Ischemic stroke in children treated for acute lymphoblastic leukemia: a retrospective study

Stroke in Pediatric Cancer Patients: A Systematic Review

OBJECTIVE

Pediatric cancer patients have an increased risk of stroke. However, there is a knowledge gap regarding stroke in early stages of pediatric cancer. The objective of this project is to describe the current knowledge on stroke in pediatric cancer patients.

DESIGN

Systematic review.

MATERIALS AND METHODS

After Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, literature search was conducted in PubMed, Cochrane, and Google Scholar from January 1, 1995, up to February 1, 2022.

RESULTS

A total of 3499 studies were identified, of which 8 met inclusion criteria. The incidence of stroke in pediatric cancer patients varied between 0.47% and 2.9%, and prevalence between 1% and 3%. The risk factors identified were leukemia diagnosis, cranial radiation, thrombocytopenia, coagulopathy, and infection. There was a higher rate of diagnosis with magnetic resonance imaging than with computed tomography scan. Treatment was inconsistent, and patients with cancer were less likely to receive antithrombotic treatment when compared with patients without cancer. The highest mortality was among hemorrhagic stroke. Recurrence rate was 5% to 19%.

CONCLUSIONS

The risk for stroke is increased in the pediatric cancer population and can lead to devastating results. The available reports include few patients, with heterogeneous cancer diagnoses and outcomes. Large-scale multicenter studies are needed, focusing on early diagnosis, risk factors, and management strategies of stroke in children with underlying cancer.

Neurological Involvement in Pediatric Patients with Acute Leukemia: A Retrospective Cohort

Acute leukemia (AL) is an important cause of morbidity and mortality in children, and neurological manifestations (NM) are frequent. The objective of this study was to analyze neurological manifestations in children with acute leukemia from cases attended in the last five years at the Centro Médico Nacional “20 de Noviembre”. Methods: Conducting a retrospective and analytical study from 1 January 2015 to 31 December 2020 in children with AL classified according to sex, age range and AL type. Participants were grouped according the presence of NM. Results: We analyzed 607 patients: 54.85% boys and 44.14% girls, with a mean age of 7.27 ± 4.54 years. When comparing groups, the NM group was significantly older (p = 0.01), and the highest prevalence was between 6 and 12 years old. ALL was predominant over the other lineages (p ≤ 0.01). The most frequent NM was CNS infiltration, seizures, headache and neuropathy. Death outcomes occurred in 18.7% of children with AML, 11.8% with ALL and 50% with MPAL (p ≤ 0.002). The NM group was associated with higher mortality during a follow-up time of 77.9 ± 49 months (44.4% vs. 8.9% deaths, NM vs. non-NM, respectively; OR = 3.3; 95% CI 2.4 to 4.6; p ≤ 0.0001). Conclusions: ALL was the most prevalent leukemia type. CNS infiltration, seizures, headache, neuropathy and PRES were the most frequent symptoms in the NM group. NM was associated with a higher mortality rate.

Stroke in Middle Eastern children with cancer: prevalence and risk factors

Objective

To determine the prevalence and to characterize the different types of strokes in children with cancer at the Children’s Cancer Center of Lebanon (CCCL), in addition to assess the factors and clinical findings leading to stroke in children.

Methods

We retrospectively reviewed the medical records and brain images (MRIs and CTs) of children admitted to the CCCL and diagnosed with cancer between years 2008 and 2017. Brain images were reviewed for the strokes’ onset, size, location, possible origin, its recurrence and type: intracranial hemorrhage (ICH), acute arterial ischemic stroke, and cerebral sinus venous thrombosis (CSVT) with and without venous infarct. Medical charts of the patients were reviewed for age, sex, their type of cancer, the treatment protocol they followed, and abnormal findings on their laboratory studies and neurological exams.

Results

Out of the 905 charts reviewed, twenty-seven children with variable types of cancer had strokes, with a prevalence of 2.9%. Their median age at cancer diagnosis was 9.4 (4.8-13.7) years and the median age at stroke onset was 10.6 (6.7-15.5) years. The median time between the cancer diagnosis and the stroke episode was 6 months. CSVT cases were the most common (60%) followed by acute arterial ischemic (22%) and hemorrhagic strokes (18%), with CSVT being the latest to occur. We observed that the different types of strokes were related to some types of cancer. Of the children that had acute arterial ischemic stroke in this cohort, 83% had brain tumors, of the children who had CSVT, 87.5% had leukemia, and of the children who had hemorrhagic stroke, 40% had leukemia. Neurological abnormalities were more prevalent in acute arterial ischemic stroke (80%). Patients with CSVT recovered better than those with other types of strokes. Strokes recurred in 60% of ischemic strokes. L-Asparaginase was significantly associated with CSVT.

