Utility of the N-back task in survivors of childhood acute lymphoblastic leukemia

Novel computerized neurocognitive test battery is sensitive to cancer-related cognitive deficits in survivors

PURPOSE

There is increasing interest in developing new methods to improve sensitivity in detecting subtle cognitive deficits associated with cancer and its treatments. The current study aimed to evaluate the ability of a novel computerized battery of cognitive neuroscience-based tests to discriminate between cognitive performance in breast cancer survivors and controls.

METHODS

Breast cancer survivors (N = 174) and age-matched non-cancer controls (N = 183) completed the Enformia Cogsuite Battery of cognitive assessments, comprised of 7 computerized tests of multiple cognitive domains. Primary outcome measures included accuracy, reaction times (RT), and coefficients of variation (CV) for each task, as well as global scores of accuracy, RT, and CV aggregated across tests.

RESULTS

Linear regressions adjusting for age, education, and remote vs. in-office administration showed that compared to non-cancer controls, survivors had significantly lower performance on measures of attention, executive function, working memory, verbal ability, visuospatial ability, and motor function. Survivors had significantly greater CV on measures of attention, working memory, and processing speed, and significantly slower RT on measures of verbal fluency.

CONCLUSIONS

The Cogsuite battery demonstrates sensitivity to cancer-related cognitive dysfunction across multiple domains, and is capable of identifying specific cognitive processes that may be affected in survivors.

IMPLICATIONS FOR CANCER SURVIVORS

The sensitivity of these tasks to subtle cognitive deficits has advantages for initial diagnosis of cancer-related cognitive dysfunction, as well as detecting changes in survivors' cognitive function over time. The remote delivery of the battery may help overcome barriers associated with in-office administration and increase access to neurocognitive evaluation.

Remote, Computerised Cognitive Assessment for Breast Cancer- and Treatment-Related Cognitive Dysfunction: Psychometric Characteristics of the Cogsuite Neurocognitive Battery

OBJECTIVE

Cancer-related cognitive dysfunction (CRCD) is a significant concern for breast cancer survivors. The Cogsuite battery was developed to improve sensitivity to CRCD with the use of cognitive experimental measures, clarify specific cognitive processes impacted and to be capable of being administered either in-office or remotely.

METHODS

In sum, 357 breast cancer survivors and non-cancer controls completed the Cogsuite Battery in-office (n = 76) or remotely (n = 281). Measure validity, sensitivity to demographic factors, correlations with standard neuropsychological measures and intercorrelations of Cogsuite variables were assessed. Test-retest reliability was evaluated in-office (n = 24) and remotely (n = 80).

RESULTS

Test-retest reliability for most variables assessed was adequate to strong. Internal validity, as indicated by the confirmation of expected condition effects within each measure, was established for all measures. Assessment of external validity found age, but not education, was a significant predictor in the majority of measures. Assessment of criterion validity found that Cogsuite variables were correlated with standard measures in psychomotor speed, working memory and executive function, but not associated with self-reported cognition or mood.

CONCLUSIONS

Cogsuite is reliable and valid, and is sensitive to the effects of increasing age on cognition. The addition of the Cogsuite battery to standard assessment may improve sensitivity to CRCD and identify underlying processes that may be affected. Remote use of the Cogsuite battery in appropriate settings will lessen the burden for providers, researchers and survivors in research and clinical contexts.

Relationship Between Dual-Task Walking and Level of Conflict Between Gait and Concurrent Tasks in Adolescents

This study aimed to determine the role of resource conflict in dual-task (DT) effects on gait and concurrent tasks in children and adolescents. Gait was evaluated with and without concurrent tasks (visual-manual, visual-vocal and auditory-vocal). The roles of condition (single vs dual) and type of concurrent task in DT effect were tested by Repeated Measured of ANOVA. Relative changes from single to DT conditions were compared using One-Way ANOVA. There were significant reductions in gait speed, cadence, and stride length, and increases in double support time, step time and variability in step time, and no change in variability in stride length, step width, and concurrent task performance from single to DT conditions. DT effects on gait parameters and concurrent tasks were comparable across DT conditions.

