Neuropsychological dysfunction and neuroimaging abnormalities in neurologically intact adults with sickle cell anemia

Determinants of cognitive dysfunction in adults with sickle cell-related stroke or suspected neurological morbidity

ABSTRACT

The prognosis of sickle cell disease (SCD) in adults is determined primarily by damage to targeted organs such as the brain. Cognitive dysfunction in SCD is a common chronic neurological manifestation, but studies remain mostly descriptive in adults. The objective of this study was to better characterize the cognitive profile and the association between cognitive dysfunction and brain lesions. We included adult patients with SCD referred for a neurological assessment. An adapted battery of neuropsychological tests was used to assess cognitive deficits. Brain or arterial abnormalities were assessed using brain magnetic resonance imaging/magnetic resonance angiography and a cervical and transcranial Doppler ultrasound. The cognitive profile of 96 patients was characterized by deficits in processing speed (58%), short-term memory (34%), and working memory (24%). Brain infarcts were found in 56% of patients and intracranial vasculopathy in 49%. Twenty percent of patients had no brain abnormalities. Processing speed dysfunction was associated with territorial infarcts (odds ratio [OR], 3.1; P = .03) and education outside of France (OR, 4.7; P = .02). Short-term memory dysfunction was associated with territorial infarcts (OR, 3.4; P = .01) and a low educational level (OR, 8.2; P = .01). Working memory dysfunction was associated with a low educational level (OR, 4.3; P = .05) and vasculopathy (OR, 3.7; P = .03). Cognitive dysfunction appears to be a hallmark sign of SCD, particularly for adults with sickle cell-related stroke or suspected neurological morbidity. Assessment of such dysfunction could be used in longitudinal follow-up and clinical trials.

End Organ Affection in Sickle Cell Disease

Sickle cell disease is an orphan disease affecting ethnic minorities and characterized by profound systemic manifestations. Although around 100,000 individuals with SCD are living in the US, the exact number of individuals is unknown, and it is considered an orphan disease. This single-gene disorder leads to red blood cell sickling and the deoxygenation of hemoglobin, resulting in hemolysis. SCD is associated with acute complications such as vaso-occlusive crisis, infections, and chronic target organ complications such as pulmonary disease and renal failure. While genetic therapy holds promise to alter the fundamental disease process, the major challenge in the field remains the target end organ damage and ways to mitigate or reverse it. Here, we provide an overview of the clinical manifestations and pathogenesis with a focus on end-organ damage and current therapeutic options, including recent FDA-approved stem cell and gene editing therapies.

Reversibility of Cognitive Deficits and Functional Connectivity With Transfusion in Children With Sickle Cell Disease

BACKGROUND AND OBJECTIVES

People with sickle cell disease (SCD) are at risk of cognitive dysfunction independent of stroke. Diminished functional connectivity in select large-scale networks and white matter integrity reflect the neurologic consequences of SCD. Because chronic transfusion therapy is neuroprotective in preventing stroke and strengthening executive function abilities in people with SCD, we hypothesized that red blood cell (RBC) transfusion facilitates the acute reversal of disruptions in functional connectivity while white matter integrity remains unaffected.

METHODS

Children with SCD receiving chronic transfusion therapy underwent a brain MRI measuring white matter integrity with diffusion tensor imaging and resting-state functional connectivity within 3 days before and after transfusion of RBCs. Cognitive assessments with the NIH Toolbox were acquired after transfusion and then immediately before the following transfusion cycle.

RESULTS

Sixteen children with a median age of 12.5 years were included. Global assessments of functional connectivity using homotopy (p = 0.234) or modularity (p = 0.796) did not differ with transfusion. Functional connectivity within the frontoparietal network significantly strengthened after transfusion (median intranetwork Z-score 0.21 [0.17-0.30] before transfusion, 0.29 [0.20-0.36] after transfusion, p < 0.001), while there was not a significant change seen within the sensory motor, visual, auditory, default mode, dorsal attention, or cingulo-opercular networks. Corresponding to the change within the frontoparietal network, there was a significant improvement in executive function abilities after transfusion (median executive function composite score 87.7 [81.3-90.7] before transfusion, 90.3 [84.3-93.7] after transfusion, p = 0.021). Participants with stronger connectivity in the frontoparietal network before transfusion had a significantly greater improvement in the executive function composite score with transfusion (r = 0.565, 95% CI 0.020-0.851, p = 0.044). While functional connectivity and executive abilities strengthened with transfusion, there was not a significant change in white matter integrity as assessed by fractional anisotropy and mean diffusivity within 16 white matter tracts or globally with tract-based spatial statistics.

DISCUSSION

Strengthening of functional connectivity with concomitant improvement in executive function abilities with transfusion suggests that functional connectivity MRI could be used as a biomarker for acutely reversible neurocognitive injury as novel therapeutics are developed for people with SCD.

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Quality of life, mood disorders, and cognitive impairment in adults with β-thalassemia

Advances in understanding the disease process in β-thalassemia supported development of various treatment strategies that resulted in improved survival. Improved survival, however, allowed multiple morbidities to manifest and cemented the need for frequent, lifelong treatment. This has directly impacted patients' health-related quality of life and opened the door for various psychiatric and cognitive disorders to potentially develop. In this review, we summarize available evidence on quality of life, depression and anxiety, suicidality, and cognitive impairment in adult patients with β-thalassemia while sharing our personal insights from experience in treating patients with both transfusion-dependent and non-transfusion-dependent forms.

Distribution of Silent Cerebral Infarcts in Adults With Sickle Cell Disease

BACKGROUND AND OBJECTIVES

Previously we demonstrated that 90% of infarcts in children with sickle cell anemia occur in the border zone regions of cerebral blood flow (CBF). We tested the hypothesis that adults with sickle cell disease (SCD) have silent cerebral infarcts (SCIs) in the border zone regions, with a secondary hypothesis that older age and traditional stroke risk factors would be associated with infarct occurrence in regions outside the border zones.

METHODS

Adults with SCD 18-50 years of age were enrolled in a cross-sectional study at 2 centers and completed a 3T brain MRI. Participants with a history of overt stroke were excluded. Infarct masks were manually delineated on T2-fluid-attenuated inversion-recovery MRI and registered to the Montreal Neurological Institute 152 brain atlas to generate an infarct heatmap. Border zone regions between anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA) were quantified using the Digital 3D Brain MRI Arterial Territories Atlas, and logistic regression was applied to identify relationships between infarct distribution, demographics, and stroke risk factors.

RESULTS

Of 113 participants with SCD (median age 26.1 years, interquartile range [IQR] 21.6-31.4 years, 51% male), 56 (49.6%) had SCIs. Participants had a median of 5.5 infarcts (IQR 3.2-13.8). Analysis of infarct distribution showed that 350 of 644 infarcts (54.3%) were in 4 border zones of CBF and 294 (45.6%) were in non-border zone territories. More than 90% of infarcts were in 3 regions: the non-border zone ACA and MCA territories and the ACA-MCA border zone. Logistic regression showed that older participants have an increased chance of infarcts in the MCA territory (odds ratio [OR] 1.08; 95% CI 1.03-1.13; p = 0.001) and a decreased chance of infarcts in the ACA-MCA border zone (OR 0.94; 95% CI 0.90-0.97; p < 0.001). The presence of at least 1 stroke risk factor did not predict SCI location in any model.

DISCUSSION

When compared with children with SCD, in adults with SCD, older age is associated with expanded zones of tissue infarction that stretch beyond the traditional border zones of CBF, with more than 45% of infarcts in non-border zone regions.

