Physiological correlates of intellectual function in children with sickle cell disease: hypoxaemia, hyperaemia and brain infarction

Academic achievement in Ugandan children with sickle cell anaemia: A cross-sectional study

Objective

Academic achievement in school-age children is crucial for advancing learning goals. Children with sickle cell anaemia (SCA) in Sub-Saharan Africa may be at risk of disease-associated school difficulties. Limited data exist on the academic achievement of children with SCA in the region. This study aimed to assess academic achievement of children with SCA in Uganda compared to siblings without SCA.

Design and setting

A cross-sectional study conducted at Mulago Hospital SCA Clinic in Uganda.

Participants

School-going children (6-12 years) with SCA and age-matched sibling controls without SCA.

Outcome measures

Academic achievement was tested using the Wide Range Achievement Test, Fourth Edition (WRAT4). Outcome measures were spelling, mathematical computation, word reading, and sentence comprehension by age-normalized Z-scores on the WRAT4 test.

Results

Among 68 SCA and 69 control, the mean age (standard deviation) was 9.44 (2.04) and 9.42 (2.02) years and males were 55.9% and 46.4% respectively. Mean haemoglobin was 7.9 (SD 0.89)g/dL in the SCA group versus 12.8 (SD 0.89)g/dL in the controls, (p<0.001). Children with SCA scored lower in spelling, (mean difference [95% confidence interval] - 0.36 [-0.02 to -0.69], p=0.04) and mathematical computation, (mean difference [95% confidence interval] -0.51 [-0.17 to -0.85], p=0.003) than the controls. In the SCA group, lower scores in spelling correlated with age, while males performed better than females in mathematical computation.

Conclusion

School-aged children with SCA are at risk of poor performance in spelling and mathematical computation. Our findings support the need for educational evaluation and possible support, especially in these two areas.

Mind the gap: trajectory of cognitive development in young individuals with sickle cell disease: a cross-sectional study

STUDY OBJECTIVES

Compared to typically developing children and young adults (CYA-TD), those living with Sickle Cell Disease (CYA-SCD) experience more cognitive difficulties, particularly with executive function. Few studies have examined the relative importance of silent cerebral infarction (SCI), haemoglobin and arterial oxygen content on age-related cognitive changes using cross-sectional or longitudinal (developmental trajectory) data. This study presents cohort data from a single timepoint to inform studies with multiple timepoints.

METHODS

We compared cross-sectional raw and scaled scores as age-related changes in cognition (trajectories) in CYA-SCD and age-and ethnicity-matched CYA-TD. We also compared cross-sectional age-related changes in cognition (trajectories) in CYA-SCD with and without SCI to CYA-TD. General cognitive abilities were assessed using Wechsler Intelligence Scales, including the Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) underpinning IQ. Executive function was evaluated using the Delis-Kaplan Executive Function System (D-KEFS) Tower subtest and the Behaviour Rating Inventory of Executive Function (BRIEF) questionnaire. SCI were identified from contemporaneous 3 T MRI; participants with overt stroke were excluded. Recent haemoglobin was available and oxygen saturation (SpO2) was measured on the day of the MRI.

RESULTS

Data were available for 120 CYA-SCD [62 male; age = 16.78 ± 4.79 years; 42 (35%) with SCI] and 53 CYA-TD (23 male; age = 17.36 ± 5.16). Compared with CYA-TD, CYA-SCD experienced a delayed onset in VCI and slower rate of development for BRIEF Global Executive Composite, Metacognition Index (MI), and Behaviour Regulation Index. The rate of executive function development for the BRIEF MI differed significantly between CYA-TD and CYA-SCD, with those with SCI showing a 26% delay compared with CYA-TD. For CYA-SCD with SCI, arterial oxygen content explained 22% of the variance in VCI and 37% in PRI, while haemoglobin explained 29% of the variance in PRI.

CONCLUSION

Age-related cognitive trajectories of CYA-SCD may not be impaired but may progress more slowly. Longitudinal studies are required, using tests unaffected by practice. In addition to initiation of medical treatment, including measures to improve arterial oxygen content, early cognitive intervention, educational support, and delivery of extracurricular activities could support cognitive development for CYA-SCD.Graphical Abstract.

The Development of Neuroimaging Biomarkers for Cognitive Decline in Sickle Cell Disease

Sickle cell disease (SCD) is complicated by neurologic complications including vasculopathy, hemorrhagic or ischemic overt stroke, silent cerebral infarcts and cognitive dysfunction. Patients with SCD, even in the absence of vasculopathy or stroke, have experience cognitive dysfunction that progresses with age. Transcranial Doppler ultrasound and structural brain MRI are currently used for primary and secondary stroke prevention, but laboratory or imaging biomarkers do not currently exist that are specific to the risk of cognitive dysfunction in patients with SCD. Recent investigations have used advanced MR sequences assessing cerebral hemodynamics, white matter microstructure and functional connectivity to better understand the pathophysiology of cognitive decline in SCD, with the long-term goal of developing neuroimaging biomarkers to be used in risk prediction algorithms and to assess the efficacy of treatment options for patients with SCD.

Corrected cerebral blood flow and reduced cerebral inflammation in berk sickle mice with higher fetal hemoglobin

Fetal hemoglobin (HbF) is known to lessen the severity of sickle cell disease (SCD), through reductions in peripheral vaso-occlusive disease and reduced risk for cerebrovascular events. However, the influence of HbF on oxygen delivery to high metabolism tissues like the brain, or its influence on cerebral perfusion, metabolism, inflammation or function have not been widely studied. We employed a Berkley mouse model (BERK) of SCD with gamma transgenes q3 expressing exclusively human α- and β^S-globins with varying levels of γ globin expression to investigate the effect of HbF expression on the brain using magnetic resonance imaging (MRI), MRI diffusion tensor imaging (DTI) and spectroscopy (MRS) and hematological parameters. Hematological parameters improved with increasing γ level expression, as did markers for brain metabolism, perfusion and inflammation. Brain microstructure assessed by DTI fractional anisotropy improved, while myo-inositol levels increased, suggesting improved microstructural integrity and reduced cell loss. Our results suggest that increasing γ levels not only improves sickle peripheral disease, but also improves brain perfusion and oxygen delivery while reducing brain inflammation while protecting brain microstructural integrity.

Developmental delay in infants and toddlers with sickle cell disease: a systematic review

AIM

To summarize developmental delay among infants and toddlers with sickle cell disease (SCD).

METHOD

This systematic review included studies that reported developmental outcomes of children with SCD between 0 months and 48 months of age and followed standards set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Ten studies were included, describing 596 unique developmental assessments. The rate of developmental delay ranged from 17.5% to 50% and increased with age. Cognition was the only domain included in all studies and the most frequently identified delay. One study reported that more severe SCD genotypes predicted worse development, while five studies reported no difference in rates of developmental delay across genotypes.

