Neural Correlates of Remotely versus In-person Administered Symbol Digit Modalities Test in Multiple Sclerosis

Abstract

AbstractBackgroundPrior studies in multiple sclerosis (MS) support reliability of telehealth-delivered cognitive batteries, although, to date, none have reported predictive external validity, i.e., relationships of cognitive test performance to neural correlates across administration modalities. In this study we aimed to compare brain-behavior relationships, using the Symbol Digit Modalities Test (SDMT), the most reliable and sensitive cognitive measure in MS, measured from patients seen via telehealth versus in-person.MethodsSDMT was administered to individuals with MS either in-person (N=60, mean age=39.7) or remotely via video conference (N=51, mean age=47.4). Magnetic resonance imaging (MRI) data was collected in 3-Tesla scanners. Using 3D-T1 images cerebral, cortical, deep gray, cerebral white matter and thalamic nuclei volumes were calculated. Using a meta-analysis approach with an interaction term for participant group, individual regression models were run for each MRI measure having SDMT as the outcome variable in each model. In addition, the correlation and average difference between In-person and Remote group effect sizes across the MRI measures were calculated. Finally, for each MRI variable I2score was quantified to test the heterogeneity between the groups.ResultsAdministration modality did not affect the association of SDMT with MRI measures. Brain tissue volumes showing high associations with the SDMT in one group also showed high associations in the other (r= 0.83; 95% CI = [0.07, 0.86]). The average difference between the In-person and the Remote group effect sizes was not significant (βRemote- βIn-person= 0.14, 95% CI = [-0.04, 0.34]). Across MRI measures, the average I2value was 14%, reflecting very little heterogeneity in the relationship of SDMT to brain volume.ConclusionWe found consistent relationships to neural correlates across in-person and remote SDMT administration modalities. Hence, our study can be considered a step towards providing predictive external validity to remote administration of the SDMT in MS.HighlightsSymbol Digit Modalities Test (SDMT) was administered to individuals with MS either in-person or remotely via video conference.Administration modality did not affect the association of SDMT with MRI measures.Brain tissue volumes showing high associations with the SDMT in one group also showed high associations in the other.The average difference between the In-person and the Remote group effect sizes was not significant.This study can be considered a step towards providing predictive external validity to remote administration of the SDMT in MS.