Neuroinflammation underlies the development of social stress induced cognitive deficit in sickle cell disease

Cognitive deficit is a debilitating complication of SCD with multifactorial pathobiology. Here we show that neuroinflammation and dysregulation in lipidomics and transcriptomics profiles are major underlying mechanisms of social stress-induced cognitive deficit in SCD. Townes sickle cell (SS) mice and controls (AA) were exposed to social stress using the repeat social defeat (RSD) paradigm concurrently with or without treatment with minocycline. Mice were tested for cognitive deficit using novel object recognition (NOR) and fear conditioning (FC) tests. SS mice exposed to RSD without treatment had worse performance on cognitive tests compared to SS mice exposed to RSD with treatment or to AA controls, irrespective of their RSD or treatment disposition. Additionally, compared to SS mice exposed to RSD with treatment, SS mice exposed to RSD without treatment had significantly more cellular evidence of neuroinflammation coupled with a significant shift in the differentiation of neural progenitor cells towards astrogliogenesis. Additionally, brain tissue from SS mice exposed to RSD was significantly enriched for genes associated with blood-brain barrier dysfunction, neuron excitotoxicity, inflammation, and significant dysregulation in sphingolipids important to neuronal cell processes. We demonstrate in this study that neuroinflammation and lipid dysregulation are potential underlying mechanisms of social stress-related cognitive deficit in SS mice.

Mouse models of sickle cell disease: Imperfect and yet very informative

The root cause of sickle cell disease (SCD) has been known for nearly a century, however, few therapies to treat the disease are available. Over several decades of work, with advances in gene editing technology and after several iterations of mice with differing genotype/phenotype relationships, researchers have developed humanized SCD mouse models. However, while a large body of preclinical studies has led to huge gains in basic science knowledge about SCD in mice, this knowledge has not led to the development of effective therapies to treat SCD-related complications in humans, thus leading to frustration with the paucity of translational progress in the SCD field. The use of mouse models to study human diseases is based on the genetic and phenotypic similarities between mouse and humans (face validity). The Berkeley and Townes SCD mice express only human globin chains and no mouse hemoglobin. With this genetic composition, these models present many phenotypic similarities, but also significant discrepancies that should be considered when interpreting preclinical studies results. Reviewing genetic and phenotypic similarities and discrepancies and examining studies that have translated to humans and those that have not, offer a better perspective of construct, face, and predictive validities of humanized SCD mouse models.

Psychiatric comorbidities in adults with sickle cell disease: A narrative review

Although descriptions of quality of life and patient reports of mood in sickle cell disease (SCD) have become more common in the literature, less is known about psychiatric illness prevalence, presentation, and treatment, particularly for adults. We provide a narrative review of what is known about common and debilitating psychiatric conditions such as depression, anxiety, and cognitive impairment, specifically for adults with SCD. We discuss the limitations of the current evidence, make provisional recommendations, and identify opportunities for research and improved care.

Screening for cognitive impairment in adults with sickle cell disease: A systematic review and meta-analysis

Neurovascular disease such as symptomatic stroke, silent brain infarcts and vascular cognitive impairment are common complications of sickle cell disease (SCD) that can have devastating consequences on quality of life, employment, and social functioning.  Early recognition of neurovascular disease is a prerequisite for the timely optimization of medical care and to connect patients to adaptive resources. While cognitive impairment has been well described in children, currently available data are limited in adults. As a result, guidance on the optimal cognitive screening strategies in adults is scarce. We conducted a systematic review to identify the different screening tools that have been evaluated in SCD. A meta-analysis was performed to estimate the prevalence of suspected cognitive impairment in this population. In this qualitative synthesis, we present 8 studies that evaluated 6 different screening tools. Patient characteristics that impacted on cognitive screening performance included age, education level, and a prior history of stroke. We report a pooled prevalence of 38% [14-62%] of suspected cognitive impairment. We discuss the relative benefits and limitations of the different screening tools to help clinicians select an adapted approach tailored to their specific patients' needs. Further studies are needed to establish and validate cognitive screening strategies in patients with diverse cultural and educational backgrounds.

Academic performance in Jamaican children with sickle cell disease

OBJECTIVE

Children with sickle cell disease (SCD) are at risk for neurocognitive deficits that can affect school performance, and psychosocial functioning. The aim of this study was to assess the academic performance of school-aged children with SCD in Jamaica compared to their school peers.

METHOD

A cross-sectional survey of academic performance was done in a group of children 11 to 13 years of age, using a standardized state administered examination, the Grade Six Achievement Test (GSAT), covering 5 subjects. Scores were obtained from the Ministry of Education (MOE) for eligible children with SCD, as well as mean scores with standard deviation for unaffected classmates by gender. Socio-demographic and clinical data were obtained from our sickle cell clinic database and an interview administered questionnaire.

RESULTS

Sixty-four children satisfied eligibility criteria. Children with SCD had lower percentage scores and significantly lower mean z-scores for 4 of 5 subjects (p < 0.05). Males had significantly lower mean z-scores compared with females. Thirty-seven children (57.8%) were classified as underperformers. Haemoglobin level was a significant predictor of subject score rank.

CONCLUSION

Children with SCD in Jamaica perform worse in standardized school examinations than their class peers with boys being particularly vulnerable.

"The Patient Should Have a Choice": Adults with Sickle Cell Disease Advise Integration of Telemedicine into the Comprehensive Sickle Cell Disease Care Model

BACKGROUND

Adults with sickle cell disease (SCD) constitute a unique and vulnerable patient population with complex healthcare needs including routine follow-up visits and acute care evaluations. The COVID-19 pandemic accelerated healthcare systems' transition to providing telemedicine care. The purpose of this qualitative study was to elicit the perspectives of adults with SCD about their experience with telemedicine during the COVID-19 pandemic and to understand their preferences with respect to future telemedicine care.

METHODS

Adults with SCD who had a telemedicine visit between March August 2020 and were cared for at our SCD center were eligible to participate in a one-time interview. Interviews were audio taped, transcribed, and analyzed using NVIVO software.

RESULTS

Among 30 interviewed subjects, 28 transcripts were available for analysis. Analysis identified that participants compared telemedicine to in-person care across several domains including (a) how time is used, (b) personal safety, (c) pain management, and (d) maintaining caring relationships. Participants agreed that telemedicine care was most appropriate for follow-up care and less useful for painful crises or urgent needs. They expressed concerns about the need to expand telemedicine to other specialities and to ensure that privacy and technical support are provided.

CONCLUSIONS

Telemedicine appeals to adults with SCD for maintenance SCD care. Decisions about in-person or telemedicine care need to be made in discussion with the patient with particular attention to pain management preferences. Ultimately, telemedicine is an option that adults with SCD would like to see continue and that has the potential to expand access to care to more geographically distant regions.

Brain Volumes and Cognition in Patients with Sickle Cell Anaemia: A Systematic Review and Meta-Analysis

Cognitive decline is a major problem in paediatric and adult patients with sickle cell anaemia (SCA) and affects the quality of life. Multiple studies investigating the association between quantitative and qualitative neuroimaging findings and cognition have had mixed results. Hence, the aetiology of cognitive decline in this population is not clearly understood. Several studies have established cerebral atrophy in SCA children as well as adults, but the relationship between cognition and brain volumes remains unclear. The purpose of this systematic review was therefore to evaluate the literature on regional brain volumes and their association with cognitive outcomes. We also meta-analysed studies which compared regional brain volumes between patients and controls. Studies report that patients with SCA tend to have lower grey matter volumes, including total subcortical volumes in childhood as compared to controls, which stabilise in young adulthood and may be subjected to decline with age in older adulthood. White matter volumes remain stable in children but are subjected to reduced volumes in young adulthood. Age and haemoglobin are better predictors of cognitive outcomes as compared to regional brain volumes.

Molecular and environmental contributors to neurological complications in sickle cell disease

Sickle cell disease (SCD) is an inherited hemoglobinopathy in which affected hemoglobin polymerizes under hypoxic conditions resulting in red cell distortion and chronic hemolytic anemia. SCD affects millions of people worldwide, primarily in Sub-Saharan Africa and the Indian subcontinent. Due to vaso-occlusion of sickled red cells within the microvasculature, SCD affects virtually every organ system and causes significant morbidity and early mortality. The neurological complications of SCD are particularly devastating and diverse, ranging from overt stroke to covert cerebral injury, including silent cerebral infarctions and blood vessel tortuosity. However, even individuals without evidence of neuroanatomical changes in brain imaging have evidence of cognitive deficits compared to matched healthy controls likely due to chronic cerebral hypoxemia and neuroinflammation. In this review, we first examined the biological contributors to SCD-related neurological complications and then discussed the equally important socioenvironmental contributors. We then discuss the evidence for neuroprotection from the two primary disease-modifying therapies, chronic monthly blood transfusions and hydroxyurea, and end with several experimental therapies designed to specifically target these complications.

