Language Processing Deficits in Sickle Cell Disease in Young School-Age Children

Neurocognitive outcome in children with sickle cell disease after myeloimmunoablative conditioning and haploidentical hematopoietic stem cell transplantation: a non-randomized clinical trial

Background

Due to the risk of cerebral vascular injury, children and adolescents with high-risk sickle cell disease (SCD) experience neurocognitive decline over time. Haploidentical stem cell transplantation (HISCT) from human leukocyte antigen-matched sibling donors may slow or stop progression of neurocognitive changes.

Objectives

The study is to determine if HISCT can ameliorate SCD-associated neurocognitive changes and prevent neurocognitive progression, determine which specific areas of neurocognitive functioning are particularly vulnerable to SCD, and determine if there are age-related differences in neurocognitive functioning over time.

Methods

We performed neurocognitive and neuroimaging in SCD recipients following HISCT. Children and adolescents with high-risk SCD who received parental HISCT utilizing CD34+ enrichment and mononuclear cell (T-cell) addback following myeloimmunoablative conditioning received cognitive evaluations and neuroimaging at three time points: pre-transplant, 1 and 2 years post-transplant.

Results

Nineteen participants (13.1 ± 1.2 years [3.3-20.0]) received HISCT. At 2 years post-transplant, neuroimaging and cognitive function were stable. Regarding age-related differences pre-transplantation, older children (≥13 years) had already experienced significant decreases in language functioning (p < 0.023), verbal intelligence quotient (p < 0.05), non-verbal intelligence quotient (p < 0.006), and processing speed (p < 0.05), but normalized post-HISCT in all categories.

Conclusion

Thus, HISCT has the potential to ameliorate SCD-associated neurocognitive changes and prevent neurocognitive progression. Further studies are required to determine if neurocognitive performance remains stable beyond 2 years post-HISCT.Clinical trial registration: The study was conducted under an investigator IND (14359) (MSC) and registered at clinicaltrials.gov (NCT01461837).

Neurodevelopmental Outcomes in Preterm Children with Sickle Cell Disease

OBJECTIVES

To explore the combined effect of pediatric sickle cell disease (SCD) and preterm birth on cognitive functioning.

METHODS

Cognitive functioning was examined in children ages 6-8 with high risk SCD genotypes born preterm (n = 20) and full-term (n = 59) and lower risk SCD genotypes/no SCD born preterm (n = 11) and full-term (n = 99) using tests previously shown to be sensitive to SCD-related neurocognitive deficits. Factorial ANOVAs and log linear analyses were conducted to examine the relationship between SCD risk, preterm birth status, and cognitive outcomes. Continuous scores were examined for specific tests. Children were categorized as having an abnormal screening outcome if at least one cognitive score was ≥1.5 standard deviations below the population mean.

RESULTS

Children with elevated risk due to high risk SCD and preterm birth performed worse than other groups on a test of expressive language but not on tests that emphasize processing speed and working memory. There was a three-way interaction between preterm status, SCD risk, and abnormal screening outcome, which was largely driven by the increased likelihood of abnormal cognitive scores for children with high risk SCD born preterm.

CONCLUSIONS

The combination of SCD and preterm birth may confer increased risk for language deficits and elevated rates of abnormal cognitive screenings. This suggests that neurodevelopmental risk imparted by comorbid SCD and preterm birth may manifest as heterogenous, rather than specific, patterns of cognitive deficits. Future studies are needed to clarify the domains of cognitive functioning most susceptible to disease-related effects of comorbid SCD and preterm birth.

Chronic pediatric diseases and risk for reading difficulties: a narrative review with recommendations

