Serum and cerebrospinal fluid S100b protein and neuron-specific enolase in relation to postoperative cognitive dysfunction in orthopedic patients

Abstract

GRAZ-01-1 Introduction: The incidence of postoperative cognitive dysfunction (PCD) is high in the elderly undergoing hip fracture fixation. We assessed serum (s) and cerebrospinal fluid (csf) S100b protein and neuron-specific enolase (NSE) in relation to PCD in these patients. Methods: In 26 females and 10 males, 83 ± 7.5 yr ASA I-III undergoing hip fracture fixation under spinal anaesthesia, we measured s and csf NSE and S100b the day of operation. We assessed preoperative cognitive function (PreCF) as: 1 Normal n = 12; 2 Slow, difficult n = 14; 3 Confusion/delirium n = 6; 4 Dementia n = 4; and early PostCF as unchanged and deteriorated graded as: 1 Communication/memory gaps, 2 Lethargy, 3 Confusion/Delirium, 4 Dementia. Paired and unpaired t-tests were used for statistical analysis. FIGUREFigureResults: sNSE and S100b were higher P > 0.000 and lower P > 0.000 respectively than csf values in all patients. There was no significant difference between unchanged and deteriorated patients overall. Eleven out of thirty-six patients (30%), including two with normal PreCF, deteriorated: memory gaps 4, lethargy 2, delirium 5. In lethargic and delirious patients csfS100b was high. Conclusions: sNSE and sS100b differed significantly compared to their csf values. Only csfS100b seems predictive of PCD suggesting that in severe PCD neuronal damage might already be in progress. Normal PreCF decreases the probability of PCD.