Cognitive and fine motor deficits in a pediatric sickle cell disease cohort of mixed ethnic origin

Prediction of Functional Academic Outcomes by Fine Motor Skills in Individuals With Sickle Cell Disease

IMPORTANCE

Individuals with sickle cell disease (SCD) are at heightened risk of poor neurocognitive and academic outcomes. The relationship between fine motor skills and academic outcomes is not well understood.

OBJECTIVE

To compare the fine motor skills of individuals with SCD with normative expectations, test whether demographic and medical factors are associated with fine motor performance, and determine the impact of fine motor performance on academic performance.

DESIGN

Cross-sectional.

SETTING

St. Jude Children's Research Hospital.

PARTICIPANTS

Individuals with SCD (N = 376; ages 8-24 yr).

OUTCOMES AND MEASURES

Fine motor outcomes included visual-motor integration, manual dexterity, and graphomotor speed. Academic outcomes included math fluency and word reading. Demographic and medical variables were obtained via medical records and interviews.

RESULTS

Compared with normative expectations, the performance of individuals with SCD on all fine motor measures was lower than expected. Male sex, lower socioeconomic status, and lower oxygen saturation was associated with slower graphomotor speed. Lower socioeconomic status and older age were associated with lower visual-motor integration scores. Performance on all fine motor measures was positively associated with math fluency and word reading.

CONCLUSIONS AND RELEVANCE

Individuals with SCD exhibited poorer than expected fine motor skills across multiple motor domains, and these deficits were associated with poorer academic outcomes. Early referral to intervention services for fine motor skills may facilitate improved academic outcomes for individuals with SCD. Plain-Language Summary: This study had three objectives: (1) Compare the fine motor skills of people with sickle cell disease (SCD) with normative expectations, (2) test whether demographic and medical factors are associated with fine motor performance, and (3) determine the impact of fine motor performance on academic performance. We found that SCD is a risk factor for lower than expected fine motor performance across multiple fine motor domains and that these deficits also affect functional academic skills.

Prevention of neurovascular complications in children with Sickle Cell Disease in the real-world setting: What adult medicine physicians should know

Neurovascular complications represent one of the most detrimental manifestations of Sickle Cell Disease (SCD), affecting many patients since infancy. They include overt stroke, silent cerebral infarcts and neurocognitive disorders. In fact, neurodevelopment can be impaired in children resulting in cognitive dysfunction in adults with SCD. This review is meant to resume the most recent guidelines about the prevention of SCD neurovascular complications and to highlight the open challenges in their implementation. Transcranial Doppler, Magnetic Resonance Imaging/Angiography and neurocognitive test are useful screening tools. Chronic transfusion regimen, hematopoietic stem cell transplantation and neurocognitive rehabilitation find indications in the context of primary and secondary prevention of neurovascular complications of SCD. However, international guidelines are often difficult to bring into the real world due to the lack of appropriate instruments and trained personnel. Many challenges have still to be faced to guarantee the best possible neurocognitive function to each child affected by SCD.

Executive Function and Processing Speed in Children Living with Sickle Cell Anemia

Executive function and processing speed difficulties are observed in children living with sickle cell anemia (SCA). The influence of processing speed on executive function is not well understood. We recruited 59 children living with SCA and 24 matched controls aged 8-18 years between 2010 and 2016 from clinics in the UK. Children completed tests in processing speed and cognitive flexibility, subdomains of executive function. MRI scans were conducted within one year of testing; oxygen saturation was obtained on the day of testing. Hemoglobin levels were obtained from medical records. Caregivers completed the executive function questionnaire. Hierarchical linear regressions found that hemoglobin, oxygen saturation, age, infarct status, and processing speed were not independent predictors for any model. However, for all cognitive flexibility tests, there was a significant interaction between infarct status and processing speed; children without silent cerebral infarction (SCI) with faster processing speed had better cognitive flexibility. Our findings indicate that, when interpreting executive function difficulties, it is important to account for the relationship between SCI status and processing speed. More research is needed to elucidate the mechanisms, but clinically, including executive function testing as part of clinic visits by embedding psychologists within the healthcare team would appear to be a critical step.

Neurocognitive functioning in preschool children with sickle cell disease

BACKGROUND

Children with sickle cell disease (SCD) experience neurodevelopmental delays; however, there is limited research with preschool-age children. This study examined neurocognitive risk and protective factors in preschoolers with SCD.