Literacy is a major social determinant of health, rooted in skills that develop during early childhood. Children arriving at kindergarten unprepared to learn to read are more likely to have low reading proficiency thereafter. General and health literacy are highly correlated, affecting understanding of health conditions, treatment adherence, and transition to self-care and adult healthcare services. The American Academy of Pediatrics (AAP) recommends literacy and school readiness promotion during well-visits and neurodevelopmental surveillance is emphasized across primary and subspecialty care. While genetic and environmental risk factors for reading difficulties are well-established, risks related to complex and chronic medical conditions are less appreciated and under-researched. This review applies an eco-bio-developmental framework to explore literacy across five complex chronic conditions affecting millions of children worldwide: asthma, cancer, congenital heart disease, epilepsy, and sickle cell disease. In each, integration of an efficient reading brain network may be impacted by direct factors, such as ischemia, anesthesia, and/or medications, and also indirect factors, such as altered parent-child routines, hospital stays, and missed school. By integrating literacy into care management plans for affected children, pediatric primary care and specialty providers are poised to identify risks early, target guidance and interventions, and improve academic and health outcomes. IMPACT: While genetic and environmental risk factors for reading difficulties are well-established, risks related to complex and/or chronic medical conditions such as asthma, cancer, congenital heart disease, epilepsy, and sickle cell disease are substantial, less appreciated, and under-researched. General and health literacy are highly correlated, with implications for the understanding one's health condition, treatment adherence, and transitioning to self-care, which is especially important for children with complex and/or chronic illness. Pediatric primary care and specialty providers are poised to integrate reading and literacy into care management plans for children with complex and/or chronic illness, including early screening, guidance, support, and interventions.

Reading intervention targeting phonemic awareness and symbol imagery in children with sickle cell disease

Children with sickle cell disease (SCD) frequently have diminished academic attainment and are particularly vulnerable to reading dysfunction. We explored the effectiveness of a multisensory reading intervention offered during the summer to children with SCD at our institution. Subjects with reading deficits were identified through parent report, clinical findings, or school meetings. Summer reading programs utilizing Phonemic Awareness and Symbol Imagery were provided. The Lindamood-Bell Auditory Conceptualization/Phonemic Awareness Test, Third Edition (LAC-3), and the Symbol Imagery Test were used as pre- and postintervention examinations to measure progress. Fifteen students (median age 9.4 years, range 6-14 years, eight females, all African American) received the Phonemic Awareness intervention, two times a week for 6 weeks. The subjects showed statistically significant gains in standard scores derived from the LAC-3 (mean change 7.9 points, p < .001), with associated improvements in age equivalency (AE) and grade equivalency (GE). Twenty-nine students (median age 9 years, range 6-17 years, 13 females, all African American) participated in the Symbol Imagery reading program, also two times a week for 6 weeks. These students showed significant gains in overall standard scores (mean change 9.8 points, p < .001). Although results should be interpreted with caution due to small sample sizes, we found that summer reading clinics for children with SCD improved phonological processing and symbol imagery skills, potentially leading to substantial gains in reading capability.

Association between hearing impairment, school performance and cognitive function in children and adolescents with sickle cell disease

OBJECTIVE

To investigate the association among hearing impairment, school performance, and cognitive function in children and adolescents with sickle cell disease.

METHODS

Thirty-one participants with sickle cell disease (SCD) and 31 healthy participants in the control-comparison group (CG), both aged 8-17 years underwent auditory system evaluation (pure tone audiometry and acoustic reflex), were screened for the risks of (central) auditory processing disorder and dysfunction of cognitive function using the Scale of Auditory Behaviors (SAB) and the Mini-Mental State Examination (MMSE), respectively, and were interviewed to obtain clinical data and data on school performance.

RESULTS

In the SCD group, eight (25.8%) participants presented with sensorineural hearing loss (SNHL). The group with SCD and SNHL presented a higher occurrence of poor school performance than the group of participants with SCD without SNHL (p= 0.016). The MMSE score for aspects related to attention and calculation in the SCD group with SNHL was lower than in the SCD group without SNHL (p= 0.016). In the SAB, the SCD group with SNHL presented a lower score than the SCD group without SNHL in aspects related to academic performance and attention.

CONCLUSION

Hearing impairment in children and adolescents with SCD, specifically SNHL, is associated with poor school performance and enhances the risk of cognitive impairment in terms of attention and calculation.

Co-Occurrence of Neurodevelopmental Disorders in Pediatric Sickle Cell Disease

OBJECTIVE

The objective of this study is to retrospectively determine the co-occurrence, associated characteristics, and risk factors for neurodevelopmental disorders (NDD) in a pediatric sickle cell disease (SCD) clinic population.

METHOD

We investigated the co-occurrence and features of NDD in pediatric SCD through a retrospective cohort study conducted between July 2017 and January 2019. The participants were patients with SCD younger than 18 years of age identified from our institutions' clinic rosters and medical records databases.