INTERPRETATION

These findings emphasize the need for standardized screening to identify children with SCD at risk of delay at a young age to facilitate appropriate referrals for therapeutic intervention. Frequent and comprehensive developmental screening is necessary among all SCD genotypes.

Neuronal injuries in cerebral infarction and ischemic stroke: From mechanisms to treatment (Review)

Stroke is the leading cause of disabilities and cognitive deficits, accounting for 5.2% of all mortalities worldwide. Transient or permanent occlusion of cerebral vessels leads to ischemic strokes, which constitutes the majority of strokes. Ischemic strokes induce brain infarcts, along with cerebral tissue death and focal neuronal damage. The infarct size and neurological severity after ischemic stroke episodes depends on the time period since occurrence, the severity of ischemia, systemic blood pressure, vein systems and location of infarcts, amongst others. Ischemic stroke is a complex disease, and neuronal injuries after ischemic strokes have been the focus of current studies. The present review will provide a basic pathological background of ischemic stroke and cerebral infarcts. Moreover, the major mechanisms underlying ischemic stroke and neuronal injuries are summarized. This review will also briefly summarize some representative clinical trials and up-to-date treatments that have been applied to stroke and brain infarcts.

Study of montelukast in children with sickle cell disease (SMILES): a study protocol for a randomised controlled trial

Background

Young children with sickle cell anaemia (SCA) often have slowed processing speed associated with reduced brain white matter integrity, low oxygen saturation, and sleep-disordered breathing (SDB), related in part to enlarged adenoids and tonsils. Common treatments for SDB include adenotonsillectomy and nocturnal continuous positive airway pressure (CPAP), but adenotonsillectomy is an invasive surgical procedure, and CPAP is rarely well-tolerated. Further, there is no current consensus on the ability of these treatments to improve cognitive function. Several double-blind, randomised controlled trials (RCTs) have demonstrated the efficacy of montelukast, a safe, well-tolerated anti-inflammatory agent, as a treatment for airway obstruction and reducing adenoid size for children who do not have SCA. However, we do not yet know whether montelukast reduces adenoid size and improves cognition function in young children with SCA.

Methods

The Study of Montelukast In Children with Sickle Cell Disease (SMILES) is a 12-week multicentre, double-blind, RCT. SMILES aims to recruit 200 paediatric patients with SCA and SDB aged 3–7.99 years to assess the extent to which montelukast can improve cognitive function (i.e. processing speed) and sleep and reduce adenoidal size and white matter damage compared to placebo. Patients will be randomised to either montelukast or placebo for 12 weeks. The primary objective of the SMILES trial is to assess the effect of montelukast on processing speed in young children with SCA. At baseline and post-treatment, we will administer a cognitive evaluation; caregivers will complete questionnaires (e.g. sleep, pain) and measures of demographics. Laboratory values will be obtained from medical records collected as part of standard care. If a family agrees, patients will undergo brain MRIs for adenoid size and other structural and haemodynamic quantitative measures at baseline and post-treatment, and we will obtain overnight oximetry.

Discussion

Findings from this study will increase our understanding of whether montelukast is an effective treatment for young children with SCA. Using cognitive testing and MRI, the SMILES trial hopes to gain critical knowledge to help develop targeted interventions to improve the outcomes of young children with SCA.

Trial registration

ClinicalTrials.govNCT04351698. Registered on April 17, 2020. European Clinical Trials Database (EudraCT No. 2017-004539-36). Registered on May 19, 2020

Hydroxyurea Use Associated with Nonverbal and Executive Skills in Sickle Cell Anemia

OBJECTIVE

Hydroxyurea (HU) is used in children with sickle cell disease (SCD) to increase fetal hemoglobin (HF), contributing to a decrease in physical symptoms and potential protection against cerebral microvasculopathy. There has been minimal investigation into the association between HU use and cognition in this population. This study examined the relationship between HU status and cognition in children with SCD.

METHODS

Thirty-seven children with SCD HbSS or HbS/β0 thalassaemia (sickle cell anemia; SCA) ages 4:0-11 years with no history of overt stroke or chronic transfusion completed a neuropsychological test battery. Other medical, laboratory, and demographic data were obtained. Neuropsychological function across 3 domains (verbal, nonverbal, and attention/executive) was compared for children on HU (n = 9) to those not taking HU (n = 28).

RESULTS

Children on HU performed significantly better than children not taking HU on standardized measures of attention/executive functioning and nonverbal skills. Performance on verbal measures was similar between groups.

CONCLUSIONS

These results suggest that treatment with HU may not only reduce physical symptoms, but may also provide potential benefit to cognition in children with SCA, particularly in regard to attention/executive functioning and nonverbal skills. Replication with larger samples and longitudinal studies are warranted.

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.

Silent cerebral infarcts in patients with sickle cell disease: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Silent cerebral infarcts (SCIs) are the most common neurological complication in children and adults with sickle cell disease (SCD). In this systematic review, we provide an overview of studies that have detected SCIs in patients with SCD by cerebral magnetic resonance imaging (MRI). We focus on the frequency of SCIs, the risk factors involved in their development and their clinical consequences.

METHODS

The databases of Embase, MEDLINE ALL via Ovid, Web of Science Core Collection, Cochrane Central Register of Trials via Wiley and Google Scholar were searched from inception to June 1, 2019.

RESULTS

The search yielded 651 results of which 69 studies met the eligibility criteria. The prevalence of SCIs in patients with SCD ranges from 5.6 to 80.6% with most studies reported in the 20 to 50% range. The pooled prevalence of SCIs in HbSS and HbSβ⁰ SCD patients is 29.5%. SCIs occur more often in patients with the HbSS and HbSβ⁰ genotype in comparison with other SCD genotypes, as SCIs are found in 9.2% of HbSC and HbSβ⁺ patients. Control subjects showed a mean pooled prevalence of SCIs of 9.8%. Data from included studies showed a statistically significant association between increasing mean age of the study population and mean SCI prevalence. Thirty-three studies examined the risk factors for SCIs. The majority of the risk factors show no clear association with prevalence, since more or less equal numbers of studies give evidence for and against the causal association.

CONCLUSIONS

This systematic review and meta-analysis shows SCIs are common in patients with SCD. No clear risk factors for their development were identified. Larger, prospective and controlled clinical, neuropsychological and neuroimaging studies are needed to understand how SCD and SCIs affect cognition.

A pilot study to screen for poor academic performance in children with sickle cell disease in the outpatient setting

BACKGROUND

Children with sickle cell disease (SCD) are at risk for neurocognitive deficits, which can lead to effects on academic performance and later job attainment. However, screening in children at high risk for poor academic performance (PAP) in a clinic setting has been limited. The goal was to identify young children with SCD at high risk for PAP via administration of a standardized screening tool at the clinic visit.

PROCEDURE

Parents of 20 patients were asked to complete the Behavior Assessment System for Children, 3rd edition (BASC-3) Parent Rating Scale. Children ages six to nine years and all SCD genotypes were included. Those patients who scored at least 1 standard deviation below the mean were considered high risk. Statistics was used to associate demographic, academic, and laboratory data with risk status (RS).

