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BACKGROUND: Although complete nidal obliteration of brain arteriovenous malformations (AVM) is generally presumed to represent durable cure, postobliteration hemorrhage, and AVM recurrence have become increasingly recognized phenomena. The goal of the study was to define hemorrhage and nidal recurrence risks of obliterated AVMs treated with stereotactic radiosurgery (SRS). METHODS: This is a retrospective cohort study from the International Radiosurgery Research Foundation comprising AVM patients treated between 1987 and 2020. Patients with AVM obliteration on digital subtraction angiography (DSA) were included. Outcomes were (1) hemorrhage and (2) AVM recurrence. Follow-up duration began at the time of AVM obliteration and was censored at subsequent hemorrhage, AVM recurrence, additional AVM treatment, or loss to follow-up. Annualized risk and survival analyses were performed. A sensitivity analysis comprising patients with AVM obliteration on magnetic resonance imaging or DSA was also performed for postobliteration hemorrhage. RESULTS: The study cohort comprised 1632 SRS-treated patients with AVM obliteration on DSA. Pediatric patients comprised 15% of the cohort, and 42% of AVMs were previously ruptured. The mean imaging follow-up after AVM obliteration was 22 months. Among 1607 patients with DSA-confirmed AVM obliteration, 16 hemorrhages (1.0%) occurred over 2223 patient-years of follow-up (0.72%/y). Of the 1543 patients with DSA-confirmed AVM obliteration, 5 AVM recurrences (0.32%) occurred over 2071 patient-years of follow-up (0.24%/y). Of the 16 patients with postobliteration hemorrhage, AVM recurrence was identified in 2 (12.5%). In the sensitivity analysis comprising 1939 patients with post-SRS AVM obliteration on magnetic resonance imaging or DSA, 16 hemorrhages (0.83%) occurred over 2560 patient-years of follow-up (0.63%/y). CONCLUSIONS: Intracranial hemorrhage and recurrent arteriovenous shunting after complete nidal obliteration are rare in AVM patients treated with SRS, and each phenomenon harbors an annual risk of <1%. Although routine postobliteration DSA cannot be recommended to SRS-treated AVM patients, long-term neuroimaging may be advisable in these patients.
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Malformações Arteriovenosas Intracranianas , Radiocirurgia , Encéfalo/patologia , Criança , Seguimentos , Humanos , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/radioterapia , Malformações Arteriovenosas Intracranianas/cirurgia , Hemorragias Intracranianas/etiologia , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Hematoma and perihematomal edema volumes are important radiographic markers in spontaneous intracerebral hemorrhage. Accurate, reliable, and efficient quantification of these volumes will be paramount to their utility as measures of treatment effect in future clinical studies. Both manual and semi-automated quantification methods of hematoma and perihematomal edema volumetry are time-consuming and susceptible to inter-rater variability. Efforts are now underway to develop a fully automated algorithm that can replace them. A (QUANTUM) study to establish inter-quantification method measurement equivalency, which deviates from the traditional use of measures of agreement and a comparison hypothesis testing paradigm to indirectly infer quantification method measurement equivalence, is described in this article. The Quantification of Hematoma and Perihematomal Edema Volumes in Intracerebral Hemorrhage study aims to determine whether a fully automated quantification method and a semi-automated quantification method for quantification of hematoma and perihematomal edema volumes are equivalent to the hematoma and perihematomal edema volumes of the manual quantification method. METHODS/DESIGN: Hematoma and perihematomal edema volumes of supratentorial intracerebral hemorrhage on 252 computed tomography scans will be prospectively quantified in random order by six raters using the fully automated, semi-automated, and manual quantification methods. Primary outcome measures for hematoma and perihematomal edema volumes will be quantified via computed tomography scan on admission (<24 h from symptom onset) and on day 3 (72 ± 12 h from symptom onset), respectively. Equivalence hypothesis testing will be conducted to determine if the hematoma and perihematomal edema volume measurements of the fully automated and semi-automated quantification methods are within 7.5% of the hematoma and perihematomal edema volume measurements of the manual quantification reference method. DISCUSSION: By allowing direct equivalence hypothesis testing, the Quantification of Hematoma and Perihematomal Edema Volumes in Intracerebral Hemorrhage study offers advantages over radiology validation studies which utilize measures of agreement to indirectly infer measurement equivalence and studies which mistakenly try to infer measurement equivalence based on the failure of a comparison two-sided null hypothesis test to reach the significance level for rejection. The equivalence hypothesis testing paradigm applied to artificial intelligence application validation is relatively uncharted and warrants further investigation. The challenges encountered in the design of this study may influence future studies seeking to translate artificial intelligence medical technology into clinical practice.