Conclusions

The prevalence of strokes was 2.9% in children with cancer. We were able to identify factors related to the types of the stroke that occurred in children including the type and location of the cancer the type of treatment received, and stroke recurrence.

Thrombosis Complications in Pediatric Acute Lymphoblastic Leukemia: Risk Factors, Management, and Prevention: Is There Any Role for Pharmacologic Prophylaxis?

Pediatric acute lymphoblastic leukemia (ALL) has achieved close to 90% cure rates through extensive collaborative and integrative molecular research, clinical studies, and advances in supportive care. Despite this high achievement, venous thromboembolic complications (VTE) remain one of the most common and potentially preventable therapy-associated adverse events in ALL. The majority of thromboses events involve the upper central venous system which is related to the use and location of central venous catheters (CVC). The reported rates of symptomatic and asymptomatic CVC-related VTE range from 2.6 to 36.7% and 5.9 to 43%, respectively. Thrombosis can negatively impact not only disease-free survival [e.g., therapy delays and/or interruption, omission of chemotherapy agents (e.g., asparaginase therapy)] but also can result in long-term adverse effects that can impair the quality of life of ALL survivors (e.g., post-thrombotic syndrome, central nervous system (CNS)-thrombosis related complications: seizures, neurocognitive deficits). In this review, will discuss thrombosis pathophysiology in pediatric ALL, risk factors, treatment, and prevention strategies. In addition, the recently published clinical efficacy and safety of direct oral anticoagulants (DOACs) use in thrombosis treatment, and their potential role in primary/secondary thrombosis prevention in pediatric patients with ALL will be discussed. Future clinical trials involving the use of these novel oral anticoagulants should be studied in ALL not only for primary thrombosis prevention but also in the treatment of thrombosis and its secondary prevention. These future research findings could potentially extrapolate to VTE prevention strategies in other pediatric cancer diagnoses and children considered at high risk for VTE.

Pediatric Stroke: Overview and Recent Updates

Stroke can occur at any age or stage in life. Although it is commonly thought of as a disease amongst the elderly, it is important to highlight the fact that it also affects infants and children. In both populations, strokes have a high rate of morbidity and mortality. Arguably, it is more detrimental in the pediatric population given the occurrence at a younger age and therefore, a longer duration of disability, potentially over the entire lifespan. The high rate of morbidity and mortality in pediatrics is attributed to significant delays in diagnosis, as well as misdiagnosis. Acute stroke management is time dependent. Patients who receive acute treatment with either intravenous (IV) tissue plasminogen activator (tPA) or mechanical thrombectomy, have improved mortality and functional outcomes. Additionally, the earlier treatment is initiated, the higher the likelihood of preserving penumbra, restoring cerebral blood flow and potentially reversing symptoms, thereby limiting disability. Prompt identification is essential as it leads to improved patient care in such a narrow therapeutic window. It enhances the care received during hospitalization and reduces the risk of early stroke recurrence. Despite limited data and lack of large randomized clinical trials in pediatrics, both IV tPA and mechanical thrombectomy have been successfully used. Bridging the gap of acute stroke management in the pediatric population is an essential part of minimizing adverse outcomes. In this review, we discuss the epidemiology of pediatric stroke, the diverse etiologies, presentation as well as both acute and preventative management.

Cancer-associated thrombosis in pediatric patients

Childhood malignancy and especially acute lymphoblastic leukemia are increasingly associated with thromboembolism. The etiology of pediatric cancer associated thrombosis is multifactorial and may reflect a tumor mass effect, tumor thrombi, alterations of the hemostatic system, treatment-related hazards (e.g. procoagulant changes induced by chemotherapy), presence of central venous lines and comorbidities (e.g. inherited thrombophilia). With over 80% cure rates of childhood cancer, strategies for prevention as well as for early diagnosis and optimal treatment of thromboembolism in children with malignancies are of major importance. While the use of therapeutic low molecular weight heparin prevails, prospective studies regarding guidelines for treatment or prevention are currently lacking. This review will address the epidemiology, etiology and risk factors for thrombosis, describe the presently available evidence associated with current therapy, and offer a glimpse into future treatment options.

