Acute flaccid myelitis: cause, diagnosis, and management.

Acute flaccid myelitis (AFM) is a disabling, polio-like illness mainly affecting children. Outbreaks of AFM have occurred across multiple global regions since 2012, and the disease appears to be caused by non-polio enterovirus infection, posing a major public health challenge. The clinical presentation of flaccid and often profound muscle weakness (which can invoke respiratory failure and other critical complications) can mimic several other acute neurological illnesses. There is no single sensitive and specific test for AFM, and the diagnosis relies on identification of several important clinical, neuroimaging, and cerebrospinal fluid characteristics. Following the acute phase of AFM, patients typically have substantial residual disability and unique long-term rehabilitation needs. In this Review we describe the epidemiology, clinical features, course, and outcomes of AFM to help to guide diagnosis, management, and rehabilitation. Future research directions include further studies evaluating host and pathogen factors, including investigations into genetic, viral, and immunological features of affected patients, host-virus interactions, and investigations of targeted therapeutic approaches to improve the long-term outcomes in this population.

Temporal patterns in the risk of chronic health conditions in survivors of childhood cancer diagnosed 1970-99: a report from the Childhood Cancer Survivor Study cohort.

BACKGROUND: Treatments for childhood cancer have evolved over the past 50 years, with the goal of maximising the proportion of patients who achieve long-term survival, while minimising the adverse effects of therapy. We aimed to assess incidence patterns of serious chronic health conditions in long-term survivors of childhood cancer across three decades of diagnosis and treatment. METHODS: We used data from the Childhood Cancer Survivor Study, a retrospective cohort with longitudinal follow-up of 5-year survivors of common childhood cancers (leukaemia, tumours of the CNS, Hodgkin lymphoma, non-Hodgkin lymphoma, Wilms tumour, neuroblastoma, soft tissue sarcoma, or bone tumours) who were diagnosed before the age of 21 years and from 1970 to 1999 in North America. We examined the cumulative incidence of severe to fatal chronic health conditions occurring up to 20 years post-diagnosis among survivors, compared by diagnosis decade. We used multivariable regression models to estimate hazard ratios per diagnosis decade, and we added treatment variables to assess whether treatment changes attenuated associations between diagnosis decade and chronic disease risk. FINDINGS: Among 23 601 survivors with a median follow-up of 21 years (IQR 15-25), the 20-year cumulative incidence of at least one grade 3-5 chronic condition decreased significantly from 33·2% (95% CI 32·0-34·3) in those diagnosed 1970-79 to 29·3% (28·4-30·2; p<0·0001) in 1980-89, and 27·5% (26·4-28·6; p=0·012 vs 1980-89) in 1990-99. By comparison, the 20-year cumulative incidence of at least one grade 3-5 condition in 5051 siblings was 4·6% (95% CI 3·9-5·2). The 15-year cumulative incidence of at least one grade 3-5 condition was lower for survivors diagnosed 1990-99 compared with those diagnosed 1970-79 for Hodgkin lymphoma (17·7% [95% CI 15·0-20·5] vs 26·4% [23·8-29·1]; p<0·0001), non-Hodgkin lymphoma (16·9% [14·0-19·7] vs 23·8% [19·9-27·7]; p=0.0053), astrocytoma (30·5% [27·8-33·2] vs 47·3% [42·9-51·7]; p<0·0001), Wilms tumour (11·9% [9·5-14·3] vs 17·6% [14·3-20·8]; p=0·034), soft tissue sarcoma (28·3% [23·5-33·1] vs 36·5% [31·5-41·4]; p=0·021), and osteosarcoma (65·6% [60·6-70·6] vs 87·5% [84·1-91·0]; p<0·0001). By contrast, the 15-year cumulative incidence of at least one grade 3-5 condition was higher (1990-99 vs 1970-79) for medulloblastoma or primitive neuroectodermal tumour (58·9% [54·4-63·3] vs 42·9% [34·9-50·9]; p=0·00060), and neuroblastoma (25·0% [21·8-28·2] vs 18·0% [14·5-21·6]; p=0·0045). Results were consistent with changes in treatment as a significant mediator of the association between diagnosis decade and risk of grade 3-5 chronic conditions for astrocytoma (HR per decade without treatment in the model = 0·77, 95% CI 0·64-0·92; HR with treatment in the model=0·89, 95% CI 0·72-1·11; pmediation=0·0085) and Hodgkin lymphoma (HR without treatment=0·75, 95% CI 0·65-0·85; HR with treatment=0·91, 95% CI 0·73-1·12; pmediation=0·024). Temporal decreases in 15-year cumulative incidence comparing survivors diagnosed 1970-79 to survivors diagnosed 1990-99 were noted for endocrinopathies (5·9% [5·3-6·4] vs 2·8% [2·5-3·2]; p<0·0001), subsequent malignant neoplasms (2·7% [2·3-3·1] vs 1·9% [1·6-2·2]; p=0·0033), musculoskeletal conditions (5·8% [5·2-6·4] vs 3·3% [2·9-3·6]; p<0·0001), and gastrointestinal conditions (2·3% [2·0-2·7] vs 1·5% [1·3-1·8]; p=0·00037), while hearing loss increased (3·0% [2·6-3·5] vs 5·7% [5·2-6·1]; p<0·0001). INTERPRETATION: Our results suggest that more recently treated survivors of childhood cancer had improvements in health outcomes, consistent with efforts over the same time period to modify childhood cancer treatment regimens to maximise overall survival, while reducing risk of long-term adverse events. Continuing advances in cancer therapy offer promise of further reducing the risk of long-term adverse events in childhood cancer survivors. However, achieving long-term survival for childhood cancer continues to come at a cost for many survivors, emphasising the importance of long-term follow-up care for this population. FUNDING: National Cancer Institute and the American Lebanese-Syrian Associated Charities.

