Geographic Population

North American, European, or Australian population+0Japanese population (+3 pts)+3Finnish population (+5 pts)+5

Hypertension (Treated or Untreated)

No hypertension+0Hypertension (+1 pt)+1

Age

< 70 years+0≥ 70 years (+1 pt)+1

Aneurysm Size (Maximum Diameter)

< 7.0 mm+07.0–9.9 mm (+3 pts)+310–19 mm (+6 pts)+6≥ 20 mm (+10 pts)+10

Earlier SAH from a Different Aneurysm

No prior SAH+0Prior SAH from different aneurysm (+1 pt)+1

Aneurysm Site

Middle cerebral artery (MCA), other non-listed+0ICA (internal carotid artery) (+1 pt)+1Posterior communicating artery (PcomA) (+1 pt)+1Anterior communicating or anterior cerebral artery (+2 pts)+2Posterior circulation (vertebrobasilar) (+4 pts)+4

PHASES Score for Unruptured Intracranial Aneurysm

PHASES Score for Unruptured Intracranial Aneurysm