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1.
J Neurooncol ; 145(3): 595, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31768714

RESUMO

In the original article, the author names were published incorrectly. The names are correct in this publication.

2.
Can J Neurol Sci ; 46(5): 550-558, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31179961

RESUMO

BACKGROUND: Brain neoplasms are the second-most prevalent cancer of childhood for which surgical resection remains the main treatment. Intraoperative MRI is a useful tool to optimize brain tumor resection. It is, however, not known whether intraoperative MRI can detect complications such as hyperacute ischemic infarcts. METHODS: A retrospective analysis of pre- and intraoperative MRIs including DWI sequence and correlation with early and 3-month postoperative MRIs was conducted to evaluate the incidence of hyperacute arterial infarct during pediatric brain tumor resection. Patient demographics, pathological type, tumor location, resection type as well as preoperative tumoral vessel encasement, evolution of the area of restricted diffusion were collected and analyzed comparatively between the group with acute infarct and the control group. Extent of the hyperacute infarct was compared to both early postsurgical and 3-month follow-up MRIs. RESULTS: Of the 115 cases, 13 (11%) developed a hyperacute arterial ischemic infarct during brain tumor resection. Tumoral encasement of vessels was more frequent in the infarct group (69%) compared to 25.5% in the control group. Four cases showed additional vessel irregularities on intraoperative MRI. On early follow-up, the infarcted brain area had further progressed in six cases and was stable in seven cases. No further progression was noted after the first week post-surgery. CONCLUSIONS: Hyperacute infarcts are not rare events to complicate pediatric brain tumor resection. Tumoral encasement of the circle of Willis vessels appears to be the main risk factor. Intraoperative DWI underestimates the final extent of infarcted tissue compared to early postsurgical MRI.


Présence d'infarctus ischémiques hyper-aigus révélés par des IRM peropératoires de diffusion dans le cas de chirurgies visant à traiter le cancer du cerveau chez l'enfant.Contexte: Chez l'enfant, les néoplasmes du cerveau viennent au second rang des cancers pour lesquels la résection chirurgicale demeure le principal traitement. L'IRM peropératoire est un outil efficace pour maximiser la résection d'une tumeur cérébrale. On ignore toutefois de quelle façon cet outil peut permettre de détecter des complications telles que les infarctus ischémiques hyper-aigus. Méthodes:Nous avons tout d'abord effectué une analyse rétrospective des IRM préopératoires et peropératoires, ce qui inclut des IRM de diffusion. Nous avons aussi cherché à établir des corrélations avec des IRM post-opératoires, certaines effectuées tout juste après une résection et d'autres après 3 mois, afin d'évaluer l'incidence d'infarctus ischémiques hyper-aigus survenant en cours de résection. Des données portant sur les caractéristiques des patients, sur la pathologie tumorale, sur l'emplacement des tumeurs, sur le type de résection ainsi que sur l'envahissement vasculaire tumoral préopératoire et sur l'évolution de la région de diffusion restreinte ont été collectées. Nous avons ensuite effectué une analyse comparative entre notre groupe de patients et un groupe de témoins. L'ampleur des infarctus ischémiques hyper-aigus a été comparée au moyen d'IRM réalisées tout juste après une résection et d'IRM de suivi après trois mois. Résultats:Sur un total de 115 cas, 13 (11 %) ont donné à voir un infarctus ischémique hyper-aigu au cours d'une résection. L'envahissement vasculaire tumoral était plus fréquent dans le groupe de jeunes patients ayant donné à voir un infarctus (69 %) comparativement à 25,5 % dans le groupe des témoins. Quatre cas ont aussi montré, lors d'IRM peropératoires, des irrégularités additionnelles en ce qui a trait aux vaisseaux sanguins. Lors de suivis effectués rapidement après une résection, les régions du cerveau affectées par un infarctus avaient continué à croître davantage chez 6 cas et étaient demeurées stables chez 7 autres cas. Aucune autre progression n'a été notée à la suite d'une IRM menée une semaine plus tard. Conclusions:Les infarctus ischémiques hyper-aigus ne sont pas des événements inhabituels. Comme on le sait, ils peuvent entraîner des complications au moment d'effectuer la résection d'une tumeur cérébrale chez l'enfant. L'envahissement vasculaire tumoral du polygone de Willis semble être ici le principal facteur de risque. Les IRM de diffusion peropératoires ont tendance à sous-estimer l'étendue finale des tissus affectés par un infarctus ischémique comparativement aux IRM effectuées tout juste après une résection.


