Postoperative cognitive dysfunction after cochlear implantation.

PURPOSE: Postoperative cognitive dysfunction (PCD) is a subtle, prolonged deterioration in cognition after surgery. This complication has been frequently investigated, mainly after major (cardiac) surgery. However, the incidence after cochlear implantation is unknown. Therefore, the aim of the study was to investigate the incidence and possible risk factors of PCD in severely hearing-impaired older adults after cochlear implantation.

METHODS: In a prospective cohort study, 26 older participants (age: M = 70, SD = 8 years), scheduled for cochlear implantation, were assessed prior to and 1 week after implantation by means of the Montreal Cognitive Assessment (MoCA). The incidence of PCD was calculated. In addition, the following possible risk factors were recorded: age, sex, education, duration of hearing impairment, preoperative signs of depression and anxiety, duration of anesthesia, anesthetic and surgical events and postoperative complications.

RESULTS: The incidence of PCD was 11.5%, defined by a Z score of change in MoCA scores ≥ 1.96 (i.e., a decrease of ≥ 4 points). The incidence of PCD was corrected for practice effects by incorporating data from a reference group. Besides an effect of age on the postoperative cognitive performance, no significant risk factors were identified.

CONCLUSIONS: The incidence of PCD after cochlear implantation is lower than after major surgeries, but higher than after other minor surgeries. Routine cognitive screening before and after cochlear implantation is recommended to identify patients with PCD and to provide additional care for these patients.