18. Vascular diseases of Brain, AVM

Question 1

Aneurysms - general:

Answer 1

Description: bulging of blood vessel wall, can rupture and cause hemorrhagic stroke

Symptoms: asymptomatic until rupture –> severe headache, nausea, neurological

Location: anterior communicating a. 30-40%

Question 2

Aneurysms - imaging:

Answer 2

DSA (golden standard):
detailed assessment + treatment plan
delineation of anatomy

MRA:
non-invasive, aneurysm-sac and neck

CT NO CONTRAST:
initial assessment to detect hemorrhage
CTA:
identify aneurysms and relationship with surrounding structures

USG:
vasospasm after aSAH (velocity > 150cm/s –> ischemia)

Question 3

Aneurysms - treatment:

Answer 3

Endovascular treatment:

1. Coiling - place microcatheter into sac, fill with coil (limiting factor is width of neck) -

Wide-neck aneurysm: stent around neck to hold coil

Balloon remodeling: temporary inflation of neck

2. Flow diverter - special stent (redirect flow and change from turbulent to laminar –> shrinking of sac)
3. Liquid embolic system - embolic substance via microcatheter

Open surgery:
Clipping - around neck

Question 4

AVM - general:

Answer 4

Description: congenital anomalies, complex tangle of blood vessels where arteries connect directly to veins without capillary beds

Symptoms: headache, seizures, neurological deficits

Question 5

AVM - imaging:

Answer 5

DSA (golden standard):
technique: CONTRAST + X-ray

MRI:
t1/t2 - anatomical detail
MRA - vascular architecture
Gradient-Echo: blood products + identify bleeding

CT:
NO CONTRAST - acute bleeding
CTA - blood vessels + nidus and feeding arteries

Question 6

AVM - treatment:

Answer 6

DSA:
embolization - glue into AVM to block it

Surgery:
excision of AVM

Stereotactic Radiosurgery:
high-dose radiation

Question 7

AVM - grading:

Answer 7

Spetzler-Marting Grade (mortality of surgical resection):
1-2: small (<3cm), superficial, non-neuro deficits
3: intermediate, medium-size
4-5: big (>6cm), deep, neuro-deficits

Question 8

Persistent Carotid-Basilar anastomosis

Answer 8

Description: disruption of vertebro-basilar system during embryogenesis

Cause: ICA supply basilar artery in embryo before vertebral aa. form (HOT: hypoglossal, otic, trigeminal)

Question 9

Cerebral cavernous malformation (Cavernoma):

Answer 9

Description:
Cluster of abnormal blood vessels like mulberry

MRI:
t2w - bright center + hypointense ring (hemosiderin)