Assuntos
Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/etiologia , Neoplasias Encefálicas/cirurgia , Imagem de Difusão por Ressonância Magnética/métodos , Complicações Intraoperatórias/diagnóstico por imagem , Procedimentos Neurocirúrgicos/efeitos adversos , Infarto Encefálico/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Complicações Intraoperatórias/epidemiologia , Complicações Intraoperatórias/etiologia , Período Intraoperatório , Masculino , Estudos Retrospectivos
3.
J Craniofac Surg ; 30(6): 1631-1634, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30921065

RESUMO

BACKGROUND: Cranial vault surgery for craniosynostosis is generally managed postoperatively in the intensive care unit (ICU). The purpose of the present study was to examine our center's experience with the postoperative management of otherwise healthy patients with nonsyndromic craniosynostosis (NSC) without routine ICU admission. METHODS: A retrospective cohort study of patients with NSC operated using a variety of vault reshaping techniques in our pediatric center between 2009 and 2017 was carried out. Patients with documented preexisting comorbidities that would have required admission to the ICU regardless of the surgical intervention were excluded. RESULTS: A total of 102 patients were included in the study. Postoperatively, 100 patients (98%) were admitted as planned to a general surgical ward following observation in the recovery room. Two patients (2%) required ICU admission due to adverse intraoperative events. There were no patients who required transfer to the ICU from the recovery area or surgical ward. Within the surgical ward cohort, 6 patients (6%) had minor postoperative complications that were readily managed on the surgical floor. Postoperative anemia requiring transfusion was the most common complication. CONCLUSION: The results from this study suggest that otherwise healthy patients with NSC undergoing cranial vault surgery can potentially be safely managed without routine admission to the ICU postoperatively. Key elements are proper preoperative screening, access to ICU should an adverse intraoperative event occur and necessary postoperative surgical care. The authors hope that this experience will encourage other craniofacial surgeons to reconsider the dogma of routine ICU admission for this patient population.


Assuntos
Craniossinostoses/cirurgia , Transfusão de Sangue , Hospitalização , Humanos , Unidades de Terapia Intensiva , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/epidemiologia , Período Pós-Operatório , Estudos Retrospectivos , Crânio
4.
J Neurooncol ; 140(2): 435-444, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30097824

RESUMO

INTRODUCTION: Pediatric pilocytic astrocytomas (PAs) are low grade gliomas and the most common brain tumors in children. They often represent a therapeutic challenge when incompletely resected as they can recur and progress despite the use of several lines of chemotherapeutic agents or even radiation therapy. Genetic alterations leading to activation of the mitogen-activated-protein-kinase pathway are a hallmark of this disease and offer an interesting therapeutic alternative through the use of targeted inhibitors. METHODS: Here, we describe six children with sporadic PA who were treated with trametinib, a MEK inhibitor, following progression under conventional therapies. Retrospective chart review was performed. RESULTS: The median age at diagnosis was 2.3 years (y) old [range 11 months (m)-8.5 y old]. KIAA1549-BRAF fusion was identified in five cases, and hotspot FGFR1/NF1/PTPN11 mutations in one. All patients received at least one previous line of chemotherapy (range 1-4). The median time on treatment was 11 m (range 4-20). Overall, we observed two partial responses and three minor responses as best response; three of these patients are still on therapy. Treatment was discontinued in the patient with progressive disease. The most frequent toxicities were minor to moderately severe skin rash and gastro-intestinal symptoms. Two patients had dose reduction due to skin toxicity. Quality of life was excellent with decreased hospital visits and a close to normal life. CONCLUSION: Trametinib appears to be a suitable option for refractory pediatric low-grade glioma and warrants further investigations in case of progression.


Assuntos
Antineoplásicos/uso terapêutico , Astrocitoma/tratamento farmacológico , Neoplasias Encefálicas/tratamento farmacológico , Piridonas/uso terapêutico , Pirimidinonas/uso terapêutico , Antineoplásicos/efeitos adversos , Astrocitoma/diagnóstico por imagem , Astrocitoma/genética , Astrocitoma/fisiopatologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/fisiopatologia , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Lactente , Masculino , Inibidores de Proteínas Quinases/uso terapêutico , Piridonas/efeitos adversos , Pirimidinonas/efeitos adversos , Retratamento , Estudos Retrospectivos
5.
Can J Neurol Sci ; 44(3): 329-331, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28073391

RESUMO

Absence of the cervical pedicle is a very rare congenital anomaly, easily misrecognized as a unilateral facet dislocation in a setting of acute trauma or a neoplastic process like a nerve sheath tumor. Although correct diagnosis can be achieved on the cervical radiograph and confirmed by the CT, MRI Myelography is clearly of additional value because shows the specific relationship and orientation of the nerve roots. To the best to our knowledge, this is the first description of MR Myelography findings.