RESULTS

A total of 276 participants were eligible for study inclusion, and 65 participants were found to have various NDD. Children with SCD and NDD were more likely to have a history of multiple SCD-related complications in comparison to children with SCD without NDD. Children with SCD and NDD were more likely to use disease-modifying therapies in comparison to children with SCD without NDD (χ2 27.2, p < 0.001).

CONCLUSION

Children with SCD and NDD have higher odds of having certain disease-related complications and higher use of disease-modifying treatments than children with SCD who do not have NDD. Screening and diagnoses of NDD may be relevant to clinical management of pediatric SCD.

Fostering equity in education and academic outcomes in children with sickle cell disease

OBJECTIVE

Children with Sickle Cell Disease (SCD), who are predominantly Black, face academic disparities in part because of the impact of longstanding racially biased education systems. Adverse systemic factors in addition to neurologic complications put children with SCD at risk for poor academic outcomes. Providing caregivers with information on how to select quality schools and advocate for their child's specific educational needs may influence academic outcomes and reduce educational disparities. We aimed to provide information to caregivers of children with SCD on school selection/quality, enrollment, and special education options.

METHODS

Forty-six caregivers of children with SCD between the ages of 2 and 5:11 years participated in a structured informational session. Caregivers' sense of empowerment regarding educational options for their child was assessed via survey before and after the structured informational session.

RESULTS

Caregivers reported feeling more informed and empowered following their participation in an informational session on school selection/quality, enrollment, and special education options for their child than before the informational session.

CONCLUSIONS

It is essential that families of children with SCD have the knowledge, skills, and sense of empowerment to access quality schools beginning in early childhood. Future research will determine if this intervention will improve children's access to academic support and academic outcomes. We theorize improvements in academic outcomes along with addressing systemic disparities may ultimately create a positive impact on vocational and quality of life outcomes in the lives of children with SCD.

Executive function in children with sickle cell anemia on transfusion: NIH toolbox utility in the clinical context

OBJECTIVE

The aim of this study was to establish the utility of the NIH Toolbox as a cognitive screener of executive functions in the clinical context. Additionally, we aimed to investigate whether age and time on transfusion were related to executive function performance. Method: Twenty-eight children and adolescents with sickle cell anemia (SCA) between 8 and 18 years (M = 13.28, SD = 3.05) on transfusion treatment were included. Participants completed five NIH Toolbox tasks (three executive function tasks and two non-executive function control tasks). Results: Mean scores on one of the three executive function measures (inhibitory control) fell below the average range (M = 81.36, SD = 14.01) with approximately 70% of children from both groups below the average range. Scores for processing speed (M = 86.82, SD = 22.01) and cognitive flexibility (M = 85.75, SD = 12.67) were low averages. As expected, scores on non-executive measures (language and memory) fell within the average range. No significant differences were observed between children with silent stroke and no stroke on executive function measures. Older age (p < .01) and length of time on transfusion (p < .05) predicted lower inhibitory control scores. Conclusions: Findings provide evidence for poor development of inhibitory control with age in this patient population. As the NIH Toolbox successfully highlighted expected deficits in this patient population, this study supports the use of this tool as a brief screening measure for children with SCD. The clinical and theoretical implications of the findings are discussed.

Social-environmental factors and cognitive and behavioral functioning in pediatric sickle cell disease

Sickle cell disease (SCD), an inherited blood disorder that primarily affects individuals of African descent, is associated with serious medical complications as well as numerous social-environmental risk factors. These social-environmental factors are linked to long-standing social inequities, such as financial hardship and racial discrimination, both of which impact cognitive and behavioral functioning in youth. Previous research on the relationship between social-environmental risk and psychological functioning has primarily relied on non-modifiable, unidimensional measures of socioeconomic status (SES), such as income and parental education, as a proxy for social-environmental risk. The current study aimed to address the limitations associated with typical SES-type measures by comparing the unique and shared association of SES and more targeted and modifiable social-environmental factors (e.g., parent and family functioning) with specific areas of cognitive and behavioral adjustment in pediatric SCD. Seventy children ages 4-8 years old and their parents completed measures of social-environmental risk and psychological adjustment. Exploratory factor analysis indicated parent and family functioning measures were largely independent of SES. Parent and family functioning predicted phonological processing and ADHD symptoms above and beyond SES alone. In addition, the predictive ability of social-environmental risk factors appears to vary by genotype severity for measures of social functioning and math problem-solving ability. Future studies are needed to explore more specific and well-supported models of modifiable social-environmental risk and the relative impact of social-environmental risk on cognitive and behavioral functioning.