Venous Thromboembolism in Children: From Diagnosis to Management

Venous thromboembolism (VTE) in children is a rare occurrence, although in recent decades we have seen an increase due to several factors, such as the rise in survival of subjects with chronic conditions, the use of catheters, and the increased sensitivity of diagnostic tools. Besides inherited thrombophilia, acquired conditions such as cardiovascular diseases, infections, chronic disorders, obesity and malignancy are also common risk factors for paediatric VTE. The treatment of paediatric VTE consists of the use of heparins and/or vitamin K antagonists to prevent dissemination, embolization, and secondary VTE. Randomized clinical trials of direct oral anticoagulants in paediatric VTE are ongoing, with the aim to improve the compliance and the care of patients. We reviewed the physiological and pathological mechanisms underlying paediatric thrombosis and updated the current diagnosis and treatment options.

Cancer-associated stroke: Pathophysiology, detection and management (Review)

Numerous types of cancer have been shown to be associated with either ischemic or hemorrhagic stroke. In this review, the epidemiology and pathophysiology of stroke in cancer patients is discussed, while providing vital information on the diagnosis and management of patients with cancer and stroke. Cancer may mediate stroke pathophysiology either directly or via coagulation disorders that establish a state of hypercoagulation, as well as via infections. Cancer treatment options, such as chemotherapy, radiotherapy and surgery have all been shown to aggravate the risk of stroke as well. The clinical manifestation varies greatly depending upon the underlying cause; however, in general, cancer‑associated strokes tend to appear as multifocal in neuroimaging. Furthermore, several serum markers have been identified, such as high D‑Dimer levels and fibrin degradation products. Managing cancer patients with stroke is a delicate matter. The cancer should not be considered a contraindication in applying thrombolysis and recombinant tissue plasminogen activator (rTPA) administration, since the risk of hemorrhage in cancer patients has not been reported to be higher than that in the general population. Anticoagulation, on the contrary, should be carefully examined. Clinicians should weigh the benefits and risks of anticoagulation treatment for each patient individually; the new oral anticoagulants appear promising; however, low‑molecular‑weight heparin remains the first choice. On the whole, stroke is a serious and not a rare complication of malignancy. Clinicians should be adequately trained to handle these patients efficiently.

Thrombosis in pediatric patients with leukemia

Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children. It is reportedly the most common malignancy associated with thromboembolism in the pediatric age group. Over the last 2 decades, venous thromboembolism (VTE) has been increasingly diagnosed among pediatric ALL patients with an estimated incidence ranging from about 5% (for symptomatic cases) to about 30-70% (following sequential imaging studies in asymptomatic children). The etiology is multifactorial and may stem from alterations of the hemostatic system following various chemotherapy protocols (including use of l-Asparaginase), the presence of central venous lines (CVL), as well as comorbidities, e.g. inherited thrombophilia risk factors. Most symptomatic thrombotic events occur in the upper venous system or in the central nervous system (CNS). Prospective studies on the establishment of guidelines for treatment or prevention are lacking. The following review will address the epidemiology, etiology and risk factors for thrombosis, describe the currently available evidence, and address issues associated with diagnosis and treatment.

Evaluation and Management of Acute-Onset Hemiparesis in an Adolescent With Leukemia

Emergency departments (EDs) are alert to the possibility of stroke and the need for early interventions to improve long-term clinical outcomes. However, new-onset hemiparesis in pediatric patients with leukemia may be due to a number of different etiologies, including most common side effects from chemotherapeutic agents. We present a case of a 15-year-old boy with pre-B acute lymphoblastic leukemia on chemotherapy, having recently received a high-dose methotrexate infusion in addition to intrathecal methotrexate therapy, who presented to our ED with acute right-sided hemiparesis. He was initially suspected as having a possible ischemic stroke. Magnetic resonance imaging (diffusion-weighted and fluid-attenuated inversion recovery sequence) demonstrated focal areas of diffusion restriction, an early sign of delayed-onset methotrexate neurotoxicity. Our patient received appropriate supportive care and leucovorin rescue with gradual clinical recovery, after a prolonged hospitalization and acute care rehabilitation over the course of several months. Our case illustrates the need for ED providers to consider methotrexate neurotoxicity in pediatric oncology patients presenting with acute neurologic changes.

