Stroke and stroke prevention in sickle cell anemia in developed and selected developing countries

Clinical Insights into Sickle Cell Disease: A Comprehensive Multicenter Retrospective Analysis of Clinical Characteristics and Outcomes Across Different Age Groups

Background: Sickle cell disease (SCD) is a genetic hematological disorder associated with significant mortality and a range of complex complications that manifest differently across various age groups. Methods: This study aimed to evaluate the demographic, clinical, and laboratory characteristics of SCD patients in Taif City, Saudi Arabia, with a focus on variations among children, adolescents, adults, and middle-aged individuals. A multicenter retrospective cohort study included 129 patients with confirmed diagnosis of SCD between January 2018 to October 2023 and divided into 4 cohorts. The analysis compared hospital stay durations, admission rates, SCD complications, and medication usage. Results: Among the participants, 35 were children (27%), 18 adolescents (14%), 63 adults (49%), and 13 middle-aged individuals (10%). Clinical complications as splenic disease in children (34.3%) were more frequent compared to adolescents (5.6%) and adults (4.8%). Additionally, chronic kidney disease was more prevalent in middle-aged patients (15.4%). Pain was reported in 65.1% of patients, with vascular occlusive crises occurring in 41.1%. Treatment adherence varied, with children showing higher penicillin use (74.3%), while opioid usage was greater in middle-aged patients (76.9%). Conclusions: The findings underscore the necessity for age-specific management strategies in SCD. Further research with larger populations is suggested to enhance the understanding of disease progression and treatment efficacy across different age groups.

Stroke Prevention and Treatment for Youth with Sickle Cell Anemia: Current Practice and Challenges and Promises for the Future

PURPOSE OF REVIEW

Sickle cell anemia (SCA) is an autosomal recessive inherited hemoglobinopathy that results in a high risk of stroke. SCA primarily affects an underserved minority population of children who are frequently not receiving effective, multi-disciplinary, preventative care. This article reviews primary and secondary stroke prevention and treatment for children with SCA for the general adult and pediatric neurologist, who may play an important role in providing critical neurologic evaluation and care to these children.

RECENT FINDINGS

Primary stroke prevention is efficacious at reducing ischemic stroke risk, but it is not consistently implemented into clinical practice in the United States, resulting in these children remaining at high risk. Acute symptomatic stroke management requires neurology involvement and emergent transfusion to limit ischemia. Furthermore, while chronic transfusion therapy is a proven secondary preventative modality for those with prior symptomatic or silent cerebral infarcts, it carries significant burden. Newer therapies (e.g., stem cell therapies and voxelotor) deserve further study as they may hold promise in reducing stroke risk and treatment burden. Effective primary and secondary stroke prevention and treatment remain a challenge. Informing and engaging neurology providers to recognize and provide critical neurologic evaluation and treatment has potential to close care gaps.

Potassium dynamics in sickle cell anemia: clinical implications and pathophysiological insights

Potassium dynamics are critical in the pathophysiology of sickle cell anemia (SCA), a genetic disorder characterized by the presence of abnormally shaped red blood cells that lead to various complications such as vaso-occlusive crises and hemolytic anemia. This review focuses on the clinical implications and pathophysiological insights of potassium regulation in SCA, highlighting its impact on disease progression and potential therapeutic strategies. The dysregulation of potassium transport in SCA leads to significant K+ efflux and cellular dehydration, exacerbating the sickling process. Dehydrated sickle cells, due to potassium loss, become more rigid and prone to causing blockages in small blood vessels, leading to painful vaso-occlusive crises and ischemia. Furthermore, chronic hemolysis in SCA, aggravated by potassium imbalance, contributes to severe anemia and systemic complications. These insights underscore the importance of maintaining potassium homeostasis to mitigate disease severity and improve patient outcomes. Therapeutic strategies targeting potassium regulation show promise in managing SCA. Inhibitors of the Gardos channel, such as senicapoc, have demonstrated potential in reducing sickling and hemolysis. Additionally, hydration therapy plays a crucial role in maintaining electrolyte balance and preventing RBC dehydration. A comprehensive approach that includes monitoring and correcting electrolyte imbalances, along with standard treatments like hydroxyurea and blood transfusions, is essential for effective disease management.

