Empirically derived profiles of neurocognitive functioning in youth and young adults with sickle cell disease.

OBJECTIVE: Sickle cell disease (SCD) is an inherited blood disorder associated with neurocognitive deficits. In contrast to variable-centered approaches, no known research has utilized person-centered strategies to identify multidimensional patterns of neurocognitive functioning of an individual with SCD. The purpose of the present study was to create empirically derived profiles and identify predictors of neurocognitive functioning subgroups among youth and young adults with SCD. METHODS: Individuals with SCD (N = 393, mean age 14.05 years, age range 8-24, 50.4% female/49.6% male) completed neurocognitive assessments. Latent profile analysis derived subgroups/classes of neurocognitive functioning and determined relations with demographic and medical variables. RESULTS: Three latent classes emerged: average functioning (n = 102, 27%), low average functioning (n = 225, 60%), and exceptionally low functioning (n = 46, 12%). Older age was associated with membership in the low average and exceptionally low functioning groups (relative to the average group). Being prescribed hydroxyurea was associated with membership in the average functioning group (relative to the low average group) and absence of hydroxyurea use was associated with membership in the exceptionally low group (relative to the low average group). Lower social vulnerability was associated with membership in the average functioning group compared to the low average and exceptionally low groups. CONCLUSIONS: Clinicians can help reduce disparities in cognitive development for individuals with SCD by promoting early treatment with hydroxyurea and implementing methods to reduce social vulnerabilities that can interfere with access to evidence-based care.

Examining the influence of pain and fatigue on neurocognitive functioning in adolescents and young adults with sickle cell disease.

Pain and fatigue are among the most common and impactful complications of sickle cell disease (SCD). Individuals with SCD are also more likely to have neurocognitive deficits. Previous studies have suggested that pain and fatigue might influence neurocognitive functioning in patients with SCD. However, these studies are limited by small sample sizes and inadequate measurement of cognitive performance. The present study aimed to investigate the relationship between pain and fatigue with neurocognitive functioning using performance-based measures of neurocognition. Pain and fatigue were not associated with neurocognitive performance. Implications and directions for future research are discussed.

Health literacy correlates with abbreviated full-scale IQ in adolescent and young adults with sickle cell disease.

INTRODUCTION: Sickle cell disease (SCD) is a chronic condition with progressive neurocognitive deficits. Health literacy (HL) is essential during adolescence and young adulthood, as the transition to adult care requires healthcare decisions. HL is known to be low in SCD; however, relation between general cognitive ability and HL has not been investigated. METHODS: This cross-sectional study included adolescent and yound adults (AYAs) with SCD from two institutions. Logistic regression measured the association between HL, measured by the Newest Vital Sign tool, and general cognitive ability, measured with abbreviated full-scale intelligence quotient (FSIQ) on the Wechsler Abbreviated Scale of Intelligence. RESULTS: Our cohort contained 93 participants at two sites: 47 (51%) at Memphis, TN and 46 (49%) at St. Louis, MO, ranging from ages 15-45 years (mean = 21 years) and with a majority (70%) possessing a high school education or greater. Only 40/93 participants (43%) had adequate HL. Lower abbreviated FSIQ (p < .0001) and younger age at assessment (p = .0003) were associated with inadequate HL. For every standard score point increase in abbreviated FSIQ, the odds of having adequate HL compared to limited or possibly limited HL increase by 1.142 (95% confidence interval [CI]: 1.019-1.322) and 1.116 (95% CI: 1.045-1.209), respectively, after adjusting for age, institution, income, and educational attainment. CONCLUSIONS: Understanding and addressing HL is imperative in improving self-management and health outcomes. Among AYA with SCD, low HL was prevalent and influenced by abbreviated FSIQ. Routine screening for neurocognitive deficits and HL should be performed to guide development of interventions to adapt to the HL of AYA with SCD.

Social determinants of neurocognitive and academic performance in sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is associated with poor neurocognitive outcomes due to biomedical and psychosocial factors. The aims of this study were to investigate associations between household and neighborhood socioeconomic status (SES) with cognitive and academic outcomes in SCD and to determine if these relationships were modified by sickle genotype, fetal hemoglobin, or age. PROCEDURE: We prospectively recruited patients to complete a battery of neurocognitive and academic measures. Household SES was measured using the Barratt Simplified Measure of Social Status, a composite index of parent education and occupation. The Social Vulnerability Index was used to classify individuals based on social vulnerabilities at the neighborhood level. RESULTS: Overall, 299 patients between the ages of 4 and 18 (mean = 11.4, standard deviation = 4.3) years diagnosed with SCD (57% SS/SB0 -thalassemia) completed testing. Stepwise multivariate models demonstrated that patients with low social vulnerability (i.e., high SES) at the neighborhood level displayed intelligence and math scores that were 4.70 and 7.64 points higher than those living in areas with moderate social vulnerability, respectively (p < .05). Reading performance did not differ based on neighborhood SES; however, the effect of neighborhood SES was dependent on age, such that older participants living in neighborhoods with moderate or high levels of social vulnerability displayed poorer reading scores than those with low social vulnerability (p < .05). CONCLUSIONS: This study identified patients with SCD at higher risk of poor academic performance based on SES. Interventions addressing academic difficulties should be offered to all children with SCD, but should be emergently offered to this subpopulation.

