Cognitive-motor dual-task interference in adults with sickle cell disease

Background: Sickle cell disease (SCD) is a genetic disorder that causes physical and cognitive impairment due to hemolysis, painful vaso-occlusion episodes, joint avascular necrosis, and strokes. As individuals with SCD age and develop conditions impacting their physical and cognitive function, their ability to multitask successfully and safely may decline. Cognitive-motor dual-task interference occurs when there is deterioration in one or both tasks while dual-tasking relative to single-tasking. Dual-task assessment (DTA) is a valuable measure of physical and cognitive function; however, there is limited data on DTA in adults with SCD. Research question: Is DTA a feasible and safe method of measuring physical and cognitive function in adults with SCD? What patterns of cognitive-motor interference occur in adults with SCD? Methods: We enrolled 40 adults with SCD (mean age 44 years, range 20-71) in a single-center prospective cohort study. We used usual gait speed as the measure of motor performance and verbal fluency (F, A, and S) as the measure of cognitive performance. We measured feasibility as the proportion of consented participants able to complete the DTA. We calculated the relative dual-task effect (DTE %) for each task and identified patterns of dual-task interference. Results: Most consented participants completed the DTA (91%, 40/44) and there were no adverse events. There were 3 main dual-task interference patterns for the first trial using letter 'A ': Motor Interference (53%, n = 21), Mutual Interference (23%, n = 9), and Cognitive-Priority Tradeoff (15%, n = 6). For the second trial using letter 'S ', there were two main dual-task interference patterns: Cognitive-Priority Tradeoff (53%, n = 21) and Motor Interference (25%, n = 10). Statement of significance: DTA was feasible and safe in adults with SCD. We identified specific patterns of cognitive-motor interference. This study supports further evaluation of DTA as a potentially useful tool to measure physical and cognitive function in ambulatory adults with SCD.