Assuntos
Vértebras Cervicais/anormalidades , Vértebras Cervicais/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Mielografia/métodos , Adolescente , Humanos , Masculino
6.
Childs Nerv Syst ; 32(12): 2415-2422, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27757571

RESUMO

PURPOSE: Three-tesla intraoperative MRI (iMRI) is a promising tool that could help confirm complete resections and disconnections in pediatric epilepsy surgery, leading to improved outcomes. However, a large proportion of epileptogenic pathologies in children are poorly defined on imaging, which brings into question the utility of iMRI for these cases. Our aim was to compare postoperative seizure outcomes between iMRI- and non-iMRI-based epilepsy surgeries. METHODS: We performed a comparative retrospective analysis of non-iMRI- versus iMRI-based epilepsy surgeries with 2-year follow-up. Patients were stratified into well-defined cases (WDCs), poorly defined cases (PDCs), and diffuse hemispheric cases (DHCs). Primary outcomes were rates of complete seizure freedom and surgical complications. Secondary outcomes included good (Engel class I/II) seizure outcome, extent of resection/disconnection, and operative duration. Regression models were used to adjust for confounding. RESULTS: Thirty-nine iMRI-based and 39 non-iMRI-based surgeries were included. The distributions of age, sex, and lesion class in each era were similar, but the distributions of individual pathologies varied. Seizure freedom and complication rates at 2-year follow-up were not different between the groups, but Engel class I/II outcome was more common in the iMRI group. Extent of resection/disconnection and length of surgery were similar in both groups. PDCs had the worst outcomes, which were unchanged by the use of iMRI. CONCLUSION: Three-tesla iMRI-based epilepsy surgery may have the potential to improve patient outcomes. However, we conclude that iMRI, in its current state of use at our institute, does not improve outcomes for children undergoing epilepsy surgery. Given that its use appears safe, further research on this technology is warranted, particularly for the most challenging PDCs.


Assuntos
Epilepsia/cirurgia , Imageamento por Ressonância Magnética/métodos , Monitorização Intraoperatória/métodos , Procedimentos Neurocirúrgicos/métodos , Cirurgia Assistida por Computador/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Adulto Jovem
7.
J Craniofac Surg ; 26(1): 113-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25534061

RESUMO

BACKGROUND: Cranioplasty can be performed either with gold-standard, autologous bone grafts and osteotomies or alloplastic materials in skeletally mature patients. Recently, custom computer-generated implants (CCGIs) have gained popularity with surgeons because of potential advantages, which include preoperatively planned contour, obviated donor-site morbidity, and operative time savings. A remaining concern is the cost of CCGI production. The purpose of the present study was to objectively compare the operative time and relative cost of cranioplasties performed with autologous versus CCGI techniques at our center. METHODS: A review of all autologous and CCGI cranioplasties performed at our institution over the last 7 years was performed. The following operative variables and associated costs were tabulated: length of operating room, length of ward/intensive care unit (ICU) stay, hardware/implants utilized, and need for transfusion. RESULTS: Total average cost did not differ statistically between the autologous group (n = 15; $25,797.43) and the CCGI cohort (n = 12; $28,560.58). Operative time (P = 0.004), need for ICU admission (P < 0.001), and number of complications (P = 0.008) were all statistically significantly less in the CCGI group. The length of hospital stay and number of cases needing transfusion were fewer in the CCGI group but did not reach statistical significance. CONCLUSION: The results of the present study demonstrated no significant increase in overall treatment cost associated with the use of the CCGI cranioplasty technique. In addition, the latter was associated with a statistically significant decrease in operative time and need for ICU admission when compared with those patients who underwent autologous bone cranioplasty. LEVEL OF EVIDENCE: IV, therapeutic.