Internalizing Symptoms in Adolescents With Sickle Cell Disease.

OBJECTIVE: Sickle cell disease (SCD) is a genetic blood disorder that may affect patients' mood and behavior. However, measuring the prevalence of internalizing symptoms (anxiety and depression) in patients with SCD has been elusive. We assessed internalizing symptoms in adolescents with SCD to evaluate prevalence and to test whether neurocognitive performance and frequency of pain-related episodes were associated with internalizing concerns. METHODS: One hundred eighty-five patients (57% HbSS/HbSß0-thalassemia, 43% HbSC/HbSß+-thalassemia), ages 12-18 years, received a neuropsychological evaluation as a part of a larger cohort study. Internalizing symptoms were measured using the Behavior Assessment System for Children, Second or Third Edition. Scores on the depression and anxiety scales were compared to normative values using Wilcoxon signed rank test. Spearman correlations examined associations between neurocognitive performances and internalizing symptoms. Robust multivariable regression models measured associations between internalizing symptoms and age, sex, sickle genotype, total hemoglobin, fetal hemoglobin, socioeconomic status, and frequency of pain episodes. RESULTS: Parent- and self-reported ratings of internalizing symptoms were not elevated compared to normative expectations. Overall, 1.8% and 6.3% of the sample displayed clinically elevated symptoms of anxiety and depression based on self-report, respectively. There were no associations between internalizing symptoms and neurocognitive performance (all p > .05). In multivariable analyses, the frequency of pain episodes was positively associated with self-reported anxiety (p = .006) and parent-reported depressive symptoms (p = .017). CONCLUSIONS: Adolescents with SCD do not report elevated internalizing symptoms compared to normative expectations. Further research is needed to examine the trajectory of internalizing symptoms and the bidirectional relationship between pain and psychosocial functioning in SCD.

Catechol-O-methyltransferase gene (COMT) is associated with neurocognitive functioning in patients with sickle cell disease.

PURPOSE: Neurocognitive impairment is a common and debilitating complication of sickle cell disease (SCD) resulting from a combination of biological and environmental factors. The catechol-O-methyltransferase (COMT) gene modulates levels of dopamine availability in the prefrontal cortex. COMT has repeatedly been implicated in the perception of pain stimuli and frequency of pain crises in patients with SCD and is known to be associated with neurocognitive functioning in the general population. The current study aimed to examine the associations of genetic variants in COMT and neurocognitive functioning in patients with SCD. PATIENTS AND METHODS: The Sickle Cell Clinical Research and Intervention Program (SCCRIP) longitudinal cohort was used as a discovery cohort (n = 166). The genotypes for 5 SNPs (rs6269, rs4633, rs4818, rs4680, and rs165599) in COMT were extracted from whole genome sequencing data and analyzed using a dominant model. A polygenic score for COMT (PGSCOMT) integrating these 5 SNPs was analyzed as a continuous variable. The Cooperative Study of Sickle Cell Disease (CSSCD, n = 156) and the Silent Cerebral Infarction Transfusion (SIT, n = 114) Trial were used as 2 independent replication cohorts. Due to previously reported sex differences, all analyses were conducted separately in males and females. The Benjamini and Hochberg approach was used to calculate false discovery rate adjusted p-value (q-value). RESULTS: In SCCRIP, 1 out of 5 SNPs (rs165599) was associated with IQ at q<0.05 in males but not females, and 2 other SNPs (rs4633 and rs4680) were marginally associated with sustained attention at p<0.05 in males only but did not maintain at q<0.05. PGSCOMT was negatively associated with IQ and sustained attention at p<0.05 in males only. Using 3 cohorts' data, 4 out of 5 SNPs (rs6269, rs4633, rs4680, rs165599) were associated with IQ (minimum q-value = 0.0036) at q<0.05 among male participants but not female participants. The PGSCOMT was negatively associated with IQ performance among males but not females across all cohorts. CONCLUSION: Select COMT SNPs are associated with neurocognitive abilities in males with SCD. By identifying genetic predictors of neurocognitive performance in SCD, it may be possible to risk-stratify patients from a young age to guide implementation of early interventions.