Fueling the FIRES: Hemophagocytic lymphohistiocytosis in febrile infection-related epilepsy syndrome.

OBJECTIVES: Although secondary hemophagocytic lymphohistiocytosis (HLH) has been reported in children with critical illness of various etiologies, it has not been reported in patients with febrile infection-related epilepsy syndrome (FIRES). We describe a series of patients with concurrent HLH and FIRES in an effort to establish common pathophysiologic abnormalities. METHODS: Five patients with FIRES who were assessed for HLH were identified from a neurocritical care database. All were previously healthy and had extensive diagnostic testing. All had clinical deterioration with multiorgan dysfunction prompting HLH screening 20-29 days after hospitalization. Markers for inflammatory dysregulation were assessed in cerebrospinal fluid (CSF) and serum at various time points. Outcomes were assessed 6 months after presentation. RESULTS: Three patients met clinical criteria for secondary HLH. Elevation of specific cytokines/chemokines was variable. CSF neopterin, high mobility group box 1 (HMGB1), and C-X-C motif chemokine ligand 8 (CXCL8) were significantly elevated in all. Interleukin-1ß (IL-1ß) and IL-18 were not elevated in any of the samples. Treatment and outcomes were variable. SIGNIFICANCE: We describe 3 patients with HLH and FIRES. The co-occurrence of these 2 rare disorders suggests the possibility of a common immune dysregulation phenotype prolonging epileptogenesis. HLH screening in critically ill patients with FIRES may yield a broader understanding of shared inflammatory processes.

The dynamic role of genetics on cortical patterning during childhood and adolescence.

Longitudinal imaging and quantitative genetic studies have both provided important insights into the nature of human brain development. In the present study we combine these modalities to obtain dynamic anatomical maps of the genetic contributions to cortical thickness through childhood and adolescence. A total of 1,748 anatomic MRI scans from 792 healthy twins and siblings were studied with up to eight time points per subject. Using genetically informative latent growth curve modeling of 81,924 measures of cortical thickness, changes in the genetic contributions to cortical development could be visualized across the age range at high resolution. There was highly statistically significant (P < 0.0001) genetic variance throughout the majority of the cerebral cortex, with the regions of highest heritability including the most evolutionarily novel regions of the brain. Dynamic modeling of changes in heritability over time demonstrated that the heritability of cortical thickness increases gradually throughout late childhood and adolescence, with sequential emergence of three large regions of high heritability in the temporal poles, the inferior parietal lobes, and the superior and dorsolateral frontal cortices.

Anaplastic Ependymoma in a Child With Sickle Cell Anemia: A Case Report Highlighting Treatment Challenges for Young Children With Central Nervous System Tumors and Underlying Vasculopathy.