RESULTS

Four of 20 patients (20%) were found to be at risk by the BASC-3. A significant association was found between those with a history of PAP and RS (P = 0.001). A trend toward association was found between baseline hemoglobin, reticulocyte count, and RS. Children not at risk had a higher hemoglobin level and lower reticulocyte count (P = 0.37 and P = 0.20, respectively). Those on hydroxyurea were significantly less likely to score as at risk (P = 0.014), whereas those with siblings may be at greater risk (P = 0.037).

CONCLUSION(S)

A parent-directed screening tool may identify children with SCD in need of additional school support. Further prospective studies are necessary to understand correlations found between hemoglobin, reticulocyte count, and hydroxyurea treatment and risk for PAP.

Laboratory Biomarkers, Cerebral Blood Flow Velocity, and Intellectual Function in Children with Sickle Cell Disease

Objective

The aim of this preliminary study was to describe putative markers of cerebral vasculopathy and investigate relationships among these markers, demographic factors, and cognitive function in a young sample of neurologically normal children with SCD. Study Design. Thirty-eight children with homozygous HbS, aged 4-11 years, were included. Estimated IQ and markers of coagulation and endothelial activation, hemolysis, and inflammation, as well as transcranial Doppler velocities, hydroxyurea use, and demographic information were obtained.

Results

Using multiple regression analyses, there were few significant independent associations between biomarkers or blood flow velocity and estimated IQ. Lactic dehydrogenase (LDH) independently predicted cognitive function, but blood flow velocity did not mediate this relationship. Maternal education, patient age, and hydroxyurea status were independent predictors of cognition. Given the small sample size, a LASSO statistical model was employed to further identify potential predictors of IQ, which identified LDH, absolute neutrophil count (ANC), platelet count, thrombin-antithrombin (TAT), tissue factor (TF), maternal education, age, and hydroxyurea as potential predictors of cognition.

Conclusions

In addition to effects of age and maternal education, some vasculopathic markers are associated with cognitive function in young children with SCD, and these relationships do not appear to be mediated through blood flow velocity. Although the lack of association among certain variables was not as predicted, results provide support for further research regarding the influence of vasculopathic markers on cognitive function in children with SCD without stroke, especially intravascular hemolysis and coagulation/endothelial activation, and a possible role for HU treatment in preventing or reversing cognitive decline.

Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence

Vitamins and minerals are essential to humans as they play essential roles in a variety of basic metabolic pathways that support fundamental cellular functions. In particular, their involvement in energy-yielding metabolism, DNA synthesis, oxygen transport, and neuronal functions makes them critical for brain and muscular function. These, in turn, translate into effects on cognitive and psychological processes, including mental and physical fatigue. This review is focused on B vitamins (B1, B2, B3, B5, B6, B8, B9 and B12), vitamin C, iron, magnesium and zinc, which have recognized roles in these outcomes. It summarizes the biochemical bases and actions of these micronutrients at both the molecular and cellular levels and connects them with cognitive and psychological symptoms, as well as manifestations of fatigue that may occur when status or supplies of these micronutrients are not adequate.

Ischemic sequelae and other vascular diseases

Although pediatric stroke is associated with higher survival rates compared with adult stroke, a substantial body of evidence indicates significant neuropsychologic morbidity in pediatric stroke survivors. Neuroplasticity does not guarantee good outcome in children. The general trends observed in the literature are reviewed as is the profile observed in common causes of pediatric stroke: congenital heart disease, moyamoya disease, and sickle cell disease. The neuropsychologic profile of pediatric stroke patients is heterogeneous due to the multiplicity of associated causes. Stroke in early infancy and large strokes are associated with cognitive impairment while more limited disorders, such as phasic deficit, are observed in childhood stroke. Executive dysfunction is common in pediatric stroke, but social interaction skills are usually preserved. Congenital heart disease and sickle cell disease are associated with global neuropsychologic dysfunction while cognition is usually preserved in moyamoya. Executive dysregulation is instead more frequently reported in this population. Further study of maladaptive processes after pediatric stroke will allow identification of predictors of functional and neuropsychologic outcomes and permit personalization of care.

The Role of Family Functioning in the Development of Executive Functions in Preschool Children with Sickle Cell Anemia

Executive functions are compromised in children with sickle cell anemia. There is limited research on the development of executive functions in preschool children with sickle cell anemia and the factors that contribute to executive dysfunction. We looked at the relation between biomedical and environmental factors, including family functioning and socioeconomic status, and executive functions in 22 preschool children with sickle cell anemia. We found that family functioning was the strongest predictor of executive outcomes in young children with sickle cell anemia with no evidence for an influence of disease severity at this early stage.

Cognitive profile of children with sickle cell anemia compared to healthy controls

OBJECTIVE

To evaluate the cognitive abilities of children and adolescents with sickle cell anemia diagnosed through neonatal screening and to compare them with healthy controls, adjusting the results to their socioeconomic status.

METHODS

Cognitive assessment was performed with the Wechsler WISC-III scale in 64 children and adolescents with sickle cell anemia and in 64 controls matched by gender and age, without the disease and without neurological impairment; socioeconomic status was measured by the Criterion Brasil.

RESULTS

All cognitive scores were lower in the group of patients. The mean overall IQ, Verbal IQ, and Performance IQ were, respectively, 90.95 for the group of patients and 113.97 for the controls (p<0.001); 91.41 for the group of patients and 112.31 for the controls (p<0.001); 92.34 for the group of patients and 113.38 for the controls (p<0.001). Scores for processing speed, distraction resistance, and perceptual organization were also significantly lower in patients. A direct and significant correlation was detected between socioeconomic status and cognitive scores. In the multivariate analysis, for the same socioeconomic status, a child with sickle cell anemia had an average IQ of 21.2 points lower than the mean IQ observed for the controls (p<0.001), indicating that the disease, adjusted for the socioeconomic effect, is a strong predictor of the overall IQ.

CONCLUSION

The cognitive impairment of children with sickle cell anemia is severe and manifests even when the disease effect is adjusted to the socioeconomic status. In the authors' view, such impairment requires an early preventive approach in order to avoid this cognitive damage.

Increasing Educational Attainment in Adolescents with Sickle Cell Disease

Adolescents with sickle cell disease (SCD), a chronic condition primarily impacting African Americans, experience challenges graduating high school. Understanding demographic, educational, and community-level correlates of disease is critical to creating effective interventions for these youths. This study aimed to examine 1) educational attainment for adolescents with SCD, 2) neighborhood correlates of their education, and 3) feasibility of a pilot to increase General Education Diploma (GED) class enrollment. Findings suggest demographic characteristics influence educational attainment. Improving educational attainment in adolescents with SCD requires understanding risk beyond disease severity. Identifying risk and protective neighborhood-level factors can inform interventions to improve educational attainment. Feasibility of programming to increase GED enrollment should be further investigated.

