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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 angiograms were performed in 14 children with sickle cell disease and clinical findings of cerebral infarction. The angiogram was normal in four patients. Ten patients had abnormalities in the carotid artery or its branches. The internal carotid artery was stenosed or occluded usually with bilateral disease. The anterior and middle cerebral arteries were involved in nine patients and branch occlusion was frequent. The posterior fossa arteries were not involved in these patients. The risk of angiography is low if appropriate precautions are taken. In these patients the indications for arteriography were to evaluate the effects of hypertransfusion therapy on cerebrovascular disease.
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PMID:Cerebral infarction secondary to sickle cell disease: arteriographic findings. 677 Jun 33

Although there is as yet no definitive treatment for patients with sickle cell disease there has been considerable improvement in the overall management of these patients in recent years. This stems largely from a better understanding of the disease process. The risks from infection in infancy and childhood due to asplenia ae now well known, and children at risk ar being identified and treated. The role of platelets and the activation of clotting factors, while still controversial, are now acknowledged as appropriate areas for research. The judicious use of blood transfusions for cerebral infarction has improved the prognosis for this complication, as it has for pregnancy and the fetus. Blood transfusion, however, has its own hazards in sickle cell disease and the extent to which it can be used requires further investigation. Finally, the broad spectrum of hematological findings and individual clinical variations in sickle cell disease is now better understood.
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PMID:The clinical effects of Hb S, an overview. 702 72

A variety of neurological complications occur with sickle cell hemoglobinopathy. The most striking and most common is cerebral infarction. It is also the most devastating. Because of the high recurrence rate in untreated patients, cerebral infarction is the most debilitating neurological complication. The observed frequency varies from 6% to as high as 34% in different reports. The pathogenesis, clinical features, and demography are discussed. Diagnostic procedures should include a spinal tap to rule out potentially treatable lesions. CT scan and cerebral angiography may also be helpful in certain cases. Transfusion therapy remains the mainstay of management in the acute phase of cerebral infarction. There is considerable evidence to indicate that long-term transfusion programs are effective in the prevention of recurrences. Intracranial hemorrhage, spinal cord infarction, isolated neuropathies due to anatomical proximity to infarcted bones, lead neuropathy, auditory problems, and ocular manifestations are other neurological problems which can affect patients with sickle cell disease.
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PMID:Neurological complications of sickle cell anemia. 716 88

Forty-five patients with homozygous sickle cell disease who had tonsillectomy for recurrent tonsillitis, when compared with 45 matched controls with haemoglobin genotype AA, showed significant differences in the clinical manifestations and complications of recurrent tonsillitis between the two groups. Although throat swabs in the sickle cell group were mostly negative because they were on prophylactic penicillin, all tonsils harboured Streptococcus pneumoniae when cultured. This study suggests the tonsils to be the more specific source of pneumococcal infection that causes systemic complications which increase morbidity and mortality in sickle cell disease. Although the sickle cell patients may be less clinically symptomatic with tonsillitis, the incidence of serious complications caused by pneumococcal infections, now shown to arise from the tonsils, is significant. Adenotonsillar hypertrophy is linked with an increased risk of a sleep apnoea which causes serious neurological complications such as cerebral infarction and stroke. Tonsillectomy has greatly reduced the incidence of complications from pneumococcal infections in the sickle cell group and should therefore be recommended for sickle cell patients taking prophylactic penicillin and still developing pneumococcal infections.
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PMID:The significance of recurrent tonsillitis in sickle cell disease. 792 45

We prospectively evaluated a group of patients with sickle cell disease and a clinical history of prior stroke, comparing transcranial Doppler sonography (TCD) to both magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) to determine its efficacy for the detection of flow abnormalities associated with prior cerebral infarction. Using MRI as the standard examination, there was 94% sensitivity and 30% specificity, and using MRA as the standard examination, there was 91% sensitivity and 22% specificity. We concur with other reports that the transcranial Doppler examination is a highly sensitive study. In our group of sickle cell disease patients with prior stroke, TCD reliably detected flow abnormalities that correlated to areas of prior cerebral infarction.
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PMID:Correlation of transcranial Doppler ultrasonography with MRI and MRA in the evaluation of sickle cell disease patients with prior stroke. 793

