Comparison of Postoperative Cognitive Decline Using the Mini-Mental State Examination and Montreal Cognitive Assessment After Minor Elective Surgery in Elderly

Introduction and aim Postoperative cognitive dysfunction (POCD) is an important complication associated with increased morbidity, mortality, and reduced quality of life. Generally, studies have focused on major surgery so there is little evidence of the incidence of cognitive dysfunction in minor surgery. We aimed to compare the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in terms of detecting cognitive decline in elderly patients after elective inguinal herniorrhaphy procedure with general or spinal anesthesia. Material and methods This observational study was conducted from June 2014 to March 2015 at Ankara Numune Education and Research Hospital. The type of anesthesia was determined according to the anesthesiologist's preference who is blind to the study. Patients were grouped according to anesthesia received: general or spinal anesthesia. The MMSE and MoCA were evaluated presurgery and 24 hours after the operation. Results The postoperative (24th hour) MMSE scores of patients (26.23±2.77) were significantly lower than the preoperative scores (27.17±1.93) in only the general anesthesia group (p =0.003). The postoperative (24th hour) MoCA scores (22.87±3.88 for general and 23.13±4.08 for spinal anesthesia) were significantly lower than the preoperative scores (24.32±3.19 for general and 24.35±2.84 for spinal anesthesia) in both the general and spinal anesthesia groups (p =0.000 and 0.019, respectively). The incidence of postoperative cognitive dysfunction was 32.9% using the MoCA and 15.2% using the MMSE (p=0,018). Conclusion Early POCD is an important problem after elective minor surgeries, even with spinal anesthesia, in elderly patients. The MoCA is an alternative tool that can be more sensitive than the MMSE to identify cognitive decline in elderly patients undergoing minor surgeries under both general and spinal anesthesia.