Co-Occurrence of Neurodevelopmental Disorders in Pediatric Sickle Cell Disease

Current developmental screening practices in young children with sickle cell disease

Despite recent developmental screening guidelines, rates of neurodevelopmental disorders (NDDs) remain lower than expected in children with sickle cell disease (SCD). A retrospective chart review identified 276 eligible patients; 214 charts were available for developmental screening and 207 charts for autism-specific screening. Developmental surveillance/screening was conducted in 70% of charts and autism-specific screening in 19% of charts. Validated tools were used in 32% of developmental screenings and 92% of autism-specific screenings. Many children (57%) were screened outside recommended ages. In conclusion, children with SCD are not regularly receiving appropriate developmental screening and surveillance by their healthcare providers.

Subanesthetic ketamine: the way forward for pain management in sickle cell disease patients?

INTRODUCTION

Patients with sickle cell disease (SCD) present recurrent episodes of acute pain, the hallmark of the disease, and some will also develop chronic pain. Currently, the treatment of SCD acute pain only targets its symptoms, rather than underlying mechanisms, and is directed by expert and consensus guidelines.

AREAS COVERED

While opioids remain the mainstay of therapy for acute pain and are also used to treat SCD-related chronic pain, in some patients, opioids are ineffective or are associated with severe undesirable side effects. In those instances, clinicians caring for patients with SCD face an unmet need for effective non-opioid analgesics. Recently, the use of subanesthetic ketamine has been explored as a strategy to meet this need. While definitive evidence of its efficacy is lacking, some information exists suggesting that subanesthetic ketamine improves pain control and may have opioid-sparing effects in SCD-related acute pain. However, ketamine can also yield undesirable psychotomimetic and cardiovascular effects.

EXPERT OPINION

After weighing potential risks and benefits, in the absence of better alternatives and in settings where it can be administered safely, ketamine may be a reasonable option for patients with SCD-related acute refractory pain.

Developmental disorders in children born to women with sickle cell disease: A report from the Boston Birth Cohort

Children exposed to maternal sickle cell disease (SCD) have many theoretical risks for developmental disorders, but little is known about long‐term outcomes for these children. We used the Boston Birth Cohort to compare developmental outcomes between children exposed to maternal SCD and matched, unexposed controls. Children with exposure to maternal SCD had increased risk of attention deficit hyperactivity disorder (OR 5.12, 95% CI 1.36–19.19, p = 0.02) and obesity (OR 2.74, 95% CI 1.10–6.87, p = 0.03). In utero and/or environmental exposures may help explain these findings. Further studies of outcomes of children born to women with SCD are needed.

Sluggish Cognitive Tempo in Pediatric Sickle Cell Disease

Background

Sickle cell disease (SCD) imparts risk for a range of neurodevelopmental and neurocognitive disorders. Sluggish cognitive tempo (SCT) is a distinct syndrome that often co-occurs with attention-deficit/hyperactivity disorder (ADHD) but has not been described in SCD. We investigated the reliability and validity of a SCT measure in SCD and examined associations with biopsychosocial risk factors and functional outcomes.

Materials and Methods

Caregivers (n = 85) of children with SCD ages 7-16 reported on socio-demographics and the Kiddie-Sluggish Cognitive Tempo (K-SCT) measure, Behavior Rating Inventory of Executive Function, and Conners 3. Disease-related characteristics were extracted from health records.

Results

The K-SCT demonstrated excellent internal consistency (α = 0.92) and test-retest reliability (r = 0.82, p < 0.001). K-SCT scores were correlated with ADHD-Inattention (r = 0.64, p < 0.001) and ADHD-Hyperactive/Impulsive (r = 0.46, p < 0.001) scores, as well as functional outcomes, including learning problems (r = 0.69, p < 0.001). In multivariate analyses controlling for ADHD symptoms, SCT accounted for unique variance in learning (b = 9.67, p < 0.01) and executive functioning (b = 5.93, p < 0.01). Nearly all participants (93%) with elevated levels of co-occurring SCT and ADHD-Inattention symptoms had significant learning problems.