Sickle Cell Disease and Stroke

Cerebral infarction is a common complication of sickle cell disease and may manifest as overt stroke or cognitive impairment associated with "silent" cerebral infarction on magnetic resonance imaging. Vasculopathy may be diagnosed on transcranial Doppler or magnetic resonance angiography. The risk factors in sickle cell disease for cognitive impairment, overt ischemic stroke, silent cerebral infarction, overt hemorrhagic stroke, and vasculopathy defined by transcranial Doppler or magnetic resonance angiography overlap, with severe acute and chronic anemia, acute chest crisis, reticulocytosis, and low oxygen saturation reported with the majority. However, there are differences reported in different cohorts, which may reflect age, geographic location, or neuroimaging techniques, for example, magnetic resonance imaging field strength. Regular blood transfusion reduces, but does not abolish, the risk of neurological complications in children with sickle cell disease and either previous overt stroke or silent cerebral infarction or abnormal transcranial Doppler. There are relatively few data on the use of hydroxyurea or other management strategies. Early assessment of the risk of neurocognitive complications is likely to become increasingly important in the management of sickle cell disease.

Effect of revascularization on cognitive outcomes in intracranial steno-occlusive disease: a systematic review

OBJECTIVESteno-occlusive diseases of the cerebral vasculature have been associated with cognitive decline. The authors performed a systematic review of the existing literature on intracranial steno-occlusive disease, including intracranial atherosclerosis and moyamoya disease (MMD), to determine the extent and quality of evidence for the effect of revascularization on cognitive performance.METHODSA systematic search of PubMed/MEDLINE, the Thomson Reuters Web of Science Core Collection, and the KCI Korean Journal Database was performed to identify randomized controlled trials (RCTs) in the English-language literature and observational studies that compared cognitive outcomes before and after revascularization in patients with steno-occlusive disease of the intracranial vasculature, from which data were extracted and analyzed.RESULTSNine papers were included, consisting of 2 RCTs and 7 observational cohort studies. Results from 2 randomized trials including 142 patients with symptomatic intracranial atherosclerotic steno-occlusion found no additional benefit to revascularization when added to maximal medical therapy. The certainty in the results of these trials was limited by concerns for bias and indirectness. Results from 7 observational trials including 282 patients found some cognitive benefit for revascularization for symptomatic atherosclerotic steno-occlusion and for steno-occlusion related to MMD in children. The certainty of these conclusions was low to very low, due to both inherent limitations in observational studies for inferring causality and concerns for added risk of bias and indirectness in some studies.CONCLUSIONSThe effects of revascularization on cognitive performance in intracranial steno-occlusive disease remain uncertain due to limitations in existing studies. More well-designed randomized trials and observational studies are needed to determine if revascularization can arrest or reverse cognitive decline in these patients.

Factors Influencing the Academic Performance of Children with Sickle Cell Anaemia in Ekiti, South West Nigeria

BACKGROUND

There is a paucity of information on factors that influence the school performance of children with sickle cell anaemia (SCA) in Nigeria, despite her huge burden of the disease.

METHODS

In total, 101 children with SCA were recruited at a paediatric clinic in Nigeria. Their socio-demographic-matched classmates were the controls. Academic performance and cognitive functioning were obtained from school reports and Ziler's Draw-a-Person Test, respectively. Factors influencing the academic performance were determined.

RESULTS

Children with SCA had higher rates of school absence and lower haemoglobin concentration (p < 0.05). There was no difference in overall school performance between children with SCA and controls (59.0 vs. 60.6%; p = 0.256). School absenteeism > 1 week independently predicts poor school performance among the study participants (odds ratio = 15.71; 95% confidence interval = 5.93-41.66; p =0.000). Most SCA children with poor performance were absent from school for > 1 week.

CONCLUSION

There is need to address causes of school absenteeism among children with SCA.

Overnight auto-adjusting continuous airway pressure + standard care compared with standard care alone in the prevention of morbidity in sickle cell disease phase II (POMS2b): study protocol for a randomised controlled trial

Background

In addition to pain, sickle cell anaemia (HbSS) complications include neurocognitive difficulties in attention and processing speed associated with low daytime and night-time oxygen saturation compounded by obstructive sleep apnoea (OSA). In the general population OSA is treated with continuous positive airways pressure (CPAP). The aim of this single-blind, randomised, controlled phase II trial is to compare auto-adjusting CPAP (APAP) with standard care to standard care alone in individuals with HbSS to determine whether the intervention improves attention and processing speed, brain structure, pain and quality of life.

Methods/Design

Eligibility criteria include: ability to provide informed consent; age > 8 years; diagnosis of HbSS; and mean overnight saturation of < 90% for < 30% of the night (i.e. not meeting current criteria for overnight oxygen therapy). Key exclusion criteria are: overnight respiratory support; respiratory or decompensated cardiac failure; chronic transfusion; or contraindications to APAP therapy or magnetic resonance imaging (MRI).

Sixty individuals with HbSS (30 children and 30 adults) will be randomised to standard care + APAP or standard care alone for six months. Minimisation factors are: age group (8–11, 12–15, 16–22 and > 23 years); silent infarction on MRI; minimum overnight oxygen saturation > 90% or < 90%; and hydroxyurea use.

For APAP individuals, the intervention is administered at home. Adherence and effectiveness are recorded using software documenting hours of use each night and overnight oximetry. Participant support in terms of appropriate facemask and facilitating adherence are provided by an unblinded sleep physiologist.

The primary outcome is change in the cancellation subtest from the Wechsler scales. Secondary outcomes include general cognitive functioning, quantitative brain MRI, blood and urine chemistry, quality of life and daily pain via a smartphone App (GoMedSolutions, Inc) and, where possible MRI heart, echocardiography, and 6-min walk. These outcomes will be assessed at baseline and after six months of treatment by assessors blind to treatment assignment.

Discussion

Altering oxygen saturation in HbSS may lead to bone marrow suppression. This risk will be reduced by monitoring full blood counts at baseline, two weeks, three months and six months, providing treatment as appropriate and reporting as safety events.

Trial registration

ISRCTN46012373. Registered on 10 July 2015.

Protocol Version: 6.0 Date: 24th December 2015

Sponsor: University Hospital Southampton. Sponsor’s protocol code: RHMCHIOT53

Disease severity and slower psychomotor speed in adults with sickle cell disease

Psychomotor slowing is common in children with sickle cell disease (SCD), but little is known about its severity in adults. We conducted a cross-sectional study to quantify psychomotor speed, measured with the digit symbol substitution test (DSST), in relationship with disease severity in adults with SCD attending an outpatient clinic (n = 88, age 36.3 years). Genotype was used to group patients in "severe" (homozygous for hemoglobin S or compound heterozygous with β⁰ thalassemia) or "moderate" groups (compound heterozygous for HbS, with either HbC or β⁺ thalassemia). Analyses were repeated after exclusion of patients with a history of stroke (n = 11). Mild impairment in processing speed was detectable in both the "severe" and the "moderate" group (30% and 9%, respectively; age-adjusted P = .14). Compared with the "moderate" group, those in the "severe" group had significantly lower standardized DSST scores (P = .004), independent of adjustment for factors that differed between the groups: hemoglobin, ferritin, hydroxyurea use, blood pressure parameters, and stroke history. Results were similar after excluding patients with stroke. Psychomotor slowing in SCD differs in relationship to genotype; this difference appears unrelated to history of stroke or severity of anemia and other risk factors examined cross-sectionally. Although less prevalent, mild cognitive impairment was also detectable in patients with a less severe genotype. Longitudinal studies of SCD should include all diseases genotypes and examine factors that would reduce the risk of slow processing speed and perhaps more general cognitive impairment in each subgroup.