Assessment of transition readiness to predict health care utilization during transition to adult care in sickle cell disease.

BACKGROUND: Transition-age patients with sickle cell disease (SCD) are at risk for poor outcomes associated with incomplete transition readiness and neurocognitive deficits. Study objectives were to: 1) test if a SCD-specific measure of self-management skills was associated with transition outcomes and 2) evaluate if caregiver-reported executive functioning was associated with self-management skills and transition outcomes among youth with SCD. RESEARCH DESIGN AND METHODS: Youth/caregivers were selected from a longitudinal cohort study. Caregivers completed the Behavior Rating Inventory of Executive Function (BRIEF); caregivers and youth completed the Self-Management Skills Checklist (SMSC) at a median age of 16.8 ± 0.6 years. Non-parametric tests compared SMSC and transition outcomes. Regression assessed the incremental validity of SMSC in predicting transition outcomes. RESULTS: In total, 95 participants (54% male, 55% severe genotype) completed the SMSC assessment. Most participants (87%) transferred to adult care within six months and 87% were retained for at least 12 months. BRIEF and caregiver-reported SMSC assessments were weakly, negatively correlated (ρ = -0.25, p = 0.0392) but were not significant in predicting transition outcomes (p > 0.05). CONCLUSIONS: The SMSC and executive function did not predict adult care engagement. Development of readiness assessments that predict care engagement and reflect self-efficacy is important for monitoring transition-aged patients with SCD.

Neurocognitive functioning in children with sickle cell anemia and history of abnormal transcranial doppler ultrasonography.

BACKGROUND: Transcranial doppler (TCD) ultrasonography can be used to identify stroke risk in children with sickle cell anemia. Previous studies have reported mixed findings on neurocognitive outcomes in children with elevated TCD. This study examined associations between TCD velocity and neurocognitive outcomes in children and adolescents without prior history of stroke. PROCEDURE: Participants were selected from the Sickle Cell Clinical Research Intervention Program cohort. The highest recorded mean maximum TCD velocity was selected for analysis, along with participant's most recent data from serial neurocognitive surveillance. RESULTS: A total of 200 children with sickle cell anemia completed neurocognitive testing (109 males, 91 females; mean age 12.7 years [SD = 3.56]). Most participants were prescribed hydroxyurea (72%) at the time of neurocognitive testing and nearly 16% had a history of chronic transfusions prior to neurocognitive evaluation. Mean age at time of highest TCD value was 6.6 years (SD = 2.5) and 13.5% of screenings were abnormal (≥200 cm/s). Mean interval between TCD and most recent neurocognitive evaluation was 6.1 years (±3.5). There were no significant differences in the interval between TCD and neurocognitive testing across normal, conditional, and abnormal groups. Maximum TCD velocity was not significantly associated with neurocognitive outcomes in multivariate models. CONCLUSIONS: History of elevated TCD in the absence of overt stroke should not be considered a risk factor for poor neurocognitive outcomes in children and adolescents with sickle cell anemia on modern disease-modifying therapy.

Adaptive Functioning in Children and Adolescents With Sickle Cell Disease.

OBJECTIVE: Risk for neurocognitive deficits in sickle cell disease (SCD) is well established, yet minimal research has evaluated the risk for deficits in adaptive functioning. We assessed adaptive functioning in pediatric patients with SCD to test the hypothesis that disease, treatment, and demographic factors were associated with adaptive outcomes. METHODS: Two hundred fifty-six patients (57% HbSS/HbSß0-thalassemia and 43% HbSC/HbSß+-thalassemia), ages 8-18, received routine neuropsychological assessments as part of a larger prospective lifetime cohort study. Adaptive functioning was measured using the Behavior Assessment System for Children, Second or Third Edition. Adaptive scores were compared with normative values using t-test or Wilcoxon signed rank test and linear regression models were used to measure associations between adaptive functioning and age, hydroxyurea (HU) use, sickle genotype, and socioeconomic status. Furthermore, we examined the influence of intellectual and executive functioning on adaptive behavior using hierarchical linear regression analyses. RESULTS: Parent ratings of adaptive functioning skills did not differ from normative expectations (all false discovery rate [FDR] adjusted p-value [pFDR] > 0.05). Social vulnerability was negatively associated with adaptive scores on most adaptive scales in both genotypes (pFDR < 0.05). HU treatment was not significantly associated with any adaptive scale. Overall IQ was positively associated with Functional Communication and Leadership only for those with HbSS/HbSß0-thalassemia. Higher parent ratings of executive difficulties were correlated with lower adaptive scores (estimate = -0.64, standard error = 0.051, p < .001). CONCLUSIONS: Poorer parent-rated adaptive skills were associated with increased social vulnerability, lower Full-Scale IQ, and parent-rated executive difficulties. Most adaptive scores were in the normal range; however, parent ratings may not fully capture the impact of disease complications and neurocognitive deficits on daily functioning.

