Relationship of Postoperative Serum Neuro-Specific Enolase Levels with Postoperative Delirium Occurring after Microvascular Depression Surgery in Older Patients

There is a high incidence of postoperative delirium (POD) following microvascular decompression (MVD) surgery. Neuronal survival, differentiation, and neurite regeneration are regulated by neuro-specific enolase (NSE). Therefore, we investigated and assessed whether circulating NSE levels are related to POD after MVD surgery. We recruited a total of 209 patients and 209 age- and gender-matched healthy controls. A retrospective review of electronic medical records was conducted, and serum NSE levels were measured in the serum of patients before and after surgery, as well as the serum of controls. Patients were categorized according to the presence of POD. Postoperative patient serum levels of NSE were significantly higher compared to preoperative levels. Additionally, postoperative serum NSE levels were remarkably higher in POD patients than non-POD patients. In addition, there was no significant correlation between NSE levels and the type and severity of postoperative delirium. Age (OR = 1.153, 95% CI = 1.040–1.277, p = 0.006), the levels of serum NSE (OR = 1.326, 95% CI = 1.177–1.494, p < 0.001), and the levels of serum S100β (OR = 1.006, 95% CI = 1.000–1.012, p = 0.048) were the three independent variables for predicting POD. A significant correlation existed between serum S100β levels and serum NSE levels (t = 2.690, p = 0.008). In terms of area under the precision–recall curve, the discriminatory ability of serum NSE levels (AUC = 0.876, 95% CI = 0.829–0.924, p < 0.0001) was close to that of the serum S100β level (AUC = 0.879, 95% CI = 0.825–0.933, p < 0.0001) and significantly higher than that of age (AUC = 0.813, 95% CI = 0.755–0.871, p < 0.0001). Combining all three features produced a dramatic improvement over individual effects. The NSE level in serum was a stronger indicator of the likelihood of POD after MVD surgery in the older population. The clinical determination of this factor might be useful for distinguishing older patients at risk of POD after MVD surgery on the basis of their clinical findings.