Evaluation for inherited and acquired prothrombotic defects predisposing to symptomatic thromboembolism in children with acute lymphoblastic leukemia: a protocol for a prospective, observational, cohort study

BACKGROUND

Thromboembolism (TE) is a serious complication in children with acute lymphoblastic leukemia (ALL). The incidence of symptomatic thromboembolism is as high as 14% and case fatality rate of ~15%. Further, development of thromboembolism interferes with the scheduled chemotherapy with potential impact on cure rates. The exact pathogenesis of ALL-associated thromboembolism is unknown. Concomitant administration of asparaginase and steroids, two important anti-leukemic agents, is shown to increase the risk of ALL-associated TE. Dana-Farber Cancer Institute (DFCI) ALL studies reported ~10% incidence of thrombosis with significantly increased risk in older children (≥10 yrs.) and those with high-risk ALL. The majority (90%) of thromboembolic events occurred in the Consolidation phase of therapy with concomitant asparaginase and steroids when high-risk patients (including all older patients) receive higher dose steroids. Certain inherited and acquired prothrombotic defects are known to contribute to the development of TE. German investigators documented ~50% incidence of TE during therapy with concomitant asparaginase and steroids, in children with at least one prothrombotic defect. However, current evidence regarding the role of prothrombotic defects in the development of ALL-associated TE is contradictory. Although thromboprophylaxis can prevent thromboembolism, ALL and it's therapy can increase the risk of bleeding. For judicious use of thromboprophylaxis, identifying a population at high risk for TE is important. The risk factors, including prothrombotic defects, predisposing to thrombosis in children with ALL have not been defined.

METHODS

This prospective, observational cohort study aims to evaluate the prevalence of inherited prothrombotic defects in children with ALL treated on DFCI 05-01 protocol and the causal relationship of prothrombotic defects in combination with patient and disease-related factors to the development of TE. We hypothesize that the combination of prothrombotic defects and the intensive therapy with concomitant high dose steroids and asparaginase increases the risk of TE in older patients and patients with high-risk ALL.

DISCUSSION

The results of the proposed study will help design studies of prophylactic anticoagulant therapy. Thromboprophylaxis given to a targeted population will likely reduce the incidence of TE in children with ALL and ultimately improve their quality of life and prospects for cure.

Age at cancer diagnosis, non-O blood group and asparaginase therapy are independently associated with deep venous thrombosis in pediatric oncology patients: A risk model

INTRODUCTION

Pediatric oncology patients are at increased risk for deep venous thrombosis (DVT). Determining the sub-population of children at increased DVT risk is critical for optimum clinical management. Therefore, the aim of the current study was to identify clinical risk factors for DVT which are easily identifiable at cancer diagnosis.

MATERIALS AND METHODS

A Canadian multicenter case control study in survivors of childhood cancer. Survivors who had DVT (Cases) while being treated for pediatric cancer where matched by center with a minimum of two survivors who did not experience DVT (Controls). Clinical information including age at diagnosis, type of cancer and chemotherapy were collected. Genotyping of blood group was done by single nucleotide polymorphisms analysis.

RESULTS

218 subjects were recruited at 4 Canadian pediatric centers. Multivariable analysis demonstrated 3 significant variables (reported as Odds Ratio (OR), (95% CI), p value): age at diagnosis p<0.001, non-O blood group OR 2.6 (1.3-5.2) p=0.005 and asparaginase treatment OR 2.4 (1.2-4.8) p=0.011. In order to optimise clinical utility, we reanalysed the study data with age at diagnosis categorised into four subgroups 0-≤2years, >2-≤7years, >7≤10years, >10years. A significant association with DVT were seen in children 0-≤2years (OR 3.1 (1.1-8.3) p=0.026) and >10years (OR 3.8, 1.7-8.5 p=0.001). Significant associations with DVT remained for non-O blood group, OR 2.2 (1.2-4.4) p=0.016 and asparaginase treatment, OR 2.1 (1.1-4.0) p=0.027. The value for the clinical risk model receiver operating characteristics curve was 0.67.