Toward Automated Detection of Silent Cerebral Infarcts in Children and Young Adults With Sickle Cell Anemia

BACKGROUND

Silent cerebral infarcts (SCI) in sickle cell anemia (SCA) are associated with future strokes and cognitive impairment, warranting early diagnosis and treatment. Detection of SCI, however, is limited by their small size, especially when neuroradiologists are unavailable. We hypothesized that deep learning may permit automated SCI detection in children and young adults with SCA as a tool to identify the presence and extent of SCI in clinical and research settings.

METHODS

We utilized UNet-a deep learning model-for fully automated SCI segmentation. We trained and optimized UNet using brain magnetic resonance imaging from the SIT trial (Silent Infarct Transfusion). Neuroradiologists provided the ground truth for SCI diagnosis, while a vascular neurologist manually delineated SCI on fluid-attenuated inversion recovery and provided the ground truth for SCI segmentation. UNet was optimized for the highest spatial overlap between automatic and manual delineation (dice similarity coefficient). The optimized UNet was externally validated using an independent single-center prospective cohort of SCA participants. Model performance was evaluated through sensitivity and accuracy (%correct cases) for SCI diagnosis, dice similarity coefficient, intraclass correlation coefficient (metric of volumetric agreement), and Spearman correlation.

RESULTS

The SIT trial (n=926; 31% with SCI; median age, 8.9 years) and external validation (n=80; 50% with SCI; age, 11.5 years) cohorts had small median lesion volumes of 0.40 and 0.25 mL, respectively. Compared with the neuroradiology diagnosis, UNet predicted SCI presence with 100% sensitivity and 74% accuracy. In magnetic resonance imaging with SCI, UNet reached a moderate spatial agreement (dice similarity coefficient, 0.48) and high volumetric agreement (intraclass correlation coefficient, 0.76; ρ=0.72; P<0.001) between automatic and manual segmentations.

CONCLUSIONS

UNet, trained using a large pediatric SCA magnetic resonance imaging data set, sensitively detected small SCI in children and young adults with SCA. While additional training is needed, UNet may be integrated into the clinical workflow as a screening tool, aiding in SCI diagnosis.

Association of Cerebral Hemodynamics and Anemia on Processing Speed in Adults with Sickle Cell Disease

Background and Purpose

Compared to healthy controls, adult patients with Sickle Cell Disease (SCD) are anemic, and therefore have higher cardiac output and Cerebral Blood Flow (CBF) to maintain brain oxygenation. They also demonstrate comparatively more cognitive deficits due to either overt strokes or silent cerebral ischemia. However, there are few correlative studies between CBF and cognitive deficits, specifically processing speed in SCD. Such studies are important to develop biomarkers of central brain processing and ischemia for diagnosis, prognosis, and evaluating the effectiveness of potential interventions. This pilot cross-sectional study tested the hypotheses that adults with SCD and elevated CBF demonstrate lower central brain processing speed than controls on average and that CBF is inversely correlated with processing speed.

Methods

We conducted a pilot cross-sectional study to assess the relation-ships between CBF, central brain processing speed, and hemoglobin levels in asymptomatic adults with SCD and controls from an urban academic medical center. MRI acquisitions at 3T consisted of 2D phase-contrast quantitative arteriograms (Qflow) of the bilateral internal carotid and vertebral arteries and 3D pseudo-continuous arterial spin labeling (pCASL) of the brain. Participants were patients with SCD (hemoglobin [Hb]SS, [Hb] SBetaThal°, or [Hb]SC) aged 22-52 years of African American descent (N=7) or community controls (Hb AA) (n=3). Processing speed was assessed as an in-direct functional marker of ischemia using a recommended test from the NIH Toolbox for Assessment of Neurological and Behavioral Function, the Pattern Comparison Processing Speed Test. t-tests were used to compare means of CBF, hemoglobin, and cognition between SCD patients and healthy controls. Among SCD patients only multivariate correla-tions were used to evaluate relationships between brain perfusion in specific brain regions vs. processing speed and CBF. The significance level was set at p≤0.05.

Results

Adults with SCD reported higher CBF compared to healthy con-trols (72.15±28.90 vs. 47.23±12.30 ml/min/100g, p=0.04), and lower hemoglobin concentration (8.64±2.33 vs. 13.33±0.58, p=0.001). Heart rate in SCD patients was higher than in controls (86.29±1.37 vs. 74.00±2.10, p=0.04). Patients with SCD demonstrated lower processing speed (96.14±21.04 vs.123±13.74, p=0.02) than controls. Among adult patients with SCD, perfusion in specific regions of the brain showed an inverse relationship with processing speed, as did whole-brain CBF (p=0.0325).

Conclusion

These findings, although from a small sample, lend a degree of validity to the claim that processing speed is slower in people with SCD than in controls and that CBF is significantly higher in SCD patients com-pared to controls. The results also lend credence to the finding that the degree of processing speed deficiencies among adults with SCD is correlated with the degree of elevated CBF, which is known to correspond with the degree of anemia associated with SCD.

Examining Mental Health, Education, Employment, and Pain in Sickle Cell Disease

Importance

Pain related to sickle cell disease (SCD) is complex and associated with social determinants of health. Emotional and stress-related effects of SCD impact daily quality of life and the frequency and severity of pain.

Objective

To explore the association of educational attainment, employment status, and mental health with pain episode frequency and severity among individuals with SCD.

Design, Setting, and Participants

This is a cross-sectional analysis of patient registry data collected at baseline (2017-2018) from patients treated at 8 sites of the US Sickle Cell Disease Implementation Consortium. Data analysis was performed from September 2020 to March 2022.

Main Outcomes and Measures

Electronic medical record abstraction and a participant survey provided demographic data, mental health diagnosis, and Adult Sickle Cell Quality of Life Measurement Information System pain scores. Multivariable regression was used to examine the associations of education, employment, and mental health with the main outcomes (pain frequency and pain severity).

Results

The study enrolled a total of 2264 participants aged 15 to 45 years (mean [SD] age, 27.9 [7.9] years; 1272 female participants [56.2%]) with SCD. Nearly one-half of the participant sample reported taking daily pain medication (1057 participants [47.0%]) and/or hydroxyurea use (1091 participants [49.2%]), 627 participants (28.0%) received regular blood transfusion, 457 (20.0%) had a depression diagnosis confirmed by medical record abstraction, 1789 (79.8%) reported severe pain (rated most recent pain crises as ≥7 out of 10), and 1078 (47.8%) reported more than 4 pain episodes in the prior 12 months. The mean (SD) pain frequency and severity t scores for the sample were 48.6 (11.4) and 50.3 (10.1), respectively. Educational attainment and income were not associated with increased pain frequency or severity. Unemployment (β, 2.13; 95% CI, 0.99 to 3.23; P < .001) and female sex (β, 1.78; 95% CI, 0.80 to 2.76; P < .001) were associated with increased pain frequency. Age younger than 18 years was inversely associated with pain frequency (β, -5.72; 95% CI, -7.72 to -3.72; P < .001) and pain severity (β, 5.10; 95% CI, -6.70 to -3.51; P < .001). Depression was associated with increased pain frequency (β, 2.18; 95% CI, 1.04 to 3.31; P < .001) but not pain severity. Hydroxyurea use was associated with increased pain severity (β, 1.36; 95% CI, 0.47 to 2.24; P = .003), and daily use of pain medication was associated with both increased pain frequency (β, 6.29; 95% CI, 5.28 to 7.31; P < .001) and pain severity (β, 2.87; 95% CI, 1.95 to 3.80; P < .001).

Conclusions and Relevance

These findings suggest that employment status, sex, age, and depression are associated with pain frequency among patients with SCD. Depression screening for these patients is warranted, especially among those experiencing higher pain frequency and severity. Comprehensive treatment and pain reduction must consider the full experiences of patients with SCD, including impacts on mental health.