A 3-year-old boy with sickle cell anemia (SCA) presented with progressive daily emesis and was found to have an anaplastic ependymoma. Radiation therapy and chemotherapy are usually employed after subtotal resections of anaplastic ependymomas, although the benefits from chemotherapy are unclear. To mitigate the risks of adjuvant treatment in this patient at risk for SCA-associated vasculopathy, renal impairment, and other end-organ damage, proton beam irradiation without chemotherapy was chosen. Scheduled packed red blood cell transfusions were instituted to maintain sickle hemoglobin levels less than 30%. This case highlights treatment complexities for malignant brain tumors in patients predisposed to treatment-related adverse effects.

Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results.

INTRODUCTION: Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up. METHODS: Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions. RESULTS: A new, proposed definition of "post-operative pediatric CMS" was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed. DISCUSSION: The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.

Patterns and severity of vincristine-induced peripheral neuropathy in children with acute lymphoblastic leukemia.

Vincristine, a critical component of combination chemotherapy treatment for pediatric acute lymphoblastic leukemia (ALL), can lead to vincristine-induced peripheral neuropathy (VIPN). Longitudinal VIPN assessments were obtained over 12 months from newly diagnosed children with ALL (N = 128) aged 1-18 years who received vincristine at one of four academic children's hospitals. VIPN assessments were obtained using the Total Neuropathy Score-Pediatric Vincristine (TNS©-PV), National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE©), Balis© grading scale, and Pediatric Neuropathic Pain Scale©-Five (PNPS©-5). Of children who provided a full TNS©-PV score, 85/109 (78%) developed VIPN (TNS©-PV ≥4). Mean TNS©-PV, grading scale, and pain scores were low. CTCAE©-derived grades 3 and 4 sensory and motor VIPN occurred in 1.6%/0%, and 1.9%/0% of subjects, respectively. VIPN did not resolve in months 8-12 despite decreasing dose density. VIPN was worse in older children. Partition cluster analysis revealed 2-3 patient clusters; one cluster (n = 14) experienced severe VIPN. In this population, VIPN occurs more commonly than previous research suggests, persists throughout the first year of treatment, and can be severe.

Paroxysmal Sympathetic Hyperactivity in Critically Ill Children with Encephalitis and Meningoencephalitis.

BACKGROUND: Autonomic dysfunction in pediatric patients with acquired brain injury is often encountered and greatly understudied. We sought to identify the incidence of Paroxysmal Sympathetic Hyperactivity (PSH) in critically ill pediatric patients with meningoencephalitis and encephalitis, associated risk factors and influence on outcome. METHODS: Children admitted to the pediatric intensive care unit (PICU) with a diagnosis of meningoencephalitis and/or encephalitis were identified from a single institution Neurocritical Care database. The patients were stratified as having a bacterial or non-bacterial cause of their meningoencephalitis/encephalitis. Data from their hospitalization was supplemented with a retrospective review of the electronic medical record. PSH was defined as episodic lability in heart rate and/or blood pressure, hyperthermia, diaphoresis, dystonic posturing, tachypnea and/or agitation without any other cause. Statistical analysis was performed using t-test and chi-squared to compare outcomes and risk factors between patients with PSH and without. RESULTS: PSH was found in 41 % of children studied. Subgroup analysis revealed patients with non-bacterial encephalitis were more likely to experience PSH (51 %) as compared to those with bacterial causes (27 %). Fever and/or seizures on presentation and female gender were associated with higher occurrence of PSH but only in the non-bacterial etiology group. There were trends toward increased length of PICU and overall hospital stay for patients with PSH. CONCLUSIONS: PSH was found in a high percentage of our patients with significant variation in risk factors and outcome noted between patients with bacterial and nonbacterial causes of their meningoencephalitis/encephalitis.

Treatment developments and the unfolding of the quality of life discussion in childhood medulloblastoma: a review.

