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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cerebral blood flow (CBF) has been studied by the xenon-133 (133Xe) inhalation method in 16 children with suspected sickle cell cerebrovascular disease. Abnormalities consisting of decreases in total, hemispheral, or regional CBF were found in 17 of 26 studies. Eleven studies performed immediately after stroke, transient ischemic attack, or depression of state of alertness showed abnormalities. In addition to confirming regional cerebrovascular insufficiency in children with stroke due to major cerebral artery occlusion, the method detected diffuse decrease in CBF in children with stupor, coma, and seizures who had normal angiographic findings. In contrast, six of seven studies obtained after exchange transfusion or during maintenance on hypertransfusion therapy showed normal findings. The difference between results in patients with acute neurologic disturbances and those receiving transfusion therapy was statistically significant (P less than .005). The data indicate that the 133Xe method reliably demonstrates cerebrovascular impairment in sickle cell disease. They also suggest that CBF changes in patients with sickle cell disease can be reversed by exchange transfusion and by hypertransfusion therapy. The 133Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke.
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PMID:Cerebral blood flow in sickle cell cerebrovascular disease. 671 16

Cerebrovascular accident (CVA) is a major complication of sickle cell disease. The incidence and mortality of and risk factors for CVA in sickle cell disease patients in the United States have been reported only in small patient samples. The Cooperative Study of Sickle Cell Disease collected clinical data on 4,082 sickle cell disease patients enrolled from 1978 to 1988. Patients were followed for an average of 5.2 +/- 2.0 years. Age-specific prevalence and incidence rates of CVA in patients with the common genotypes of sickle cell disease were determined, and the effects of hematologic and clinical events on the risk of CVA were analyzed. The highest rates of prevalence of CVA (4.01%) and incidence (0.61 per 100 patient-years) were in sickle cell anemia (SS) patients, but CVA occurred in all common genotypes. The incidence of infarctive CVA was lowest in SS patients 20 to 29 years of age and higher in children and older patients. Conversely, the incidence of hemorrhagic stroke in SS patients was highest among patients aged 20 to 29 years. Across all ages the mortality rate was 26% in the 2 weeks after hemorrhagic stroke. No deaths occurred after infarctive stroke. Risk factors for infarctive stroke included prior transient ischemic attack, low steady-state hemoglobin concentration and rate of and recent episode of acute chest syndrome, and elevated systolic blood pressure. Hemorrhagic stroke was associated with low steady-state hemoglobin and high leukocyte count.
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PMID:Cerebrovascular accidents in sickle cell disease: rates and risk factors. 941 96

While the problem of stroke in the patients with sickle cell disease (SCD) has been known for more than 75 years, adequate preventive and treatment strategies are just now being tested. Recent data on prevalence and incidence have been obtained from the Cooperative Study of Sickle Cell Disease of more than 4000 patients with SCD observed in 23 US clinical centers over a 10-year period.1 The overall age-specific incidence of first stroke in SCD (homozygous sickle cell anemia) is low (0.13%) at ages younger than 24 months, increasing to just over 1% at ages 2 to 5 years, with only a slight decrement to 0.79% at ages 6 to 9 years. The risk of brain infarction declines until a second peak is seen at ages older than 50 years, when the incidence again increases to nearly 1.3%. Although intracranial hemorrhage does occur in young children with SCD, the risk is low compared with older children and adults. The Cooperative Study of Sickle Cell Disease reported risk factors for infarction to be prior transient ischemic attack, low steady-state hemoglobin values, and rate and recency of episodes of acute chest syndrome, as well as elevated systolic blood pressure. Risk factors for intracranial hemorrhage included low steady-state hemoglobin values and a high leukocyte count. The burden of cerebrovascular disease is even higher if subclinical magnetic resonance imaging (MRI) lesions, presumed to be ischemic, are included. The prevalence of such lesions is more than 22% in patients with SCD, and most of these patients have not reported symptoms, although specialized neuropsychological testing shows lower scores in children with silent lesions on MRI scans. Patients with a history of clinical stroke typically have infarcts in the cortex and deep white matter, whereas silent infarcts tend to be more limited to deep white matter. Common infarction patterns are characterized by wedge-shaped lesions of large-vessel territories; border zone infarctions, particularly of the middle and cerebral artery watershed region; and small punctate lesions of the deep white matter. Fat embolism to the brain and venous thromboses are encountered rarely.
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PMID:Stroke prevention and treatment in sickle cell disease. 1129 86

