Functional Connectivity in Frontoparietal Network: Indicator of Preoperative Cognitive Function and Cognitive Outcome Following Surgery in Patients with Glioma.

BACKGROUND: Patients with diffuse glioma are known to have impaired cognitive functions preoperatively. However, the mechanism of these cognitive deficits remains unclear. Resting-state functional connectivity in the frontoparietal network (FPN) is associated with cognitive performance in healthy subjects. For this reason, it was hypothesized that functional connectivity of the FPN would be related to cognitive functioning in patients with glioma. To assess this relationship, preoperative cognitive status was correlated to patient-specific connectivity within the FPN. Further, we assessed whether connectivity could predict neuropsychologic outcome following surgery. METHODS: Sixteen patients with diffuse glioma underwent neuropsychologic assessment and preoperative functional magnetic resonance imaging using task (n-back) and resting-state scans. Thirteen patients had postoperative cognitive assessment. An index of patient-specific functional connectivity in the FPN was derived by averaging connectivity values between 2 prefrontal and 2 parietal cortex regions defined by activation during the n-back task. The relationship of these indices with cognitive performance was assessed. RESULTS: Higher average connectivity within the FPN is associated with lower composite cognitive scores. Higher connectivity of the parietal region of the tumor-affected hemisphere is associated specifically with lower fluid cognition. Lower connectivity of the parietal region of the nontumor hemisphere is associated with worse neuropsychologic outcome 1 month after surgery. CONCLUSION: Resting-state functional connectivity between key regions of the FPN is associated with cognitive performance in patients with glioma and is related to cognitive outcome following surgery.

Assessment of Cognitive, Emotional, and Motor Domains in Patients with Diffuse Gliomas Using the National Institutes of Health Toolbox Battery.

OBJECTIVE: Patients with brain tumors are known to have deficits in cognitive, motor, and emotional domains. Comprehensive evaluation of the patient with brain tumor includes taking into account all these domains at baseline and throughout treatment. Standard neuropsychological assessment methods, however, are lengthy, expensive, and often are variable. The authors appraised the feasibility of using a brief, inexpensive, comprehensive, and standardized neuropsychological battery, the National Institutes of Health (NIH) Toolbox, to assess these domains in patients with diffuse glioma. METHODS: Eighteen patients were recruited and completed the NIH Toolbox Cognitive Battery, 2 motor tests (Grip Strength and Grooved Pegboard), and the NIH Toolbox Emotional Battery. Fully corrected T scores are reported, as well as composite scores of fluid and crystallized cognition. Follow-up cognitive (n = 13) and motor assessment (n = 12) were performed at 1 month after surgery. RESULTS: The total time to complete the battery was approximately 60 minutes. A total of 78% of patients demonstrated significant impairment on one or more cognitive test, whereas 37% had impaired fluid cognition. Crystallized and overall composite cognitive scores were relatively intact, with 16% of patients showing significant impairment. A total of 22% of patients had impaired strength in the left hand, and 22% had impaired dexterity in both hands. In addition, 50% of patients showed impairment in one or more emotional domain. At 1 month after surgery, a significant decrease in crystallized cognition was observed. CONCLUSIONS: The NIH Toolbox represents a feasible alternative to current neuropsychological batteries in the assessment of neurosurgical patients. It can be administered quickly, inexpensively, and will give the neurosurgical community a common currency when reporting neuropsychological results.

Development of a frailty index for patients with coronary artery disease.

OBJECTIVES: To construct a brief frailty index for older patients with coronary artery disease (CAD) undergoing coronary angiography that includes physical, cognitive, and psychosocial criteria and accurately predicts future disability and decline in health-related quality of life (HRQL). DESIGN: Prospective cohort. SETTING: An urban tertiary care hospital in Alberta, Canada. PARTICIPANTS: Three hundred seventy-four patients aged 60 and older (73% male) undergoing cardiac catheterization for CAD between October 2003 and May 2007. MEASUREMENTS: Potential frailty criteria examined at baseline (before the procedure) included measures of balance, gait speed, cognition, self-reported health, body mass index (BMI), depressive symptoms, and living alone. The outcomes assessed over 1 year were dependency in activities of daily living (ADLs) and HRQL. RESULTS: The five best-fitting criteria from regression analyses for ADL decline were poor balance (risk ratio (RR)=2.4, 95% confidence interval (CI)=1.4­4.0), abnormal BMI (RR=1.8, 95% CI=1.1­3.0), impaired Trail-Making Test Part B performance (RR=2.3, 95% CI=1.3­4.2), depressive symptoms (RR=1.8, 95% CI=1.1­3.1), and living alone (RR=2.2, 95% CI=1.3­3.8). Using the five criteria as separate variables or as a summary frailty index yielded identical areas under the receiver operating characteristic curve (0.76, 95% CI=0.66­0.84). Patients with three or more criteria (vs none) were at statistically significant greater risk for increased disability (RR=10.4, 95% CI=4.4­24.2) and decreased HRQL (RR=4.2, 95% CI=2.3­7.4) after 1 year. CONCLUSION: This brief frailty index including physical, cognitive, and psychosocial criteria was predictive of increased disability and decreased HRQL at 1 year in older patients with CAD undergoing angiography. This index may have applications for clinicians and researchers but requires further validation.