Date Presented 04/22/21
Sickle cell disease (SCD) is a genetic blood disorder that is characterized by chronic anemia that can cause both serious physical and neurological complications. In this study, we analyze the deleterious effects that SCD can have on cognition and the importance of evaluations and interventions provided by OTs and the interprofessional team alike in working with this population.
Primary Author and Speaker: Deborah Blady
Additional Authors and Speakers: Huda Yousef, Hanan Khalil
Contributing Authors: Khalid El-Salem, Ziad Hawamdeh, and Patrícia Almeida
BACKGROUND: Sickle Cell Disease (SCD) is a genetic blood disorder affecting over 100,000 individuals, primarily African Americans, in the United States. SCD is characterized by abnormal red blood cells, which can obstruct proper blood flow to the body's vital organs. This causes complications including pain, stroke, and chronic anemia. Cognitive dysfunction is well documented among children with SCD and negatively impacts academic, social and everyday functioning. The impact on functional performance has been linked to deficits in processing speed, attention and IQ.
PURPOSE: There is minimal existing research to address cognitive dysfunction in adolescents and adults with SCD, but there are identified associations between lower cognitive functioning and decreased occupational participation, lower perceived quality of life and depression. The purpose of this study is to evaluate cognitive and functional task-performance in adults with SCD. We assessed cognitive domains including attention, processing speed and memory through neuropsychological and task-based testing.
DESIGN: The study is a cross-sectional analysis of an observational prospective cohort trial. Participants were recruited from the sickle cell clinics at Washington University School of Medicine (WUSM). Participants were 14 years of age and older and were followed for at least 3 years.
METHODS: Participants completed the Weschler Abbreviated Scale of Intelligence (WASI-II), National Institutes of Health Toolbox Cognition Battery (NIHTBCB), the medication subtest of the Executive Function Performance Test (EFPT-M), and the Weekly Calendar Planning Activity (WCPA-S) at baseline. Demographic and medical history were obtained from the participants' medical records. T-tests were conducted to compare baseline individual measure and composite scores from the WASI-II and NIHTBCB to normative data. Baseline results on the EFPT-M were compared to normative Control and Stroke groups. Since no normative data yet exists for the WCPA-S, descriptive statistics were used to describe participants' performance. For this analysis we focused on the results of the EFPT-M and the WCPA-S to assess how cognitive dysfunction impacts functional task performance.
RESULTS: Participants (n = 50) had a mean age of 23.1 years. Most participants (64%) had the most severe form of SCD and the majority (60%) reported highest education level as some college or more. A little less than half (42%) reported a history of stroke. Participants' mean score on the EFPT-M (2.08) was significantly higher than normative Control (mean difference = 1.66, p < .001) and Mild Stroke (mean difference = 1.16, p <.001) groups. During the pre-task interview, 47/49 participants stated they thought they could complete the EFPT-M without help; however only 7/49 were able to complete the task without any cues. On average participants spent 13.67 minutes to complete the WCPA-S (range 6.77-45.48), used 5.79 strategies (range 1-12), and made 3.5 errors (range 0-9). On the after-task interview, most participants stated they thought the task was easy and that they completed the task accurately.
CONCLUSION: Adults with SCD have significant deficits in their ability to accurately complete functional daily tasks and most demonstrate poor self-awareness and underestimate their need for assistance. These results highlight the need for self-awareness training and appropriate cognitive rehabilitation among adults with SCD. Occupational therapists have the distinctive skill set to address these deficits by providing cognitive evaluation and timely interventions to improve long-term health and functional outcomes for this population.
References
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