Cognitive-motor dual-task interference in adults with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a genetic disorder that causes physical and cognitive impairment due to hemolysis, painful vaso-occlusion episodes, joint avascular necrosis, and strokes. As individuals with SCD age and develop conditions impacting their physical and cognitive function, their ability to multitask successfully and safely may decline. Cognitive-motor dual-task interference occurs when there is deterioration in one or both tasks while dual-tasking relative to single-tasking. Dual-task assessment (DTA) is a valuable measure of physical and cognitive function; however, there is limited data on DTA in adults with SCD.

RESEARCH QUESTION

Is DTA a feasible and safe method of measuring physical and cognitive function in adults with SCD? What patterns of cognitive-motor interference occur in adults with SCD?

METHODS

We enrolled 40 adults with SCD (mean age 44 years, range 20-71) in a single-center prospective cohort study. We used usual gait speed as the measure of motor performance and verbal fluency (F, A, and S) as the measure of cognitive performance. We measured feasibility as the proportion of consented participants able to complete the DTA. We calculated the relative dual-task effect (DTE %) for each task and identified patterns of dual-task interference.

RESULTS

Most consented participants completed the DTA (91%, 40/44) and there were no adverse events. There were 3 main dual-task interference patterns for the first trial using letter 'A': Motor Interference (53%, n = 21), Mutual Interference (23%, n = 9), and Cognitive-Priority Tradeoff (15%, n = 6). For the second trial using letter 'S', there were two main dual-task interference patterns: Cognitive-Priority Tradeoff (53%, n = 21) and Motor Interference (25%, n = 10).

STATEMENT OF SIGNIFICANCE

DTA was feasible and safe in adults with SCD. We identified specific patterns of cognitive-motor interference. This study supports further evaluation of DTA as a potentially useful tool to measure physical and cognitive function in ambulatory adults with SCD.

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

INTRODUCTION

Sickle cell disease (SCD) is a chronic condition with progressive neurocognitive deficits. Health literacy (HL) is essential during adolescence and young adulthood, as the transition to adult care requires healthcare decisions. HL is known to be low in SCD; however, relation between general cognitive ability and HL has not been investigated.

METHODS

This cross-sectional study included adolescent and yound adults (AYAs) with SCD from two institutions. Logistic regression measured the association between HL, measured by the Newest Vital Sign tool, and general cognitive ability, measured with abbreviated full-scale intelligence quotient (FSIQ) on the Wechsler Abbreviated Scale of Intelligence.

RESULTS

Our cohort contained 93 participants at two sites: 47 (51%) at Memphis, TN and 46 (49%) at St. Louis, MO, ranging from ages 15-45 years (mean = 21 years) and with a majority (70%) possessing a high school education or greater. Only 40/93 participants (43%) had adequate HL. Lower abbreviated FSIQ (p < .0001) and younger age at assessment (p = .0003) were associated with inadequate HL. For every standard score point increase in abbreviated FSIQ, the odds of having adequate HL compared to limited or possibly limited HL increase by 1.142 (95% confidence interval [CI]: 1.019-1.322) and 1.116 (95% CI: 1.045-1.209), respectively, after adjusting for age, institution, income, and educational attainment.

CONCLUSIONS

Understanding and addressing HL is imperative in improving self-management and health outcomes. Among AYA with SCD, low HL was prevalent and influenced by abbreviated FSIQ. Routine screening for neurocognitive deficits and HL should be performed to guide development of interventions to adapt to the HL of AYA with SCD.

Early Strokes Are Associated with More Global Cognitive Deficits in Adults with Sickle Cell Disease

This study sought to link neurocognitive profiles in sickle cell disease (SCD) patients with clinical characteristics. We conducted a prospective cohort study of adults with SCD who underwent comprehensive neuropsychological assessment at the UMGGR clinic at Henri Mondor Hospital, Créteil (France). A cluster analysis was performed based on neuropsychological testing scores. The association between clusters and clinical profiles was assessed. Between 2017 and 2021, 79 patients with a mean age of 36 [range 19-65] years were included. On principal component analysis, a 5-factor model presented the best fit (Bartlett's sphericity test [χ2 (171) = 1345; p < 0.001]), explaining 72% of the variance. The factors represent distinct cognitive domains and anatomical regions. On hierarchical classification, three clusters emerged. Cluster 1 (n = 24) presented deficits in all five factors compared to Cluster 3 (n = 33). Cluster 2 (n = 22) had deficits in all factors, but to a lesser extent than Cluster 1. MoCA scores mirrored the severity of these cognitive deficits. Age, genotype and stroke prevalence did not differ significantly between clusters. However, the time of first stroke occurrence differed significantly between Cluster 1 and 2-3: 78% of strokes occurred during childhood, whereas 80% and 83% occurred during adulthood in Clusters 2 and 3, respectively. Educational attainment was also reduced in Cluster 1. SCD patients with childhood stroke seem to be at increased risk of a global cognitive deficit profile. In addition to existing methods of primary and secondary stroke prevention, early neurorehabilitation should be prioritized in order to reduce the long-term cognitive morbidity of SCD.

Effects of regional brain volumes on cognition in sickle cell anemia: A developmental perspective

Background and objectives

Cognitive difficulties in people with sickle cell anemia (SCA) are related to lower processing speed index (PSI) and working memory index (WMI). However, risk factors are poorly understood so preventative strategies have not been explored. Brain volumes, specifically white matter volumes (WMV) which increases through early adulthood, have been associated with better cognition in healthy typically developing individuals. In patients with SCA, the reduced WMV and total subcortical volumes noted could explain cognitive deficits. We therefore examined developmental trajectories for regional brain volumes and cognitive endpoints in patients with SCA.

Methods

Data from two cohorts, the Sleep and Asthma Cohort and Prevention of Morbidity in SCA, were available. MRI data included T1-weighted axial images, pre-processed before regional volumes were extracted using Free-surfer. PSI and WMI from the Weschler scales of intelligence were used to test neurocognitive performance. Hemoglobin, oxygen saturation, hydroxyurea treatment and socioeconomic status from education deciles were available.

Results

One hundred and twenty nine patients (66 male) and 50 controls (21 male) aged 8-64 years were included. Brain volumes did not significantly differ between patients and controls. Compared with controls, PSI and WMI were significantly lower in patients with SCA, predicted by increasing age and male sex, with lower hemoglobin in the model for PSI but no effect of hydroxyurea treatment. In male patients with SCA only, WMV, age and socioeconomic status predicted PSI, while total subcortical volumes predicted WMI. Age positively and significantly predicted WMV in the whole group (patients + controls). There was a trend for age to negatively predict PSI in the whole group. For total subcortical volume and WMI, age predicted decrease only in the patient group. Developmental trajectory analysis revealed that PSI only was significantly delayed in patients at 8 years of age; the rate of development for the cognitive and brain volume data did not differ significantly from controls.

Discussion

Increasing age and male sex negatively impact cognition in SCA, with processing speed, also predicted by hemoglobin, delayed by mid childhood. Associations with brain volumes were seen in males with SCA. Brain endpoints, calibrated against large control datasets, should be considered for randomized treatment trials.

Managing the Cerebrovascular Complications of Sickle Cell Disease: Current Perspectives

The importance of protecting brain function for people with sickle cell disease (SCD) cannot be overstated. SCD is associated with multiple cerebrovascular complications that threaten neurocognitive function and life. Without screening and preventive management, 11% of children at 24% of adults with SCD have ischemic or hemorrhagic strokes. Stroke screening in children with SCD is well-established using transcranial Doppler ultrasound (TCD). TCD velocities above 200 cm/s significantly increase the risk of stroke, which can be prevented using chronic red blood cell (RBC) transfusion. RBC transfusion is also the cornerstone of acute stroke management and secondary stroke prevention. Chronic transfusion requires long-term management of complications like iron overload. Hydroxyurea can replace chronic transfusions for primary stroke prevention in a select group of patients or in populations where chronic transfusions are not feasible. Silent cerebral infarction (SCI) is even more common than stroke, affecting 39% of children and more than 50% of adults with SCD; management of SCI is individualized and includes careful neurocognitive evaluation. Hematopoietic stem cell transplant prevents cerebrovascular complications, despite the short- and long-term risks. Newer disease-modifying agents like voxelotor and crizanlizumab, as well as gene therapy, may treat cerebrovascular complications, but these approaches are investigational.