PURPOSE: To describe how the quality of life (QOL) discussion in childhood medulloblastoma (MB) relates to treatment developments, survival and sequelae from 1920 to 2014. METHODS: Articles containing "childhood medulloblastoma" and "quality of life" were identified in PubMed. Those containing phrases pertaining to psychological, emotional, behavioral or social adjustment in the title, abstract or keywords were selected. Inclusion of relevant older publications was assured by cross-checking references. RESULTS: 1920-1930s: suction, electro-surgery, kilovolt (KV) irradiation. Survival = months. Focus on operative mortality, symptoms and survival. 1940s: radiotherapy improved. 1950s: chemotherapy and intubation. Survival = years. Opinions oscillated between optimism/awareness of physical sequelae of radiotherapy. 1960s: magnified vision, ventriculo-peritoneal (VP) shunts, megavolt (MV) irradiation. Long-term survival shifted the attention towards neurological problems, disability and carcinogenesis of radiotherapy. 1970s: CT, microscope, bipolar coagulation, shunt filters, neuroanesthesia, chemotherapy trials and staging studies. Operative mortality decreased and many patients (re)entered school; emphasis on neuropsychological sequelae, IQ and academic performance. 1980s: magnetic resonance imaging (MRI), Cavitron ultrasonic aspiration (CUSA), laser surgery, hyper-fractionated radiotherapy (HFRT). Cerebellar mutism, psychological and social issues. 1990s: pediatric neurosurgery, proton beams, stem cell rescue. Reflections on QOL as such. 21st century: molecular genetics. Premature aging, patterns of decline, risk- and resilience factors. DISCUSSION: QOL is a critical outcome measure. Focus depends on survival and sequelae, determined after years of follow-up. Detailed measurements are limited by time, money and human resources, and self-reporting questionnaires represent a crude measure limited by subjectivity. Therapeutic improvements raise the question of QOL versus cure. QOL is a potential primary research endpoint; multicenter international studies are needed, as are web-based tools that work across cultures.

Individualized Care Delivery for Children With Autism and Related Disabilities Undergoing Overnight Video Electroencephalography (EEG): One Hospital's Experience With a Coordinated Team Approach.

Background and Purpose: Children with developmental disabilities have increased risk of epilepsy and need for overnight video electroencephalographic (EEG) monitoring. However, video EEGs have historically been considered difficult to complete for this population. An autism support service at a pediatric tertiary care hospital implemented a coordinated team approach to help children with developmental disability tolerate overnight video EEGs. The project included completion of a caregiver-report preprocedure questionnaire that then was shared with the multidisciplinary team and used to create individualized care plans. The current study aims to describe rates of video EEG completion and need for lead placement under general anesthesia among children with autism and related disabilities who received these supports. Methods: Rates of video EEG completion and general anesthesia use were analyzed for children referred to the support service between April 2019 and November 2021. Results: A total of 182 children with developmental disability (mean age = 10.3 years, 54.9% diagnosed with autism) met inclusion criteria. 92.9% (n = 169) of children successfully completed EEG (leads on ≥12 hours). Only 19.2% (n = 35) required general anesthesia for video EEG lead placement. The majority (80.2%) of parents (n = 146) completed the preprocedure questionnaire. Video EEG outcomes did not differ based on completion of the questionnaire. Parent-reported challenges with communication and cooperation were associated with shorter video EEG duration and greater use of general anesthesia. Conclusions: These findings suggest that most children with developmental disability can complete video EEG with sufficient support. Preprocedure planning can identify children who would benefit from additional accommodations. Further research is necessary to clarify which supports are most helpful.

Glial Fibrillary Acidic Protein (GFAP) Astrocytopathy: An Emerging Cause of Meningoencephalomyelitis in Children and Adolescents.

Introduction: We describe 5 children with GFAP astrocytopathy with the goal of further characterizing this rare form of meningoencephalomyelitis. Methods: Retrospective chart review of patients diagnosed with GFAP astrocytopathy between 2019 and 2021. Results: Patients were 8-17 years old, and all were male. Fever, headache, and vomiting were common presenting symptoms, and weakness, tremor, and ataxia were common initial examination findings. Initial magnetic resonance imaging (MRI) showed spinal cord abnormalities in 2 patients and leptomeningeal enhancement in 1. Most patients had cerebral spinal fluid pleocytosis, and all screened negative for malignancy. Three patients progressed to coma, and all were treated with immunosuppressant therapy. By discharge, all patients had improved over their clinical nadir, although none had returned to baseline. Discussion: GFAP astrocytopathy is a recently recognized cause of meningoencephalomyelitis in children. Here, we expand our understanding of this entity with the goal of aiding those treating children with GFAP astrocytopathy.