Parent reported sleep problems in preschool children with sickle cell anemia and controls in East London

Snoring and poor sleep may affect cognition, particularly in young children with chronic conditions. Parents of London preschoolers with sickle cell anemia (SCA; n = 22), matched controls (n = 24), and unselected typically developing (n = 142) preschoolers completed sleep questionnaires. Preschoolers with SCA had significantly more sleep problems when compared to matched controls and the larger population. Snoring occurred at least one to two nights a week for 79% of the SCA group. This is compared with 25% of matched controls and 33% of larger population. Randomized controlled trials to improve sleep in young children with SCA already at-risk for cognitive dysfunction should be considered.

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.

Intelligence quotient in paediatric sickle cell disease: a systematic review and meta-analysis

AIM

Sickle cell disease (SCD) is the commonest cause of childhood stroke worldwide. Magnetic resonance imaging (MRI) is routinely used to detect additional silent cerebral infarction (SCI), as IQ is lower in SCI as well as stroke. This review assesses the effect of infarction on IQ, and specifically whether, compared to healthy controls, IQ differences are seen in children with SCI with no apparent MRI abnormality.

METHOD

A systematic review was conducted to include articles with an SCD paediatric population, MRI information, and Wechsler IQ. A meta-analysis of 19 articles was performed to compare IQ in three groups: stroke vs SCI; SCI vs no SCI; and no SCI vs healthy controls.

RESULTS

Mean differences in IQ between all three groups were significant: stroke patients had lower IQ than patients with SCI by 10 points (six studies); patients with SCI had lower IQ than no patients with SCI by 6 points (17 studies); and no patients with SCI had lower IQ than healthy controls by 7 points (seven studies).

INTERPRETATION

Children with SCD and no apparent MRI abnormality have significantly lower IQ than healthy controls. In this chronic condition, other biological, socioeconomic, and environmental factors must play a significant role in cognition.

Cognition and the Default Mode Network in Children with Sickle Cell Disease: A Resting State Functional MRI Study

Cerebrovascular complications are frequent events in children with sickle cell disease, yet routinely used techniques such as Transcranial Doppler (TCD), Magnetic Resonance (MRI) and Angiography (MRA), insufficiently explain the cause of poor cognitive performances. Forty children with SS-Sβ° (mean age 8 years) underwent neurocognitive evaluation and comprehensive brain imaging assessment with TCD, MRI, MRA, Resting State (RS) Functional MRI with evaluation of the Default Mode Network (DMN). Sixteen healthy age-matched controls underwent MRI, MRA and RS functional MRI.Children with SCD display increased brain connectivity in the DMN even in the absence of alterations in standard imaging techniques. Patients with low neurocognitive scores presented higher brain connectivity compared to children without cognitive impairment or controls, suggesting an initial compensatory mechanism to maintain performances. In our cohort steady state haemoglobin level was not related to increased brain connectivity, but SatO2<97% was. Our findings provide novel evidence that SCD is characterized by a selective disruption of connectivity among relevant regions of the brain, potentially leading to reduced cognition and altered functional brain dynamics. RS functional MRI could be used as a useful tool to evaluate cognition and cerebral damage in SCD in longitudinal trials.

Cognitive Functions and Psychological Problems in Children with Sickle Cell Anemia

OBJECTIVE

To study the cognitive functions and psychological problems in children with Sickle cell anemia (SCA).

METHODS

Children with SCA were compared with an age, sex- and community- matched control group of children with no SCA. Malins Intelligence Scale for Indian children, modified PGI memory scale, and Childhood Psychopathology Measurement Schedule were used to assess cognitive functions and psychological problems.

RESULTS

Verbal quotient, performance quotient and intelligence quotient in SCA group were 77, 81, 78, respectively versus 92, 95, 93, respectively in non-SCA group (P <0.001). Borderline intellectual functioning and mild mental retardation were more common in SCA (70< and 16<, respectively). Children with SCA had impaired attention, concentration and working memory and more behavior problems compared to children without SCA.

CONCLUSION

Cognitive functions are impaired in children with SCA and they have more psychological problems. Facilities for early identification and remediation of psychological and intellectual problems should be incorporated with health care services for children with sickle cell anemia.

Adults with sickle cell disease may perform cognitive tests as well as controls when processing speed is taken into account: a preliminary case-control study

AIMS

This study aimed to: (1) evaluate cognitive function among adults with sickle cell disease using a computer-administered neuropsychological test; and (2) replicate previously identified differences in processing speed between patients with sickle cell disease and controls.

BACKGROUND

Previous evidence suggests that, compared with controls, adult patients with sickle cell disease have poorer cognitive functioning across most domains but the most significant deficits appear to be in the area of processing speed.

DESIGN

Cross-sectional case-control study conducted from June 2008-June 2010.

METHODS

Cognitive functioning was measured using computerized, self-administered, neuropsychological tests among 31 patients with sickle cell disease and 17 controls matched for age, gender and race. The assessment averaged 30 minutes and scores were recorded for seven computerized tests: verbal and visual memory, finger tapping, symbol digit coding, Stroop test, shifting attention and continuous performance.

RESULTS

Patients with sickle cell disease scored 10·76 points lower on the CNS Vital Signs processing speed domain than controls. Although non-significant, patients scored 5·73 points lower on the full index than controls but after adjusting for processing speed, mean scores for patients were 3 points greater compared with controls. Differences in executive functioning and attention were not significant and memory did not differ between groups.

CONCLUSION

Using a brief, computer-administered 30-minute neuropsychological test, we were able to replicate previous findings showing a greater than 10-point deficit in processing speed among patients with sickle cell disease. When differences in processing speed are taken into account, patients perform equally well or better than controls on cognitive tasks.

Prevalence of Developmental Delay and Contributing Factors Among Children With Sickle Cell Disease

BACKGROUND

Children with sickle cell disease (SCD) are at higher risk for deficits in cognition compared to the general population, even at young ages. Disease severity has been co-assessed in earlier studies, but the home environment has not. The purpose of the current study was to investigate the development of young children with SCD and secondarily, the impact of environmental and family factors.