Pediatric Sickle Cell Disease and Stroke: A Literature Review

Both ischemic and hemorrhagic strokes in children can be a complication of sickle cell disease, which also affects adults. The occurrence is high without any screening or preventative care. This review article found that although transcranial Doppler (TCD) has reduced the prevalence of stroke in pediatric patients, there is still a need for an epidemiological survey to define such screening for adults, the ideal dose of hydroxyurea to reduce the incidence of stroke, and to identify silent cerebral stroke to prevent its complications. Increased hydroxyurea prescription and specific antibiotic and vaccination regimes lowered the occurrence of this condition. In pediatric cases with a time-averaged mean of the maximal velocity greater than 200cm/s, transcranial Doppler screening and preventive chronic transfusion for at least the first year have lowered the occurrence of stroke by up to 10 times. The ideal dose of hydroxyurea is still debatable, but it seems to reduce the risk of the first stroke to a comparable level in the average population. Adult ischemic and hemorrhagic stroke prevention has not yet received the same attention. Though there are fewer studies, sickle cell disease is also more common than age-matched controls in terms of silent cerebral infarction on magnetic resonance imaging (MRI), as well as other neurological problems such as cognitive impairment, seizures, and headaches. Currently, there is no evidence-supported way to prevent ischemic stroke in adults at any age. Also, there is no defined ideal dose of hydroxyurea that can be helpful in preventing strokes. Data also lack a way to identify a silent cerebral infarction, so its complications can be prevented. An additional epidemiological survey may help in the prevention of the condition. The primary aim of this article was to emphasize the importance of information on clinical, neuropsychological, and quantitative MRI assessment of sickle cell patients to understand the epidemiology and etiology of stroke in sickle cell patients to prevent stroke and its related morbidity.

Should Magnetic Resonance Angiography Be Used for Screening of Intracranial Aneurysm in Adults with Sickle Cell Disease?

Magnetic resonance imaging (MRI) is used in patients with sickle cell disease (SCD) to detect silent cerebral infarcts. MR angiography (MRA) can identify arterial stenoses and intracranial aneurysms (ICANs) associated with SCD. In this study, we aimed to estimate the prevalence of ICANs in asymptomatic adult patients with SCD referred from the SCD clinic for routine screening by MRI/MRA using a 3T-MRI scanner. Findings were independently reviewed by two neuroradiologists. Between 2016 and 2020, 245 asymptomatic adults with SCD were stratified according to genotype (SS/S-β0thalassemia and SC/Sβ+). ICANs were found in 27 patients (11%; 0.95 CI: 8-16%). ICANs were more frequent in SS/S-β0thalassemia patients (20/118 or 17%; 0.95 CI: 11-25%) than in SC/βb+ patients (7/127 or 6%; 0.95 CI: 2-11%; p = 0.007). Individuals with SCD (particularly SS/S-β0thalassemia) have a higher prevalence of ICANs than the general population. We believe that MRA should be considered in the current American Society of Hematology guidelines, which already contain a recommendation for MRI at least once in adult SCD patients. However, the clinical significance of preventive treatment of unruptured aneurysms remains controversial.

Adhesion molecules and cerebral microvascular hemodynamic abnormalities in sickle cell disease

Cerebrovascular abnormalities are a common feature of sickle cell disease that may be associated with risk of vaso-occlusive pain crises, microinfarcts, and cognitive impairment. An activated endothelium and adhesion factors, VCAM-1 and P-selectin, are implicated in sickle cell vasculopathy, including abnormal hemodynamics and leukocyte adherence. This study examined the association between cerebral expression of these adhesion factors and cortical microvascular blood flow dynamics by using in-vivo two-photon microscopy. We also examined the impact of blood transfusion treatment on these markers of vasculopathy. Results showed that sickle cell mice had significantly higher maximum red blood cell (RBC) velocity (6.80 ± 0.25 mm/sec, p ≤ 0.01 vs. 5.35 ± 0.35 mm/sec) and more frequent blood flow reversals (18.04 ± 0.95 /min, p ≤ 0.01 vs. 13.59 ± 1.40 /min) in the cortical microvasculature compared to controls. In addition, sickle cell mice had a 2.6-fold (RFU/mm2) increase in expression of VCAM-1 and 17-fold (RFU/mm2) increase in expression of P-selectin compared to controls. This was accompanied by an increased frequency in leukocyte adherence (4.83 ± 0.57 /100 μm/min vs. 2.26 ± 0.37 /100 μm/min, p ≤ 0.001). We also found that microinfarcts identified in sickle cell mice were 50% larger than in controls. After blood transfusion, many of these parameters improved, as results demonstrated that sickle cell mice had a lower post-transfusion maximum RBC velocity (8.30 ± 0.98 mm/sec vs. 11.29 ± 0.95 mm/sec), lower frequency of blood flow reversals (12.80 ± 2.76 /min vs. 27.75 ± 2.09 /min), and fewer instances of leukocyte adherence compared to their pre-transfusion imaging time point (1.35 ± 0.32 /100 μm/min vs. 3.46 ± 0.58 /100 μm/min). Additionally, we found that blood transfusion was associated with lower expression of adhesion factors. Our results suggest that blood transfusion and adhesion factors, VCAM-1 and P-selectin, are potential therapeutic targets for addressing cerebrovascular pathology, such as vaso-occlusion, in sickle cell disease.

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.

Quantitative susceptibility mapping (QSM) and R2* of silent cerebral infarcts in sickle cell anemia

Silent cerebral infarction (SCI) is the most commonly reported radiological abnormality in patients with sickle cell anemia (SCA) and is associated with future clinical stroke risk. To date, there have been few histological and quantitative MRI studies of SCI and multiple radiological definitions exist. As a result, the tissue characteristics and composition of SCI remain elusive. The objective of this work was therefore to investigate the composition of segmented SCI lesions using quantitative MRI for R2 * and quantitative magnetic susceptibility mapping (QSM). 211 SCI lesions were segmented from 32 participants with SCA and 6 controls. SCI were segmented according to two definitions (FLAIR+/-T1w-based threshold) using a semi-automated pipeline. Magnetic susceptibility (χ) and R2 * maps were calculated from a multi-echo gradient echo sequence and mean SCI values were compared to an equivalent region of interest in normal appearing white matter (NAWM). SCI χ and R2 * were investigated as a function of SCI definition, patient demographics, anatomical location, and cognition. Compared to NAWM, SCI were significantly less diamagnetic (χ = -0.0067 ppm vs. -0.0153 ppm, p < 0.001) and had significantly lower R2 * (16.7 s-1 vs. 19.2 s-1, p < 0.001). SCI definition had a significant effect on the mean SCI χ and R2 * , with lesions becoming significantly less diamagnetic and having significantly lower R2 * after the application of a more stringent T1w-based threshold. SCI-NAWM R2 * decrease was significantly greater in patients with SCA compared with controls (-2.84 s-1 vs. -0.64 s-1, p < 0.0001). No significant association was observed between mean SCI-NAWM χ or R2* differences and subject age, lesion anatomical location, or cognition. The increased χ and decreased R2 * in SCI relative to NAWM observed in both patients and controls is indicative of lower myelin or increased water content within the segmented lesions. The significant SCI-NAWM R2 * differences observed between SCI in patients with SCA and controls suggests there may be differences in tissue composition relative to NAWM in SCI in the two populations. Quantitative MRI techniques such as QSM and R2 * mapping can be used to enhance our understanding of the pathophysiology and composition of SCI in patients with SCA as well as controls.

Validation of the NIH Toolbox-Cognition Battery against legacy neurocognitive measures in adults with cognitive impairments: An exploratory analysis

OBJECTIVE

The purpose of this exploratory study was to describe associations between NIH Toolbox-Cognition Battery subtests and legacy measures of neurocognitive function in two samples with neurological conditions (stroke and sickle cell disease (SCD)).

METHOD

This exploratory secondary analysis uses data from two studies that assessed cognition at one time point using the NIH Toolbox-Cognition Battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and subtests from the Delis-Kaplan Executive Functions System (DKEFS). People with stroke (n = 26) and SCD (n = 64) were included. Associations between the NIH Toolbox-Cognition Battery subtests and corresponding legacy measures were examined using linear correlations, Bland-Altman analysis, and Lin's Concordance Correlation Coefficient.