Paraneoplastic neurologic disorders in children.

Paraneoplastic neurologic syndromes are rare disorders that have potentially devastating effects on the developing brain. Recently, there has been increased interest in possible immunotherapy for these disorders. Recognition of paraneoplastic syndromes in children may lead to early detection and treatment of the pediatric cancer and may diminish the neurologic damage that is the major source of morbidity in children with successfully treated tumors. This article reviews the presenting symptoms, immunology, long-term sequelae, and management options for paraneoplastic neurologic syndromes, focusing on those most commonly reported in children: opsoclonus-myoclonus ataxia, limbic encephalitis, and anti-NMDAR encephalitis. The child neurologist plays an important role in recognizing these disorders, initiating a tumor search, and directing ongoing treatment and management of neurologic symptoms after oncologic treatment is complete. Given the rarity of these conditions, multisite collaborative efforts are needed to develop standardized approaches to characterization and treatment.

Management considerations for stroke-like episodes in MELAS with concurrent COVID-19 infection.

There have been considerations since the beginning of the Coronavirus pandemic that COVID-19 infection, like any other viral illness, can trigger neurological and metabolic decompensation in patients with mitochondrial diseases. At the time of writing, there were no published reports reviewing experiences and guidelines about management of COVID-19 infection in this patient population. We present a challenging case of an adult patient with a known diagnosis of Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like Episodes (MELAS) complicated by COVID-19 infection. She initially presented with altered mental status and vomiting and went on to develop a stroke-like episode, pancreatitis, and pneumatosis intestinalis. We review salient features of her hospitalization, including initiation of thromboprophylaxis in relation to intravenous arginine therapy, caution regarding medications such as remdesivir, and the incidence of gastrointestinal complications.

Longitudinal assessment of late-onset neurologic conditions in survivors of childhood central nervous system tumors: a Childhood Cancer Survivor Study report.

Background: Survivors of childhood central nervous system (CNS) tumors experience high rates of treatment-related neurologic sequelae. Whether survivors continue to be at increased risk for new events as they age is unknown. Methods: Adverse neurologic health conditions in 5-year survivors of CNS tumors from the Childhood Cancer Survivor Study (n = 1876) were evaluated longitudinally at a median 23.0 years from diagnosis (range, 5.1-38.9), median age at last evaluation 30.3 years (range, 6.1-56.4). Multivariable regression estimated hazard ratios (HRs) and 95% CIs. Results: From 5 to 30 years post diagnosis, cumulative incidence increased for seizures from 27% to 41%, motor impairment 21% to 35%, and hearing loss 9% to 23%. Risks were elevated compared with siblings (eg, seizures HR: 12.7; 95% CI: 9.6-16.7; motor impairment HR: 7.6; 95% CI: 5.8-9.9; hearing loss HR: 18.4; 95% CI: 13.1-25.9). Regional brain doses of radiation therapy were associated with development of new deficits (eg, frontal ≥50 Gy and motor impairment HR: 2.0; 95% CI: 1.2-3.4). Increased risk for motor impairment was also associated with tumor recurrence (HR: 2.6; 95% CI: 1.8-3.8), development of a meningioma (HR: 2.3; 95% CI: 0.9-5.4), and stroke (HR: 14.9; 95% CI: 10.4-21.4). Seizure risk was doubled by recurrence (HR: 2.3; 95% CI: 1.6-3.2), meningioma (HR: 2.6; 95% CI: 1.1-6.5), and stroke (HR: 2.0; 95% CI: 1.1-3.4). Conclusions: CNS tumor survivors remain at risk for new-onset adverse neurologic events across their lifespans at a rate greater than siblings. Cranial radiation, stroke, tumor recurrence, and development of meningioma were independently associated with late-onset adverse neurologic sequelae.

Alexander Disease.

Alexander disease is a leukodystrophy caused by dominant missense mutations in the gene encoding the glial fibrillary acidic protein. Individuals with this disorder often present with a typical neuroradiologic pattern including white matter abnormalities with brainstem involvement, selective contrast enhancement, and structural changes to the basal ganglia/thalamus. In rare cases, focal lesions have been seen and cause concern for primary malignancies. Here the authors present an infant initially diagnosed with a chiasmatic astrocytoma that was later identified as having glial fibrillary acidic protein mutation-confirmed Alexander disease. Pathologic and radiologic considerations that were helpful in arriving at the correct diagnosis are discussed.