METHODS

The current study is a baseline cross-sectional evaluation of a prospective, single-center cohort. Children with SCD between the ages of 1 and 42 months and their primary caregiver were included. Participants lived within 30 miles of the site and spoke English. Children underwent developmental evaluation using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Home visits were completed and screened using the Home Observation for Measurement of the Environment (HOME).

RESULTS

Over 3 years, 43 caregiver-child dyads consented and participated. Over 50% of children scored significantly below average on cognition and expressive language subscales. SCD severity was not associated with BSID-III scores. Socioeconomic status (SES) determined by the Diez-Roux method positively correlated (r = 0.401, P < 0.01) with the home environment. The HOME correlated (r = 0.360, P < 0.05) with the cognitive subscale on the BSID-III.

CONCLUSIONS

Given the high prevalence of developmental delay in this population, identifying modifiable factors to maximize developmental progress is essential. The home environment would be a targeted method for intervention. Future research is needed to identify the benefits of home-based intervention for this population.

Novel insights in the management of sickle cell disease in childhood

Sickle cell disease (SCD) is a life-threatening genetic disorder characterized by chronic hemolytic anemia, vascular injury and multiorgan dysfunctions. Over the last few decades, there have been significant improvements in SCD management in Western countries, especially in pediatric population. An early onset of prophylaxis with Penicillin and a proper treatment of the infections have increased the overall survival in childhood. Nevertheless, management of painful episodes and prevention of organ damage are still challenging and more efforts are needed to better understand the mechanisms behind the development of chronic organ damages. Hydroxyurea (Hydroxycarbamide, HU), the only medication approved as a disease-modifying agent by the United States Food and Drug Administration and the European Medicines Agency, is usually under-used, especially in developing countries. Currently, hematopoietic stem-cell transplantation is considered the only curative option, although its use is limited by lack of donors and transplant-related toxicity. SCD symptoms are similar in children and adults, but complications and systemic organ damages increase with age, leading to early mortality worldwide. Experts in comprehensive care of young patients with SCD, especially those approaching the transition age to adulthood, are missing, leading people to rely on urgent care, increasing health care utilization costs and inappropriate treatments. It would be important to establish programs of comprehensive healthcare for patients with SCD from birth to adulthood, to improve their quality and expectancy of life.

Evolution of sickle cell disease from a life-threatening disease of children to a chronic disease of adults: The last 40 years

Over the past 40 years, public health measures such as universal newborn screening, penicillin prophylaxis, vaccinations, and hydroxyurea therapy have led to an impressive decline in sickle cell disease (SCD)-related childhood mortality and SCD-related morbidity in high-income countries. We remain cautiously optimistic that the next 40 years will be focused on meeting current challenges in SCD by addressing chronic complications of SCD to reduce mortality and improve quality of life in a growing population of adults with SCD in high-income countries, while simultaneously decreasing the disparity of medical care between high and low-income countries.

Transition Needs of Adolescents With Sickle Cell Disease

OBJECTIVE

This article describes how adolescents with sickle cell disease (SCD) perceive their ability to perform everyday tasks required for transition to adult health care and independent living.

METHOD

The Adolescent Autonomy Checklist (AAC) was adapted to include skills associated with managing SCD (AAC-SCD) and was administered to adolescents during clinic visits. Participants indicated "can do already" or "needs practice" for 100 activities in 12 categories.

RESULTS

Of 122 patients, the percentage of adolescents who needed practice was greatest in living arrangements (38.7%), money management (35.8%), vocational skills (29.6%), and health care skills (25.5%). We found a significant effect of age and of cerebrovascular injury on the percentage of those who reported "needs practice" in multiple categories. We found no effect of gender and limited effect of hemoglobin phenotype on any skill category.

CONCLUSION

Findings support the need for educational intervention to improve transition skills in adolescents with SCD.

Cognitive and behavior deficits in sickle cell mice are associated with profound neuropathologic changes in hippocampus and cerebellum

Strokes are perhaps the most serious complications of sickle cell disease (SCD) and by the fifth decade occur in approximately 25% of patients. While most patients do not develop strokes, mounting evidence indicates that even without brain abnormalities on imaging studies, SCD patients can present profound neurocognitive dysfunction. We sought to evaluate the neurocognitive behavior profile of humanized SCD mice (Townes, BERK) and to identify hematologic and neuropathologic abnormalities associated with the behavioral alterations observed in these mice. Heterozygous and homozygous Townes mice displayed severe cognitive deficits shown by significant delays in spatial learning compared to controls. Homozygous Townes also had increased depression- and anxiety-like behaviors as well as reduced performance on voluntary wheel running compared to controls. Behavior deficits observed in Townes were also seen in BERKs. Interestingly, most deficits in homozygotes were observed in older mice and were associated with worsening anemia. Further, neuropathologic abnormalities including the presence of large bands of dark/pyknotic (shrunken) neurons in CA1 and CA3 fields of hippocampus and evidence of neuronal dropout in cerebellum were present in homozygotes but not control Townes. These observations suggest that cognitive and behavioral deficits in SCD mice mirror those described in SCD patients and that aging, anemia, and profound neuropathologic changes in hippocampus and cerebellum are possible biologic correlates of those deficits. These findings support using SCD mice for studies of cognitive deficits in SCD and point to vulnerable brain areas with susceptibility to neuronal injury in SCD and to mechanisms that potentially underlie those deficits.

Prevention of Morbidity in sickle cell disease--qualitative outcomes, pain and quality of life in a randomised cross-over pilot trial of overnight supplementary oxygen and auto-adjusting continuous positive airways pressure (POMS2a): study protocol for a randomised controlled trial

BACKGROUND

Sickle cell anaemia (SCA) is an inherited disorder of haemoglobin. Patients experience long-term health care problems, affecting quality of life (QOL) including frequent acute pain, which is difficult to document in trials except as hospital admissions. Pilot data suggests that overnight respiratory support, either supplementary oxygen or auto-adjusting continuous positive airways pressure (APAP), is safe and may have clinical benefit. This pilot trial aims to determine which intervention is more acceptable to participants and whether there are other advantages of one over the other, e.g. in respiratory function or haematological parameters, before conducting the Phase 2 trial of overnight respiratory support funded by the National Institutes of Health Research.

METHODS/DESIGN

This is a pilot cross-over interventional trial with the order of interventions decided by simple randomization. Ten adults (age over 18 years) and 10 children (aged between 8 and 18 years) with homozygous sickle cell disease (haemoglobin SS, HbSS), recruited regardless of symptoms of sleep-disordered breathing, will undergo overnight pulse oximetry and will have two interventions, overnight oxygen and APAP, for a week each in randomised order with a washout week between interventions. Participants will complete online diaries via an iPad throughout the 29 days of the study and will complete QOL questionnaires and have measurement of haematology, biochemistry, spirometry and lung volumes (adults only) at 3 time points, at baseline and after each intervention, as well as in-depth semi-structured qualitative interviews after each intervention, carried out by an experienced psychologist. Both qualitative and statistical methods will be used to analyze the data. The primary outcome is qualitative data looking at participant experience from the transcribed interviews after each intervention. The participant's view on feasibility, acceptability and preference will specifically be explored. The QOL, laboratory and lung function data will be compared with baseline for each arm.

