Unruptured Cerebral Aneurysms: Evaluation and Management

Table 1

PHASES aneurysm risk score [11].

Population
North American or European (except Finnish)	0 point
Japanese	3 points
Finnish	5 points
Hypertension
No	0 point
Yes	1 point
Age
Less than 70 years	0 point
Greater than or equal to 70 years	1 point
Size of aneurysm
Less than 7.0 mm	0 point
7.0 mm–9.9 mm	3 points
10.0 mm–19.9 mm	6 points
Greater than or equal to 20 mm	10 points
Earlier subarachnoid hemorrhage from another aneurysm
No	0 point
Yes	1 point
Site of aneurysm
Internal carotid artery	0 point
Middle cerebral artery	2 points
Others like anterior cerebral artery, posterior communicating	4 points
artery, or posterior circulation aneurysms
PHASES risk score	5-year risk of aneurysm rupture
Less than or equal to 2	0.4%
3	0.7%
4	0.9%
5	1.3%
6	1.7%
7	2.4%
8	3.2%
9	4.3%
10	5.3%
11	7.2%
Greater than or equal to 12	17.8%