The prevention and management of stroke in sickle cell anaemia

Prevalence and Risk Factors of Stroke Among Children With Sickle Cell Disease: A Retrospective Study at a Tertiary Care Center

Background Sickle cell disease (SCD) is a common autosomal recessive inherited hemoglobin disorder in many countries. Neurological complications are among the most disabling complications in SCD. Stroke and cerebral vasculopathy can lead to further neurological insult. Ischemic insults, stroke, and silent infarcts are preventable causes of morbidity and mortality in SCD patients. Understanding the epidemiology and characteristics of such patients will help to prevent complications.  Methodology This is a retrospective study conducted in a tertiary care center in Saudi Arabia. Cases of SCD admitted to the pediatric ward between the years 2019 to 2023 were included in the study. Demographic data, clinical diagnosis, and frequency of prior admissions were collected. Brain imaging results were reviewed and included. Furthermore, the study assessed common risk factors leading to developing a stroke in SCD pediatric patients. Risk factors and clinical outcomes after stroke were also included. Results Eighty-one patients were enrolled. The mean age of stroke patients was 8.21±3.50 years while the mean age of non-stroke patients was 6.24±3.76 years. More than half of the patients were females in both the stroke (61.50%) and non-stroke groups (52.90%). Thirteen SCD patients (16%) were diagnosed with stroke. Previous history of stroke, high mean corpuscular volume (MCV), and low red blood cells count (RBC) were statistically significant risk factors for stroke (p<0.0001), (p<0.0001), (p<0.03), respectively.  Conclusion Stroke is one of the most devastating complications of SCD. The prevalence of stroke among SCD patients in our study was 16%. Transcranial Doppler ultrasound screening is the most important predictor of stroke.

Transcranial doppler as screening method for sickling crises in children with sickle cell anemia: a latin America cohort study

Background

Sickle cell anemia (SCA) is the leading cause of childhood stroke. We aimed to evaluate whether altered cerebral flow velocities, as measured by transcranial Doppler (TCD), are associated with vaso-occlusive complications in addition to stroke in pediatric SCA patients.

Methods

We evaluated 37 children aged between 2 and 16 years with SCA who underwent screening for TCD between January 2012 and October 2018. Genotypic profiles and demographic data were collected, TCD examinations were performed during follow-up, and the presence of sickling crises was compared. Survival analyses were performed using simple frailty models, in which each predictor variable was analyzed separately in relation to the occurrence of a sickling crisis.

Results

The variables related to sickle cell crises in the univariate analysis were peak systolic velocity (PSV) in the middle cerebral artery (MCA), hazard ratio (HR) 1.01 (1.00—1.02) p = 0.04; end-diastolic velocity (EDV) in the MCA, HR 1.02 (1.01—1.04) p = 0.01; time average mean maximum velocity (TAMMV) in the basilar artery (BA), HR 1.02 (1.00—1.04) p = 0.04; hemoglobin, HR 0.49 (0.38—0.65) p < 0.001; hematocrit, HR 0.78 (0.71—0.85) p < 0.001; leukocyte counts, HR 1.1 (1.05—1.15) p < 0.001; platelets counts, HR 0.997 (0.994—0.999) p = 0.02; and reticulocyte numbers, HR 1.14 (1.06—1.23) p < 0.001.

Conclusions

Our results indicate PSV and EDV in the MCA and TAMMV in the BA as markers of risk for the occurrence of sickling crises in SCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03429-5.

Treatment of arterial ischemic stroke in children

Stroke is a rare but increasingly recognized disorder in children. Current therapies for arterial ischemic stroke include thrombolytic, antithrombotic and antiplatelet agents, blood transfusion and surgery. Adult studies, pediatric case studies and expert opinion form the basis for these treatment strategies. Thrombolytic agents are increasingly used but, as in adults, the majority of arterial ischemic strokes in children are treated with antiplatelet and antithrombotic agents. Sickle-cell patients, a distinct subset of the pediatric stroke population, are treated primarily with transfusion therapy. Pediatric arterial ischemic stroke studies are needed to determine the most appropriate course of treatment. An international study is currently in progress to formally study the incidence, risk factors, treatment strategies and outcomes of stroke in children.