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Edema Encefálico , Inteligência Artificial , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico por imagem , Edema/diagnóstico por imagem , Hematoma/diagnóstico por imagem , HumanosRESUMO
Cortical spreading depolarizations (CSDs) are characterized by waves of diminished electroencephalography activity that propagate across the cortex with subsequent loss of ionic homeostasis. CSDs have been found in many pathological conditions, including migraine, traumatic brain injury, and ischemic stroke. Because of CSD-associated ionic and metabolic disturbances at the peri-infarct area after ischemic stroke, it is thought that CSDs exacerbate tissue infarction and worsen clinical outcomes. Microglia, the main innate immune cells in the brain, are among the first responders to brain tissue damage. Recent studies demonstrated that microglia play a critical role in CSD initiation and propagation. In this article, we discuss the significance of CSD in the setting of ischemic stroke and how microglia may modulate peri-infarct CSDs, also known as iso-electric depolarizations. Finally, we discuss the significance of microglial Ca2+ and how it might be used as a potential therapeutic target for patients with ischemic stroke.
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Isquemia Encefálica , Depressão Alastrante da Atividade Elétrica Cortical , AVC Isquêmico , Humanos , Infarto , MicrogliaRESUMO
BACKGROUND AND PURPOSE: Ischemic injury triggers multiple pathological responses in the brain tissue, including spreading depolarizations across the cerebral cortex (cortical spreading depolarizations [CSD]). Microglia have been recently shown to play a significant role in the propagation of CSD. However, the intracellular responses of myeloid cells during ischemic stroke have not been investigated. METHODS: We have studied intracellular calcium activity in cortical microglia in the stroke model of the middle cerebral artery occlusion, using the murine Polr2a-based and Cre-dependent GCaMP5 and tdTomato reporter (PC::G5-tdT). High-speed 2-photon microscopy through cranial windows was employed to record signals from genetically encoded indicators of calcium. Inflammatory stimuli and pharmacological inhibition were used to modulate microglial calcium responses in the somatosensory cortex. RESULTS: In vivo imaging revealed periodical calcium activity in microglia during the hyperacute phase of ischemic stroke. This activity was more frequent during the first 6 hours after occlusion, but the amplitudes of calcium transients became larger at later time points. Consistent with CSD nature of these events, we reproducibly triggered comparable calcium transients with microinjections of potassium chloride (KCl) into adjacent cortical areas. Furthermore, lipopolysaccharide-induced peripheral inflammation, mimicking sterile inflammation during ischemic stroke, produced significantly greater microglial calcium transients during CSD. Finally, in vivo pharmacological analysis with CRAC (calcium release-activated channel) inhibitor CM-EX-137 demonstrated that CSD-associated microglial calcium transients after KCl microinjections are mediated at least in part by the CRAC mechanism. CONCLUSIONS: Our findings demonstrate that microglia participate in ischemic brain injury via previously undetected mechanisms, which may provide new avenues for therapeutic interventions.
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Sinalização do Cálcio , AVC Isquêmico/fisiopatologia , Microglia , Doença Aguda , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Encefalite/induzido quimicamente , Encefalite/fisiopatologia , Processamento de Imagem Assistida por Computador , Infarto da Artéria Cerebral Média/fisiopatologia , Lipopolissacarídeos , Camundongos , Microscopia de Fluorescência por Excitação Multifotônica , Células Mieloides , Cloreto de Potássio/farmacologia , Córtex Somatossensorial/fisiopatologiaRESUMO
Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.