DISCUSSION

Patient and public involvement is an integral part of this trial and the key outcome is the qualitative result, which is dependent on obtaining good quality data to advise on participant feasibility, acceptability and preference. This is being addressed by using a standard interview. The development of a pain endpoint is another important outcome and collecting daily measurements is likely to be challenging. Research results will be used to inform design of the Phase 2 trial.

TRIAL REGISTRATION

ISRCTN46078697 18 July 2014.

Hemoglobinopathies and sleep--The road less traveled

Sickle cell disease and thalassemia are common hereditary blood disorders associated with increased systemic inflammation, tissue hypoxia, endothelial dysfunction and end-organ damage, the latter accounting for the substantial morbidity and abbreviated lifespan associated with these conditions. Sleep perturbations in general, and sleep-disordered breathing in particular are also highly prevalent conditions and the mechanisms underlying their widespread end-organ morbidities markedly and intriguingly overlap with the very same pathways implicated in the hemoglobinopathies. However, little attention has been given to date to the potential contributing role of sleep disorders to sickle cell disease manifestations. Here, we comprehensively review the pathophysiological mechanisms and clinical manifestations linking disturbed sleep and hemoglobinopathies, with special emphasis on sickle cell disease. In addition to a broad summary of the available evidence, we identify many of the research gaps that require attention and future investigation, and provide the scientific contextual setting that should enable opportunities to investigate the intertwined pathophysiological mechanisms and clinical outcomes of sleep disorders and hemoglobinopathies.

Patterns of cerebral ischemia in children with moyamoya

BACKGROUND

Moyamoya disease is characterized by progressive cerebrovascular stenosis with recurrent cerebral ischemic events. Transient ischemic attacks are often associated with hyperventilation in children with moyamoya, suggesting hypoperfusion rather than thrombotic vaso-occlusion as a prominent mechanism. The patterns of ischemia and severity of steno-occlusive disease in such children may elucidate these mechanisms.

METHODS

Children, 1 month to 18 years, with moyamoya, observed over 11 years were analyzed. A study neuroradiologist reviewed all presurgical neuroimaging. Ischemic injury was categorized into cortical, subcortical, and watershed infarction. Angiographic findings were staged using a standardized method.

RESULTS

Twenty children, 15 girls, median age 6.4 years, were included. All children had magnetic resonance imaging and angiography, and in 16, conventional angiography was available. All 40 hemispheres, in 20 children, were evaluated. The initial clinical presentation included neurological deficits in 17, recurrent transient ischemic attacks in 7, headache in 8, seizures in 8, and alteration in consciousness in 4 children. Infarcts were bilateral in 13 (65%) children (ischemia alone in 14, ischemic stroke with hemorrhagic transformation in two, and primary hemorrhage in two). Infarcts were cortical and/or subcortical in 13 (65%), both deep and cortical watershed in 11 (55%), and cortical watershed alone in 5 (25%) children. The predominant vascular territory involved was the middle cerebral artery. The internal carotid arterial system was involved in all, with stage IV being the most frequent angiographic stage.

CONCLUSIONS

Ischemic injury in deep watershed zones is common in childhood moyamoya and may reflect non-vaso-occlusive ischemic mechanisms. Location and severity of vascular involvement may correlate with various patterns of ischemic infarction in moyamoya disease and requires further study.

Hypoxia and inflammation in children with sickle cell disease: implications for hippocampal functioning and episodic memory

Children with sickle cell disease (SCD) suffer from systemic processes (e.g., chronic anemia, recurrent hypoxic-ischemic events, chronic inflammation) that have been associated with neurocognitive impairment in a range of clinical populations, but which have been largely understudied in relation to specific domains of cognitive functioning in children with SCD. This review focuses on episodic memory, as the hippocampus may be especially vulnerable to the systemic processes associated with SCD. The first part of the paper outlines the pathophysiology of SCD and briefly reviews the extant literature on academic and cognitive functioning in children with SCD, emphasizing the dearth of research on episodic memory. Next, the complex systemic processes of hypoxia and inflammation associated with SCD are reviewed, along with research that has associated these processes with hippocampal damage and memory impairment. The paper concludes with suggestions for future research that are informed, in part, by the literature on developmental amnesia.

Parent education and biologic factors influence on cognition in sickle cell anemia

Children with sickle cell anemia have a high prevalence of silent cerebral infarcts (SCIs) that are associated with decreased full-scale intelligence quotient (FSIQ). While the educational attainment of parents is a known strong predictor of the cognitive development of children in general, the role of parental education in sickle cell anemia along with other factors that adversely affect cognitive function (anemia, cerebral infarcts) is not known. We tested the hypothesis that both the presence of SCI and parental education would impact FSIQ in children with sickle cell anemia. A multicenter, cross-sectional study was conducted in 19 US sites of the Silent Infarct Transfusion Trial among children with sickle cell anemia, age 5-15 years. All were screened for SCIs. Participants with and without SCI were administered the Wechsler Abbreviated Scale of Intelligence. A total of 150 participants (107 with and 43 without SCIs) were included in the analysis. In a multivariable linear regression model for FSIQ, the absence of college education for the head of household was associated with a decrease of 6.2 points (P = 0.005); presence of SCI with a 5.2 point decrease (P = 0.017); each $1000 of family income per capita with a 0.33 point increase (P = 0.023); each increase of 1 year in age with a 0.96 point decrease (P = 0.023); and each 1% (absolute) decrease in hemoglobin oxygen saturation with 0.75 point decrease (P = 0.030). In conclusion, FSIQ in children with sickle cell anemia is best accounted for by a multivariate model that includes both biologic and socioenvironmental factors.

Determinants of academic performance in children with sickle cell anaemia

Background

Some factors are known to influence the academic performance of children with Sickle Cell Anaemia (SCA). Information on their effects in these children is limited in Nigeria. The factors which influence academic performance of children with SCA in Enugu, Nigeria are determined in this study.

Methods

Consecutive children with SCA aged 5–11 years were recruited at the weekly sickle cell clinic of the University of Nigeria Teaching Hospital (UNTH) Enugu, Nigeria. Their age- and sex- matched normal classmates were recruited as controls. The total number of days of school absence for 2009/2010 academic session was obtained for each pair of pupils from the class attendance register. Academic performance was assessed using the average of the overall scores in the three term examinations of same session. Intelligence ability was determined with Draw-A-Person Quotient (DAPQ) using the Draw-A-Person Test while socio-economic status was determined using the occupational status and educational attainment of each parent.

Results

Academic performance of children with SCA showed statistically significant association with their socio-economic status (χ2 = 9.626, p = 0.047), and significant correlation with DAPQ (r = 0.394, p = 0.000) and age (r = -0.412, p = 0.000). However, no significant relationship existed between academic performance and school absence in children with SCA (r = -0.080, p = 0.453).