The short-term beneficial effect of hydroxyurea (HU) in sickle cell disease (SCD) has been proven by randomized studies in children and adults. The Belgian registry of HU-treated SCD patients was created to evaluate its long-term efficacy and toxicity. The median follow-up of the 93 patients registered is 3.5 years; clinical and laboratory data have been obtained for 82 patients at 1 year, 61 at 2 years, 44 at 3 years, 33 at 4 years, and 22 after 5 years. On HU, the number of hospitalizations and days hospitalized dropped significantly. Analysis of the 22 patients with a minimum of 5 years of follow-up confirm a significant difference in the number of hospitalizations (P =.0002) and days in the hospital (P <.01), throughout the treatment when compared to prior to HU therapy. The probabilities of not experiencing any event or any vaso-occlusive crisis requiring hospitalization during the 5 years of treatment were, respectively, 47% and 55%. On HU, the rate per 100 patient-years of severe events was estimated to be 3.5% for acute chest syndrome, 1.2% for aplastic crisis, 0.4% for splenic sequestration; it was 0% for the 9 patients with a history of stroke or transient ischemic attack followed for an average of 4 years. No important adverse effect occurred. Long-term chronic treatment with HU for patients with SCD appears feasible, effective, and devoid of any major toxicity; in patients with a history of stroke, HU may be a valid alternative to chronic transfusion support. (Blood. 2001;97:3628-3632)
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PMID:Five years of experience with hydroxyurea in children and young adults with sickle cell disease. 1209 15

We conducted a retrospective study to determine whether the presence of moyamoya collaterals influenced the risk of recurrence of cerebrovascular events (CVEs: stroke or transient ischemic attack) in patients with sickle cell disease placed on chronic transfusions after a stroke. Forty-three patients with homozygous sickle cell anemia (HbSS) and 1 with HbSO(Arab) (16 females, 28 males) who had suffered strokes while under the age of 18 were studied. All patients had been on transfusions aimed at maintaining the sickle hemoglobin (HbS) level below 30%. They were followed for a mean of 6.6 years (2.2 to 20.4 years). The presence of collaterals was diagnosed based on either magnetic resonance angiography or conventional angiography. Eighteen (41%) of the 44 patients suffered recurrent CVEs. Nineteen (43%) (6 females, 13 males) patients had moyamoya collaterals. Eleven (58%) of these 19 experienced 21 total recurrent CVEs, including 4 strokes in 4 patients (21%). In comparison, 7 (28%) of 25 patients without moyamoya collaterals experienced 9 recurrent CVEs (P <.05) with only 1 recurrent stroke (4%). Moyamoya patients were also more likely to have 2 recurrent CVEs (42% vs 8%, P <.05) as well as poorer neuropsychological testing results. A proportional hazards regression analysis indicated that patients with moyamoya were more than twice as likely to incur a subsequent CVE (hazard ratio, 2.40; 95% confidence interval, 0.85, 6.75). We conclude that up to 41% of patients with sickle cell disease experience recurrent CVEs after an initial stroke despite chronic transfusions and that the risk of recurrence is significantly higher for those who have moyamoya collaterals.
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PMID:Moyamoya syndrome in childhood sickle cell disease: a predictive factor for recurrent cerebrovascular events. 1196 76

Cerebrovascular accident (CVA) is a major cause of morbidity and death in sickle cell anemia (SCA). Transfusion of packed erythrocytes is widely used to prevent this complication. However, chronic transfusion may lead to iron overload, alloimmunization, or infections. Cost and compliance may compromise transfusion therapy. A possible alternative, the prophylactic use of hydroxyurea (HU), has not been tried to determine whether it may prevent recurrent stroke. We used HU in five children with SCA who had suffered stroke, in three of them after a first episode and in the other two after a second CVA. Four had infarctive stroke and one a transient ischemic attack (TIA). Four patients took HU at a dose of 40 mg/kg/d, one patient at 30 mg/kg/d. None of the patients had recurrent stroke during 42-112 months of observation. None experienced pain crises. In all, HbF increased significantly and was maintained above 14.7% during treatment. The total Hb concentration increased 19.5 g/L (median) above the value before treatment. HU was well tolerated. None of the five children had leukopenia or thrombocytopenia during therapy. HU appears to prevent recurrence of stroke in SCA without risk of major toxicity.
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PMID:Hydroxyurea (HU) for prevention of recurrent stroke in sickle cell anemia (SCA). 1241 May 69