RESULTS

Linear correlations and Lin's Concordance Correlation Coefficient were poor to strong in both samples on NIH Toolbox-CB subtests: Flanker Inhibitory Control and Attention (r = .35 to .48, Lin CCC = .27 to .37), Pattern Comparison Processing Speed (r = .40 to .65, Lin CCC = .37 to .62), Picture Sequence Memory (r = .19 to .55, Lin CCC = .18 to .48), Dimensional Change Card Sort (r = .39 to .77, Lin CCC = .38 to .63), Fluid Cognition Composite (r = .88 to .90, Lin CCC = .60 to .79), and Total Cognition Composite (r = .64 to .83, Lin CCC = .60 to .78). Bland-Altman analyses demonstrated wide limits of agreement across all subtests (-3.17 to 3.78).

CONCLUSIONS

The NIH Toolbox-Cognition Battery subtests may behave similarly to legacy measures as an overall assessment of cognition across samples at risk for neurological impairment. Findings should be replicated across additional clinical samples.

An evaluation of patient-reported outcomes in sickle cell disease within a conceptual model

PURPOSE

To examine the relations between patient-reported outcomes (PROs) within a conceptual model for adults with sickle cell disease (SCD) ages 18 - 45 years enrolled in the multi-site Sickle Cell Disease Implementation Consortium (SCDIC) registry. We hypothesized that patient and SCD-related factors, particularly pain, and barriers to care would independently contribute to functioning as measured using PRO domains.

METHODS

Participants (N = 2054) completed a 48-item survey including socio-demographics and PRO measures, e.g., social functioning, pain impact, emotional distress, and cognitive functioning. Participants reported on lifetime SCD complications, pain episode frequency and severity, and barriers to healthcare.

RESULTS

Higher pain frequency was associated with higher odds of worse outcomes in all PRO domains, controlling for age, gender and site (OR range 1.02-1.10, 95% CI range [1.004-1.12]). Reported history of treatment for depression was associated with 5 of 7 PRO measures (OR range 1.58-3.28 95% CI range [1.18-4.32]). Fewer individual barriers to care and fewer SCD complications were associated with better outcomes in the emotion domain (OR range 0.46-0.64, 95% CI range [0.34-0.86]).

CONCLUSIONS

Study results highlight the importance of the biopsychosocial model to enhance understanding of the needs of this complex population, and to design multi-dimensional approaches for providing more effective interventions to improve outcomes.

A case-control and seven-year longitudinal neurocognitive study of adults with sickle cell disease in Ghana

Ageing in sickle cell disease (SCD) is associated with a myriad of end-organ complications, including cerebrovascular damage and cognitive impairment (CI). Although CI is very common in SCD, little is known about cognitive functioning and how it changes with age. This study examines cognitive patterns of 63 adults with SCD and 60 non-SCD, age- and education-matched controls in Ghana. Of those adults with SCD, 34 completed the neuropsychological battery at baseline and again seven years later. In cross-sectional data, adults with SCD performed worse than controls in all cognitive test domains (p < 0.01 for all). The seven-year follow-up data showed that the group exhibited a significant decline in visuospatial abilities (ranging from Cohen's d = 1.40 to 2.38), and to a lesser extent, in processing speed and executive functioning. Exploratory analyses showed a significant time-by-education interaction, indicating that education may be protective from decline in cognitive performance. These findings have implications for clinical practice. Early neuropsychological surveillance coupled with early assessment and remedial programmes will provide avenues for enhancing the quality of life of adults living with SCD in Ghana.

Overview of therapeutic targets in management of dementia

Dementia is defined as a gradual cognitive impairment that interferes with everyday tasks, and is a leading cause of dependency, disability, and mortality. According to the current scenario, millions of individuals worldwide have dementia. This review provides with an overview of dementia before moving on to its subtypes (neurodegenerative and non-neurodegenerative) and pathophysiology. It also discusses the incidence and severity of dementia, focusing on Alzheimer's disease with its different hypotheses such as Aβ cascade hypothesis, Tau hypothesis, inflammatory hypothesis, cholinergic and oxidative stress hypothesis. Alzheimer's disease is the most common type and a progressive neurodegenerative illness distinct by neuronal loss and resulting cognitive impairment, leading to dementia. Alzheimer's disease (AD) is considered the most familiar neurodegenerative dementias that affect mostly older population. There are still no disease-modifying therapies available for any dementias at this time, but there are various methods for lowering the risk to dementia patients by using suitable diagnostic and evaluation methods. Thereafter, the management and treatment of primary risk elements of dementia are reviewed. Finally, the future perspectives of dementia (AD) focusing on the impact of the new treatment are discussed.

RANK/RANKL/OPG axis genes relation to cognitive impairment in children with transfusion-dependent thalassemia: a cross-sectional study

Background

RANK/RANKL/OPG axis was implicated in many pathological conditions. The study aimed to assess the relationship between the studied RANK, RANKL, and OPG polymorphisms and alleles and cognitive impairment in children with transfusion-dependent thalassemia (TDT).

Methods

This study included 60 TDT children. Real-time PCR was done for: rs1805034, rs1245811, and rs75404003 polymorphisms for the RANK gene, rs9594782 and rs2277438 polymorphisms for the RANKL gene, and rs207318 polymorphism for the OPG gene. The intelligence quotient (IQ) was assessed using the Wechsler Intelligence Scale for Children-Third Edition.

Results

TDT children had a low average total IQ, verbal IQ, and borderline performance IQ. RANK rs1805034 (C > T) had a significant effect on total IQ (p = 0.03). Its TT polymorphism and the CT polymorphism of RANKL rs9494782 (C > T) had a significantly lower total IQ (p = 0.01 for both). The G allele of the RANKL rs2277438 (G > A) had a significantly lower total IQ (p = 0.02). RANK rs1805034 (C > T) and RANKL rs2277438 (G > A) significantly affected verbal IQ (p = 0.01 and 0.03). TT genotype of RANK rs1805034 (C > T) had significantly lower verbal IQ (p = 0.002). Furthermore, the GG genotype of RANKL rs2277438 (G > A) had a significantly lower verbal and performance IQ than the AA genotype (p = 0.04 and 0.01 respectively), and its G allele had a significantly lower performance IQ than the A allele (p = 0.02).

Conclusion

TDT children had low average total and verbal IQ while their performance IQ was borderline. The RANK/RANKL/OPG pathway affects cognition in TDT children, as some of the studied genes’ polymorphisms and alleles had significant effects on total, verbal, and performance IQ of the studied TDT children.

Quantification of Silent Cerebral Infarction on High-Resolution FLAIR and Cognition in Sickle Cell Anemia

Research in sickle cell anemia (SCA) has used, with limited race-matched control data, binary categorization of patients according to the presence or absence of silent cerebral infarction (SCI). SCI have primarily been identified using low-resolution MRI, with radiological definitions varying in lesion length and the requirement for abnormality on both fluid attenuated inversion recovery (FLAIR) and T1-weighted images. We aimed to assess the effect of published SCI definitions on global, regional, and lobar lesion metrics and their value in predicting cognition. One hundred and six patients with SCA and 48 controls aged 8-30 years underwent 3T MRI with a high-resolution FLAIR sequence and Wechsler cognitive assessment. Prevalence, number, and volume of lesions were calculated using a semi-automated pipeline for SCI defined as: (1) Liberal: any length (L-SCI); (2) Traditional: >3 mm in greatest dimension (T-SCI); (3) Restrictive; >3 mm in greatest dimension with a corresponding T1-weighted hypo-intensity (R-SCI). Globally, as hypothesized, there were large effects of SCI definition on lesion metrics in patients and controls, with prevalence varying from 24-42% in patients, and 4-23% in controls. However, contrary to hypotheses, there was no effect of any global metric on cognition. Regionally, there was a consistent distribution of SCI in frontal and parietal deep and juxta-cortical regions across definitions and metrics in patients, but no consistent distribution in controls. Effects of regional SCI metrics on cognitive performance were of small magnitude; some were paradoxical. These findings expose the challenges associated with the widespread use of SCI presence as a biomarker of white-matter injury and cognitive dysfunction in cross-sectional high-resolution MRI studies in patients with SCA. The findings indicate that with high-resolution MRI: (1) radiological definitions have a large effect on resulting lesion groups, numbers, and volumes; (2) there is a non-negligible prevalence of lesions in young healthy controls; and (3) at the group-level, there is no cross-sectional association between global lesion metrics and general cognitive impairment irrespective of lesion definition and metric. With high-resolution multi-modal MRI, the dichotomy of presence or absence of SCI does not appear to be a sensitive biomarker for the detection of functionally significant pathology; the search for appropriate endpoints for clinical treatment trials should continue.