Fetal hemoglobin modulates neurocognitive performance in sickle cell anemia✰,✰✰.

PURPOSE OF THE STUDY: Fetal hemoglobin (HbF) is a modifier of the clinical and hematologic phenotype of sickle cell anemia (SCA). Three quantitative trait loci (QTL) modulate HbF expression. The neurocognitive effects of variants in these QTL have yet to be explored. We evaluated the relation between 11 SNPs in the three HbF QTL: BCL11A, MYB, the HBB gene cluster, and full-scale intelligence (IQ) in SCA. PATIENTS AND METHODS: The prospective longitudinal cohort study, Sickle Cell Clinical Research and Intervention Program, was used as a discovery cohort (n = 166). The genotypes for 11 SNPs were extracted through whole genome sequencing and were analyzed using an additive model. A polygenic score for HbF (PGSHbF) integrating the numbers of low HbF alleles from 11 SNPs was analyzed as a continuous variable. The Cooperative Study of Sickle Cell Disease (n = 156) and the Silent Cerebral Infarction Transfusion (n = 114) Trial were used as two independent replication cohorts. Benjamini and Hochberg approach was used to calculate false discovery rate adjusted p-value (pFDR). RESULTS: HbF was positively associated with IQ (minimum raw p = 0·0018) at pFDR<0·05. HbF mediated the relationship between two BCL11A SNPs, rs1427407 and rs7606173, HBS1L-MYB: rs9494142, and PGSHbF with IQ (minimum raw p = 0·0035) at pFDR<0·05. CONCLUSION: As the major modulator of the severity of SCA, HbF also influences neurocognition, which is done through mediation of its QTL. These findings have implications for early identification of neurocognitive risk and targeted intervention.

Neurocognitive risk in sickle cell disease: Utilizing neuropsychology services to manage cognitive symptoms and functional limitations.

Sickle cell disease (SCD) is an inherited blood disorder that is associated with developmental delays and neurocognitive deficits. This review details key findings related to neurocognitive outcomes for children and adults with emphasis on the impact of neurological correlates and disease severity. Associations between neurocognition, demographic factors and social determinants of health are also reviewed. Emerging literature has reported on the neurocognitive impact of SCD in children and adolescents in Africa and Europe, including children from immigrant communities. Neurocognitive deficits are linked to poor functional outcomes, including transition from paediatric to adult care, medication adherence and unemployment. Integrating neuropsychology into multidisciplinary care for individuals with SCD can assist with identification and management of neurocognitive concerns, intervention development, individualized care plan development and continued multidisciplinary research.

Neurocognitive functioning in preschool children with sickle cell disease.

BACKGROUND: Children with sickle cell disease (SCD) experience neurodevelopmental delays; however, there is limited research with preschool-age children. This study examined neurocognitive risk and protective factors in preschoolers with SCD. PROCEDURE: Sixty-two patients with SCD (60% HbSS/HbSß0 -thalassemia; 40% HbSC/HbSß+ -thalassemia) between the ages of 3 and 6 years (mean = 4.77 years) received a neuropsychological evaluation as routine systematic surveillance. Patients were not selected for disease severity, prior central nervous system findings, or existing cognitive concerns. Thirty-four patients (82% HbSS/HbSß0 -thalassemia) were prescribed hydroxyurea (HU) at the time of their neuropsychological evaluation. On average, these patients had been prescribed HU at 2.15 (standard deviation = 1.45) years of age. The average dose was 28.8 mg/kg/day. Besides genotype, there were no group differences in medical or demographic factors based on HU treatment status. RESULTS: Patients with HbSS/HbSß0 -thalassemia scored below normative expectations on measures of intelligence, verbal comprehension, and school readiness (false discovery rate-adjusted p-value [pFDR ] < .05). Age, sickle genotype, and HU treatment exposure were not associated with measured neurocognitive outcomes (pFDR  > .05). Greater social vulnerability at the community level was associated with poorer performance on measures of intellectual functioning, verbal comprehension, visuomotor control, and school readiness, as well as parent report of executive dysfunction (pFDR  < .05). Greater household socioeconomic status was positively associated with academic readiness. CONCLUSIONS: Preschoolers with severe SCD (HbSS/HbSß0 -thalassemia) perform below age expectations on measures of intelligence and academic readiness. Sociodemographic factors were stronger drivers of neurocognitive performance than disease severity or disease-modifying treatment. Neurodevelopmental interventions targeting the home and broader community environment are needed.