CONCLUSIONS

We have shown 3 independent risk factors for DVT in childhood cancer.

Acute Central Nervous System Complications in Pediatric Acute Lymphoblastic Leukemia

BACKGROUND

The outcome of childhood acute lymphoblastic leukemia has improved because of intensive chemotherapy and supportive care. The frequency of adverse events has also increased, but the data related to acute central nervous system complications during acute lymphoblastic leukemia treatment are sparse. The purpose of this study is to evaluate these complications and to determine their long term outcome.

PATIENTS AND METHODS

We retrospectively analyzed the hospital reports of 323 children with de novo acute lymphoblastic leukemia from a 13-year period for acute neurological complications. The central nervous system complications of leukemic involvement, peripheral neuropathy, and post-treatment late-onset encephalopathy, and neurocognitive defects were excluded.

RESULTS

Twenty-three of 323 children (7.1%) suffered from central nervous system complications during acute lymphoblastic leukemia treatment. The majority of these complications (n = 13/23; 56.5%) developed during the induction period. The complications included posterior reversible encephalopathy (n = 6), fungal abscess (n = 5), cerebrovascular lesions (n = 5), syndrome of inappropriate secretion of antidiuretic hormone (n = 4), and methotrexate encephalopathy (n = 3). Three of these 23 children (13%) died of central nervous system complications, one from an intracranial fungal abscess and the others from intracranial thrombosis. Seven of the survivors (n = 7/20; 35%) became epileptic and three of them had also developed mental and motor retardation.

CONCLUSIONS

Acute central neurological complications are varied and require an urgent approach for proper diagnosis and treatment. Collaboration among the hematologist, radiologist, neurologist, microbiologist, and neurosurgeon is essential to prevent fatal outcome and serious morbidity.

Factor V Leiden 1691G/A and prothrombin gene 20210G/A polymorphisms as prothrombotic markers in adult Egyptian acute leukemia patients

Factor V Leiden 1691G/A and prothrombin gene 20210G/A mutations are the most common genetic defects leading to thrombosis. This work aimed to study the FV Leiden and the prothrombin gene polymorphism in adult Egyptian patients with acute leukemia and their importance in thrombophilia screening. The study included 76 patients with acute leukemia and 100 healthy controls. Genotyping was done by real-time polymerase chain reaction technique. For factor V Leiden, the frequency of G/A mutation conferred more than 2.5-fold of increased risk of (OR 2.639 95 % CI 1.045-6.669). The frequency of factor V Leiden combined (G/A + A/A) genotypes conferred 2.83-fold of increased risk (OR 2.828, CI 1.13-7.075), The A allele conferred almost threefold increased risk (OR 2.824, 95 % CI 1.175-6.785). Despite higher frequency in patients compared to controls, there was no risk of association between prothrombin gene mutation and acute leukemia in adult Egyptians nor was there between combined genotypes of prothrombin gene mutation and factor V Leiden.

Management of thrombotic complications in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children, and has been reported as the most common malignancy associated with thromboembolism in the pediatric age group. Treatment with Escherichia coli asparaginase, concomitant steroids, presence of central venous lines, and thrombophilic abnormalities are established risk factors for thromboembolism. The incidence varies with age, co-morbidities and chemotherapy regimens but the risk is highest during the induction and intensification phases. Treatment is necessary in majority of children to prevent serious sequelae. Mortality from thromboembolic events in any location is 2 to 4 % and the risk of recurrence is 7 to 10 %, further enhanced in the setting of malignancy. Randomized trials of venous thromboembolism (VTE) management in pediatric patients with ALL are lacking due to the low overall incidence, resulting in considerable variation in practice. The objective of this article is to review current knowledge on the treatment and prevention of thrombosis associated with pediatric ALL.

Hemorrhagic and ischemic stroke in children with cancer

BACKGROUND

Adult survivors of childhood cancer have an increased risk of cerebrovascular disease; little is known about early stroke risk in childhood cancer. Our objectives were to assess stroke prevalence in children with cancer, to establish cancer and stroke type, and to determine if modifiable risk factors for stroke were present.