Neurocognitive Changes in Sickle Cell Disease: A Comprehensive Review

Background:

Sickle cell disease (SCD) is a type of hemoglobinopathy characterized by abnormal hemoglobin molecules, which includes numerous acute and chronic complications. Ischemic stroke, silent cerebral infarction, headache, and neurocognitive impairment are the most common neurological complications associated with SCD.

Summary:

Acute anemia because of SCD can cause cognitive impairments because of cerebral hypoxia. Cognitive abnormalities in SCD manifest in various aspects such as working memory, verbal learning, executive functions, and attention. These neurocognitive impairments have been associated with poor functional results, such as transitioning from juvenile to adult care, adherence to medications, and unemployment.

Key message:

In this review, we focus on neurocognitive aspects of SCD patients based on different imaging techniques, psychological batteries, associated neuromarkers, and interventions for managing of cognitive deficiencies..

The Montreal cognitive assessment as a cognitive screening tool in sickle cell disease: Associations with clinically significant cognitive domains

Adults with sickle cell disease (SCD) are at risk for cognitive impairment, which causes significant morbidity. Guidelines support routine cognitive screening, but no screening test is validated in this population. We explored the Montreal Cognitive Assessment (MoCA) as a possible screening test in SCD. We administered the MoCA; a literacy test, the Wide Range Achievement Test, fourth edition (WRAT-4); and a health literacy test, the Shortened Test of Functional Health Literacy in Adults (S-TOFHLA) to adults with SCD and gathered clinical variables through chart review. Spearman's rho, Mann-Whitney, and Kruskal-Wallis tests and quantile regression models were used. Among our sample of 49 adults with SCD, the median MoCA score was 25.0 [interquartile range (IQR) 22.0-28.0]. Higher educational attainment was associated with MoCA scores (p = 0.001). In multivariable models, MoCA scores were associated with S-TOFHLA (p = 0.001) and WRAT-4 Reading (p = 0.002) scores, and overt stroke (p = 0.03) at the median. This pilot study adds to the limited literature of cognitive screening tests in adults with SCD and demonstrates a relationship between MoCA scores and measures of literacy and health literacy. The MoCA is a promising option for briefly screening for cognitive impairment in adults with SCD, though further study is needed to confirm its validity.

Adaptive Functioning in Children and Adolescents With Sickle Cell Disease

OBJECTIVE

Risk for neurocognitive deficits in sickle cell disease (SCD) is well established, yet minimal research has evaluated the risk for deficits in adaptive functioning. We assessed adaptive functioning in pediatric patients with SCD to test the hypothesis that disease, treatment, and demographic factors were associated with adaptive outcomes.

METHODS

Two hundred fifty-six patients (57% HbSS/HbSß0-thalassemia and 43% HbSC/HbSß+-thalassemia), ages 8-18, received routine neuropsychological assessments as part of a larger prospective lifetime cohort study. Adaptive functioning was measured using the Behavior Assessment System for Children, Second or Third Edition. Adaptive scores were compared with normative values using t-test or Wilcoxon signed rank test and linear regression models were used to measure associations between adaptive functioning and age, hydroxyurea (HU) use, sickle genotype, and socioeconomic status. Furthermore, we examined the influence of intellectual and executive functioning on adaptive behavior using hierarchical linear regression analyses.

RESULTS

Parent ratings of adaptive functioning skills did not differ from normative expectations (all false discovery rate [FDR] adjusted p-value [pFDR] > 0.05). Social vulnerability was negatively associated with adaptive scores on most adaptive scales in both genotypes (pFDR < 0.05). HU treatment was not significantly associated with any adaptive scale. Overall IQ was positively associated with Functional Communication and Leadership only for those with HbSS/HbSß0-thalassemia. Higher parent ratings of executive difficulties were correlated with lower adaptive scores (estimate = -0.64, standard error = 0.051, p < .001).

CONCLUSIONS

Poorer parent-rated adaptive skills were associated with increased social vulnerability, lower Full-Scale IQ, and parent-rated executive difficulties. Most adaptive scores were in the normal range; however, parent ratings may not fully capture the impact of disease complications and neurocognitive deficits on daily functioning.

The Sickle Cell Disease Functional Assessment (SCD-FA) tool: a feasibility pilot study

Background

The life expectancy for individuals with sickle cell disease (SCD) has greatly increased over the last 50 years. Adults with SCD experience multiple complications such as cardiopulmonary disease, strokes, and avascular necrosis that lead to limitations that geriatric populations often experience. There are no dedicated instruments to measure functional decline and functional age to determine risk of future adverse outcomes in older adults with SCD. The objective of this study was to assess the feasibility of performing the Sickle Cell Disease Functional Assessment (SCD-FA).

Methods

We enrolled 40 adults with SCD (20 younger adults aged 18–49 years as a comparison group and 20 older adults aged 50 years and older) in a single-center prospective cohort study. Participants were recruited from a comprehensive sickle cell clinic in an academic center in the southeastern United States. We included measures validated in an oncology geriatric assessment enriched with additional physical performance measures: usual gait speed, seated grip strength, Timed Up and Go, six-minute walk test, and 30-second chair stand. We also included an additional cognitive measure, which was the Montreal Cognitive Assessment, and additional patient-reported measures at the intersection of sickle cell disease and geriatrics. The primary outcome was the proportion completing the assessment. Secondary outcomes were the proportion consenting, duration of the assessment, acceptability, and adverse events.

Results

Eighty percent (44/55) of individuals approached consented, 91% (40/44) completed the SCD-FA in its entirety, and the median duration was 89 min (IQR 80–98). There were no identified adverse events. On the acceptability survey, 95% (38/40) reported the length as appropriate, 2.5% (1/40) reported a question as upsetting, and 5% (2/40) reported portions as difficult. Exploratory analyses of physical function showed 63% (25/40) had a slow usual gait speed (< 1.2 m/s).

Conclusion

The SCD-FA is feasible, acceptable, and safe and physical performance tests identified functional impairments in adults with SCD. These findings will inform the next phase of the study where we will assess the validity of the SCD-FA to predict patient-important outcomes in a larger sample of adults with SCD.

Cognitive Impairment in Primary and Secondary Headache Disorders

Purpose of Review

To critically evaluate the recent literature on cognitive impairment and headache.

Recent Findings

Neurocognitive symptoms are prevalent, debilitating, and occur often with both primary and secondary headache disorders.

Summary

This is a “narrative review of the current literature in PubMed on cognitive function and headache.” Migraine is associated with cognitive impairment years before a migraine diagnosis. In young and middle-aged adults, migraine is associated with deficits in attention, executive function, processing speed, and memory. It is unlikely that migraine is associated with dementia. Although methodologically difficult to assess, there does not seem to be an association between tension-type headache and cognitive dysfunction. In early to midlife, cluster headache seems to be associated with executive dysfunction. Several secondary headache syndromes relevant to clinicians managing headache disorders are associated with poorer cognitive performance or distinctive cognitive patterns, including those attributed to chronic cerebral or systemic vascular disorders, trauma, and derangements of intracranial pressure and volume, including frontotemporal brain sagging syndrome.