Although the prevalence of seizures in children with sickle cell disease (SCD) is 10 times that of the general population, there are few prospectively collected data on mechanism. With transcranial Doppler and magnetic resonance imaging (MRI) and angiography, we evaluated 76 patients with sickle cell disease, 29 asymptomatic and 47 with neurological complications (seizures, stroke, transient ischemic attack, learning difficulty, headaches, or abnormal transcranial Doppler), who also underwent bolus-tracking perfusion MRI. The six patients with recent seizures also had electroencephalography. Group comparisons (seizure, nonseizure, and asymptomatic) indicated that abnormal transcranial Doppler was more common in the seizure (4/6; 67%) and nonseizure (26/41; 63%) groups than in the asymptomatic (10/29; 34%) group (chi2; p = 0.045), but abnormal structural MRI (chi2; p = 0.7) or magnetic resonance angiography (chi2; p = 0.2) were not. Relative decreased cerebral perfusion was found in all seizure patients and in 16 of 32 of the remaining patients with successful perfusion MRI (p = 0.03). In the seizure patients, the perfusion abnormalities in five were ipsilateral to electroencephalographic abnormalities; one had normal electroencephalogram results. These findings suggest that vasculopathy and focal hypoperfusion may be factors in the development of sickle cell disease-associated seizures.
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PMID:Sickle cell disease: ischemia and seizures. 1631 82

Cerebrovascular disorders are an important cause of mortality and chronic morbidity in children. Ischemic stroke is more common than cerebral venous thrombosis and hemorrhagic stroke in children. Several medical disorders have been associated with stroke in children, and a thorough evaluation of underlying causes is needed to determine the best treatment and prevention strategy. The treatment and prevention of stroke in children is not well studied, and current recommendations are based on adult studies, nonrandomized trials, or expert opinion. Children with stroke require immediate, special attention and if possible should be stabilized and transferred to an institution that can offer pediatric neurovascular expertise and care. All children with stroke should be referred to or have their care managed by a pediatric neurologist. The treatment of stroke in adults is well studied, and when applicable this evidence should be considered in the treatment of children with stroke. Data from animal and adult stroke studies have demonstrated a benefit for the aggressive treatment of infection, fever, blood pressure, hypo/hyperglycemia, intracranial pressure, and seizures, and should be applied to children with stroke. The use of thrombolytic, antithrombotic, and antiplatelet therapies is based on adult studies, cohort studies, and/or expert opinion. Two consensus guidelines regarding the treatment of arterial ischemic stroke and cerebral venous thrombosis were recently published and recommend the use of anticoagulants or antiplatelet agents in the acute setting, depending on the underlying cause of stroke. The evidence for the primary prevention of stroke in children is restricted to sickle cell disease (SCD) and derived from the Stroke Prevention in Sickle Cell Study Project studies. Long-term chronic transfusion therapy to maintain hemoglobin S levels below 30% is indicated in children with SCD and intracranial stenosis. It has also been recently determined that chronic transfusion therapy should not be stopped in children with SCD and an increased risk for stroke. The recurrence rate of arterial ischemic stroke (AIS) in children ranges from 6% to 30% and is highest among children with recurrent transient ischemic attack, cardiac disease, arteriopathies, and metabolic and coagulation abnormalities. Recommendations for secondary prevention are based on adult studies and the underlying pathophysiology of the stroke. Antiplatelet therapy (aspirin 1-5 mg/kg/day) is recommended in most children with a history of AIS. Although there is minimal evidence to support its use in children, anticoagulation may be indicated in AIS associated with extracranial arterial dissection, prothrombotic disorders, cardiac disease, severe intracranial stenosis, and recurrent AIS while on antiplatelet therapy.
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PMID:Treatment and prevention of cerebrovascular disorders in children. 1622 70

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations.
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PMID:Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke: co-sponsored by the Council on Cardiovascular Radiology and Intervention: the American Academy of Neurology affirms the value of this guideline. 1697 25

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations.
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PMID:Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke: co-sponsored by the Council on Cardiovascular Radiology and Intervention: the American Academy of Neurology affirms the value of this guideline. 1653 23


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