoon sign - bruises around eyes
Both take ~1 day to develop

Question 27

What is a laceration

Answer 27

When a brain contusion causes rupture of the pia mater

Question 28

what is DAI

Answer 28

Most common non-bleed related cause of coma - shear and tensile forces of trauma = damage to axons

Can lead to cognitive and behavioural changes further down the line