Conclusions

Academic performance of children with SCA is influenced by their intelligence ability, age and socio-economic status but not negatively affected by their increased school absenteeism.

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.

The use of stimulant medication to treat neurocognitive deficits in patients with pediatric cancer, traumatic brain injury, and sickle cell disease: a review

Several chronic health conditions of childhood, including pediatric cancers, traumatic brain injury (TBI), and sickle cell disease (SCD) are associated with significant neurocognitive impairments that can compromise educational attainment and future vocational opportunities. The prominence of attentional deficits as part of the neurocognitive sequelae associated with each of these conditions has led some researchers to draw parallels with another chronic condition that manifests in childhood, specifically the inattentive subtype of attention-deficit/hyperactivity disorder (ADHD). Because ADHD shares similar neurocognitive and symptomatological features with pediatric cancer, TBI, and SCD, stimulant medications may be indicated to treat associated deficits in each condition. However, relatively few studies have investigated the safety and effectiveness of stimulant medications in treating neurocognitive sequelae in children with cancer, TBI, or SCD. Thus, clinicians have received little guidance regarding a potentially useful treatment modality for ameliorating the neurocognitive deficits that can profoundly impact the educational, psychosocial, and vocational development of youth with these chronic health conditions. We provide a review of the literature and synthesize current developments in research regarding treatment with stimulant medication for children with cancer, TBI, and SCD, as well as discuss special considerations for each condition.

Effect of omega-3 (n-3) fatty acid supplementation in patients with sickle cell anemia: randomized, double-blind, placebo-controlled trial

BACKGROUND

Blood cell aggregation and adherence to vascular endothelium and inflammation play a central role in vaso-occlusive crisis in sickle cell disease. The antiaggregatory, antiadhesive, antiinflammatory, and vasodilatory omega-3 (n-3) fatty acids (DHA and EPA) are significantly reduced in patients with the disease.

OBJECTIVE

The aim was to investigate the therapeutic potential of omega-3 fatty acids for patients with homozygous sickle cell disease in a randomized, placebo-controlled, double-blind trial.

DESIGN

One hundred forty patients recruited from a single center in Sudan were randomly assigned and received, daily, 1 (age 2-4 y), 2 (age 5-10 y), 3 (age 11-16 y), or 4 (age ≥17 y) omega-3 capsules containing 277.8 mg DHA and 39.0 mg EPA or placebo for 1 y. Of these patients, 128 were followed up and the data were obtained. The primary and secondary endpoints-rates of clinical vaso-occlusive crisis and hemolytic events, blood transfusion rate, school attendance, and blood count-were analyzed by intention-to-treat analysis (n = 140).

RESULTS

Omega-3 treatment reduced the median rate of clinical vaso-occlusive events (0 compared with 1.0 per year, P < 0.0001), severe anemia (3.2% compared with 16.4%; P < 0.05), blood transfusion (4.5% compared with 16.4%; P < 0.05), white blood cell count (14.4 ± 3.3 compared with 15.6 ± 4.0 ×10(3)/μL; P < 0.05), and the OR of the inability to attend school at least once during the study period because of illness related to the disease to 0.4 (95% CI: 0.2, 0.9; P < 0.05).

CONCLUSION

The findings of this trial, which need to be verified in a large multicenter study, suggest that omega-3 fatty acids can be an effective, safe, and affordable therapy for sickle cell anemia. This trial was registered with Current Controlled Trials as ISRCTN80844630.

Transition and sickle cell disease

Sickle cell disease (SCD), the most common genetic disease screened for in the newborn period, occurs in ~1 in 2400 newborns in the general population and 1 in 400 individuals of African descent in the United States. Despite the relative high prevalence and low pediatric mortality rate of SCD when compared with other genetic diseases or chronic diseases in pediatrics, few evidence-based guidelines have been developed to facilitate the transition from pediatrics to an internal medicine or family practice environment. As with any pediatric transition program, common educational, social, and health systems themes exist to prepare for the next phase of health care; however, unique features characterizing the experience of adolescents with SCD must also be addressed. These challenges include, but are not limited to, a higher proportion of SCD adolescents receiving public health insurance when compared with any other pediatric genetic or chronic diseases; the high proportion of overt strokes or silent cerebral infarcts (~30%) affecting cognition; risk of low high school graduation; and a high rate of comorbid disease, including asthma. Young adults with SCD are living longer; consequently, the importance of transitioning from a pediatric primary care provider to adult primary care physician has become a critical step in the health care management plan. We identify how the primary care physicians in tandem with the pediatric specialist can enhance transition interventions for children and adolescents with SCD.

Barriers in transition from pediatrics to adult medicine in sickle cell anemia

Transition of care from pediatric to adult providers is an essential step in the care of young adults with sickle cell anemia. Transition programs should be developed by individual institutions to systematically enhance the transition process for their patients. Prior to transfer, patients must be educated about their disease and personal medical history and develop skill sets required to navigate the adult health care setting. The objective of this literature review is to identify key concepts associated with transition of care for patients with sickle cell anemia. First, transition programs should be developed so that education about transition can begin at an early age. The readiness of patients and families should be assessed and education tailored to meet individual patient needs. Finally, the emotions and fears about transition should be recognized and addressed prior to transition.

Capturing PLMS and their variability in children with sickle cell disease: does ankle activity monitoring measure up to polysomnography?

OBJECTIVES

To test agreement and define differences in periodic limb movements in sleep (PLMS) measured by polysomnography and an ankle activity monitor, and to describe PLMS variability across nights, feasibility of home monitoring, and correlates of PLMS in children with sickle cell disease (SCD).

METHODS

Twenty children with SCD and restless legs syndrome (RLS) symptoms or polysomnography-documented PLMS underwent concurrent attended polysomnography and ankle activity monitoring over one to two nights and home activity monitoring for three nights. Serum iron and ferritin were measured pre- and post-polysomnography.

RESULTS

Adequate sensitivity (1.00), specificity (0.69), and mean bias (5.0±7.4 PLMS/h) for identifying elevated PLMS by activity monitor were obtained when scoring the period from sleep onset to offset rather than time in bed per manufacturer recommendation, and using a cut-point of 10 PLMS/h. Compared to activity monitor, only polysomnographic PLMS demonstrated periodicity, at inter-movement intervals (IMI) 20-35 s; the activity monitor overscored PLMS at the beginning and end of sleep and at shorter IMI (5-15s; p≤0.003), suggesting misclassification of nonperiodic leg movements as PLMS by activity monitor. PLMS varied across four nights by 16.1±13.4 PLMS/h. Post-polysomnography ferritin was associated (positively) with PLMS (p=0.034); RLS symptoms were not.

CONCLUSIONS

Ankle activity monitoring is a valid screening measure for PLMS in children with SCD and can readily be performed at home. Interpretation should incorporate a threshold for elevated PLMS of 10/h and scoring from sleep onset to offset, which could be identified with concurrent wrist actigraphy, to better account for true PLMS.