Selective Difficulties in Lexical Retrieval and Nonverbal Executive Functioning in Children With HbSS Sickle Cell Disease

Language deficits in multilingual children with sickle cell disease (SCD) are poorly understood. We tested the hypothesis that selective language deficits in this population could relate to an impaired frontal lobe functioning often associated with high-risk homozygous HbS disease (HbSS). In all, 32 children from immigrant communities with HbSS SCD aged 6 to 12 years (mean age = 9.03, n = 9 with silent infarcts) and 35 demographically matched healthy controls (mean age = 9.14) were tested on their naming skills, phonological and semantic fluency, attention, and selected executive functions (response inhibition and planning skills). Analyses of variance showed significant differences between patients and controls in inhibition and planning (p = .001 and .001), and phonological fluency (p = .004). The poorer performance in phonological fluency of the children with SCD was not associated with any visible brain damage to language areas. Hierarchical regression analyses showed that, whereas the control children's vocabulary knowledge explained their performance in the phonological fluency tasks, only inhibition skills accounted for variance in the performance of the children with SCD. These results suggest a selective impairment of verbal and nonverbal executive functioning (i.e., planning, inhibition, and phonological fluency) in children with SCD, with deficits possibly owing to frontal area hypoxia.

Does Obstructive Sleep Apnea Increase Cognitive Deficits in Pediatric Sickle Cell Disease?

OBJECTIVES

Although pediatric obstructive sleep apnea (OSA) is estimated to affect 2-3% of the general population, its prevalence in sickle cell disease (SCD) is much higher, with research suggesting a prevalence rate of upwards of 40%. Despite the similar underlying pathophysiological mechanisms of neurocognitive effects in pediatric OSA and SCD, there is a scarcity of information on how these two conditions interact. The aim of this study was to better understand the contribution of sleep apnea to neurocognitive deficits in children diagnosed with SCD.

METHOD

This study assessed cognitive function in 26 children with comorbid SCD and OSA, 39 matched comparisons with SCD only, and 59 matched comparisons in children without a chronic health condition.

RESULTS

There were significant differences on measures of processing speed and reading decoding, with children without a chronic health condition scoring better than both chronic health condition groups. Additionally, the no chronic health condition group performed better on a test of quantitative knowledge and reasoning and a test of visual-spatial construction than the SCD-only group. Contrary to our hypotheses, there were no between-group differences suggesting an additive impact of OSA on cognition. Exploratory analyses revealed associations within the group that had OSA showing that more severe OSA correlated with lower performance on measures of processing speed and quantitative knowledge/reasoning.

CONCLUSIONS

Children with comorbid OSA and SCD do not present with greater deficits in cognitive functioning than children with SCD alone. However, severe OSA may confer additional risk for neurocognitive impairments.

Predictive validity of developmental screening in young children with sickle cell disease: a longitudinal follow-up study

AIM

To assess the predictive validity of developmental screenings in children with sickle cell disease (SCD) for academic outcomes and stroke risk.

METHOD

Parent questionnaires and medical record data were collected for a cohort receiving developmental screenings between September 2004 and May 2008 as toddlers or early school age. Screening outcomes were dichotomized (positive, negative) by a priori criteria. Questionnaires assessed school and social functioning, services received, and quality of life. Medical record data assessed general SCD morbidity and stroke risk.

RESULTS

Forty-one toddlers (mean age 2y 5mo; 25 males, 16 females) and 49 early school-age children (mean age 6y 5mo; 26 males, 23 females) completed follow-up. The mean follow-up period was 8 years 6 months (range 6.1-10.8y). For toddlers, positive screenings for language delays predicted lower academic performance (p=0.023). For older children, positive screenings for cognitive delays predicted more frequent academic/attentional problems at school (p<0.001), grade retention (p=0.007), and lower academic performance (p=0.001). Positive screenings were associated with an earlier onset of school problems and lower quality of life. Positive screenings for language/cognitive delays predicted increased stroke risk (both p<0.05).

INTERPRETATION

Screening for language or cognitive development in young children with SCD predicts academic outcomes and stroke risk.

WHAT THIS PAPER ADDS

Developmental screening predicts academic outcomes in sickle cell disease. Children with concerning language/cognitive screenings have early-onset school difficulties. Developmental screenings may help predict cerebrovascular complications.

