Table 4.

Neurocognitive performance (age-normalized z scores) for patients with chronic kidney disease (CKD), controls, the subgroups of CKD with presence and absence of positive extrema cerebral blood flow (CBF). In general, CKD subjects showed poorer neurocognitive functions than controls. CKD subjects with presence of positive extrema in CBF measurements showed poorer neurocognitive functions than those without presence.

		TNB verbal memory	TNB verbal working memory	TNB executive function	CNB language reasoning	CNB non-verbal reasoning	CNB spatial processing
CKD	mean±SD	0.15±1.60	0.05±1.29	−0.67±1.18	−0.61±1.14	−0.38±0.93	−0.46±1.06
Control	mean±SD	0.90±1.90	0.68±1.57	−0.11±1.11	−0.19±1.01	0.002±1.02	0.10±1.12
Wilcoxon rank sum test (CKD vs. Control)	P-value	0.03	0.02	0.005	0.02	0.04	0.006
CKD subgroup with positive extrema CBF	mean±SD	−0.61±1.12	−0.21±1.36	−0.68±1.10	−0.48±1.02	−0.60±0.86	−0.67±1.06
CKD subgroup without positive extrema CBF	mean±SD	0.57±1.65	0.20±1.23	−0.66±1.23	−0.68±1.21	−0.26±0.95	−0.35±1.06
Wilcoxon rank sum test (with vs. without positive extrema CBF in CKD)	P-value	0.003	0.188	0.689	0.568	0.191	0.222

Note.--CNB: computerized neurocognitive battery, TNB: traditional neurocognitive battery. Both CNB and TNB are age adjusted z-scores.