Deficit In Reaction Time During Virtual Tasks Is Associated With Depression In Patients With Multiple Sclerosis

Abstract

the rests and symptom inventory was collected before and after the protocols. Results: No significant changes in spatiotemporal parameters and affective response were detected (both groups and conditions), while a significant increase in the perception of effort was observed for HC in both conditions. The total score for the symptom inventory was significantly higher for pwMS after both protocols. Significant differences in walking speed and perception of effort were identified between MS patients and HC in both conditions. Although without significant change, a trend for the increase in walking speed was identified for pwMS in the feedback condition. Conclusion: The intermittent 12-minutes walking with real-time feedback on walking speed did not significantly change spati-otemporal parameters and symptoms perception, however the identified trend of increment in walking speed suggest that real-time feedback could serve as a strategy for walking rehabilitation to maintain speed and decrease walking-fatigability. Background: Event-related potentials (ERPs) are valuable tools for the early detection and monitoring of cognitive impairment in people with Multiple Sclerosis (pwMS) and towards the evaluation of the effectiveness of treatment. The Symbol Digit Modalities Test (SDMT) is the gold-standard screening tool for cognitive processing speed, often impaired in pwMS. With the aid of ERPs, neurophysiological processes during SDMT can be quantitively assessed, potentially serving as an early biomarker for cognitive impairment. Aim: To explore the ERPs correlates of the SDMT for the detection and monitoring of cognitive impairment in pwMS. Methods: We developed an EEG-SDMT paradigm, with a list of symbols corresponding to a number at the top of a PC screen and symbol-digit pairs (180; 50% correct) presented at the center. Key-press reaction times (RTs) for correct/incorrect pairs are measured together with 32-channel EEG obtaining stimulus-averaged ERPs. Thirty pwMS (21 F; age 51.67 ± 10.66 years) and 16 healthy controls (HC) (12 F; age 49.25 ± 13.52 years) were recruited. Results: SDMT-ERPs presented a positive peak in the centro-parietal regions (amplitude: HC 14.07 ± 5.05 μV; pwMS 11.50 ± 5.63 μV; Wilcoxon test, FDR corrected p = n.s.) that displayed a significantly longer latency in pwMS (607.75 ± 117.75 msec) vs HC (506.66 ± 89.15 msec) (Wilcoxon test, FDR corrected p < 0.05). Latency was also significantly correlated with RTs in the computerized SDMT (r = .291; p < 0.05). RTs and raw scores in the clinical SDMT were significantly correlated (r =-.724; p < 0.01). Conclusion: Our EEG-SDMT paradigm allowed to obtain an ERP correlate of neuroelectrical activity during SDMT performance , which was significantly affected in pwMS and cognitive impairment. These preliminary findings prompt further validation of this tool for the early detection of cognitive involvement, for monitoring the natural history and response to pharmacologic and non-pharmacologic interventions. Background: Multiple Sclerosis (MS) is a neurological disease, related to different factors and systems. Symptoms such as fatigue, anxiety and depression impact the quality of life in MS patients. Rehabilitation programs have used virtual reality (VR) to monitor, control, maintain or improve func-tionality and increase transfer from virtual to reality in people with MS (pwMS). Objective: To evaluate the reaction time during a virtual reality task (VR) in pwMS and the association with fatigue, anxiety and depression. Methods: This cross-sectional study included 57 pwMS (age range: 23-77 years old, EDSS: 0-7.5)) and 27 healthy controls (age range: 23-57 years old). The beck Inventory was applied to evaluate depression and anxiety. The Modified Fatigue Impact Scale (MFIS) was used to measure fatigue perception. Reaction time was measured during a VR task using a software in computer. The reaction time was measured in milliseconds, and was the time taken between the beginning of the stimulus and the beginning of the motor response. A correlation Results: Significant correlations were found between MFIS and BDI for anxiety and depression; and, between BDI and reaction