Developmental Screening in Pediatric Sickle Cell Disease: Disease-Related Risk and Screening Outcomes in 4 Year Olds

OBJECTIVE

Studies of early child development in sickle cell disease (SCD) have found modest associations between disease-related risks and developmental status in infants and toddlers, but such associations are evident by early elementary school. We screened 4-year-old children with SCD using 2 screening strategies to assess if biomedical risk factors for neurologic disease are related to developmental screening outcomes at this intermediate age.

METHODS

Seventy-seven 4-year-old children with SCD (M = 4.5 yrs, SD = 0.3 yrs) completed developmental screenings at routine hematology visits using child testing (Fluharty Preschool Speech and Language Screenings Test, 2nd edition) and parent-report (Ages and Stages Questionnaire, 2nd edition) procedures. Genotype and other biomedical variables were coded from medical records.

RESULTS

Children with higher-risk SCD genotypes (n = 52) showed lower performance than children with lower-risk genotypes (n = 25) on a measure related to neurologic disease risk in older children (syntactic processing); genotype risk was also related to rates of positive screenings on parent-reported developmental milestones (52% positive screenings in high-risk genotypes vs 12% in low-risk genotypes). Screening outcomes were also related to transcranial Doppler ultrasound findings assessing cerebral blood flow.

CONCLUSION

Developmental screening at age 4 may be a useful target age for identifying preschoolers with sickle cell-related neurodevelopmental concerns. Parent report of developmental milestones and behavioral testing each may have a role in screening for children in need of follow-up services to address potential neurodevelopmental effects from SCD.

Association of social-environmental factors with cognitive function in children with sickle cell disease

The aim of this study was to examine the relationship between cognitive function in pediatric sickle cell disease (SCD) patients and mothers' reports of social-environmental stress, depressive symptoms, and parenting. A total of 65 children with SCD completed comprehensive neuropsychological testing to assess several domains of cognitive functioning, including general intellectual ability, academic achievement, and executive function. Mothers reported on demographics, social-environmental stress, depressive symptoms, and parenting. As predicted, children with SCD significantly underperformed relative to normative data on measures of cognitive function. Associations between maternal social-environmental stress, maternal depressive symptoms, and parenting were mixed. The results show partial support for the hypothesis that greater stress and depressive symptoms and less positive parenting are associated with poorer cognitive function in children with SCD. Linear regression analyses showed that maternal financial stress was the strongest predictor across all domains of cognitive function. The findings replicate and extend past research, reaffirming that children with SCD are at risk for cognitive impairment across multiple domains. Additionally, social-environmental stress, particularly financial strain, is linked to mothers' depressive symptoms and parenting behaviors as well as children's cognitive function. Future studies using direct observations of parenting behaviors are needed. These findings, along with recent research on parenting interventions, may inform the development of concrete, teachable parenting and coping skills to improve cognitive functioning in children with SCD.

Feasibility of Home-Based Computerized Working Memory Training With Children and Adolescents With Sickle Cell Disease

BACKGROUND

Children with sickle cell disease (SCD) are at increased risk for neurocognitive deficits, yet the literature describing interventions to ameliorate these problems and promote academic achievement is limited. We evaluated the feasibility and preliminary efficacy of a home-based computerized working memory (WM) training intervention (Cogmed) in children with SCD.

PROCEDURE

Youth with SCD between the age of 7 and 16 years completed an initial neuropsychological assessment; those with WM deficits were loaned an iPad on which they accessed Cogmed at home. Participants were instructed to work on Cogmed 5 days each week for 5 weeks (25 training sessions). We examined Cogmed usage characteristics and change on WM assessment scores following the intervention.

RESULTS

Of the 21 participants (M age = 11.38, SD = 2.78; Mdn age = 10.00, interquartile range [IQR] = 5.00; 52% female) screened, 60% exhibited WM deficits (n = 12) and received the intervention and 50% (n = 6) completed Cogmed. The mean number of sessions completed was 15.83 (SD = 7.73; Mdn = 17.00, IQR = 16.00); females were more likely to complete Cogmed, χ(2) (1) = 6.00, P = 0.01. Participants who reported lower SCD-related pain impact completed more sessions (r = 0.71, P = 0.01). Children who completed Cogmed exhibited improvements in verbal WM, visuospatial short-term memory, and visuospatial WM.