Assuntos
Autoenxertos/economia , Substitutos Ósseos/economia , Transplante Ósseo/economia , Desenho Assistido por Computador , Craniotomia/educação , Procedimentos de Cirurgia Plástica/economia , Adolescente , Adulto , Benzofenonas , Materiais Biocompatíveis/economia , Transfusão de Sangue/economia , Criança , Pré-Escolar , Estudos de Coortes , Custos e Análise de Custo , Cuidados Críticos/economia , Feminino , Seguimentos , Custos de Cuidados de Saúde , Unidades Hospitalares/economia , Humanos , Cetonas/economia , Tempo de Internação/economia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Polietilenoglicóis/economia , Polímeros , Próteses e Implantes/economia , Cirurgia Assistida por Computador/economia , Adulto Jovem
8.
Epilepsy Behav ; 29(1): 53-62, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23933913

RESUMO

Validity of two models of hemispheric specialization was compared. The "material-specific impairment" model was radicalized as postulating that left hemisphere (LH) lesions impair processing of verbal material and that right hemisphere (RH) lesions impair processing of visuospatial material, independently of response-bias distortions. The "response-bias distortion" model was radicalized as postulating that LH lesions distort response style toward omissiveness and that RH lesions distort response style toward commissiveness, regardless of material-specific impairments. Participants had comparable left (N=27) or right (N=24) hemisphere cortical lesions having occurred between birth and early adolescence. Four cognitive neuropsychological tests were adjusted to optimize applicability and comparability of the two theoretical models: Rey Complex Figure, Kimura's Recurring Figures, the Story Recall subtest of the Children's Memory Scale, and the California Verbal Learning Test. Both models significantly, independently, and equally distinguished the LH from the RH patients. Both these forms of hemispheric specialization seemed to be implemented very early in life and very rigidly. Intrahemispheric lesion sites, e.g., frontal vs nonfrontal, held no significant relation to the effects described above.


Assuntos
Viés , Encéfalo/patologia , Transtornos Cognitivos/etiologia , Dominância Cerebral/fisiologia , Epilepsia/complicações , Epilepsia/patologia , Adolescente , Adulto , Fatores Etários , Aprendizagem por Associação , Criança , Transtornos Cognitivos/patologia , Feminino , Humanos , Masculino , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Modelos Biológicos , Índice de Gravidade de Doença , Aprendizagem Verbal , Percepção Visual , Adulto Jovem
9.
Neurosurg Focus ; 34(6): E6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23724840

RESUMO

Hypothalamic hamartomas are uncommon but well-recognized developmental malformations that are classically associated with gelastic seizures and other refractory seizure types. The clinical course is often progressive and, in addition to the catastrophic epileptic syndrome, patients commonly exhibit debilitating cognitive, behavioral, and psychiatric disturbances. Over the past decade, investigators have gained considerable knowledge into the pathobiological and neurophysiological properties of these rare lesions. In this review, the authors examine the causes and molecular biology of hypothalamic hamartomas as well as the principal clinical features, neuroimaging findings, and electrophysiological characteristics. The diverse surgical modalities and strategies used to manage these difficult lesions are outlined in the second article of this 2-part review.


Assuntos
Ondas Encefálicas/fisiologia , Epilepsia/etiologia , Hamartoma , Doenças Hipotalâmicas , Eletroencefalografia , Hamartoma/complicações , Hamartoma/diagnóstico , Hamartoma/terapia , Humanos , Doenças Hipotalâmicas/complicações , Doenças Hipotalâmicas/diagnóstico , Doenças Hipotalâmicas/terapia , Magnetoencefalografia , Proteínas do Tecido Nervoso/metabolismo , Neuroimagem
10.
Neurosurg Focus ; 34(6): E7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23724841

RESUMO

Hypothalamic hamartomas are uncommon developmental heterotopic masses composed of an intermixed array of neurons, glia, and myelinated fibers closely associated with the mammillary bodies. Gelastic seizures, the hallmark feature of hypothalamic hamartomas, commonly present in early childhood. However, patients usually also display a disabling clinical syndrome, which may include various other types of refractory seizures with secondary generalization together with progressive cognitive, behavioral, and psychiatric dysfunction. The hamartoma itself has been unequivocally shown to be intrinsically epileptogenic. Over the past 2 decades there has been considerable effort to develop neurosurgical techniques to treat the epileptic syndrome effectively as well as to improve the neurocognitive and behavioral outcome.


Assuntos
Hamartoma/complicações , Hamartoma/terapia , Doenças Hipotalâmicas/complicações , Doenças Hipotalâmicas/terapia , Procedimentos Neurocirúrgicos/métodos , Convulsões/etiologia , Resultado do Tratamento , Pré-Escolar , Estimulação Encefálica Profunda , Endoscópios , Humanos , Imageamento por Ressonância Magnética , Masculino , Radiocirurgia , Estimulação do Nervo Vago
11.
Curr Res Neurobiol ; 5: 100117, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38020804

