Cerebrovascular disease and trauma

Question 1

What is cerebral oedema?

Answer 1

Excess accumulation of fluid in the brain parenchyma.

Question 2

What are the two types of cerebral oedema?

Answer 2

Vasogenic: Disruption of blood brain barrier.

Cytotoxic: Secondary to cellular injury e.g. hypoxia/ ischaemia.

Question 3

What is the result of cerebral oedema?

Answer 3

Raised intracranial pressure

Question 4

What are the two types of hydrocephalus?

Answer 4

Non-communicating: obstruction of flow of CSF.

Communicating: no obstruction but problems with re-absorption of CSF into venous sinuses.

Question 5

What is normal ICP?

Answer 5

ICP measured in mmHg

7–15mmHg for a supine adult.

Question 6

What are consequences of raised ICP?

Answer 6

Enclosed bony box: Pressure increases because of space occupying lesions, oedema or both.

Increased pressure forces brain against unyielding bony wall of skull + inflexible dural folds.

Results in herniation of brain structures where space is available.

Question 7

What is the definition of stroke?

Answer 7

Clinical syndrome characterised by rapidly developing clinical Sx +/- signs of focal, + at times global loss of cerebral function

with Sx lasting >24h or leading to death, with no apparent cause other than that of vascular origin.

Question 8

What is a TIA?

Answer 8

Warning stroke: should be taken very seriously.

Caused by a clot; blockage is temporary.

Most TIAs last <5m; average ~ 1m.

Unlike a stroke, when a TIA is over, usually no permanent injury to brain.

Question 9

What is the significance of TIA?

Answer 9

1/3 of those with TIA get significant infarct within 5y.

TIA= important predictor of future infarct.

Question 10

What is a non-traumatic intra-parenchymal haemorrhage?

Answer 10

Haemorrhage into substance of the brain: rupture of a small intraparenchymal vessel.

Most common in basal ganglia.

HTN causes > 50% of bleeds.

Presentation with severe headache, vomiting, rapid loss of consciousness, focal neurological signs.

Question 11

Give 7 features of arteriovenous malformations?

Answer 11

Occur anywhere in CNS.

Symptomatic between 2nd- 5th decade (mean 31y)

Present with haemorrhage, seizures, headache, focal neurological deficits.

High pressure: MASSIVE BLEEDING!!!

Seen on angiography.

Morbidity after rupture 53-81%: high in eloquent areas.

Mortality 10-17.6%

Question 12

What is the treatment of arteriovenous malformations?

Answer 12

Surgery

Embolization

Radiosurgery.

Question 13

What is a cavernous angioma?

Answer 13

Well-defined malformative lesion composed of closely packed vessels with no parenchyma interposed between vascular spaces.

Question 14

What is the pathogenesis/clinical presentation of cavernous angiomas?

Answer 14

Can be found anywhere in CNS

Usually symptomatic >50y.

Congenital, pathogenesis unknown.

Present with headache, seizures, focal deficits, haemorrhage.

Low pressure: recurrent bleeds.

Question 15

What is the treatment of cavernous angiomas?

Answer 15

Surgery

Question 16

What is this?

Answer 16

Arteriovenous malformation

Question 17

What is this?

Answer 17

Arteriovenous malformations

Question 18

What is this?

Answer 18

Cavernous angioma

Question 19

What is this?

Answer 19

Cavernous angioma

Question 20

What are subarachnoid haemorrhages?

Answer 20

Rupture of a berry aneurysm (present in 1% of gen pop)

80 %: Internal carotid artery bifurcation

20%: within the vertebro-basilar circulation.

Question 21

What is the clinical presentation of subarachnoid haemorrhages?

Answer 21

30% of patients have multiple aneurysms.

Greatest risk of rupture when 6-10mm diameter.

Present with sudden onset of severe “thunder clap” headache, vomiting, loss of consciousness.

Question 22

What is this?

Answer 22

Berry aneurysm

Question 23

What is the treatment for subarachnoid haemorrhages?

Answer 23

Endovascular tx: coils

Blocks blood flow

Question 24

What are infarctions?

Answer 24

Tissue death due to ischaemia.

Commonest form of cerebrovascular disease

70-80% of strokes

Question 25

What are risk factors for infarctions?

Answer 25

Cerebral atherosclerosis most common cause. HTN DM Smoking

Question 26

Where does the worst atherosclerosis occur?

Answer 26

In larger vessels (extra-cerebral arteries) Thrombosis formation Often near carotid bifurcation or in basilar artery.

Question 27

Where do emboli occur?