CONCLUSIONS

Initial findings suggest Cogmed is associated with WM improvement in youth with SCD; however, adherence was lower than expected. Home-based WM interventions may ameliorate SCD-related WM deficits but strategies are needed to address barriers to program completion.

Association between somatic growth trajectory and cognitive functioning in young children with sickle cell disease

Children with sickle cell disease are at risk of cognitive deficits and somatic growth delays beginning in early childhood. We examined growth velocity from age 2 years (height and body mass index progression over time) and cognitive functioning in 46 children with sickle cell disease 4 to 8 years of age. Height-for-age velocity was not associated with cognitive outcomes. Higher body mass index velocity was associated with higher scores on global cognitive and visual-motor abilities but not processing resources or academic achievement. Body mass index progression over time may be a clinically useful indicator of neurocognitive risk in sickle cell disease, as it may reflect multiple sickle cell disease-related risk factors.

EXAMINER executive function battery and neurologic morbidity in pediatric sickle cell disease

Sickle cell disease (SCD) is blood disorder with a high risk for cerebral vascular morbidities that impact neurocognitive functioning. Specific cognitive abilities are known to be more sensitive to neurologic effects of SCD than IQ scores, yet there is little consensus about which measures to use to assess neurocognitive functioning. We evaluated the ability of the Executive Abilities: Methods and Instruments for Neurobehavioral Evaluation and Research (EXAMINER) Battery to detect neurologic effects in SCD. Thirty-two youth with SCD and sixty demographically-matched comparison youth completed the EXAMINER Battery and selected tests from the Woodcock-Johnson Tests of Cognitive Ability, 3rd edition (WJ-III). Neurologic severity was examined via clinical history for morbidities and midsagittal corpus callosum (CC) area. Results indicated cognitive performance decreased with increasing neurologic morbidity across all cognitive measures; two of four EXAMINER factors were related to CC area. The association with clinical history and midsagittal CC area appeared at least as large for the Examiner Battery scores as for the WJ-III measures. The Examiner Battery showed sensitivity to neurologic history and white matter effects in SCD; this new measure compares favorably to established measures of disease-related neurocognitive effects, but would benefit from further development.

Academic performance and intelligence scores of primary school-aged children with sickle cell anemia

Children with sickle cell anemia (SCA) are faced with complications which may interfere with their educational activities including academic performance. Reports on their academic performance are mainly from developed countries and the results have been inconsistent. This study aimed to determine the academic performance of primary school-aged children with SCA in Nigeria and compare findings with a group of controls. Ninety children with SCA aged 5-11 years were consecutively recruited at the SCA clinic of UNTH Enugu and their age- and sex-matched normal classmates were enrolled as controls. Academic performance of the children with SCA was studied using the overall scores achieved in the three term examinations in the preceding academic year (2009/2010), while their intelligence quotient (IQ) was determined using the Draw-A-Person Test. The findings were compared with that of 90 controls. The mean overall academic score of the children with SCA of 62.71 ± 19.43% was similar to 67.47 ± 16.42% in the controls (P = .077). However, a significantly higher number of children with SCA (32.2% vs. 16.7% of the controls; P = .015) scored below 50%, thus, had poor performance. The mean IQ of the subjects (91.41 ±16.61%) was similar to that of the controls (95.56 ±17.31%, P = .103). However, more SCA patients had lower IQ scores than controls though not statistically significant (P = 0.083). The overall academic performance of children with SCA, therefore, compares favorably with that of controls although there is a higher prevalence of poor performance among them.

Intellectual function evaluation of first generation immigrant children with sickle cell disease: the role of language and sociodemographic factors

Background

Sickle Cell Disease (SCD) is the most common genetic disease worldwide. Neurological events are among the most worrisome clinical complications of SCD and are frequently accompanied by cognitive impairment. Intellectual function in SCD may vary according to genetic and environmental factors. Immigrant children with SCD are increasing at a global level and display specific health care needs. The aim of our multicenter study was to describe the intellectual function of first generation African immigrants with SCD and the influence of sociodemographic factors on its characteristics.

Methods

The Wechsler Intelligence Scales were administered to evaluate broad intellectual functions in children with SCD and in age-matched healthy siblings. Patients’ clinical, socio-demographic, Magnetic Resonance Imaging (MRI) and Angiography (MRA) data were correlated to intellectual function scores.