Interactions between visual working memory and visual attention among survivors of pediatric acute lymphoblastic leukemia (ALL) and their healthy peers

Introduction: There is increasing concern for adverse cognitive late effects among survivors of pediatric acute lymphoblastic leukemia (ALL) given the widespread impact they have on academic achievement, particularly working memory and attention. We assessed performance among survivors and their healthy peers on a dual task paradigm measuring visual working memory (VWM) and visual attention independently and the dynamic relationship between the two. Assessing specific subsets within cognitive domains allows for understanding the distinct nature of cognitive impairments. Method: Participants were 34 survivors of ALL who have been off-treatment and disease free for 7.5 years; and 20 healthy controls, all between the ages of 10 and 18 years. We utilized behavioral single- and dual-task paradigms. In the dual tasks, participants maintained several items in VWM while performing a visual attention task (Eriksen Flanker Task) that required processing of a target stimulus while inhibiting the processing of distractor stimuli. The single tasks involved performing only the VWM task or only the visual attention task. Results: Results revealed survivors of ALL performed significantly worse than their healthy peers on the single visual attention task but not the single VWM task. Of particular interest, group differences were obtained on the dual VWM and visual attention tasks, such that the VWM and attention tasks reciprocally interfered with each other only among survivors and not their healthy peers. Conclusions: Our results highlight a core deficit in visual attention that is exacerbated by VWM demands among survivors of ALL. The implementation of tasks from cognitive neuroscience paradigms may be sensitive to cognitive impairments experienced by cancer survivors. Assessment and intervention practices among survivors of pediatric ALL are discussed.

Characterizing neurocognitive late effects in childhood leukemia survivors using a combination of neuropsychological and cognitive neuroscience measures

Knowledge about cognitive late effects in survivors of childhood acute lymphoblastic leukemia (ALL) is largely based on standardized neuropsychological measures and parent reports. To examine whether cognitive neuroscience paradigms provided additional insights into neurocognitive and behavioral late effects in ALL survivors, we assessed cognition and behavior using a selection of cognitive neuroscience tasks and standardized measures probing domains previously demonstrated to be affected by chemotherapy. 130 ALL survivors and 158 control subjects, between 8 and 18 years old at time of testing, completed the n-back (working memory) and stop-signal (response inhibition) tasks. ALL survivors also completed standardized measures of intelligence (Wechsler Intelligence Scales [WISC-IV]), motor skills (Grooved Pegboard), math abilities (WIAT-III), and executive functions (Delis-Kaplan Executive Function System). Parents completed behavioral measures of executive functions (Behavior Rating Inventory of Executive Function [BRIEF]) and attention (Conners-3). ALL survivors exhibited deficiencies in working memory and response inhibition compared with controls. ALL survivors also exhibited deficits on WISC-IV working memory and processing speed, Grooved Pegboard, WIAT-III addition and subtraction fluency, and numerical operations, as well as DKEFS number-letter switching. Parent reports suggested more attention deficits (Conners-3) and behavioral difficulties (BRIEF) in ALL survivors compared with referenced norms. Low correspondence between standardized and experimental measures of working memory and response inhibition was noted. The use of cognitive neuroscience paradigms complements our understanding of the cognitive deficits evident after treatment of ALL. These measures could further delineate cognitive processes involved in neurocognitive late effects, providing opportunities to explore their underlying mechanisms.

Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients

Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack) with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests) may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively) with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.

Abnormal topological organization in white matter structural networks in survivors of acute lymphoblastic leukaemia with chemotherapy treatment

Previous diffusion tensor imaging (DTI) studies have detected white matter (WM) integrity abnormalities in some specific fibre bundles in acute lymphoblastic leukaemia (ALL) patients with chemotherapy. However, little is known about the changes in the topological organization of the WM structural network in ALL patients with chemotherapy. In the present study, we acquired DTI datasets from 28 ALL patients (mean age: 40.71 ± 8.58 years, years since diagnosis: 7–38) with chemotherapy and 20 matched healthy controls (mean age: 42.95 ± 6.39 years) and performed WM network analysis using a deterministic fibre-tracking approach. Graph theoretical analysis was used to compare the topological parameters of the WM networks between the two groups. Both ALL patients with chemotherapy and healthy controls had small-worldness in their WM networks. ALL patients showed significantly reduced global network efficiency, as indicated by the abnormally decreased clustering coefficient Cp and the normalized clustering coefficient γ and increased shortest path length Lp compared with healthy controls. Moreover, hubs were located more in parietal regions of healthy controls and in temporal regions in the ALL patients. We revealed the abnormal topological organization of the WM networks of ALL patients with chemotherapy, which may improve our understanding of the neural mechanism of chemotherapy in ALL from a WM topological organization level.

Monitoring and Assessment of Neuropsychological Outcomes as a Standard of Care in Pediatric Oncology

Central nervous system cancers or exposure to CNS-directed therapies increase risk for neuropsychological deficits. There are no accepted guidelines for assessment of neuropsychological functioning in this population. A multifaceted literature search was conducted and relevant literature reviewed to inform the guidelines. Studies of neuropsychological outcomes are widely documented in the pediatric oncology literature. There is strong evidence of need for neuropsychological assessment, but insufficient evidence to guide the timing of assessment, nor to recommend specific interventions. Children with brain tumors and others at high risk for neuropsychological deficits should be monitored and assessed for neuropsychological deficits.