Answer 27

Intracerebral arteries. Usually from heart or atherosclerotic plaques. Embolic occlusion usually in middle cerebral artery branches.

Question 28

What is the difference between an infarction and haemorrhagic stroke?

Answer 28

**Infarction:** * Tissue necrosis (stains) * Rarely haemorrhagic * Permanent damage in affected area * No recovery **Haemorrhage:** * Bleeding * Dissection of parenchyma * Fewer macrophages * Limited tissue damage (periphery) * Partial recovery

Question 29

What is the epidemiology of TBI?

Answer 29

Trauma single largest cause of death in \<45s. 9 deaths from head injury per 100,000. Account for 25% of all trauma deaths. **High morbidity:** * 19% vegetative or severely disabled * 31% good recovery

Question 30

What are different classifications of TBI?

Answer 30

**Non-missile + missile** Non-missile: * Acceleration/ deceleration (brain decelerates at different rate to skull) * Rotation (midline more susceptible due to rotational forces) **Cause: RTA, falls + assaults** **Resulting damage: Focal or diffuse.**

Question 31

What are fractures associated with cerebrovascular disease?

Answer 31

Fissure fractures often extend into base of skull May pass through middle ear or anterior cranial fossa Otorrhea or rhinorrhea Infection risk

Question 32

What is a contusion in the context of cerebrovascular trauma?

Answer 32

Brain in collision with skull. Surface “bruising”. If pia mater torn, becomes laceration. Lateral surfaces of hemispheres, inferior surfaces of frontal + temporal lobes. Coup = hits front of skull Contrecoup = rebound hitting back of skull

Question 33

What is diffuse axonal injury in the context of cerebrovascular trauma?

Answer 33

Occurs at moment of injury. Shear + tensile forces affecting axons. Commonest cause of coma (when no bleed). Midline structures particularly affected e.g. corpus callosum, rostral brainstem + septum pellucidum. e.g. rotational blow in boxing

Question 34

Describe the production, flow and absorption of CSF

Answer 34

CSF produced by ependymal cells of choroid plexus (mainly in lateral ventricles) From lateral ventricles, goes through interventricular foramina to 3rd ventricle Flows down cerebral aqueduct to 4th ventricle Enters subarachnoid space (via medial + lateral apertures) Drains back into venous system via arachnoid granulations

Question 35

List 3 different types of brain herniation and their consequences.

Answer 35

* *Subfalcine**: cingulate gyrus pushed under the falx cerebri (not usually clinically significant) * *Uncal/ transtentorial:** medial temporal lobe pushed under the tentorium cerebelli – affects midbrain, can cause unconsciousness * *Tonsilar:** cerebellar tonsils pushed through foramen magnum. Affects medulla + causes cardiorespiratory failure

Question 36

Which type of herniation does not involve the cerebral cortex?

Answer 36

Tonsillar (Cerebellum going through foramen magnum)

Question 37

What are the inclusions in the definition of stroke?

Answer 37

Stroke due to cerebral infarction Primary intracerebral haemorrhage Intraventricular haemorrhage Most cases of SAH

Question 38

What are the exclusions in the definition of stroke?

Answer 38

Subdural haemorrhage Epidural haemorrhage Intracerebral haemorrhage (ICH) Infarction caused by infection or tumour.

Question 39

What occurs in AVMs?

Answer 39

Blood passes quickly from artery to vein, bypassing the normal capillary networks Not supplying tissues effectively

Question 40

What is the difference between focal and global cerebral ischaemia?

Answer 40

Focal: defined vascular territory, tissue downstream of blockage dies due to lack of blood flow Global: systemic circulation fails, insufficient blood to brain on a regular basis

Question 41

Where does the anterior cerebral artery supply?

Answer 41

Midline of frontal lobes Superior medial parietal lobes

Question 42

Where does the middle cerebral artery supply?

Answer 42

Lateral cerebral cortex Subcortices

Question 43

Where does the posterior cerebral artery supply?

Answer 43

Occipital lobe Inferior temporal lobe

Question 44

What percentage of patients who experience a TIA will have a significant infarct within 5 years?

Answer 44

33%

Question 45

What is the most common cause of non-traumatic intraparenchymal haemorrhages?

Answer 45

HTN

Question 46

How may a TBI cause rhinorrhea or otorrhea?

Answer 46

Fracture may pass through middle ear or anterior cranial fossa Loss of CSF through ear or nose Indicates rupture of CSF barrier= infection risk

Question 47

Give 2 signs of skull fracture

Answer 47

Battle sign: haemorrhage over mastoid process post traumatic basilar skull fracture Panda eyes: base of skull fracture in anterior cranial fossa