Risk factors for neurocognitive impairment in patients with benign intracranial lesions

Cognitive reserve and individual differences in brain tumour patients

The aim of the paper is to determine the effects of the cognitive reserve on brain tumour patients' cognitive functions and, specifically, if cognitive reserve helps patients cope with the negative effects of brain tumours on their cognitive functions. We retrospectively studied a large sample of around 700 patients, diagnosed with a brain tumour. Each received an MRI brain examination and performed a battery of tests measuring their cognitive abilities before they underwent neurosurgery. To account for the complexity of cognitive reserve, we construct our cognitive reserve proxy by combining three predictors of patients' cognitive performance, namely, patients' education, occupation, and the environment where they live. Our statistical analysis controls for the type, side, site, and size of the lesion, for fluid intelligence quotient, and for age and gender, in order to tease out the effect of cognitive reserve on each of these tests. Clinical neurological variables have the expected effects on cognitive functions. We find a robust positive effect of cognitive reserve on patients' cognitive performance. Moreover, we find that cognitive reserve modulates the effects of the volume of the lesion: the additional negative impact of an increase in the tumour size on patients' performance is less severe for patients with higher cognitive reserve. We also find substantial differences in these effects depending on the cerebral hemisphere where the lesion occurred and on the cognitive function considered. For several of these functions, the positive effect of cognitive reserve is stronger for patients with lesions in the left hemisphere than for patients whose lesions are in the right hemisphere. The development of prevention strategies and personalized rehabilitation interventions will benefit from our contribution to understanding the role of cognitive reserve, in addition to that of neurological variables, as one of the factors determining the patients' individual differences in cognitive performance caused by brain tumours.

Postoperative cognitive functions in patients with benign intracranial lesions

The aim of this study was to assess pre- and postoperative cognitive functions in patients who underwent surgery for benign intracranial lesions. In total, 58 patients (21 men, 37 women, mean age 51.6 years [range 24–76 years]) with benign intracranial lesions (including benign tumors and vascular lesions) and neuralgia of the trigeminal nerve were included in this prospective study. Extensive cognitive testing was used to categorize attention, memory, and executive functions. Mood and pain were assessed preoperatively (t₀, mean 3.7 days before surgery), immediately after surgery/during inpatient stay (t₁, mean 7.6 days after surgery), and at first outpatient check-up (t₂, mean 99.5 days after surgery). All 58 patients were tested at t₀ and t₁, but at t₂ only 24 patients were available at t₂. The data were categorized as improvement/stable condition or deterioration and shown as percentages. The pre- and postoperative values of BDI-II and mood were compared by the Wilcoxon test for paired samples. Binary logistic regression analyses were performed to identify parameters influencing cognition in the subgroup of meningioma patients. Immediately after surgery (t₁), the percentage of patients with improvement/stable condition was > 50% in all categories in the majority of subtests (attention: 12/14 subtests, memory: 11/13 subtests, executive functions: 6/9 subtests). Similar results were shown at t₂. Mood and pain did not change significantly after surgery. Factors like age, Karnofsky performance status, and tumor volume were not shown as significant influencing factors for cognitive functions in meningioma patients. The results of this study suggest that—in contrast to neuroepithelial tumors—cognitive functions do not deteriorate after surgery of benign intracranial lesions. Further studies are necessary to evaluate the results of this study.

Predictors of pre-operative cognitive impairment in meningioma patients over 60 years old

BACKGROUND

The aim of this study was to assess the cognitive function of patients over 60 years old with meningioma using a domain-specific neuropsychological test and to investigate the relevant factors affecting pre-operative cognitive decline in different subdomains.

METHODS

We retrospectively investigated 46 intracranial meningioma patients between the ages of 60 and 85 years. All patients underwent brain MRI and neuropsychological test. Tumor size, location, peritumoral edema, and medial temporal atrophy (MTA) were examined to determine the association with cognitive impairment. We performed a logistic regression analysis to examine the odds ratios (ORs) for cognitive decline of four subdomains: verbal memory, language, visuospatial, and executive functions.

RESULTS

Tumor size and age were associated with executive dysfunction (OR 1.083, 95% confidence interval (CI) 1.006-1.166, and OR 1.209, 95% CI 1.018-1.436, respectively). There was no statistically significant association in other cognitive domains (language, verbal memory, and visuospatial function) with variables in regression analysis.

CONCLUSIONS

We conclude that tumor size and age are positively related with executive function in pre-operative meningioma patients over 60 years old.