PROCEDURE

Sixty-two patients with SCD (60% HbSS/HbSβ⁰ -thalassemia; 40% HbSC/HbSβ⁺ -thalassemia) between the ages of 3 and 6 years (mean = 4.77 years) received a neuropsychological evaluation as routine systematic surveillance. Patients were not selected for disease severity, prior central nervous system findings, or existing cognitive concerns. Thirty-four patients (82% HbSS/HbSβ⁰ -thalassemia) were prescribed hydroxyurea (HU) at the time of their neuropsychological evaluation. On average, these patients had been prescribed HU at 2.15 (standard deviation = 1.45) years of age. The average dose was 28.8 mg/kg/day. Besides genotype, there were no group differences in medical or demographic factors based on HU treatment status.

RESULTS

Patients with HbSS/HbSβ⁰ -thalassemia scored below normative expectations on measures of intelligence, verbal comprehension, and school readiness (false discovery rate-adjusted p-value [p_FDR ] < .05). Age, sickle genotype, and HU treatment exposure were not associated with measured neurocognitive outcomes (p_FDR  > .05). Greater social vulnerability at the community level was associated with poorer performance on measures of intellectual functioning, verbal comprehension, visuomotor control, and school readiness, as well as parent report of executive dysfunction (p_FDR  < .05). Greater household socioeconomic status was positively associated with academic readiness.

CONCLUSIONS

Preschoolers with severe SCD (HbSS/HbSβ⁰ -thalassemia) perform below age expectations on measures of intelligence and academic readiness. Sociodemographic factors were stronger drivers of neurocognitive performance than disease severity or disease-modifying treatment. Neurodevelopmental interventions targeting the home and broader community environment are needed.

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

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

Physical Impairment and Function in Children and Adolescents With Sickle Cell Disease: A Systematic Review

OBJECTIVE

To examine physical impairments and physical function in children and adolescents with sickle cell disease (SCD).

DATA SOURCES

PubMed, Embase (embase.com), Cumulative Index to Nursing and Allied Health (EBSCO), Cochrane Central Register of Controlled Trials (Wiley), and Dissertations and Theses (ProQuest) were searched from January 1, 1990, to September 25, 2020. References retrieved were required to include a term for SCD and a term for physical impairments or physical function. Results were limited to articles with children and adolescents and in the English language.

STUDY SELECTION

A total of 3054 nonduplicate articles were independently screened by 2 reviewers, resulting in 240 articles for full-text review. The full-text review, performed by 2 independent reviewers, resulted in 67 articles.

DATA EXTRACTION

Data were extracted from each full text to a custom Excel document by a single reviewer and were verified by a secondary reviewer.

DATA SYNTHESIS

The studies identified in this systematic review offer evidence that children and adolescents with SCD demonstrate physical impairments and physical function limitations compared with control participants as noted by varying percentages in deficits up to 19%-58% in muscle and bone composition and/or symptoms, muscle strength, cardiopulmonary function, motor performance, physical activity, and physical function domains of quality of life questionnaires.

CONCLUSIONS

Children and adolescents with SCD present with physical impairments and physical function limitations. Scientists and clinicians should consider developing collaborative standards to define and objectively measure physical impairment and function in this population to comprehensively examine the underlying factors that contribute to physical impairments and function.

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.

Mapping of long-term cognitive and motor deficits in pediatric cerebellar brain tumor survivors into a cerebellar white matter atlas

PURPOSE

Diaschisis of cerebrocerebellar loops contributes to cognitive and motor deficits in pediatric cerebellar brain tumor survivors. We used a cerebellar white matter atlas and hypothesized that lesion symptom mapping may reveal the critical lesions of cerebellar tracts.

METHODS

We examined 31 long-term survivors of pediatric posterior fossa tumors (13 pilocytic astrocytoma, 18 medulloblastoma). Patients underwent neuronal imaging, examination for ataxia, fine motor and cognitive function, planning abilities, and executive function. Individual consolidated cerebellar lesions were drawn manually onto patients' individual MRI and normalized into Montreal Neurologic Institute (MNI) space for further analysis with voxel-based lesion symptom mapping.

RESULTS

Lesion symptom mapping linked deficits of motor function to the superior cerebellar peduncle (SCP), deep cerebellar nuclei (interposed nucleus (IN), fastigial nucleus (FN), ventromedial dentate nucleus (DN)), and inferior vermis (VIIIa, VIIIb, IX, X). Statistical maps of deficits of intelligence and executive function mapped with minor variations to the same cerebellar structures.