A 7 year old Kurdish girl presented with a cerebral infarction and a resulting hemiparesis following a blood transfusion. Examination of the blood film suggested sickle cell anaemia. However a simultaneously carried out haemoglobin electrophoresis showed haemoglobin S and haemoglobin D. The diagnosis of haemoglobin SD disease was thereby established. This kind of haemoglobin disorder usually shows a mild clinical manifestation. According to our knowledge such serious cases have not been published before. With this disease the main emphasis is on the prevention of recurrent cerebral infarctions bay a long-term transfusion programme whereas the effects of the cerebral infarction are treated in the usual way.
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PMID:[Hemoglobin SD disease]. 841 45

Stroke occurs in 7-8% of children with Sickle Cell Disease (Hb SS) and is a major cause of morbidity. Rates of recurrence have been reduced from 46-90% to less than 10% through chronic blood transfusions. Prevention of first stroke, however, would be preferable because even one stroke can cause irreversible brain injury. Transcranial Doppler (TCD) ultrasound can detect arterial blood flow rates associated with subsequent stroke risk. By combining TCD screening and a potentially effective treatment, first stroke may be prevented. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) is the first stroke prevention trial in Hb SS and the first randomized, controlled use of transfusion in Hb SS. This multi-center trial is designed to test whether reducing sickle hemoglobin to 30% or less with periodic blood transfusions will reduce first-time stroke by at least 70% compared to standard care. Primary endpoints will be clinically evident symptoms of cerebral infarction with consistent findings on Magnetic Resonance Imaging and Angiography (MRI/MRA) or symptomatic intracranial hemorrhage. Secondary endpoints will be asymptomatic brain lesions detected by MRI in brain areas not involved in primary endpoints. The design calls for a 6-month start-up interval, 18 months of TCD screening and randomization, and observation for stroke from entry through month 54. Key features of the trial are standardized TCD and MRI/MRA protocols interpreted blindly, and blinded adjudication of endpoints. The sample size (60 per treatment group) is based on prospective data relating TCD velocity to risk of stroke. A time-averaged mean velocity of > or = 200 cm/sec is associated with a 46% risk of cerebral infarction over 39 months. The sample size is sufficient to detect 70% reduction in the primary endpoint at 90% power. This trial will determine if transfusion is effective in the primary prevention of stroke. Secondary aims may further the understanding of the effects of transfusion on the brain and guide future research into cerebrovascular disease in Hb SS.
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PMID:Stroke prevention trial in sickle cell anemia. 949 71

Cerebral vascular disease is a common and serious complication of sickle cell disease that mainly involves the large blood vessels of the skull base. Because recurrences are common and residual deficits severe, attention has turned to detection of preclinical cerebral involvement with the goal of preventing clinical damage. Magnetic resonance imaging (MRI), an extremely sensitive tool for detecting cerebral infarction/ischemia, has shown that 10% of asymptomatic patients exhibit white matter lesions that seem to be associated with impaired cognitive function and may be predictive of stroke; magnetic resonance angiography demonstrates occlusions of skull base arteries but is not reliable for the diagnosis of stenosis because of artifacts generated by rapid turbulent flow. Transcranial Doppler is sensitive and specific for the detection of arterial stenosis and occlusion, even in asymptomatic patients. Digitized cerebral angiography remains the gold standard investigation for pretreatment confirmation of lesions detected by Doppler and/or MRI.
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PMID:[Imaging of cerebrovascular disease in sickle cell anemia]. 1008 77