Prevention of hemoglobinopathies in Egypt

The hemoglobin disorders are the most common clinically serious single gene disorders in the world. In Egypt, beta-thalassemia is the most common type with a carrier rate varying from 5.3 to > or =9% and a gene frequency of 0.03. So, it was estimated that 1,000/1.5 million per year live births will suffer from thalassemia disease in Egypt (total live births 1,936,205 in 2006). beta-Thalassemia creates a social and financial burden for the patients' family and the Egyptian government. The high frequency of beta-thalassemia carriers with increasing rate of newly born cases is a pressing reason for the importance to develop prevention program for beta-thalassemia in Egypt. Sickle-cell disease (SCD) is not frequent in Egypt except in the Oases where the carrier rate varies from 9 to 22%. Our objectives were to provide an in-depth analysis of the current status of hemoglobinopathies in Egypt and what we need for prevention of these diseases.

Sickle cell disease in the United States: looking back and forward at 100 years of progress in management and survival

The past 100 years since James Herrick's first description of sickle cell disease in the United States have been characterized by the gradual development of management strategies. We review the progress in sickle cell disease management in the United States over the past 100 years, with emphasis on the diverse forces surrounding advances in disease management. Mortality and survival data are presented chronologically, with an attempt to highlight improvements in survival associated with specific advancements for pediatric and adult care. Finally, the future course for sickle cell disease management is explored, given the continued work in advancing the field.

Neuroimaging in assessment of risk of stroke in children with sickle cell disease

PURPOSE

Stroke and subclinical "silent infarcts" are major causes of morbidity in children with Sickle Cell Disease (SCD). Ischemic strokes are more common in younger children while hemorrhagic strokes are more frequent in adults. The goal of neuroimaging in acute stroke is to document whether the stroke is ischemic or hemorrhagic, to assess the extent of parenchymal abnormalities and to determine the presence of other cerebrovascular lesions. Computed Tomography (CT) is the primary modality for the assessment of acute stroke patients because of its 24/7 availability and ability to exclude hemorrhagic causes. Magnetic resonance imaging (MRI) and MR angiography (MRA) are recommended to determine precisely extent of infarction and detect cerebrovascular abnormalities. The goal of neuroimaging in patients with hemorrhagic stroke is to identify an arteriovenous malformation or aneurysm(s) amenable to surgery or catheter intervention.The risk of first stroke is very high in asymptomatic children with intracranial arterial mean velocities over 200 cm/s on transcranial Doppler (TCD) examination. The risk can be substantially reduced if chronic blood transfusions are timely implemented. Large cerebral vessel disease detected by TCD can be confirmed or excluded by MRI/MRA. Those with evidence of parenchymal and/or cerebrovascular lesions should be followed by preventive therapy. In patients with neurologic symptoms and negative MRI/MRA findings Positron Emission Tomography or single photon emission CT is recommended. There are no specific neuroimaging findings that suggest that blood transfusions can be safely halted in children with SCD.

The pathophysiology, prevention, and treatment of stroke in sickle cell disease

PURPOSE OF REVIEW

Stroke is one of the most devastating complications of sickle cell disease, but current research has led to improved understanding of its pathogenesis and to new approaches in the prevention of both primary and secondary stroke. This review focuses on advances reported in the past 2 years.

RECENT FINDINGS

New concepts in the pathophysiology of central nervous system events in sickle cell disease have centered around hemolytic anemia and nitric oxide metabolism. Genetic risk factors are now being explored. Major improvement in primary stroke prevention has occurred through transcranial Doppler ultrasonography screening, but utilization of this technique is far from optimal. Hydroxyurea is now being tested as an alternative approach to chronic transfusion for secondary stroke prevention through a multicenter trial. Other studies are addressing the management of silent infarcts and nocturnal hypoxemia.

SUMMARY

Increased understanding of the etiology and pathogenesis of stroke in sickle cell disease should eventually lead to improved management of all central nervous system complications. Alternative secondary stroke prevention with hydroxyurea may allow patients to avoid dependence on life-long chronic transfusion. Primary stroke prevention through transcranial Doppler ultrasonography screening may ultimately yield a dramatic reduction in the incidence of stroke in sickle cell disease.