intima + adventitia 📷

dome (apex) 📷 = minimal resistance area

5-10mm

Classification - dimensions: • <3 mm (microaneurysm) • 4 - 6 mm (small) • 7 - 10 mm (medium) • 11 - 24 mm (large) • >25 mm (GIANT)

1. Bleeding → SAH
2. Cerebral herniation (transtentorial → brainstem)
3. Acute hydrocephalus (sylvian aqueduct obstruction)

1. Vasospasm (Critical period day 4-12)) ⇒ ischemia ⇒ ↓neuro-status
2. Rebleeding → 70% die at rebleed
3. Chronic hydrocephalus (due to malabsorption, Øobstruction)

1. Thunderclap headache
2. Meningeal syndrome
3. ↑ICP → Neurologic deficit + Loss of conciousness

Survival rates:

GOOD (SV 96%) - grades 1-2 MEDIUM (SV 90%) - grade 3 POOR (SV 72%) - grade 4 RESERVED (SV 50 %) - grade 5

⭐ Star sign ⇒ 📷

Brain angioography = gold standard

brain angio-CT = imaging standard

endovascular coiling 📷(detachable, balloon, stent, flow diverter 📷)

clipping 📷 ⇒ aneurysm neck

1. coiling fails
2. Aneurysm: large neck, giant aneurysm
3. Location: MCA OR Ant. circulation+young (life expectancy >15y)

angiography

1. ↑Survival w/o disability
2. ↓ hospitalization
3. ↓short-term complication

1. ↑risk for Re-permeabilization
2. Need for pre-angiography
3. ↑cost (long term)

1. FEEDING ARTERIES 2. NIDUS 3. DRAINING VEINS

1. Progressive neurologic deficit (Epilepsy, headache, FND)
2. Children → Vascular steal → cardiac insuff.
Vascular steal:

⇒ PICTURE

1. There is an effect of impaired perfusion of the cerebral tissue surrounding the AVM ⇒ diversion to AVM = vascular steal phenomenon
2. Vascular steal is said to be the cause of progressive neuro deficits and psychiatric behaviors/manifestations seen in some AVM patients

• CT
• Angio ⇒ classic component (feeder arteries, wide venous drainage, nidus)
• CT (non-cons) → triangular, apex towards ventricle

→ CT native vs. angio: 📷

• MRI → “honeycomb” 📷

1. Embolization (endovascular)
2. Gamma-knife
3. Surgery

Grading:

• AVM size
• small (<3cm) = 1pt.
• medium (3-6cm) = 2pt.
• large (>6cm) = 3pt.
• Adjacent parenchyma eloquence
• non-eloquent = 0pt.
• eloquent = 1pt.
• Venous drainage
• superficial = 0pt.
• deep = 1pt.

Tx depending on grade:

Grade 1-2 = minor operative risk, other options: radiosurg. / endovasc. Grade 3 = surgery Grade 4 = surgery (high risk) Grade 5 = selective embolization + surgery / embolization/ observe

T ⇒ symptoms may persist + repermeabilization!

1. ASYMPTOMATIC
2. Hemorrhage
3. Mass effect → headache + seizures, FND

angio ⇒ INVISIBLE 🤡

MRI ⇒ Popcorn/berry (T2) 📷

CT ⇒ hyperdense + late enhancement

observation

F ⇒ useless

#1 gamma knife

(⇒ surgery if emergency)