Does Surgery for Adult Spinal Deformity Affect the Cognitive Abilities in Patients over 50 Years of Age?

To analyze the cognitive abilities of older patients undergoing spinal deformity surgery so as to understand whether adult spinal deformity (ASD) surgery is associated with postoperative cognitive malfunction.

A prospective longitudinal study was performed on surgical patients older than 50 years, enrolled in a prospective multicenter database. Mini-mental state examination (MMSE) was performed to assess cognitive function in addition to the health-related quality of life (HRQOL) tests; (SF-36, ODI and SRS-22) at the pre-operative, post-operative 6 weeks and 6 months points. Demographics, preoperative health status, co-morbidities and surgical characteristics were also analyzed. Descriptive statistics and repeated measures of variance analysis were performed.

A total of 90 patients with a mean age of 67.4±8.2 years were enrolled in the study; all had MMSE evaluations at 6 weeks follow-up and 58 patients had both 6 weeks and 6 months follow-up. Average (SD) surgical time, estimated blood loss, number of levels fused and hospital stay were 240.1 (111.9) minutes, 1621.2 (1058.7) ml, 11.2 (4.4) levels and 14.2 (11.45) days, respectively. On analysis, a slight increase in mean MMSE score (p > 0.05) between time points was found despite decreases of > 2 points (3 or 4) in 6 patients (6.7%) at both time points.

Although ASD surgery in older patients is recognized as challenging, this study suggests that it is not necessarily associated with a significant deterioration in the cognitive abilities of patients undergoing surgery. This may be due to the relatively minor influence of ASD itself on the cognitive abilities of the patients involved as well as to the relatively stable hemodynamic conditions obtainable during modern ASD surgery.