Fig.5. Aβ1–38/Aβ1–42 ratio improvements in the improved(n=25)and poor(n=11)cognitive groups.Before:white circle;after:black circle.Improved cognitive group showed a tendency to shift from y = 2.0895x+419.3 before surgery to y= 3.7455x−129.2 two years after surgery,and from Aβ1–42to Aβ1–38.The poor cognitive group,in contrast,showed almost no changes two years after surgery, with y = 2.132x + 1075.5 before and y = 1.96905x + 2491.1 two years after.