Cerebral infarction occurs in one quarter of all children with sickle cell anemia (SCA). There is an increased risk of stroke in siblings with SCA, suggesting genetic factors may influence risk of stroke. The authors investigated whether HLA type was associated with risk of stroke in children with SCA. Fifty-three patients with SCA underwent complete HLA typing at both HLA class I (HLA-A, B) and HLA class II (HLA-DR, DQ, DP) loci. Of the 53 patients, 22 had magnetic resonance imagining (MRI)-documented evidence of cerebral infarction, and the remaining 31 patients had negative MRI scans. Comparison of the results of HLA typing between the SCA patients with a positive and those with a negative MRI documented that the 2 groups differed with respect to the class I HLA-B (P =.012), and the class II HLA-DRB1 (P =.0008) and DQB1 (P =.029). Susceptibility associations at the HLA-DRB1 locus included both DR3 alleles, where DRB1*0301 and *0302 were both associated with an increased risk of stroke. Protective associations were found in the DR2 group, where DRB1*1501 was protective for stroke. DQB1*0201, which is in linkage disequilibrium with DRB1*0301, was also associated with stroke. Similarly, DQB1*0602, in linkage disequilibrium with DRB1*1501, was protective. Specific HLA alleles may influence the risk of stroke in children with SCA. HLA typing may prove useful in identifying SCA patients at higher risk for stroke.
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PMID:Evidence for HLA-related susceptibility for stroke in children with sickle cell disease. 1082 44

Identification and treatment of the underlying risk factors for stroke reduce the potential for additional strokes; therefore, a thorough search for treatable risk factors is justified. Because some risk factors can have a cumulative effect, even children with known risk factors for stroke sometimes need to be evaluated for other conditions. Cerebral angiography is often helpful; I recommend angiography in any child with an unexplained infarction or hemorrhage. Angiography is especially important in children with intraparenchymal hemorrhage because more than one third of such children will prove to have some type of potentially treatable congenital vascular anomaly such as an arteriovenous malformation (AVM) or aneurysm. The evidence that periodic blood transfusion effectively prevents cerebral infarction due to sickle cell disease is compelling. Transfusions apparently must be continued indefinitely to maintain the reduction of stroke risk, and without iron chelation, chronic transfusion eventually results in severe iron toxicity and, most likely, death, so the decision to begin transfusion is not an easy one. Measurement of the time-averaged mean flow velocity in the large cerebral vessels with transcranial Doppler (TCD) is highly predictive of stroke risk in these children, enough to justify its routine use in screening patients with sickle cell disease for stroke risk. I believe that patients with sickle cell disease should be offered chronic transfusion after an initial large-vessel stroke or when the TCD results suggest a high risk of stroke. The family must be made aware of the serious complications of chronic transfusion and the importance of complying with chelation once it is started. There are no controlled clinical trials to guide the use of anticoagulants, antiplatelet agents, or thrombolytic agents in children, although these drugs are being used more and more often in pediatric patients. For the most part, our approach has been adapted from our experience with adults. Heparin followed by warfarin is often used for sinovenous thrombosis and for arterial dissection. I also suggest long-term anticoagulation for children with coagulopathy or a high risk of embolism due to congenital or acquired cardiac disease. It is reasonable to use a thrombolytic agent in children with an acute infarction; because few children present soon enough after the onset of symptoms, however, thrombolysis is infrequently used. Aspirin is used more than other antiplatelet agents in children, largely because of years of experience with aspirin and the lack of evidence that other agents are more effective. Despite its frequent use, there are no unequivocal indications for the use of aspirin in children. Aspirin is often started empirically in children suspected to be at substantial risk for additional ischemic stroke but whose risk is ill defined, an approach not too dissimilar from that often used in adult patients. Although the risk of Reye's syndrome in a child taking daily aspirin for stroke prevention is a common concern, I know of no published examples of children who developed Reye's syndrome while taking prophylactic aspirin. This apparently low risk must be weighed against the often-considerable risk of ischemic stroke that could be reduced by the use of daily aspirin. In situations such as vasculopathy or infarction of unknown cause, the small risk of Reye's syndrome seems acceptable.
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PMID:Stroke in Children. 1109 55


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