Table 3.

Comparison between the groups of cognitive function impairment before and after the surgery

Cognitive function	Preoperative			Postoperative
	NIRS (n = 43)	No NIRS (n = 36)	p	NIRS (n = 43)	No NIRS (n = 36)	p
Mild impairment, n (%)	3 (6.9)	5 (13.8)	0.46	7 (16.3)	16 (44.4)	0.01
Serious impairment, n (%)	0 (0)	0 (0)	1.00	0	3 (8.3)	0.09
MoCA mean score, mean ± SD	27.1 ± 1.8	26.9 ± 1.9	0.63	26.8 ± 1.9	23.7 ± 2.5	<0.001

MoCA: Montreal Cognitive Assessment; NIRS: near infrared spectroscopy; SD: standard deviation