Neurovascular Disease

Question 1

arteriovenous malformation

Answer 1

complex tangle of abnormal arteries and veins connected together with fistulas creating a shunt that connects them directly - bypassing the normal capillary network

Question 2

are AVM congenital?

Answer 2

some are, can occur later in life

Question 3

do AVM cause any problems as they are?

Answer 3

they tend to be silent until there is a big problem, can cause a progressive neurological deficit as they steal the blood flow to tissue

Question 4

what acute problems can AVM cause

Answer 4

haemorrhage (1), seizure (2), headache

Question 5

AVM occuring in which areas of the brain are more likely to caue focla and general seizures

Answer 5

frontal lobe - generalised

temporal lobe - focal

Question 6

investigation of AVM

Answer 6

catheter angiography - navigated under x ray guidance

Question 7

investigation of AVM in acute setting

Answer 7

CT angiography is faster than catheter so may be used

Question 8

what procedure may be performed pre surgery on AVM

Answer 8

embolization - decrease blood flow through AVM allowing surgery to take place in a more blood less and controlled way

Question 9

surgical options for AVM

Answer 9

• open craniotomy
• stereotactic radiosurgery
• endovascular coiling

Question 10

which blood vessels cause SAH

Answer 10

circle of Willis (90%), also vertebro basilar circulation

Question 11

which areas of the blood vessels are high risk sites for damage (SAH)

Answer 11

bifurcation

Question 12

2y damage caused by SAH

Answer 12

damage surrounding parenchyma due to haemorrhage, infarcts due to disruption of blood supply

Question 13

most common place for berry aneurysm

Answer 13

bifurcation of anterior cerebral and communicating artery

Question 14

what are fusiform aneurysms associated with

Answer 14

diffuse atheromatous degeneration of arterial wall assoicated with hypertension

Question 15

are females or males more at risk of aneurysm rupture

Answer 15

females

Question 16

are aneurysms in the posterior or the anterior circulation more likely to rupture

Answer 16

posterior

Question 17

risk factors for aneurysms (and rupture)

Answer 17

bigger aneurysm, comorbidities (hypertension, smoking, alcohol), bleeding disorder

Question 18

name 2 drugs that increase blood pressure

Answer 18

cocaine, methamphetamine - inc risk of aneurysm rupture

Question 19

which connective tissue disease is assoicated with aneurysms

Answer 19

ehlers danlos - assoicated with very fragile blood vessels

Question 20

fibromuscular dysplasia

Answer 20

abnormal development of arteries leads to narrowing in some places - this creates a string of beads appearance

found in renal, cerebral and carotid arteries. are prone to haemorrhage, aneurysm etc

Question 21

what problems can aneurysms cause as they are - think compression

Answer 21

can compress specific CN

Question 22

which CN is at risk of compression from a posterior communicating aneurysm

Answer 22

CN III

Question 23

what is at risk of compresion from an ACOM aneurysms

Answer 23

optic chiasm

Question 24

presentation of SAH

Answer 24

• thunderclap headache - sudden onset, vvv severe, occipital typically
• n and v, collapse, seizures, coma, drowsiness (may persist for days)

Question 25

what symptoms arise in SAH due to irritation of the meninges from blood

Answer 25

meningitis - neck stiffness, photophobia, fever, Kernigs sign

Question 26

what is teh diagnostic test for SAH

Answer 26

CT

Question 27

SAH: what investigation do you perform if CT is normal, when would you do it and what findings would you expect

Answer 27

lumbar puncture - wait at least 12 hours from start of headache to allow time for blood cells to lyse and xanthochromia to develop CSF has blood in it (circulates in subarachnoid space), blood turns yellow due to breakdown and bilirubin release - xanthochromia

Question 28

management of SAH

Answer 28

* endovascular coiling - block blodo flow into aneurysms by inducing clotting of the aneurysm * craniotomy and microsurgical clipping - wide necked aneurysm

Question 29

most common cause of death after SAH treatment

Answer 29

re bleeding - 20% occur in the first few days

Question 30

who is at the biggest risk of rebleeding after SAH

Answer 30

elderly and hypertensives

Question 31

managmenet of SAH re bleeding

Answer 31

surgical clipping or coiling again

Question 32

what problems can vasospasm cause after SAH

Answer 32

* blood products can irritate arterial walls and cause spasm * this can cause ischaemia --\> focal neurological deficit/altered state of consciousness

Question 33

how long after SAH does vaosospasm occur

Answer 33

3-10 days

Question 34

how to confirm diagnosis of vasospasm?