CONCLUSION

We identified lesions to the SCP next to deep cerebellar nuclei as critical for limiting both motor and cognitive function in pediatric cerebellar tumor survivors. Future strategies safeguarding motor and cognitive function will have to identify patients preoperatively at risk for damage to these critical structures and adapt multimodal therapeutic options accordingly.

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.

Validation of the fine motor subtest of the Bayley-III with children with sickle cell disease using Rasch analysis

BACKGROUND

Children with sickle cell disease (SCD) are at risk for fine motor (FM) delays; however, screening for FM impairments is not common among young children with SCD. The Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) is the most commonly used performance-based developmental assessment. We aim to determine if the FM subtest of the Bayley-III is structured hierarchically in accordance with development and comprehensively evaluates FM development in children with SCD.

METHODS

Bayley-III assessments were completed between October 2009 and December 2013. The Bayley-III FM screening test, a shorter and more rapid method of assessing for FM impairments, was not directly administered to participants. Screening test scores were calculated from full Bayley-III scores.

RESULTS

Rasch analysis was performed using WINSTEPS. Sixty children with SCD were included in the final Rasch model. The Rasch-generated Wright map, which jointly positions items and persons on the same latent trait, illustrated that the FM items were slightly skewed towards more challenging items, indicating more difficult items may be overrepresented. High item separation values were reported (17.4), and item outfit statistics were less than 1.7. More than one third of items demonstrated overfit, indicating possible item redundancy. The FM subtest and the screening test, a shorter and faster method of assessing skills, were highly correlated (r = 0.993, p < 0.001).

CONCLUSION

The Bayley-III FM subtest is structured hierarchically, aligning with motor development, and comprehensively evaluates FM development in children with SCD. The test could be improved by reordering items, removing overfitting items and modifying screening test items to capture all ranges of development. The screening test is comprehensive and has high potential clinical utility among children with SCD.

Season of birth and sugary beverages are predictors of Raven's Standard Progressive Matrices Scores in adolescents

To investigate factors associated with cognitive functioning in healthy adolescents, a school-based cross-sectional study was conducted on 1370 adolescents aged 11–16 years that were randomly selected from all governorates of Kuwait. Raven’s Standard Progressive Matrices (SPM), a non-verbal test of intelligence, was used to measure cognitive functioning of the study participants. Data on predictors of cognitive functioning were collected from parents and adolescents. Weight and height of the participants were measured in a standardized manner and blood samples were tested in an accredited laboratory under strict measures of quality control. In multivariable linear regression analysis, factors that showed significant association with the SPM score were gender (p = 0.002), season of birth (p = 0.009), place of residence (p < 0.001), father’s (p < 0.001) and mother’s (p = 0.025) educational level, type of housing (p < 0.001), passive smoking at home (p = 0.031), sleeping hours during weekends (p = 0.017), students’ educational level (p < 0.001) and the frequency of consumption of sugary drinks (p < 0.001). The link between cognitive functioning and season of birth seems to be robust in various geographical locations including the Middle East. The association between sugary drinks and cognitive functioning highlights the importance of diet independently of obesity and support efforts to reduce consumption of sugary drinks among children.

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.

Higher executive abilities following a blood transfusion in children and young adults with sickle cell disease

Individuals with sickle cell disease (SCD) experience cognitive deficits; however, it remains unclear whether medical treatments for SCD improve cognition. Given that executive abilities are typically impaired in individuals with SCD, they were the focus of the current study. Our primary hypothesis was that executive abilities would be higher acutely soon after a blood transfusion in children and young adults with SCD. We used tests from the NIH Toolbox to assess executive abilities in 27 participants with SCD receiving chronic transfusion in comparison to 34 participants with SCD receiving hydroxyurea (HU) and 41 non-SCD demographically matched controls, all of whom were tested at two time points. Participants in the transfusion group completed cognitive testing within 3 days after a transfusion (soon after transfusion) and then within 3 days before their next transfusion (long after transfusion) over an interval of 3-7 weeks. We found that executive abilities were significantly poorer for the transfusion and HU groups than for the control group. In support of our primary hypothesis, executive abilities for the transfusion group were significantly better soon after a transfusion compared to long after a transfusion, χ2 (1) = 17.8, P < .0001. Our results demonstrate that executive abilities were higher acutely following a blood transfusion. These findings have implications for daily functioning, medical decision making, and academic achievement in children and young adults with SCD.