Challenges in Determining the Role of Rest and Exercise in the Management of Mild Traumatic Brain Injury.

Current consensus guidelines recommending physical and cognitive rest until a patient is asymptomatic after a sports concussion (ie, a mild traumatic brain injury) are being called into question, particularly for patients who are slower to recover and in light of preclinical and clinical research demonstrating that exercise aids neurorehabilitation. The pathophysiological response to mild traumatic brain injury includes a complex neurometabolic cascade of events resulting in a neurologic energy deficit. It has been proposed that this energy deficit leads to a period of vulnerability during which the brain is at risk for additional injury, explains why early postconcussive symptoms are exacerbated by cognitive and physical exertion, and is used to rationalize absolute rest until all symptoms have resolved. However, at some point, rest might no longer be beneficial and exercise might need to be introduced. At both extremes, excessive exertion and prolonged avoidance of exercise (physical and mental) have negative consequences. Individuals who have experienced a concussion need guidance for avoidance of triggers of severe symptoms and a plan for graduated exercise to promote recovery as well as optimal functioning (physical, educational, and social) during the postconcussion period.

Pediatric brain tumors.

PURPOSE OF REVIEW: Pediatric brain tumors differ from those arising in adulthood. This article discusses the presentation, location, histology, new molecular understanding, therapy, and outcome of brain tumors in children. RECENT FINDINGS: Improved biological understanding of pediatric brain tumors is resulting in new molecular-based classification and the development of rationally designed therapeutics. SUMMARY: The presentation of a pediatric brain tumor is dependent on the type of tumor, its location in the nervous system, and the age of the child. Diagnostic workup varies depending on the location of the tumor and the tumor's propensity to disseminate in the nervous system. Survival has improved for pediatric brain tumors, particularly medulloblastoma, as a result of improved surgical techniques and rational use of postoperative radiation and chemotherapy. For medulloblastoma, recent studies have sought to maintain or improve survival while decreasing neurologic sequelae, particularly from radiation in young children. For other childhood brain tumor types, improvements in outcome are not as clear-cut. New molecular insights will likely alter classification, risk stratification, and therapy in the near future.

Pediatric brain tumors and epilepsy.

Seizures are a common complication of pediatric brain tumors and their treatment. This article reviews the epidemiology, evaluation, and treatment of seizures in children with brain tumors. Seizures in known brain tumor patients may signify tumor progression or recurrence, or treatment-related brain damage, as well as other causes, including low drug levels and metabolic disturbances. Careful selection of antiepileptic medications is needed in this population. There are advantages to nonenzyme-inducing antiepileptic drugs including valproic acid, which has potential antitumoral properties as a histone deacetylase inhibitor. Tumor surgery cures many cases of pediatric tumor-associated seizures, and some children are controlled with anti-epileptic medication, however additional epilepsy surgery may be needed for refractory cases.

Biologically targeted therapeutics in pediatric brain tumors.

Pediatric brain tumors are often difficult to cure and involve significant morbidity when treated with traditional treatment modalities, including neurosurgery, conventional chemotherapy, and radiotherapy. During the past two decades, a clearer understanding of tumorigenesis, molecular growth pathways, and immune mechanisms in the pathogenesis of cancer has opened up promising avenues for therapy. Pediatric clinical trials with novel biologic agents are underway to treat various pediatric brain tumors, including high and low grade gliomas and embryonal tumors. As the therapeutic potential of these agents undergoes evaluation, their toxicity profiles are also becoming better understood. These agents have potentially better central nervous system penetration and lower toxicity profiles compared with conventional chemotherapy. In infants and younger children, biologic agents may prove to be of equal or greater efficacy compared with traditional chemotherapy and radiation therapy, and may reduce the deleterious side effects of traditional therapeutics on the developing brain. Molecular pathways implicated in pediatric brain tumors, agents that target these pathways, and current clinical trials are reviewed. Associated neurologic toxicities will be discussed subsequently. Considerable work is needed to establish the efficacy of these agents alone and in combination, but pediatric neurologists should be aware of these agents and their rationale.