Answer 34

angiogram

Question 35

management of vasospasm

Answer 35

nimodipine - a Ca channel blocker than relaxes narrowed blood vessels

Question 36

SAH leading to hydrocephalus?

Answer 36

communicating - arachnoid granulations are blocked by blood

Question 37

seizures after SAH?

Answer 37

yes

Question 38

what is the most common electrolyte disorder after SAH

Answer 38

hyponatraemia - either through SIADH or CSWS

Question 39

SAIDH

Answer 39

the hypothalamus is stimulated by trauma/ischaemia adn there is excessive release of ADH - increased water reabsorption by the kidneys - this results in fluid retention and dilutional hyponatraemia

Question 40

CSWS

Answer 40

for some reason in reponse to brain injury or trauma the kidneys excrete too much Na - fluid follows

Question 41

do SIADH and CSWS create a hypo/eu volaemia hyponatraemia

Answer 41

SIADH - euvolaemia hyponatraemia CSWS - hypovol hyponat

Question 42

does hyponatraemia indicate poor outcome?

Answer 42

it may, hyponatraemia can cause a shift in water from the EC to the IC space - worsen cerebral oedema and intracranial hypertension - inc risk of seizures and neurological injury

Question 43

management of hyponatraemia after SAH

Answer 43

**avoid fluid restriction** (normally part of SIADH management) supplement Na intake fludrocortisone - aldosterone replacement (increase Na absoprtion)

Question 44

where does the blood accumulate in extradural haematoma

Answer 44

between blood and dura

Question 45

what is the most common cause of an epidural haematoma

Answer 45

pterion fracture - injures middle meningeal artery which runs over the inner aspect of it

Question 46

what is the classical history of an epidural haematoma

Answer 46

young adult sustains closed head trauma - lucid interval (brief loss of consciousness, regain consciousness), then deteriorating state 3-4 hours later as blood accumulates

Question 47

how quickly is the decline in epidural haematoma, and why

Answer 47

froma high pressure arterial source, so rapid

Question 48

how does an epidural haematoma appear on ct

Answer 48

biconvex shape - midline shift due to pressure it does not cross teh suture lines as the dura adheres tightly here to the skull

Question 49

where does the blood collect in a subdural haematoma and from which vessels

Answer 49

between the dura and arachnoid layer. the cerebral veins drain blood from the brain out to the dural venous sinuses (located between the 2 layers of dura)

Question 50

why are teh elderly more prone to subdural haematima

Answer 50

as you get older, the brain atrophies - the bridging veins are stretched and so are more likely to rupture even with minor trauma can present acute or be chrnoic

Question 51

what other things cause brain atrophy

Answer 51

epilepsy, dementia, chronic alcoholism

Question 52

how does a subdural haematoma present in an acute situation

Answer 52

decreased state of consciousness, confusion

Question 53

how does a chronic subdural haematoma present

Answer 53

insidiously, progressive headache and confusion

Question 54

if there is a subdural haematoma and it is non fatal, so not treated, what does the blood form on the surface of the brain?

Answer 54

a yellow neo-membrane

Question 55

subdural haematoma ct

Answer 55

some of the blood may be hypodense (black) if it is chronic may see acute on chronic

Question 56

what is coup and countercoup, and which often causes the most severe injuries?

Answer 56

coup = damage at point of impact countercoup = damage occuring when brain rebounds and hits back of skull countercoup