P05.80 Cognitive functioning in patients with non-functioning pituitary adenoma before and after endoscopic transsphenoidal resection: Individual and group results

Background: Cognitive dysfunction in patients with non-functioning pituitary adenoma (NFPA) primarily pertains to memory and executive functioning. Current literature is comprised of studies employing dissimilar methodological approaches and there is little prospective research using standardized cognitive function measures before and after surgical tumor resection. This study investigated group and individual cognitive status and change over time. Material and Methods: Forty-five patients underwent neuropsychological assessment one day before and 3 months after transsphenoidal surgery. A computerized neuropsychological test-battery (CNSVS) was used to measure cognitive functioning on 7 domains: Verbal Memory, Visual Memory, Processing Speed, Psychomotor Speed, Reaction Time, Complex Attention and Cognitive Flexibility. Analyses of cognitive status and change were conducted on group and individual level. Associations of preoperative performance with tumor expansion, categorized according to Wilson-Hardy and Knosp classifications, and hormonal deficiency were investigated in exploratory analyses. Results: As a group, patients scored significantly lower than healthy controls on all domains except Visual memory before as well as three months after surgery. Fifty-six percent of patients showed impairment (z-score ≤ - 1.5) on at least one domain before surgery and 63% after surgery. Patients showed no significant change over time as a group, but we found almost equal proportions of patients showing reliable improvement, decline, and stable performance. Degree of suprasellar extension and cavernous sinus invasion did not show a significant relationship with pre-operative cognitive status. Hormonal deficiency was related to Verbal Memory performance. Conclusion: Over half of patients showed cognitive impairment before as well as after surgery and dysfunction involved processing and psychomotor speed domains in addition to memory and executive functioning. Differential patterns of reliable cognitive change over time in individual patients were masked in group-level analyses. Future studies with larger samples sizes should address predictors of peri-operative cognitive status and the varied post-surgical course.