Postoperative neurocognitive function and microembolus detection in patients undergoing neck dissection: a pilot study

Background and objective Patients undergoing oncologic neck dissection may have many of the risk factors for carotid artery stenosis, thus predisposing them to perioperative cerebral ischaemic events. The present study was designed to investigate development of postoperative neurocognitive dysfunction in these patients. Methods Twenty-six patients were assessed the day before surgery and 48 h and 12 months after surgery using a comprehensive neuropsychological test battery. Cognitive performance was compared with a matched control group to account for the practise effect associated with repeated testing. Doppler ultrasonography was used to detect intraoperative cerebral microembolism. S100 beta protein values were evaluated before and immediately after anaesthesia. Results On the second postoperative day, 26.9% of patients undergoing neck dissection had postoperative neurocognitive deficit (POCD), defined as a total deficit score of 2 SD worse than the mean performance in the control group. Microemboli were found only in the neck dissection group. S100 beta levels were significantly higher after neck dissection (Wilcoxon signed ranked test: P<0.001). After 12 months, the incidence of POCD was similar in both groups. Conclusion POCD was detectable only after neck dissection in the early postoperative period accompanied by increased incidence of microembolism and protein S100b levels, but not 12 months after surgery. Eur J Anaesthesiol 2010;27:417-424