Advances in the diagnosis and treatment of sickle cell disease

Sickle cell disease (SCD), which affects approximately 100,000 individuals in the USA and more than 3 million worldwide, is caused by mutations in the βb globin gene that result in sickle hemoglobin production. Sickle hemoglobin polymerization leads to red blood cell sickling, chronic hemolysis and vaso-occlusion. Acute and chronic pain as well as end-organ damage occur throughout the lifespan of individuals living with SCD resulting in significant disease morbidity and a median life expectancy of 43 years in the USA. In this review, we discuss advances in the diagnosis and management of four major complications: acute and chronic pain, cardiopulmonary disease, central nervous system disease and kidney disease. We also discuss advances in disease-modifying and curative therapeutic options for SCD. The recent availability of L-glutamine, crizanlizumab and voxelotor provides an alternative or supplement to hydroxyurea, which remains the mainstay for disease-modifying therapy. Five-year event-free and overall survival rates remain high for individuals with SCD undergoing allogeneic hematopoietic stem cell transplant using matched sibling donors. However, newer approaches to graft-versus-host (GVHD) prophylaxis and the incorporation of post-transplant cyclophosphamide have improved engraftment rates, reduced GVHD and have allowed for alternative donors for individuals without an HLA-matched sibling. Despite progress in the field, additional longitudinal studies, clinical trials as well as dissemination and implementation studies are needed to optimize outcomes in SCD.

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.

The Epidemiology of Neurological Complications in Adults With Sickle Cell Disease: A Retrospective Cohort Study

Introduction: Risk factors for neurological complications in sickle cell disease differ in the adult and pediatric populations. Here, we focused on neurological complications in adults with sickle cell disease.

Methods: Patients were selected using the audit data from the St George's Hospital Red Cell Database. The genotyping, demographics, clinical data, and investigation findings were collected.

Results: A total of 303 patients were enrolled in the study: hemoglobin S homozygosity (HbSS) genotype 56%, hemoglobin S and C coinheritance (HbSC) genotype 35%, and hemoglobin S and β-thalassemia coinheritance (HbSβ) thalassemia genotype 9%; the mean age was 38.8 years (±13.5 SD) with 46% males. The most common neurological complication was cerebrovascular disease (n = 37, 12%) including those with ischemic stroke (10%), cerebral vasculopathy (3%), and intracranial hemorrhage (1%). Ischemic stroke was common among the HbSS genotype compared with other genotypes (8 vs. 1.6%, p = 0.001). Comparing the patients with sickle cell disease who had suffered a stroke to those who had not, there was a higher proportion of intracranial vasculopathy (p = 0.001, in particular, Moyamoya) and cognitive dysfunction (p < 0.0001).

Conclusion: Our cohort supports previous reports that the most common neurological complication in adult sickle cell patients is cerebrovascular disease. Strategies to prevent cerebral vasculopathy and cognitive impairment should be explored.

Acceptable, hopeful, and useful: development and mixed-method evaluation of an educational tool about reproductive options for people with sickle cell disease or trait

PURPOSE

People with sickle cell disease (SCD) or trait have many reproductive options, some of which decrease the chance of passing SCD to children, including in vitro fertilization with preimplantation genetic testing (IVF + PGT). Few are aware of these options, and educational materials are needed. This study aimed to develop an accessible, non-directive patient education material about reproductive options for those with SCD or trait via a process that incorporated stakeholders from the SCD community.

METHODS

Multidisciplinary stakeholders guided development and revision of a novel pamphlet. Researchers applied health literacy scales to measure pamphlet understandability. We interviewed nine patients with SCD and six multidisciplinary clinicians to evaluate the pamphlet. Interviews were recorded, transcribed, and coded by a five-member team who developed a codebook and proposed themes that were revised by all research team members. Feedback was incorporated into a revised pamphlet.

RESULTS

A two-page pamphlet describing reproductive options for people with SCD including IVF + PGT was acceptable to key stakeholders, including people with SCD. Material about this complex topic met health literacy standards, including being written at a 5th grade level. Patients reported feeling hopeful after reviewing the pamphlet, and participants considered the pamphlet useful, clear, and appropriate for distribution in clinics and online.

CONCLUSIONS

Though awareness of reproductive options for those with SCD or trait is low, patients and providers find a novel pamphlet about this topic acceptable and useful. Educational materials about complex topics including IVF + PGT can be written at a level understandable to the average American.

Evidence-Based Minireview: In young children with severe sickle cell disease, do the benefits of HLA-identical sibling donor HCT outweigh the risks?

In case 1, a 14-month-old male child with sickle cell disease (SCD) was referred for evaluation for an allogeneic hematopoietic stem cell transplant (HCT). The patient had a history of dactylitis 3 times in his first year of life and febrile episodes twice at the consult. His 4-year-old sister was found to be human leukocyte antigen (HLA) identical. The patient was started on hydroxyurea (HU) at 2.5 years of age. His parents again sought consultation when he was 5 years old because of concerns about his medical condition. At the time, the patient had experienced 2 vaso-occlusive pain episodes (VOEs) requiring hospitalization during the previous 2 years. He had also experienced intermittent pain crises requiring rest at home for 2 to 3 days. The child has not attended school in person due to the COVID-19 pandemic. The family is considering HCT but is ambivalent about it because of potential toxicity. In case 2, an 8-year-old female child is 3 years out from HCT for SCD from her HLA-identical sibling. Before HCT, despite receiving HU, she had experienced >5 VOEs requiring hospitalization and 2 episodes of acute chest syndromes in the previous 3 years. She had also been missing almost 50 days of school days each year. After HCT, she is now attending school regularly and participating in all normal age-appropriate activities. The parents believe that HCT has been transformative in their child's life.

Cognitive Function in Adults with Beta-Thalassemia Major in Oman: A Pilot Study

Objectives

Neurocognitive dysfunction has been established in several studies in children with beta-thalassemia major (TM). However, despite its wide occurrence in populations across the Arabian Peninsula, scant attention has been paid to shedding light on neuropsychological functioning among adults with TM. This study aimed to examine the level of neuropsychological functioning among Omani adults with TM regularly followed-up at a tertiary care hospital in Oman. A related aim was to examine the factors associated with neuropsychological performance.

Methods

Standard neuropsychological tests were used to measure attention and concentration, learning and remembering, verbal fluency, and executive functioning. Participants were also gauged on indices of intellectual ability and affective range. As normative data for neuropsychological functioning in Oman is scarce, healthy age- and sex-matched controls underwent the same testing procedure. The log-linear model was used to identify factors associated with TM patients on demographic and neuropsychological performance.

Results

This study recruited 28 adult patients with TM (age 30.0±6.5) and 39 healthy controls (age 29.2±6.1). Findings suggested that having a diagnosis of TM was significantly associated with symptoms of depression (p < 0.001) and anxiety (p < 0.001), indices of executive functioning (verbal fluency) (p =0.003), working memory (digit span) (p < 0.001), and verbal and auditory attention scores (California Verbal Learning, p = 0.002).

Conclusions

The data appears to suggest that short-term memory capacity, verbal fluency, and verbal and auditory attention may be impaired in TM compared to controls. Studies on a larger cohort are therefore warranted.

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

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

Hematopoietic stem cell transplantation reverses white matter injury measured by diffusion-tensor imaging (DTI) in sickle cell disease patients

Brain injury in sickle cell disease (SCD) comprises a wide spectrum of neurological damage. Neurocognitive deficits have been described even without established neurological lesions. DTI is a rapid, noninvasive, and non-contrast method that enables detection of normal-appearing white matter lesions not detected by conventional magnetic resonance imaging (MRI). The aim of the study was to evaluate if stem cell transplantation can revert white matter lesions in patients with SCD. Twenty-eight SCD patients were evaluated with MRI and DTI before and after allogeneic hematopoietic stem cell transplantation (HSCT), compared with 26 healthy controls (HC). DTI metrics included fractional anisotropy (FA), mean diffusivity (MD), radial (RD), and axial (AD) diffusivity maps, global efficiency, path length, and clustering coefficients. Compared to HC, SCD patients had a lower FA (p = 0.0086) before HSCT. After HSCT, FA increased and was not different from healthy controls (p = 0.1769). Mean MD, RD, and AD decreased after HSCT (p = 0.0049; p = 0.0029; p = 0.0408, respectively). We confirm previous data of white matter lesions in SCD and present evidence that HSCT promotes recovery of brain injury with potential improvement of brain structural connectivity.