METHODS

Children with stroke and cancer were compared with all children seen for cancer at a single institution between 2000 and 2009. An International Classification of Disease, 9th version, code search and search of existing pediatric oncology and stroke databases identified children <18 years with ischemic stroke, intracerebral hemorrhage, and cerebral sinovenous thrombosis.

RESULTS

Of 1411 children with cancer, 15 had a stroke (1.1%, 95% CI: 0.6-1.7%). Stroke classifications were seven intracerebral hemorrhages, five ischemic strokes (one of which was followed by intracerebral hemorrhage), and three sinovenous thromboses. Stroke occurred at a median of 5 months after cancer diagnosis. Ten children with strokes had hematologic malignancies and five had brain tumors. Thirteen patients died poststroke, eight because of withdrawal of care. White blood cell count ≥48,000/mm3 was found in four children, all with intracerebral hemorrhage. Five of seven children with intracerebral hemorrhage had platelets <50,000/mm3.

CONCLUSIONS

Stroke has a prevalence of approximately 1% in children with cancer. Hemorrhagic stroke and ischemic stroke occur with approximately equal frequency; children with leukemia and brain tumors are at greatest risk.

Screening for coagulopathy and identification of children with acute lymphoblastic leukemia at a higher risk of symptomatic venous thrombosis: an AIEOP experience

INTRODUCTION

Venous thromboembolic events (VTEs) are frequent complications of childhood acute lymphoblastic leukemia (ALL) treatment. The aim of the study was to evaluate the rate of symptomatic VTEs in children with ALL and the predictive value of clinical and biological factors and routine monitoring of coagulation parameters in identifying children at a higher risk of this complication.

MATERIALS AND METHODS

Between September 2000 and July 2006, 2042 children (≥1 and younger than 18 y) with newly diagnosed ALL were enrolled in Italy in the AIEOP (Italian Association of Pediatric Hematology and Oncology)-BFM (Berlin-Frankfurt-Muenster) ALL 2000 trial. Patients with symptomatic VTEs (deep venous thromboses or cerebral venous thromboses) were identified after a careful review of clinical records. The impact of coagulation derangement at the onset of VTEs was evaluated by a nested case-control study.

RESULTS

Forty-eight (2.4%) children presented with a VTE. The rate of VTEs was higher in male patients (P=0.001); patients randomized to receive dexamethasone tended to have a higher rate of VTE compared with those who received prednisone (P=0.10). The coagulation derangement at the onset of VTE was not associated with VTE occurrence. The prevalence of a factor V Leiden G1691A mutation and the prothrombin G20210A variant was higher in children with VTE than that expected in the general population.

Extensive sinovenous thrombosis and hemorrhagic infarction during therapy for T-cell acute lymphoblastic leukemia

Sinovenous thrombosis (SVT) is a well-recognized and serious complication in children treated for acute leukemia. This frequently occurs during or immediately upon completion of induction therapy and is commonly attributed to asparaginase therapy.Headache is the first and most common clinical symptom to occur during the early development of SVT. With advancement of the thrombosis, the clinical symptoms can progress to increased sleepiness, focal neurological deficit, seizures, and altered consciousness. We report the case of a 4-year-old girl who presented after several days of headaches and anorexia, which then progressed to seizures, left-sided weakness, and altered consciousness. She was later found to have a widespread and occlusive SVT with right cerebral hemorrhagic infarction. This case is notable for the extensive nature of the cerebral SVT and the child's complete clinical recovery from the neurological event. The report discusses the relation of the thrombosis and leukemia and also emphasizes the importance of early recognition and prompt management, while incorporating a collaborative multidisciplinary approach to prevent long-term consequences.

Factor V Leiden and Prothrombin 20210A Mutations among Turkish Pediatric Leukemia Patients

This study was undertaken to determine the prevalence of the Factor V 1691 G-A and PT 20210 G-A mutations in Turkish children with leukemia. We genotyped 135 pediatric leukemia patients with for these mutations. Eleven (8%) of the 135 patients were heterozygous for the FV 1691 G-A mutation. Seven (5,1%) of the patients carried the PT 20210 G-A heterozygous mutation. Of the 135 patients, only three had thrombotic event, none of which had these two mutations, which is common in Turkish population. Our findings revealed a controversial compared to the previous reports, which needs further investigation.

