BackgroundCognitive function in patients with diffuse glioma is frequently impaired and can have a profound impact on quality of life. Accurate, reproducible and accessible tools to assess cognition are mandatory to understand the effects of the tumour and treatment. Our hypothesis was that an app-based assessment would be complementary to traditional neuropsychological testing, thereby aiding in defining cognitive profiles and trajectories during early treatment of diffuse glioma.MethodsSeventeen subjects with diffuse low-grade gliomas completed a traditional neuropsychological assessment battery before and after surgery. In addition an app-based tablet assessment (OCS-Bridge) was administered pre- and post-operatively as well as longitudinally at 3- and 12-month follow-up. Deficit rates, mean performance, and changes over time were compared using standardized z-scores between the two testing methods. Unsupervised k-means clustering was performed on individual cognitive tests in each battery.ResultsPreoperative testing showed an average of 2.88 deficits and 1.18 deficits per patient on neuropsychological testing and the tablet-based OCS-Bridge assessment, respectively. Digit span testing demonstrated agreement between testing modalities, but otherwise there was no significant correlation (Pearson’s correlation: p=0.7723, r-value = 0.0758, df = 16). Longitudinal assessment revealed dynamic changes in attention and nonverbal skills. Traditional assessment was more sensitive to memory deficits, showing 22 preoperative deficits within the cohort vs. 1 for the app-based assessment, while app-based assessment was more sensitive to nonverbal skills, showing 8 deficits preoperatively vs. none in the traditional assessment. Clustering analysis did not create clusters along the predetermined domains, indicating that certain individual tests may test more than one cognitive function.ConclusionsThese data suggest app-based assessment is reliable and complementary to data obtained from traditional neuropsychological testing. Advantages include efficiency, facilitation of longitudinal testing, and increased sensitivity in domains of non-verbal skills and attention. Patients with diffuse glioma show subtle neuropsychological impairments, unique cognitive profiles, and discrete trajectories during early treatment, therefore judicious assessment is imperative.Key PointsPatients with glioma have subtle cognitive changes requiring judicious testingApp-based assessment is effective in understanding neuropsychological functionDistinct cognitive profiles and trajectories are demonstrated during treatmentImportance of the StudyUnderstanding cognitive function over time is an essential marker of quality of life and treatment outcomes in patients with diffuse glioma. Because diffuse gliomas are associated with few impairments, careful choice of individual neurocognitive testing is paramount to ensure sufficient sensitivity. Additionally, individuals with similar presentations or seemingly innocuous tumour locations can have profound differences in cognitive outcomes (Romero-Garcia et al., 2020).Studies have demonstrated that traditional neuropsychological testing can be resource-intensive and unsuitable for administration at multiple time points. New app-based testing modalities aim to address these issues, and theoretically offer advantages in terms of novel interactive paradigms, ease of administration, and efficiency of repeated testing in longitudinal studies. However, they have not been extensively validated for use in this population, nor compared with traditional neuropsychology testing.This study compares two neurocognitive testing modalities in a single population with diffuse glioma. Our study demonstrated that patients with diffuse glioma had subtle deficits, and the two modalities were complementary in their sensitivity to deficits in different domains of cognitive function. Traditional neuropsychology testing was more sensitive to memory deficits, while app-based assessment was more sensitive nonverbal skills and attention deficits. In addition, the app-based assessment allowed identification of longitudinal cognitive trajectories, while combined analysis identified discrete cognitive profiles specific to patients with diffuse glioma. Overall these data demonstrate the importance of cognitive testing in this population and highlight the complementary role of combined testing.
Toileting Abilities Survey as a surrogate outcome measure for cognitive function: Findings from neuronopathic mucopolysaccharidosis II patients treated with idursulfase and intrathecal idursulfase
