Poster AA7 - Quantifying Cognitive and Motor Impairment in Adults with Sickle Cell Disease

Introduction: Sickle Cell Disease (SCD) is one of the most common monogenic disorders in the world. In the United States alone there are about 100,000 individuals living with SCD [1,2]. In the past, due to a lack of research and proper medical care, SCD was considered a pediatric disease with a majority of people dying in childhood from complications [3]. These complications include pain crises, organ/tissue damage, delayed growth, strokes, weakened immune systems, and more. Due to the commonality of strokes in childhood, there is a major push for consistent and extensive care for children living with SCD. Unfortunately, once they age out of pediatrics that support does not follow them. That transition period is marked as some of the worst years for SCD warriors. There is currently a severe gap in the literature surrounding the effects of SCD on motor and cognitive functioning in later adulthood. This study aims to explore that gap and contribute to what little is out there. In modern times a majority of SCD efforts are focused on prevention of the disease and management of symptoms through different medications and intense procedures in childhood. Our data can identify areas of functioning impacted the most by SCD as people age and use that to add to the call for more comprehensive care for adults living with Sickle Cell Disease.

Materials and

Methods: The SCD & Robot study conducts a short battery of four neurocognitive assessments and four motor assessments, followed by two assessment games using our Haptic TheraDrive one-degree-of-freedom robot. These were used to test for impairment in domains expected to be impacted by Sickle Cell Disease. The Montreal Cognitive Assessment (MoCA) assessed executive function, abstraction, orientation, delayed recall, attention, visuospatial function, memory, and language. Digit Symbol Coding (DSC) assessment was used to test attention. Color Trails I & II (CT) assessed executive function, visuospatial skills, and attention. Hopkins Verbal Learning (HPVL) looked at immediate/ delayed recall and recognition. Motor assessments included the 10m Walk (10mW) task to assess lower extremity impairment and mobility. Grooved Pegboard (GP) and Box & Blocks (BB) assessments focused on fine and gross motor function. Grip Strength (GS) was used to assess impaired strength. Participants also completed the Patient Health Questionnaire (PHQ-9) to assess depression, the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) was used as a quality-of-life scale for adults living with SCD. The Patient-Reported Outcome Measurement Information System (PROMIS) Pain Interference and Pain Intensity short forms measure pain in a population. For the robot assessments the Trajectory Tracking motor task was used to assess upper limb motor performance, and the Spatial Span Cognitive Task was used to assess visuospatial working memory.

Results, Conclusions, and Discussions: All SCD participants were compared to all healthy participants for these preliminary analyses. Scores represent 10 total participants, 7 with SCD (42.7 ± 13.0 years old) and 3 without (27.7 ± 3.2). Once data was normalized for age, education, and gender the z-scores and t-scores were calculated for all assessments. We report the t-scores. Overall, we see that in cognitive assessments SCD adults performed about the same as adults without SCD in Color Trails I & II, Digit Symbol Coding, with both groups scoring in the ‘normal functioning’ range (t-score> 40). In the MoCA assessment, all participants scored in the normal-mild impairment range (18-30). If we focus on just HPVL-Delayed Recall we see that our SCD participants had mild-severe impairment (26.36 ± 10.75) in this domain compared to our healthy participants (46.25 ± 6.25). In motor assessments (Figure 1), SCD participants performed worse than non-SCD participants in two evaluations, GP and BB indicating that SCD impacts gross & fine motor function. When comparing robot-based assessments, on the Spatial Span data between two matched pairs (age, education, gender) we surprisingly see an overlap in the average sequence length during the assessment, with SCD participants scoring even better than their matched pair. These results suggest that participants with SCD were able to perform tasks involving motor and cognition well.
These results suggest that there is quantifiable data supporting the negative effects of Sickle Cell Disease on aging. There is a noticeable impairment in domains like memory which supports current literature [1]. In motor impairment, we expected to see results of poorer performance in adults with SCD compared to their counterparts for several reasons including chronic pain, organ/tissue damage, and ‘accelerated aging syndrome’ [3]. Future aims for this study will be to continue recruitment until we have gathered data for 20 total participants, half with SCD and half without, this will give us 10 pairs matched for age, gender, and education.

Acknowledgements (Optional): This work was made possible through the support of the Penn Medicine Comprehensive Sickle Cell Disease Program, the Penn Medicine Rehabilitation Robotics Lab, and The Louis Stokes Alliance for Minority Participation (LSAMP) NSF-funded Post-Baccalaureate Program.