Patient-reported neurocognitive symptoms influence instrumental activities of daily living in sickle cell disease.

Individuals with sickle cell disease (SCD) experience neurocognitive decline, low medication adherence, increased unemployment, and difficulty with instrumental activities of daily living (IADL). The relationship between self-perceived cognitive difficulties and IADLs, including employment, school enrollment, independence, engagement in leisure activities, and medication adherence is unknown. We hypothesized that self-reported difficulties across neurocognitive areas would predict lower IADL skills. Adolescent and adult participants of the multi-site Sickle Cell Disease Implementation Consortium (SCDIC) (n = 2436) completed patient-reported outcome (PRO) measures of attention, executive functioning, processing speed, learning, and comprehension. Cognitive symptoms were analyzed as predictors in multivariable modeling. Outcome variables included 1) an IADL composite that consisted of employment, participation in school, reliance on others, and leisure pursuits, and 2) hydroxyurea adherence. Participants reported cognitive difficulty across areas of attention (55%), executive functioning (51%), processing speed (57%), and reading comprehension (65%). Executive dysfunction (p < 0.001) and sometimes or often experiencing learning difficulties (p < 0.001 and p = 0.04) and poor comprehension (p = 0.000 and p = 0.001), controlled for age (p < 0.001), pain (p < 0.001), and hydroxyurea use (p = 0.001), were associated with poor IADL skills. Executive functioning difficulties (p = 0.021), controlled for age (p = 0.013 for ages 25-34), genotype (p = 0.001), and hemoglobin (p = 0.004), predicted hydroxyurea non-adherence. Analysis of PRO measures indicated that cognitive dysfunction is prevalent in adolescents and adults with SCD. Cognitive dysfunction translated into clinically meaningful outcomes. PRO of cognitive symptoms can be used as an important adjunct clinical tool to monitor symptoms that impact functional skills, including engagement in societal activities and medication adherence.

Hydroxyurea treatment and neurocognitive functioning in sickle cell disease from school age to young adulthood.

Neurocognitive impairment is common in sickle cell disease (SCD) and is associated with significant functional limitations. In a cross-sectional analysis, we examined the association between hydroxyurea (HU) treatment and neurocognitive functioning from school-age to young adulthood in individuals with SCD. A total of 215 patients with HbSS/HbSß0 -thalassaemia (71% HU treated) and 149 patients with HbSC/HbSß+ -thalassaemia (20% HU treated) completed neurocognitive measures at one of four developmental stages: school-age (age 8-9 years), early adolescence (age 12-13 years), late adolescence (age 16-17 years) and young adulthood (ages 19-24 years). For participants with multiple assessments, only the most recent evaluation was included. In multivariable analysis adjusted for social vulnerability, HU treatment and sex, older age was associated with a reduction in overall intelligence quotient (IQ) of 0·55 points per year of life [standard error (SE) = 0·18, false discovery rate adjusted P value (PFDR) = 0.01] for patients with HbSS/HbSß0 -thalassaemia. Earlier initiation of HU (n = 152) in HbSS/HbSß0 -thalassaemia was associated with higher scores on neurocognitive measures across most domains, including IQ [estimate (SE) 0·77 (0·25)/year, PFDR = 0·01], after adjusting for social vulnerability, sex and treatment duration. These results support the early use of HU to limit the detrimental neurocognitive effects of SCD, while highlighting the need for additional measures to further mitigate neurocognitive deterioration.

[Formula: see text] Addressing the neurodevelopmental needs of children and adolescents with congenital heart disease: A review of the existing intervention literature.

Congenital heart disease (CHD) is among the most prevalent birth defects in the United States. Given that children with CHD are at risk for differences with development, learning, and psychosocial functioning, effective intervention becomes a central tenant of recommendations following neuropsychological consultation and evaluation. The primary focus of this review is to summarize available interventions for children and adolescents with CHD. The existing CHD literature has concentrated on early developmental services, psychopharmacological treatment, and need for academic supports. The literature is limited with regard to intervention studies that target cognitive deficits and psychosocial difficulties. To address this discrepancy, efficacious interventions that have been used to mitigate these concerns within other medical groups are also discussed in an effort to provide options for alternative recommendations and services. The current paper is intended to facilitate comprehensive care for cardiac patients by providing clinicians with a review of the available intervention literature, as well as potential interventions that may serve as supplemental strategies in the interim.