[Correlation of cerebrospinal fluid amyloid β-protein 42 and neurofilament light protein levels with postoperative neurocognitive dysfunction in elderly patients]

OBJECTIVE

To detect cerebrospinal fluid levels of amyloid beta- protein 42 (Aβ42) and neurofilament light protein (NFL) and explore their correlation with postoperative neurocognitive dysfunction (PNCD) in elderly patients.

OBJECTIVE

A total of 90 elderly patients undergoing hip or knee replacement with joint epidural anesthesia in our Hospital between January, 2017 and December, 2018 were recruited in this study. The levels of Aβ42 and NFL in the cerebrospinal fluid were detected using ELISA. Simple cognitive status assessment scale (MMSE) was used to evaluate the cognitive status of the patients 1 day before and 7 days after the surgery. All the patients underwent neurocognitive function tests, and the z-score method was used to determine the occurrence of PNCD. Spearman rank correlation analysis was used to analyze the correlation of Aβ42 and NFL levels in the cerebrospinal fluid with MMSE scores. Receiver operating characteristic curve (ROC) was used to analyze the predictive value of cerebrospinal fluid Aβ42 and NFL levels for PNCD.

OBJECTIVE

PNCD occurred in 38 of the 90 elderly patients, with an incidence of 42.2%. The level of Aβ42 in the cerebrospinal fluid was significantly lower in PNCD group than in the nonPNCD group (1.96 vs 2.54 ng/mL; t=3.29, P < 0.05); the concentration of NFL in the cerebrospinal fluid was significantly higher in PNCD group than in non- PNCD group (4.59 vs 3.16 ng/mL; t=3.72, P < 0.05). Aβ42 level in the cerebrospinal fluid was positively correlated while NFL was negatively correlated with the MMSE score of the patients (r=-0.659, P < 0.05; r=-0.626, P < 0.05). ROC curve analysis showed that the area under the curve (AUC) of cerebrospinal fluid Aβ42 and NFL levels were 0.744 and 0.768, respectively; the AUC of their combination was 0.847 for prediction of PNCD.

OBJECTIVE

Elderly patients with PNCD have significantly higher levels of Aβ42 and NFL in the cerebrospinal fluid than those without PNCD. Both Aβ42 and NFL levels in the cerebrospinal fluid can help to predict the occurrence of POCD in elderly patients, and their combination has a higher diagnostic value.