RESUMO

The K+ channel blocker 4-aminopyridine (4AP) has been extensively used to investigate the mechanisms underlying neuronal network synchronization in both in vitro and in vivo animal models of focal epilepsy. 4AP-induced effects are paralleled by an increase in both excitatory and inhibitory neurotransmitter release, but the mechanisms of action of 4AP on neuronal networks remain unclear. By employing simultaneous whole-cell patch clamp and field potential recordings from hippocampal CA3/4 pyramidal layer of acute brain slices obtained from mice (n = 30), we found that the appearance of epileptiform discharges induced by 4AP (100 µM) is consistently preceded by the transient recurrence of presumptive GABAB outward currents, which are not mirrored by any field activity. These GABAB outward currents still occurred during application of ionotropic glutamatergic antagonists (n = 12 cells) but were blocked by the GABAB receptor antagonist CGP55845 (n = 7). Our findings show that the transient occurrence of distinct GABAB outward currents precedes the appearance of 4AP-induced neuronal network synchronization leading to epileptiform activity in the rodent hippocampus in vitro.

12.
J Neurosurg Case Lessons ; 5(4)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36692062

RESUMO

BACKGROUND: Although surgery within the tegmentum of the midbrain is challenging, resection of tegmental pilocytic astrocytomas (PAs) is a standard treatment because this has been shown to outperform chemotherapy and radiotherapy in terms of long-term tumor control. Gross total resection (GTR) assisted by intraoperative neuroelectrophysiological monitoring can be achieved with a reasonable risk-to-benefit ratio, especially for well-circumscribed tumors, but careful scrutiny of magnetic resonance imaging (MRI) is critical to surgical decision making. The authors present two cases of tegmental PAs, which appeared grossly similar on MRI and were operated on via the same surgical approach using the same intraoperative adjuncts. OBSERVATIONS: The tumors had identical histopathological and molecular diagnoses but drastically different functional outcomes for the patients, with significant long-term complications for one of the children, which the authors believe was due to a slightly more invasive nature of this tumor. The authors demonstrate subtle preoperative MRI findings that might be potential clues to a more infiltrative nature of one PA versus another and present pathological findings supporting this argument. LESSONS: This report serves as a reminder that not all tegmental PAs can be managed by the same surgical approach. Subtle signs of infiltration may indicate that GTR should not be attempted.

13.
J Neurosurg Pediatr ; 32(3): 343-350, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37327188

RESUMO

OBJECTIVE: Delayed cerebral ischemia (DCI) associated with vasospasm is well described in the setting of aneurysmal subarachnoid hemorrhage (SAH). In addition, DCI is very infrequently encountered in patients who have undergone resection of a brain tumor with unclear pathophysiology. The occurrence of DCI in the pediatric population is exceedingly rare, and outcomes in this population have, to the authors' knowledge, never been systematically reviewed. Therefore, the authors present what is to their knowledge the largest series of pediatric patients with this complication and systematically reviewed the literature for individual participant data. METHODS: The authors conducted a retrospective review of 172 sellar and suprasellar tumors in pediatric patients who underwent surgery at the Montreal Children's Hospital between 1999 and 2017 to identify cases of vasospasm occurring after tumor resection. Descriptive statistics, including patient characteristics, intraoperative and postoperative findings, and outcome status, were collected. A systematic review was also conducted using three databases (PubMed, Web of Science, Embase) to identify reported cases available in the literature of vasospasm after tumor resection in children and collect individual participant data on these patients for further analysis. RESULTS: Six patients treated at Montreal Children's Hospital were identified, with an average age of 9.5 years (range 6-15 years). The prevalence of vasospasm after tumor resection was 3.5% (6/172). Vasospasm in all 6 patients occurred after craniotomy was performed to treat a suprasellar tumor. The average interval from surgery to symptoms was 3.25 days (range 12 hours-10 days). The most common tumor etiology was craniopharyngioma, seen in 4 cases. Extensive tumor encasement of blood vessels requiring significant operative manipulation was described in all 6 patients. A rapid decrease in serum sodium (exceeding 12 mEq/L/24 hrs or below 135 mEq/L) was seen in 4 patients. On final follow-up, 3 patients were left with significant disability, and all patients had persistent deficits. A systematic review of the literature revealed a total of 10 other patients whose characteristics and treatment were compared with those of the 6 patients treated at Montreal Children's Hospital. CONCLUSIONS: Vasospasm after tumor resection in children and youth is likely a rare entity, with a prevalence of 3.5% in this case series. Suprasellar tumor location (particularly craniopharyngioma tumor etiology), significant encasement of blood vessels by the tumor, and postoperative hyponatremia may be predictive factors. Outcome is poor, with most patients having significant persistent neurological deficits.


