Exploring cognitive reserve and compensatory behaviors used to maintain executive control function in adults with primary brain tumors.

다국어 초록 (Multilingual Abstract)

Technological advances have improved survival in primary brain tumor (PBT) patients, bringing a need to understand the relationship between executive control function (ECF) and self-reported cognitive function (SRCF) in survivors. Neuropsychological testing demonstrates few objective changes in some who report significant cognitive difficulties. To date, little research has explored the discrepancy between objective cognitive performance (OCP) and SRCF. This study describes the congruence of OCP to SRCF in 40 adult PBT survivors. Structured interviews with 7 exemplars describe compensatory behaviors.
Neuropsychological test scores were converted to z-scores using age- and education-specific norms. A z-score of -1.3 determined cognitive impairment; Everyday Cognitions Scale scores determined SRCF. Analyses include descriptive statistics, graphical plots, correlations, chi-square and t-tests.
The study sample (n=40) averaged 50 years old (SD 9.7), had high-grade PBT (n=35), was at least 1 year beyond completion of treatment, 1.3-25 years since diagnosis, and included 22 women. ECF was impaired in 25% of subjects, memory in 35%, and attention in 27.5%. More than half of subjects self-reported changes in memory and attention. Neither age, time since diagnosis, or tumor/treatment-specific variables were associated with OCP or SRCF scores. Dividing a scatterplot of OCP/SRCF scores into quadrants created four subject groupings.
Analyses focused on the two groups with normal OCP who had normal (congruent) or abnormal (incongruent) SCRF scores. Both groups were mostly female, middle-aged, well-educated, and 6-8 years removed from diagnosis of high-grade PBT. Those with high cognitive reserve (CR) had congruent OCP/SRCF scores and less impact of PBT-specific symptoms on quality of life; those with low CR tended to have incongruent OCP/SRCF scores, more severe symptoms that impacted quality of life, and more depressive symptoms. Low CR exemplars were socially isolated and had curtailed activities since diagnosis. High CR exemplars continued cognitively-engaging activities. During testing, all subjects exhibited similar compensatory behaviors to maintain cognitive function. Those with congruent scores tended to be less aware that they used compensatory strategies.
This study shows that CR and use of compensatory behaviors may explain discrepant relationships between OCP and SRCF, and may lead to development of interventions to minimize cognitive decline and improve quality-of-life.