Thrombosis in childhood acute lymphoblastic leukaemia: epidemiology, aetiology, diagnosis, prevention and treatment

Acute lymphoblastic leukaemia (ALL) is the most common malignancy associated with venous thromboembolism (VTE) in children. The prevalence of symptomatic VTE ranges from 0% to 36%, and the variation can be explained, at least in part, by differences in chemotherapeutic protocols. The mechanism for increased risk of VTE is associated with alterations in the haemostatic system by use of L-asparaginase (ASP) alone or in combination with vincristine or prednisone, presence of central venous lines (CVLs) and/or inherited thrombophilia. The children at greatest risk are generally those receiving Escherichia coli ASP concomitant with prednisone. The majority of symptomatic VTEs occur in the central nervous system or in the upper venous system. In the majority of cases, asymptomatic VTEs are associated with CVLs. External CVLs are affected more often than internal CVLs. Evidence-based guidelines on prevention and treatment guidelines for ALL-related VTE are lacking, and carefully designed clinical trials are needed urgently.

Management of stroke in cancer

Cerebrovascular disorders, including brain infarction, brain hemorrhage, and cerebral venous thrombosis, can occur as an early sign of cancer, but typically occur late in the clinical course. These disorders are due to a variety of pathogenic mechanisms, including coagulation disorders associated with the cancer, invasion or compression of vessels from tumor in or adjacent to the brain, and the adverse effects of cancer therapy. The appropriate therapy for these cerebrovascular disorders is empiric in most instances, because as yet there are no prospective treatment trials for them. A review of the existing literature reveals that improvement in patient quality of life and prevention of further cerebrovascular events can be obtained in some clinical situations.

Thrombosis and acute lymphoblastic leukaemia

Venous thrombosis is more frequent in patients treated for acute lymphoblastic leukaemia (ALL) than other malignancies and has distinctive causes, clinical features and remedies. The reported incidence varies from 1% to 36%, depending on the chemotherapy protocol and whether the reported cases are symptomatic or detected on screening radiography. The risk is thought to arise from increased thrombin generation at diagnosis combined with reduced thrombin inhibitory capacity due to depletion of circulating anti-thrombin (AT) by asparaginase. A number of patient and treatment variables have been reported to influence the risk of thrombosis including hereditary thrombophilia, early insertion of central venous catheters and exposure to a combination of steroids and asparaginase during induction. Erwinia asparaginase is associated with a lower risk of thrombosis compared with Escherichia coli asparaginase. The majority of symptomatic thromboses are related to central venous catheters and involve the upper venous system. Central nervous system thrombosis involving the cerebral venous sinuses is a unique feature of asparaginase-related thrombosis and is reported to occur in 1-3% of patients. Conclusive evidence to support the use of anti-coagulant treatment or AT concentrates for primary prevention is lacking, as is evidence for the efficacy of AT concentrates in the management of established thrombosis. Preventative strategies are hampered by conflicting data on factors that would enable identification of those at highest risk of thrombosis.

Ischemic stroke in children with critical illness: a poor prognostic sign

A consecutive case series of 55 children (0-17 years old) with arterial ischemic stroke is reported. Twenty of these children were critically ill at the time their stroke occurred. Mortality among these 20 children was 40%, compared with 3% in non-critically ill children with arterial ischemic stroke; overall mortality in this case series was 16%. Mortality resulted primarily from the underlying illness. Prognosis after stroke is markedly worsened in children with premorbid critical illness.

Age and high-dose methotrexate are associated to clinical acute encephalopathy in FRALLE 93 trial for acute lymphoblastic leukemia in children