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Edema Encefálico , Lesões Encefálicas , Fármacos Neuroprotetores , Barreira Hematoencefálica/metabolismo , Edema Encefálico/tratamento farmacológico , Lesões Encefálicas/complicações , Hemorragia Cerebral/complicações , Hemorragia Cerebral/tratamento farmacológico , Hematoma/complicações , Humanos , Neuroproteção , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêuticoRESUMO
Background and Purpose- The goal of this study was to systematically review the outcomes and complications after surgical resection of brain stem cavernous malformations (BCMs). Methods- A systematic literature review was performed using the PubMed database for studies published between 1986 and 2018. All studies comprising ≥2 patients with surgically resected BCMs and available follow-up data were included. Data extracted from studies included patient demographics, BCM location, and surgical outcomes. Results- Eighty-six studies comprising 2493 patients (adult and pediatric) were included for final analysis. Complete resection was achieved in 92.3% (fixed-effects pooled estimate [FE], 92.9% [91.7%-94.0%]; random-effects pooled estimate [RE], 89.4% [86.5%-92.0%]) of patients, and rehemorrhage of residual BCMs occurred in 58.6% (FE, 58.8% [49.7%-67.6%]; RE, 57.2% [43.5%-70.2%]). Postoperative morbidity occurred in 34.8% (FE, 30.9% [29.0%-32.8%]; RE, 31.1% [25.8%-36.6%]) of patients. Postoperative morbidities included motor deficit in 11.0% (FE, 9.9% [8.1%-11.7%]; RE, 11.1% [7.0%-16.0%]), sensory deficit in 6.7% (FE, 6.3% [4.8%-7.9%]; RE, 7.6% [4.5%-11.5%]), tracheostomy/gastrostomy in 6.0% (FE, 5.2% [4.3%-6.1%]; RE, 3.8% [2.6%-5.3%]), and other cranial nerve deficits in 29.4% (FE, 27.6% [25.3%-29.9%]; RE, 33.9% [25.7%-42.6%]) of patients. At final follow-up, 57.9% (FE, 57.6% [55.6%-59.6%]; RE, 57.2% [52.1%-62.3%]) and 25.9% (FE, 24.1% [22.4%-25.9%]; RE, 18.5% [14.6%-22.8%]) of patients had improvement and stability of preoperative symptoms, respectively. Mortality rate was 1.6% (FE, 1.9% [1.4%-2.5%]; RE, 1.8% [1.4%-2.5%]). Conclusions- High cure rates and low rates of postoperative morbidity can be achieved with surgery in patients with BCMs. Most patients had improved preoperative symptoms at final follow-up. To avoid rehemorrhage, complete resection should be the goal of surgery.
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Neoplasias do Tronco Encefálico/cirurgia , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos , Resultado do TratamentoRESUMO
Background and Purpose- The effects of prior hemorrhage on stereotactic radiosurgery (SRS) outcomes for pediatric arteriovenous malformations (AVMs) are not well defined. The aim of this multicenter, retrospective cohort study is to compare the SRS outcomes for unruptured versus ruptured pediatric AVMs. Methods- The International Radiosurgery Research Foundation pediatric AVM database from 1987 to 2018 was reviewed retrospectively. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes. Associations between prior hemorrhage and outcomes were adjusted for baseline differences, inverse probability weights, and competing risks. Results- The study cohort comprised 153 unruptured and 386 ruptured AVMs. Favorable outcome was achieved in 48.4% and 60.4% of unruptured and ruptured AVMs, respectively (adjusted odds ratio, 1.353; P=0.190). Cumulative AVM obliteration probabilities were 51.2%, 59.4%, 64.2%, and 70.0% for unruptured and 61.0%, 69.3%, 74.0%, and 79.3% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.311; P=0.020). Cumulative post-SRS hemorrhage probabilities were 4.5%, 5.6%, 5.6%, and 9.8% for unruptured and 4.7%, 6.1%, 6.1%, and 10.6% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.086; P=0.825). Probabilities of AVM obliteration (adjusted subhazard ratio, 0.968; P=0.850) and post-SRS hemorrhage (adjusted subhazard ratio, 1.663; P=0.251) were comparable between the 2 cohorts after inverse probability weight adjustments. Symptomatic (15.8% versus 8.1%; adjusted odds ratio, 0.400; P=0.008) and permanent (9.2% versus 5.0%; adjusted odds ratio, 0.441; P=0.045) radiation-induced change were more common in unruptured AVMs. Conclusions- The overall outcomes after SRS for unruptured versus ruptured pediatric AVMs are comparable. However, symptomatic and permanent radiation-induced change occur more frequently in pediatric patients with unruptured AVMs.
