Table 1.

Distribution of frequencies of autopsy cases with a given extent of atherosclerosis (AS) within the arteries of the circle of Willis (CaW) among different age groups

Extent of AS	Frequency of cases/% in the age group
	60–70 years	71–80 years	81 years and older
No AS	20.69	3.57	4.00
1–25% of CaW vessels with AS	17.24	7.14	12.00
26–50% of CaW vessels with AS	20.69	32.14	8.00
51–75% of CaW vessels with AS	24.14	35.71	40.00
76–100% of CaW vessels with AS	17.24	21.43	36.00

The table presents the percentage of cases without AS and with AS in a given extent in the age groups 60–70, 71–80, and 81 years and older. This observation is based on the data obtained from 82 non-selected autopsy cases. The circle of Willis was observed macroscopically for the presence or absence of the 11 arteries of the circle of Willis as previously described [70]. The extent of AS was calculated as: number of AS-affected vessels × 100/number of investigated vessels of the circle of Willis [70]. The cases analyzed here were already included in other studies under other aspects [65, 70]