Assuntos
Isquemia Encefálica , Neoplasias Encefálicas , Craniofaringioma , Neoplasias Hipofisárias , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Adolescente , Humanos , Criança , Craniofaringioma/complicações , Hemorragia Subaracnóidea/complicações , Isquemia Encefálica/complicações , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/complicações , Craniotomia/efeitos adversos , Neoplasias Hipofisárias/complicações , Vasoespasmo Intracraniano/etiologia , Vasoespasmo Intracraniano/complicações
14.
Neurol Genet ; 9(6): e200103, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37900581

RESUMO

Background and Objectives: Somatic and germline pathogenic variants in genes of the mammalian target of rapamycin (mTOR) signaling pathway are a common mechanism underlying a subset of focal malformations of cortical development (FMCDs) referred to as mTORopathies, which include focal cortical dysplasia (FCD) type II, subtypes of polymicrogyria, and hemimegalencephaly. Our objective is to screen resected FMCD specimens with mTORopathy features on histology for causal somatic variants in mTOR pathway genes, describe novel pathogenic variants, and examine the variant distribution in relation to neuroimaging, histopathologic classification, and clinical outcomes. Methods: We performed ultra-deep sequencing using a custom HaloPlexHS Target Enrichment kit in DNA from 21 resected fresh-frozen histologically confirmed FCD type II, tuberous sclerosis complex, or hemimegalencephaly specimens. We mapped the variant alternative allele frequency (AAF) across the resected brain using targeted ultra-deep sequencing in multiple formalin-fixed paraffin-embedded tissue blocks. We also functionally validated 2 candidate somatic MTOR variants and performed targeted RNA sequencing to validate a splicing defect associated with a novel DEPDC5 variant. Results: We identified causal mTOR pathway gene variants in 66.7% (14/21) of patients, of which 13 were somatic with AAF ranging between 0.6% and 12.0%. Moreover, the AAF did not predict balloon cell presence. Favorable seizure outcomes were associated with genetically clear resection borders. Individuals in whom a causal somatic variant was undetected had excellent postsurgical outcomes. In addition, we demonstrate pathogenicity of the novel c.4373_4375dupATG and candidate c.7499T>A MTOR variants in vitro. We also identified a novel germline aberrant splice site variant in DEPDC5 (c.2802-1G>C). Discussion: The AAF of somatic pathogenic variants correlated with the topographic distribution, histopathology, and postsurgical outcomes. Moreover, cortical regions with absent histologic FCD features had negligible or undetectable pathogenic variant loads. By contrast, specimens with frank histologic abnormalities had detectable pathogenic variant loads, which raises important questions as to whether there is a tolerable variant threshold and whether surgical margins should be clean, as performed in tumor resections. In addition, we describe 2 novel pathogenic variants, expanding the mTORopathy genetic spectrum. Although most pathogenic somatic variants are located at mutation hotspots, screening the full-coding gene sequence remains necessary in a subset of patients.

15.
J Neurosurg Pediatr ; 29(1): 74-82, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34624842

RESUMO

OBJECTIVE: In an attempt to improve postsurgical seizure outcomes for poorly defined cases (PDCs) of pediatric focal epilepsy (i.e., those that are not visible or well defined on 3T MRI), the authors modified their presurgical evaluation strategy. Instead of relying on concordance between video-electroencephalography and 3T MRI and using functional imaging and intracranial recording in select cases, the authors systematically used a multimodal, 3-tiered investigation protocol that also involved new collaborations between their hospital, the Montreal Children's Hospital, and the Montreal Neurological Institute. In this study, the authors examined how their new strategy has impacted postsurgical outcomes. They hypothesized that it would improve postsurgical seizure outcomes, with the added benefit of identifying a subset of tests contributing the most. METHODS: Chart review was performed for children with PDCs who underwent resection following the new strategy (i.e., new protocol [NP]), and for the same number who underwent treatment previously (i.e., preprotocol [PP]); ≥ 1-year follow-up was required for inclusion. Well-defined, multifocal, and diffuse hemispheric cases were excluded. Preoperative demographics and clinical characteristics, resection volumes, and pathology, as well as seizure outcomes (Engel class Ia vs > Ia) at 1 year postsurgery and last follow-up were reviewed. RESULTS: Twenty-two consecutive NP patients were compared with 22 PP patients. There was no difference between the two groups for resection volumes, pathology, or preoperative characteristics, except that the NP group underwent more presurgical evaluation tests (p < 0.001). At 1 year postsurgery, 20 of 22 NP patients and 10 of 22 PP patients were seizure free (OR 11.81, 95% CI 2.00-69.68; p = 0.006). Magnetoencephalography and PET/MRI were associated with improved postsurgical seizure outcomes, but both were highly correlated with the protocol group (i.e., independent test effects could not be demonstrated). CONCLUSIONS: A new presurgical evaluation strategy for children with PDCs of focal epilepsy led to improved postsurgical seizure freedom. No individual presurgical evaluation test was independently associated with improved outcome, suggesting that it may be the combined systematic protocol and new interinstitutional collaborations that makes the difference rather than any individual test.