Stroke without cerebral arteriopathy in sickle cell disease children: causes and treatment

Cerebral arteriopathy (CA) in children with sickle cell disease (SCD) is classically described as chronic stenosis of arteries in the anterior brain circulation, leading to ischemic stroke. Some studies have, however, reported strokes in children with SCD but without CA. In order to better understand the etiology and risk factors of these strokes, we retrospectively analyzed ischemic strokes occurring in a large cohort of children over a 13-year period. Between 2007 and 2020, 25 of 1,500 children with SCD had an ischemic stroke in our center. Among them, 13 (52%) had CA, described as anatomical arterial stenosis, while 12 (48%) did not. Patients with stroke without CA were older than patients with stroke attributed to SCD-CA (9.0 years old vs. 3.6 years old; P=0.008), and more frequently had SC genotype (25% vs. 0%, respectively). Their strokes more frequently involved the posterior circulation, with cerebellar involvement in 42%. Retained stroke etiologies in patients without typical SCD-related CA were reversible cerebral vasoconstriction syndrome, cerebral fat embolism, arterial thrombosis or thromboembolism, hyperviscosity, vasculitis in a context of infectious meningo-encephalitis, and severe hemodynamic failure. No recurrence was observed in the 24 months following stroke, even though 67% of the patients in this group were no longer receiving exchange transfusions. In conclusion, in a cohort of pediatric SCD patients with an efficient stroke screening strategy, half of the ischemic strokes that occurred were related to causes other than CA. They affected a different population of SCD children and systematic long-term transfusion programs may not be necessary in these cases.

Stroke in sickle cell patients, epidemiology, pathophysiology, systemic and surgical treatment options and prevention strategies

Background

A hereditary haemoglobinopathy known as sickle cell disease (SCD) affects over 100 000 people in the United States severely. Cerebrovascular disease is a prominent consequence of SCD. By the age of 30, 53% of patients have silent cerebral infarcts (SCIs) (a stroke that occurs without any obvious symptoms because it damages a small part of the brain that isn't responsible for any essential functions), and by the age of 40, 3.8% have overt strokes.

Main body

The multidimensional burden of cerebrovascular illness in SCD is reviewed in detail in this article, which includes both clinical strokes and the frequently asymptomatic SCIs. The intricate pathophysiology of SCD and stroke is explored. With SCD, there are currently very few methods for preventing primary and secondary stroke; the most common ones are hydroxyurea and blood transfusion. Nevertheless, not enough research has been done on the possible contributions of anticoagulation and aspirin to strokes linked to SCD. Promising evidence is also highlighted in the study, suggesting that new drugs intended to treat SCD may be able to alleviate leg ulcers and renal impairment in addition to reducing unusually high transcranial Doppler flow velocity – a crucial component of cerebrovascular events. Given that these novel medications specifically target haemolysis and vaso‐occlusion, the two main causes of strokes in this population, more research is desperately needed to determine whether they are effective in avoiding strokes in people with SCD. The literature review also emphasizes how common healthcare inequities are and how they hinder advancements in SCD research and management in the United States.

Conclusion

To successfully address these inequities, the evaluation recommends more funding for both SCD management and research, as well as for patient and clinician education. This multimodal viewpoint highlights the intricate terrain of cerebrovascular problems associated with SCD and the urgent need for all‐encompassing and fair strategies to improve patient outcomes and advance research.

Unlocking the link between haptoglobin polymorphism and noninfectious human diseases: insights and implications

Haptoglobin (Hp) is a polymorphic protein that was initially described as a hemoglobin (Hb)-binding protein. The major functions of Hp are to scavenge Hb, prevent iron loss, and prevent heme-based oxidation. Hp regulates angiogenesis, nitric oxide homeostasis, immune responses, and prostaglandin synthesis. Genetic polymorphisms in the Hp gene give rise to different phenotypes, including Hp 1-1, Hp 2-1, and Hp 2-2. Extensive research has been conducted to investigate the association between Hp polymorphisms and several medical conditions including cardiovascular disease, inflammatory bowel disease, cancer, transplantation, and hemoglobinopathies. Generally, the Hp 2-2 phenotype is associated with increased disease risk and poor outcomes. Over the years, the Hp 2 allele has spread under genetic pressures. Individuals with the Hp 2-2 phenotype generally exhibit lower levels of CD163 expression in macrophages. The decreased expression of CD163 may be associated with the poor antioxidant capacity in the serum of subjects carrying the Hp 2-2 phenotype. However, the Hp 1-1 phenotype may confer protection in some cases. The Hp1 allele has strong antioxidant, anti-inflammatory, and immunomodulatory properties. It is important to note that the benefits of the Hp1 allele may vary depending on genetic and environmental factors as well as the specific disease or condition under consideration. Therefore, the Hp1 allele may not necessarily confer advantages in all situations, and its effects may be context-dependent. This review highlights the current understanding of the role of Hp polymorphisms in cardiovascular disease, inflammatory bowel disease, cancer, transplantation, hemoglobinopathies, and polyuria.