Associations of transcranial doppler velocity, age, and gender with cognitive function in children with sickle cell anemia in Nigeria

Children with sickle cell anemia (SCA) have elevated cerebral blood velocity relative to healthy peers. The primary aim of this study was to evaluate the association between cerebral blood velocity, measured by transcranial Doppler (TCD) ultrasound, age, and gender with cognitive function in children with SCA in Nigeria. Eighty-three children (Mage = 9.10, SD = 1.90 years; 55% female) with SCA in Nigeria completed cognitive assessments and a TCD ultrasound. The association between TCD velocity and measures of perceptual reasoning (Raven's Progressive Matrices), working memory (WISC-IV Digit Span), and executive planning (Tower of London, TOL) were assessed. Results showed that elevated TCD velocity significantly predicted lower scores on TOL Time Violations and Total Problem-Solving Time when controlling for BMI, hemoglobin level, and parent education, suggesting that TCD velocity is related to the efficiency of executive function. Further, age was negatively related to children's performance on the Ravens Matrices and TOL Total Correct, and boys showed greater deficits on the TOL Total Correct relative to girls. Moderation analyses for gender showed that there was a conditional negative association between TCD velocity and Digit Span for boys, but not for girls. Findings suggest that children with SCA in Nigeria with elevated TCD velocity are at risk for deficits in efficiency of executive planning, and boys with elevated TCD velocity are particularly at increased risk for deficits in auditory working memory. Implications of this study are important for interventions to reduce cerebral blood velocity and the use of TCD in this population.

The impact of sickle cell anemia on the quality of life of sicklers at school age

Background

Sickle cell anemia (SCA) is prevalent in Sudan in general, and in particular in the western part of the country among Misseria tribe. School absence, depressive symptoms, embarrassment, social disturbances, and emotional disturbance present negative impact for sicklers. Therefore, an urgent call for improving the quality of life of sicklers is needed.

Objectives

To examine the impact of SCA on the quality of life of school-age children affected by the disease from the perspective of three dimensions: psychological, social, and schooling.

Materials and Methods

This is a prospective, cross-sectional, observational study carried out over 2 weeks' period in April 2011 in Western Sudan, Gineana District. This study included 107 patients within the age group of 7-15 years with confirmed diagnosis of SCA in a steady state. A sickler with SCA who had hemoglobin genotype "SS" on hemoglobin electrophoresis without crises over the past 4 weeks was considered to be in steady state. Questionnaires designed by expert covering social and psychological aspects of the disease were filled by the authors.

Results

Of 107 patients with confirmed diagnosis of SCA in steady state, 54.2% of them were male. About 17.8%, 29.6%, 23.4%, 48.6%, 16.8%, and 45.8% of the patients suffered from school absence, teasing, embarrassment due to bedwetting, embarrassment due to jaundice, failure to contribute to school activities such as sport, and depressive symptoms, respectively. Around 8.4% of the patients repeated classes. Divorce and anxiety among sicklers' families were found in 6.5% and 8.4%, respectively. Twenty-one (19.6%) families had less interest in social activities in the community.

Conclusion

Sickle cell disease has many social and psychological problems which need to be addressed. Enuresis, depressive symptoms, school absentees, and deterioration in school performance were the common problems encountered.

Assessment of Executive Functions in Preschool Children With Sickle Cell Anemia

OBJECTIVES

Children with sickle cell anemia (SCA) are commonly reported to experience executive dysfunction. However, the development of executive function (EF) in preschool-age children without stroke in this patient population has not been investigated so it is unclear when and how these deficits emerge.

METHODS

This case-control study examines the feasibility of assessing the early development of executive functioning in 22 preschool children years with SCA in the domains of processing speed, working memory, attention, inhibitory control, and cognitive flexibility, as well as everyday function, in comparison to matched control children.

RESULTS

A pattern of potential deficits in early emerging executive skills was observed in the domains of inhibitory control and cognitive flexibility. Parents reported no differences for everyday EF and no significant differences were observed for working memory and processing speed.

CONCLUSIONS

Results suggest that deficits in everyday executive difficulties, working memory, and processing speed, as commonly reported for older children with SCA, may not yet have emerged at this early developmental stage, despite specific deficits in cognitive flexibility and inhibitory control on behavioral measures. The feasibility of using available executive measures with preschool age children to characterize the development of early EF skills is discussed. (JINS, 2018, 24, 949-954).