Assuntos
Técnicas de Diagnóstico Neurológico , Epilepsias Parciais/cirurgia , Neurocirurgia/métodos , Cirurgia Assistida por Computador/métodos , Criança , Pré-Escolar , Eletrofisiologia/métodos , Epilepsias Parciais/complicações , Feminino , Humanos , Masculino , Imagem Multimodal/métodos , Neuroimagem/métodos , Convulsões/etiologia , Convulsões/cirurgia , Resultado do Tratamento
16.
Nat Genet ; 54(12): 1865-1880, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36471070

RESUMO

Canonical (H3.1/H3.2) and noncanonical (H3.3) histone 3 K27M-mutant gliomas have unique spatiotemporal distributions, partner alterations and molecular profiles. The contribution of the cell of origin to these differences has been challenging to uncouple from the oncogenic reprogramming induced by the mutation. Here, we perform an integrated analysis of 116 tumors, including single-cell transcriptome and chromatin accessibility, 3D chromatin architecture and epigenomic profiles, and show that K27M-mutant gliomas faithfully maintain chromatin configuration at developmental genes consistent with anatomically distinct oligodendrocyte precursor cells (OPCs). H3.3K27M thalamic gliomas map to prosomere 2-derived lineages. In turn, H3.1K27M ACVR1-mutant pontine gliomas uniformly mirror early ventral NKX6-1+/SHH-dependent brainstem OPCs, whereas H3.3K27M gliomas frequently resemble dorsal PAX3+/BMP-dependent progenitors. Our data suggest a context-specific vulnerability in H3.1K27M-mutant SHH-dependent ventral OPCs, which rely on acquisition of ACVR1 mutations to drive aberrant BMP signaling required for oncogenesis. The unifying action of K27M mutations is to restrict H3K27me3 at PRC2 landing sites, whereas other epigenetic changes are mainly contingent on the cell of origin chromatin state and cycling rate.


Assuntos
Cromatina , Epigenômica , Linhagem da Célula/genética , Encéfalo
17.
Pediatr Blood Cancer ; 55(4): 639-43, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20806362

RESUMO

OBJECTIVES: Assess the role of radiotherapy (RT) in the management of primary and recurrent myxopapillary ependymoma (MPE). MATERIALS AND METHODS: We conducted a retrospective review of patients with MPE treated at the Montreal Children's Hospital/McGill University Health Centre between 1985 and 2008. RESULTS: Seven children under the age of 18 were diagnosed and treated for MPE. All patients were treated with surgery to the primary site. Three patients underwent subtotal resection (STR) and received adjuvant post-operative RT. Only one patient who had spinal drop metastases received post-operative RT to the lumbosacral region following complete resection of the primary tumor. After a median follow up of 78 months (range 24-180 months), all patients were alive with controlled disease. The single patient treated with gross total resection (GTR) and adjuvant local radiation remained recurrence free. One of the three patients treated with STR and adjuvant RT had disease progression that was controlled with re-resection and further RT. Two of the three patients treated with surgery alone developed local and disseminated recurrent spinal disease that was controlled by salvage RT. CONCLUSION: Our data support the evolving literature which suggests that GTR alone provides suboptimal disease control in MPE. In our patients, RT resulted in control of residual, metastatic and/or recurrent disease. Routine adjuvant RT may improve outcomes in pediatric MPE.


Assuntos
Ependimoma/radioterapia , Neoplasias da Medula Espinal/radioterapia , Adolescente , Criança , Ependimoma/cirurgia , Feminino , Humanos , Masculino , Radioterapia Adjuvante/efeitos adversos , Estudos Retrospectivos , Neoplasias da Medula Espinal/cirurgia
18.
J Neurosurg Pediatr ; 27(1): 47-51, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33126205

RESUMO

Here, the authors present 2 cases of nongerminomatous germ cell tumor (NGGCT): a neonate with a mixed malignant germ cell tumor, 5% yolk sac tumor (YST) and 95% immature teratoma components, originating from the right mesial temporal lobe; and a 2-month-old infant with a pure YST originating from the left middle cranial fossa. These tumors with yolk sac components, which are thought to have a poor prognosis, were successfully treated with complete tumor resection alone and subtotal tumor resection with chemotherapy, respectively. Event-free survival exceeds 5 years for each patient even though neither received radiotherapy. The authors highlight the role of radical surgery and the successful treatment of neonatal YST with aggressive resection (and chemotherapy in 1 case) while avoiding radiation therapy. They also report the very rare non-midline location of these neonatal NGGCTs and emphasize the importance of considering YSTs and mixed NGGCTs with YST components in the differential diagnosis of non-midline hemispheric or skull base tumors in newborns.