Exploring new horizons: Emerging therapeutic strategies for pediatric stroke

Pediatric stroke presents unique challenges, and optimizing treatment strategies is essential for improving outcomes in this vulnerable population. This review aims to provide an overview of new, innovative, and potential treatments for pediatric stroke, with a primary objective to stimulate further research in this field. Our review highlights several promising approaches in the realm of pediatric stroke management, including but not limited to stem cell therapy and robotic rehabilitation. These innovative interventions offer new avenues for enhancing functional recovery, reducing long-term disability, and tailoring treatments to individual patient needs. The findings of this review underscore the importance of ongoing research and development of innovative treatments in pediatric stroke. These advancements hold significant clinical relevance, offering the potential to improve the lives of children affected by stroke by enhancing the precision, efficacy, and accessibility of therapeutic interventions. Embracing these innovations is essential in our pursuit of better outcomes and a brighter future for pediatric stroke care.

Global trends and regional differences in disease burden of stroke among children: a trend analysis based on the global burden of disease study 2019

BACKGROUND

Stroke is a major cause of acute neurological symptoms in children with significant long-term neurological sequelae. However, data of diseases burden on stroke among children was lack. We aimed to be dedicated to analyze and compare global trends as well as regional and sociodemographic differences in stroke prevalence, incidence, mortality and disability-adjusted life-years (DALYs) among children aged 0 ~ 14 years.

METHOD

We obtained data on annual number of incident strokes, prevalent strokes, deaths, and DALYs, age-standardized incidence rates (ASIRs), prevalence rates (ASPRs), mortality rates (ASMRs) and DALY rates (ASDRs) of stroke among individuals aged 14 years and younger during 1990-2019 from the 2019 Global Burden of Disease Study. To quantify the temporal trends, we calculated changes (%) in number, and used joinpoint regression analysis to identify the average annual percentage changes (AAPCs) of age standardized rates.

RESULT

Globally, the incident strokes and prevalent strokes increased by 18.51% and 31.97%, respectively, but DALYs due to stroke and deaths due to stroke decreased by 60.18% and 65.03%, respectively, from 1990 to 2019. During the same period, ASIR increased by 0.21% (95%CI: 0.17, 0.24) from 18.02 to 100,000 population in 1990 to 19.11 per 100,000 in 2019; ASPR increased by 0.66% (95%CI: 0.36, 0.96) from 68.88 to 100,000 population in 1990 to 81.35 per 100,000 in 2019; while ASMR (AAPC= -3.94; 95%CI: -4.07, -3.81) and ASDR (AAPC= -3.50; 95%CI: -3.64, -3.36) both decreased. In 2019, the highest age standardized incidence, prevalence, mortality, and DALY rates all occurred in low sociodemographic index (SDI) regions. The greatest increase of age standardized incidence rate (AAPC = 0.21; 95%CI: 0.18, 0.25) and prevalence rate (AAPC = 1.15; 95%CI: 0.34, 1.96) both were in high SDI regions. Eastern Sub-Saharan Africa had the highest ASIR and ASPR in 2019, and Oceania had the highest ASMR and ASDR in 2019 across 21 GBD regions. High-income North America had the largest increase in ASIR (AAPC = 0.63; 95%CI: 0.59, 0.66) and ASPR (AAPC = 1.58; 95%CI: 0.54, 2.63). Against the overall decreasing trend of ASMR, an increasing trend of ASMR was found in Zimbabwe (AAPC = 0.91; 95%CI: 0.44, 1.37) and Botswana (AAPC = 0.74; 95%CI: 0.02, 1.47).

CONCLUSION

The overall increasing stroke incidence and prevalence indicated that prevention and management of stroke among younger population should be critical in the future. Despite stroke mortality with falling trend worldwide, specific countries or territories present worrying increase in stroke mortality. Without urgent implementation of effective primary prevention strategies, the stroke burden of children will probably continue to grow across the world, particularly in high-SDI countries.

Adult Moyamoya Disease and Syndrome: Current Perspectives and Future Directions: A Scientific Statement From the American Heart Association/American Stroke Association

Adult moyamoya disease and syndrome are rare disorders with significant morbidity and mortality. A writing group of experts was selected to conduct a literature search, summarize the current knowledge on the topic, and provide a road map for future investigation. The document presents an update in the definitions of moyamoya disease and syndrome, modern methods for diagnosis, and updated information on pathophysiology, epidemiology, and both medical and surgical treatment. Despite recent advancements, there are still many unresolved questions about moyamoya disease and syndrome, including lack of unified diagnostic criteria, reliable biomarkers, better understanding of the underlying pathophysiology, and stronger evidence for treatment guidelines. To advance progress in this area, it is crucial to acknowledge the limitations and weaknesses of current studies and explore new approaches, which are outlined in this scientific statement for future research strategies.

