Postoperative cognitive dysfunction: etiology, clinical features, diagnosis

Abstract

Introduction. The present study analyzed the possibility of using neuropsychological tests to assess postoperative cognitive dysfunction. New data were obtained: in the postoperative period, hippocampal memory impairments predominate in patients, which makes it expedient to use methods for diagnosing primary modal-nonspecific memory disorders in patients who are to undergo neurosurgical intervention on the spinal cord.The aim of the study to evaluate the influence of surgery with anesthesia on the cognitive functions of middle-age patients.Materials and methods. The study included 20 middle-aged patients. All patients had to undergo spinal surgery. Patients received total intravenous anesthesia with propofol induction (4–12 mg/kg/hr). Cognitive functions before and after the operation were made with the use of the MoCA, TMT A and B, FCSRT, state-trait anxiety inventory test (STAI).Results. The development of POCD was noted in 15% of cases. The patients showed a decrease in the FCSRT prompt index (1st day = 87 ± 9.0; 2nd day = 83 ± 15; p = 0,0005), while the overall severity of cognitive impairments (total score of MoCA) did not change significantly (standard deviation according to MoCA: 24.25 ± 2.86 on day 1 and 24 ± 3.24 on the second day, p = 0.61). The RT level decreased by day 2: 44.65 ± 7.4 versus 41.1 ± 8.2 (p = 0.001). Correlation analysis did not show the relationship between the age of patients, education level, comorbidity and development of POCD; however, the duration of anesthesia was associated with a decrease in MoCA scores (Pearson’s correlation coefficient r = –0.44; p = 0.050).Conclusion. Thus, our study shows that the study of hippocampal memory impairments is important in patients with POCD. These data differ from the data of researchers presented earlier, where the most important clinical manifestations of POCD are considered to be a decrease in attention and speed of mental processes. Of course, the small sample size dictates the need for additional research.