Assuntos
Neoplasias Encefálicas/cirurgia , Fossa Craniana Média/cirurgia , Neoplasias Embrionárias de Células Germinativas/cirurgia , Neoplasias da Base do Crânio/cirurgia , Lobo Temporal/cirurgia , Saco Vitelino/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Fossa Craniana Média/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Neoplasias Embrionárias de Células Germinativas/diagnóstico por imagem , Neoplasias da Base do Crânio/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Resultado do Tratamento , Saco Vitelino/diagnóstico por imagem
19.
Neurosurgery ; 87(2): 186-192, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31620799

RESUMO

BACKGROUND: The benefit of selective dorsal rhizotomies (SDR) on motor function relative to the cerebral palsy (CP) natural history remains unknown. OBJECTIVE: To determine the functional benefit of SDR over the longitudinal CP natural history. METHODS: Retrospective, single-center, case-control study of patients post-SDR after 1990. Inclusion criteria were the following: diagnosis of spastic CP, at least 1 preoperative and 1 postoperative Gross Motor Function Measure (GMFM-88), at least 1 yr of postoperative follow-up. GMFM-88 assessments were performed at 1, 2, 3, 5, 10, and 15 yr postoperatively and converted to GMFM-66. Cases were stratified by preoperative Gross Motor Function Classification System (GMFCS) and matched against their expected natural history using published reference centiles. After age 12, our cohort and matched controls were also fitted to published nonlinear mixed models of GMFM-66 evolution over time. RESULTS: Analysis included 190 patients. Median follow-up, 5.3 yr (range: 1-16.9), median age at surgery, 4.6 yr, and 81.6% of patients grouped as GMFCS II or III pre-op. SDR patients performed statistically significantly better than their expected natural history (P < .0005). At 21 yr old, a modeled benefit of 8.435 was observed for GMFCS I (P = .0051), 0.05 for GMFCS II (P = .9647), 6.31 for GMFCS III (P < .0001), and 1.191 for GMFCS IV patients (P = .0207). CONCLUSION: These results support the use of SDR in carefully selected spastic CP children.


Assuntos
Paralisia Cerebral/cirurgia , Espasticidade Muscular/cirurgia , Rizotomia/métodos , Resultado do Tratamento , Estudos de Casos e Controles , Paralisia Cerebral/complicações , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Masculino , Atividade Motora/fisiologia , Espasticidade Muscular/etiologia , Estudos Retrospectivos , Raízes Nervosas Espinhais/cirurgia
20.
Plast Reconstr Surg Glob Open ; 8(1): e2592, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32095402

RESUMO

Despite recent advances in surgical, anesthetic, and safety protocols in the management of nonsyndromic craniosynostosis (NSC), significant rates of intraoperative blood loss continue to be reported by multiple centers. The purpose of the current study was to examine our center's experience with the surgical correction of NSC in an effort to determine independent risk factors of transfusion requirements. METHODS: A retrospective cohort study of patients with NSC undergoing surgical correction at the Montreal Children's Hospital was carried out. Baseline characteristics and perioperative complications were compared between patients receiving and not receiving transfusions and between those receiving a transfusion in excess or <25 cc/kg. Logistic regression analysis was carried out to determine independent predictors of transfusion requirements. RESULTS: A total of 100 patients met our inclusion criteria with a mean transfusion requirement of 29.6 cc/kg. Eighty-seven patients (87%) required a transfusion, and 45 patients (45%) required a significant (>25 cc/kg) intraoperative transfusion. Regression analysis revealed that increasing length of surgery was the main determinant for intraoperative (P = 0.008; odds ratio, 18.48; 95% CI, 2.14-159.36) and significant (>25 cc/kg) intraoperative (P = 0.004; odds ratio, 1.95; 95% CI, 1.23-3.07) transfusions. CONCLUSIONS: Our findings suggest increasing operative time as the predominant risk factor for intraoperative transfusion requirements. We encourage craniofacial surgeons to consider techniques to streamline the delivery of their selected procedure, in an effort to reduce operative time while minimizing the need for transfusion.

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