Results

68 children, mean age 8.95 years were evaluated. 72% spoke three languages, 21% two. FSIQ was <75 in 25% of the children. Mean VIQ was lower than PIQ in 75%. Mean verbal subtest scores were lower than performance scores. Female gender, number of languages spoken at home and mother’s employment were associated with single subtest performances (p < 0.05). MRA was abnormal in 73.4% and MRI in 35.9%. No significant correlation was established between silent lesions and intellectual function, even if patients with lesions performed worse. Fifteen siblings performed better than patients on cognitive domains, including language (p < 0.05).

Conclusions

Immigrant bilingual children with SCD seem to display a rate of cognitive impairment similar to their monolingual counterparts but a more pronounced and precocious onset of language difficulties. Adjunctive tests need to be considered in this group of patients to better define their specific deficits.

Disability among individuals with sickle cell disease: literature review from a public health perspective

CONTEXT

Young people with blood disorders face challenges in maintaining their physical health as they age. Sickle cell disease has well-documented complications in various organ systems. Increasingly, professionals, consumers, and advocates involved in blood disorders are concerned about the cumulative and ongoing effect of organ-specific complications on function and participation.

EVIDENCE ACQUISITION

Publications were identified that looked at the relationship between sickle cell disease and associated impairments and restrictions in participation as defined by the International Classification of Function, Disability, and Health (ICF).

EVIDENCE SYNTHESIS

This article organizes a literature review in PubMed using ICF terms that define functional limitations and participation restrictions in sickle cell disease.

CONCLUSIONS

Individuals with sickle cell disease experience complications in multiple organ systems that affect related functions and, consequently, participation in community living. The effects begin early in childhood and accumulate across the life course into adulthood. Intervention research is needed to understand how contextual factors can promote optimal function and participation in the face of mounting impairments.

Neurocognitive deficits in children with sickle cell disease: a comprehensive profile

BACKGROUND

Sickle cell disease (SCD) can lead to profound cerebral damage, associated with neurocognitive deficits. The aim of the current study was to evaluate a broad range of neurocognitive functions in children with SCD compared to a SES-matched control group, in order to gain more insight into the specific deficits of these patients.

METHODS

Forty-one children with homozygous SCD (HbSS or HbS-β0-thalassemia) and 38 controls were assessed on a comprehensive set of well-defined and validated measures of neurocognitive functioning. Besides general intelligence, we evaluated executive functioning extensively (including response inhibition, sustained attention, planning, visuo-spatial working memory, and verbal working memory) as well as visuo-motor functioning.

RESULTS

SCD was clearly associated with lower IQ scores. More than one in three children with SCD had a Full-scale IQ below 75. Furthermore, children with SCD showed deficits in visuo-motor functioning. Some evidence was found for executive dysfunction: Children with SCD displayed poor visuo-spatial working memory, as well as subtle deficits in sustained attention and planning. No significant differences were found between children with SCD and controls in terms of response inhibition and verbal working memory.

CONCLUSIONS

Children with SCD are at increased risk of lower intelligence, visuo-motor impairments, and executive dysfunction. These neurocognitive deficits may underlie high rates of scholastic impairments in these children. The present findings further illuminate the importance of regular neurocognitive evaluations and future neurocognitive rehabilitation programs for children with SCD.

Cerebral blood flow velocity and language functioning in pediatric sickle cell disease

We investigated the association of increased cerebral blood flow velocity with specific language abilities in children with sickle cell disease (SCD). Thirty-nine children ages 5 to 8 years old with high-risk genotypes of SCD underwent cognitive testing, which included tests of language skills, visual motor skills, and attention/working memory as part of a routine hematology health-maintenance visit. Transcranial Doppler (TCD) velocities were obtained from review of medical records, with the velocities that were in closest temporal proximity to the cognitive assessment used in the analysis. TCD velocities predicted scores on tests of syntactical skills, even when controlling for anemia severity. Semantic and phonological ability and other cognitive skills were not strongly related to TCD velocities. Elevated blood flow velocities in children with high-risk SCD may contribute to a specific language impairment or to a broader dysfunction of short-term and/or working memory. This study underscores the need for clinicians to monitor language skills of children with SCD who have elevated TCD velocities, as these cognitive abilities might be particularly sensitive to cerebrovascular disruption related to their disease.