Conclusion

The K-SCT is a reliable and valid measure of SCT in SCD. SCT symptoms are associated with learning difficulties even after controlling for ADHD symptoms. Further research is needed to understand the biopsychosocial factors that lead to SCT symptoms in SCD and examine long-term implications of SCT.

Brain Oxygen Extraction and Metabolism in Pediatric Patients With Sickle Cell Disease: Comparison of Four Calibration Models

Sickle cell disease (SCD) is an inherited hemoglobinopathy with an increased risk of neurological complications. Due to anemia and other factors related to the underlying hemoglobinopathy, cerebral blood flow (CBF) increases as compensation; however, the nature of alterations in oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in SCD remains controversial, largely attributed to the different calibration models. In addition, limited studies have been done to investigate oxygen metabolism in pediatric patients. Thus, this study used a non-invasive T2-based MR oximetry, T2-Relaxation-Under-Spin-Tagging (TRUST) MRI, to measure oxygen homeostasis in pediatric patients with SCD using four different calibration models and examined its relationship to hematological measures. It was found that, compared with controls, SCD patients showed an increased CBF, unchanged total oxygen delivery and increased venous blood T2. The results of OEF and CMRO2 were dependent on the calibration models used. When using sickle-specific, hemoglobin S (HbS) level-dependent calibration, there was a decreased OEF and CMRO2, while the bovine model showed an opposite result. OEF and CMRO2 were also associated with hemoglobin and HbS level; the direction of the relationship was again dependent on the model. Future studies with in vivo calibration are needed to provide more accurate information on the T2-Yv relationship.

Imaging Blood-Brain Barrier Permeability Through MRI in Pediatric Sickle Cell Disease: A Feasibility Study

BACKGROUND

Blood-brain barrier (BBB) disruption may lead to endothelium dysfunction and inflammation in sickle cell disease (SCD). However, abnormalities of BBB in SCD, especially in pediatric patients for whom contrast agent administration less than optimal, have not been fully characterized.

PURPOSE

To examine BBB permeability to water in a group of pediatric SCD participants using a non-invasive magnetic resonance imaging technique. We hypothesized that SCD participants will have increased BBB permeability.

STUDY TYPE

Prospective cross-sectional.

POPULATION

Twenty-six pediatric participants (10 ± 1 years, 15F/11M) were enrolled, including 21 SCD participants and 5 sickle cell trait (SCT) participants, who were siblings of SCD patients.

FIELD STRENGTH/SEQUENCE

3 T. Water extraction with phase-contrast arterial spin tagging with echo-planer imaging, phase-contrast and T₁ -weighted magnetization-prepared rapid acquisition of gradient echo.

ASSESSMENT

Water extraction fraction (E), BBB permeability-surface area product (PS), cerebral blood flow, hematological measures (hemoglobin, hematocrit, hemoglobin S), neuropsychological scores (including domains of intellectual ability, attention and executive function, academic achievement and adaptive function, and a composite score). Regions of interest were drawn by Z.L. (6 years of experience).

STATISTICAL TESTS

Wilcoxon rank sum test and chi-square test for group comparison of demographics. Multiple linear regression analysis of PS with diagnostic category (SCD or SCT), hematological measures, and neuropsychological scores. A two-tailed P value of 0.05 or less was considered statistically significant.

RESULTS

Compared with SCT participants, SCD participants had a significantly higher BBB permeability to water (SCD: 207.0 ± 33.3 mL/100 g/minute, SCT: 171.2 ± 27.2 mL/100 g/minute). SCD participants with typically more severe phenotypes also had a significantly leakier BBB than those with typically milder phenotypes (severe: 217.3 ± 31.7 mL/100 g/minute, mild: 193.3 ± 31.8 mL/100 g/minute). Furthermore, more severe BBB disruption was associated with worse hematological symptoms, including lower hemoglobin concentrations (β = -8.84, 95% confidence interval [CI] [-14.69, -3.00]), lower hematocrits (β = -2.96, 95% CI [-4.84, -1.08]), and higher hemoglobin S fraction (β = 0.77, 95% CI [0.014, 1.53]).

DATA CONCLUSION

These findings support a potential role for BBB dysfunction in SCD pathogenesis of ischemic injury.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.