The objective of the study was to assess acute neurotoxicity associated with triple intrathecal therapy (TIT)+/-high-dose methotrexate (HD MTX) in children with acute lymphoblastic leukemia (ALL). 1395 children were enrolled on FRALLE 93 protocol from 1993 to 1999. Lower-risk group (LR, n=182) were randomized to weekly low-dose MTX at 25 mg/m(2)/week (LD MTX, n=81) or HD MTX at 1.5 g/m(2)/2 weeks x 6 (n=77). Intermediate-risk group (IR, n=672) were randomized to LD MTX (n=290) or HD MTX at 8 g/m(2)/2 weeks x 4 (n=316). Higher-risk group (HR, n=541) prednisone-responder patients received LD MTX and cranial radiotherapy. HR group steroid resistant cases were grafted (autologous or allogenic). TIT (MTX, cytarabine and methylprednisolone) was given every 2 weeks during 16-18 weeks and every 3 months during maintenance therapy in LR and IR patients. 52 patients (3.7%) developed neurotoxicity. Isolated seizures: n=15 (1.1%), peripheral and spinal neuropathy: n=17 (1.2%) and encephalopathy: n=20 (1.4%). Age >10 years was significantly associated with neurotoxicity (P=0.01) and use of HD MTX is associated with encephalopathy (P=0.03). Sequels are reported respectively in 60 and 33% of spinal neuropathy and encephalopathy cases. Current strategies tailoring risk of neurological sequels has to be defined.

The neurologic complications in pediatric acute lymphoblastic leukemia patients excluding leukemic infiltration

This study presents retrospective analyses of 20 acute lymphoblastic leukemia (ALL) patients who developed neurologic complications (except leukemic infiltration). These subjects represent 9.9% of 203 ALL patients aged 16 years or younger followed in our hospital between March 1991 and January 2003. Fourteen male and six female patients, whose ages ranged between 6 and 168 months, developed 24 episodes of neurologic complications after the diagnosis of ALL. The most common complication was meningitis, which developed in six (25%) episodes, and two thirds of the patients who had meningitis were evaluated to be iatrogenic. Cerebral infarct and venous thrombosis were detected in five (21%) of the episodes. In two (8%) episodes progressive cerebral dysfunction developed after radiotherapy. The remaining 11 (45%) episodes are due to varying types of complications. Interestingly, one patient had abundant histiocytes exhibiting hemophagocytosis in the cerebrospinal fluid (CSF) examination and this patient was subsequently diagnosed with fungal meningoencephalitis, by further investigation. Six (30%) patients died; epilepsia developed in five (25%) patients in the follow-up period and the remaining nine (45%) are healthy. By close follow-up and effective treatment of thrombosis and, especially, of infections including iatrogenic meningitis in developing countries, the morbidities and mortalities of these complications can be decreased.

Thrombosis in children with malignancy

PURPOSE OF REVIEW

The association between thrombosis and malignancy in adults is well known. Children are now surviving malignancies that previously resulted in mortality. Complications, however, occur including thrombosis that result in mortality and morbidity. This review will explore the association in children and discuss the epidemiology and evidence-based diagnosis and treatment of thrombosis in this cohort.

RECENT FINDINGS

Thrombin is an important link between malignancy, metastases, and inflammation. The accurate diagnosis of thrombosis in the upper venous system is directly related to the diagnostic technique used. Antithrombotic treatment is challenging owing to higher risks of bleeding, for example, decreased platelet counts, tiffelitis, large vascular tumor, etc.

SUMMARY

Thrombosis and malignancy are associated in children. Properly designed studies are urgently required to further define the epidemiology of thrombosis in different malignancies and to find the best way to diagnose and treat thrombosis in children.

Neurodevelopment and chronic illness: Mechanisms of disease and treatment

Successful treatment of many childhood diseases once considered terminal has resulted in the emergence of long-term effects of the disease or consequences of treatment that were previously unrecognized. Many of these long-term effects involve the central nervous system (CNS) and are developmental in the way that they emerge over time. Because we are now able to observe the natural history of childhood diseases such as sickle cell anemia or HIV, or the consequences of treatment of disease such as leukemia, brain tumors, or kidney disease, we are also able to study a number of biological mechanisms that result in long-term neurocognitive impairment. While some of the neurodevelopmental outcomes can be directly linked to structural damage of the CNS, other systems (e.g., hematologic, immunologic, pulmonary) appear to play crucial indirect roles in the development of the CNS and neurocognitive abilities because of the way that they affect the course of brain development and activity of the brain across time. Important interactions between acute disease factors, biological mechanisms, age at the time of disease or treatment effect, and disruptions in patterns of development after successful treatment or management all provide support for a neurodevelopmental model of childhood chronic illness. Testing this model may make it possible to more accurately predict the timing and degree of severity of long-term neurodevelopmental consequences, provide guidance for improved treatment and prevention, and offer better understanding of neurodevelopmental disruptions that occur in other non-chronic illness related disabilities.