Stroke in sickle cell disease and the promise of recent disease modifying agents

Sickle cell disease (SCD) is an inherited hemoglobinopathy affecting approximately 100,000 individuals in the United States. Cerebrovascular disease is among the most common and debilitating complications of SCA, with 53% experiencing silent cerebral infarct by age 30 and 3.8% experiencing overt stroke by age 40 years. This review highlights the burden of cerebrovascular disease in SCD, including both stroke and silent cerebral infarct (SCI). We then discuss the pathophysiology of stroke and cerebral fat embolism in the absence of a patent foramen ovale. This review also reveals that options for primary and secondary stroke prevention in SCD are still limited to hydroxyurea and blood transfusion, and that the role of aspirin and anticoagulation in SCD stroke has not been adequately studied. Limited data suggest that the novel disease-modifying agents for SCD management may improve renal dysfunction, leg ulcers, and lower the abnormally high TCD flow velocity. Further research is urgently needed to investigate their role in stroke prevention in SCD, as these novel agents target the main stroke contributors in SCD - hemolysis and vaso-occlusion. This literature review also explores the role of healthcare disparities in slowing progress in SCD management and research in the United States, highlighting the need for more investment in patient and clinician education, SCD management, and research.

Transcranial Doppler Ultrasonography as a Diagnostic Tool for Cerebrovascular Disorders

Imaging techniques including transcranial Doppler (TCD), magnetic resonance imaging (MRI), computed tomography (CT), and cerebral angiography are available for cerebrovascular disease diagnosis. TCD is a less expensive, non-invasive, and practically simpler approach to diagnosing cerebrovascular disorders than the others. TCD is a commonly available and inexpensive diagnostic tool. However, owing to its large operator dependency, it has a narrow application area. Cerebrovascular disease indicates a group of disorders that alter the flow of blood in the brain. The brain’s functions can be temporarily or permanently impaired as a result of this change in blood flow. Timely diagnosis and treatment can restore the brain-impaired functions, resulting in a much-improved prognosis for the patients. This review summarizes the basic principles underlying the TCD imaging technique and its utility as a diagnostic tool for cerebrovascular disease.

Influence of Haptoglobin Polymorphism on Stroke in Sickle Cell Disease Patients

This review outlines the current clinical research investigating how the haptoglobin (Hp) genetic polymorphism and stroke occurrence are implicated in sickle cell disease (SCD) pathophysiology. Hp is a blood serum glycoprotein responsible for binding and removing toxic free hemoglobin from the vasculature. The role of Hp in patients with SCD is critical in combating blood toxicity, inflammation, oxidative stress, and even stroke. Ischemic stroke occurs when a blocked vessel decreases oxygen delivery in the blood to cerebral tissue and is commonly associated with SCD. Due to the malformed red blood cells of sickle hemoglobin S, blockage of blood flow is much more prevalent in patients with SCD. This review is the first to evaluate the role of the Hp polymorphism in the incidence of stroke in patients with SCD. Overall, the data compiled in this review suggest that further studies should be conducted to reveal and evaluate potential clinical advancements for gene therapy and Hp infusions.

Association of laboratory markers and cerebral blood flow among sickle cell anemia children

BACKGROUND

Stroke is one of the highest complications of sickle-cell anemia (SCA). The Transcranial Doppler (TCD) has been adopted worldwide as a gold standard method for detecting alterations in the blood velocity in cerebral arteries. In this study, we investigated the association between laboratory parameters and increased cerebral blood flow velocity in Brazilian SCA pediatric patients.

METHODS

The study included 159 pediatric patients with SCA, submitted to TCD velocity screening, and the time-averaged maximum mean velocity (TAMMV) was determined in the middle cerebral artery (MCA), anterior cerebral artery (ACA), and distal intracranial internal carotid artery (ICA). We compared cerebral blood flow in patients stratified by the following: TCD1-defined as normal, with TAMMV inferior to 170 cm/s; TCD2-conditional, with TAMMV above 170 cm/s, but less than 199 cm/s; TCD3-altered, with TAMMV greater than or equal to 200 cm/s.

RESULTS

TAMMV was negatively correlated with age and weight (p < 0.05). Moreover, TAMMV was associated or correlated with reductions in HbF, RBC, hemoglobin, hematocrit, HDL, and haptoglobin and, increases in MCV, MCH, RDW, reticulocytes, WBC, lymphocytes, monocytes, eosinophils, total and indirect bilirubin, LDH, AST, ALT, glucose, ferritin, and AAT (p < 0.05).

CONCLUSION

The current study highlights the importance of the investigation of hemolytic and inflammatory biomarkers for monitoring the clinical outcome of SCA pediatric patients, to avoid acute or chronic stroke. Moreover, glucose and HDL-C appear useful for predicting higher TAMMV.