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Fístula Arteriovenosa/cirurgia , Malformações Arteriovenosas Intracranianas/cirurgia , Radiocirurgia/métodos , Adolescente , Fístula Arteriovenosa/complicações , Hemorragia Cerebral/etiologia , Criança , Feminino , Humanos , Malformações Arteriovenosas Intracranianas/complicações , Masculino , Lesões por Radiação/epidemiologia , Lesões por Radiação/etiologia , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Contrast-enhanced ultrasound (CEUS) is a relatively new imaging modality in the realm of neurosurgical disease. CEUS permits the examination of blood flow through arteries, veins, and capillaries via intravascular contrast agents and allows vascular architectural mapping with extreme sensitivity and specificity. While it has established utility in other organ systems such as the liver and kidneys, CEUS has not been studied extensively in the brain. This report presents a review of the literature on the neurosurgical applications of CEUS and provides an outline of the imaging modality's role in the diagnosis, evaluation, and treatment of neurosurgical disease.
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Encefalopatias/diagnóstico por imagem , Meios de Contraste , Microbolhas , Neuroimagem/métodos , Ultrassonografia/métodos , Encefalopatias/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/cirurgia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/cirurgia , Previsões , Humanos , Ultrassonografia de Intervenção/métodosRESUMO
Developmental dolichoectasia of the intracranial vessels is a rare occurrence. The authors report 2 sibling pediatric patients who were born with 6p25.3 deletion, associated with carotid and vertebrobasilar dolichoectasia. MRI imaging of both children showed asymptomatic elongation and dilation of the vertebrobasilar system and "kissing" carotid arteries. A microarray analysis was also performed for both patients, which identified a 1.5-Mb deletion of 6p25.3 covering 15 genes including FOXC1, which has been implicated in defects in vascular morphogenesis.
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Deleção Cromossômica , Cromossomos Humanos Par 6/genética , Deficiências do Desenvolvimento/genética , Insuficiência Vertebrobasilar/genética , Adolescente , Artéria Basilar/patologia , Artérias Carótidas/patologia , Criança , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Imageamento por Ressonância Magnética , Masculino , Análise em Microsséries , Fenótipo , Insuficiência Vertebrobasilar/diagnóstico por imagemRESUMO
OBJECTIVE: Treatment of craniopharyngioma typically entails gross total resection (GTR) or subtotal resection with adjuvant radiation (STR-RT). We analyzed outcomes in adults with craniopharyngioma undergoing GTR versus STR-RT. METHODS: This retrospective study enrolled 115 patients with craniopharyngioma in 5 institutions. Patients with STR received postoperative RT with stereotactic radiosurgery or fractionated radiation therapy per institutional preference and ability to spare optic structures. RESULTS: Median age was 44 years (range, 19-79 years). GTR was performed in 34 patients and STR-RT was performed in 81 patients with median follow-up of 78.9 months (range, 1-268 months). For GTR, local control was 90.5% at 2 years, 87.2% at 3 years, and 71.9% at 5 years. For STR-RT, local control was 93.6% at 2 years, 90.3% at 3 years, and 88.4% at 5 years. At 5 years following resection, there was no difference in local control (P = 0.08). Differences in rates of visual deterioration or panhypopituitarism were not observed between GTR and STR-RT groups. There was no difference in local control in adamantinomatous and papillary craniopharyngioma regardless of treatment. Additionally, worse local control was found in patients receiving STR-RT who were underdosed with fractionated radiation therapy (P = 0.03) or stereotactic radiosurgery (P = 0.04). CONCLUSIONS: Good long-term control was achieved in adults with craniopharyngioma who underwent STR-RT or GTR with no significant difference in local control. First-line treatment for craniopharyngioma should continue to be maximal safe resection followed by RT as needed to balance optimal local control with long-term morbidity.
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Craniofaringioma , Neoplasias Hipofisárias , Radiocirurgia , Humanos , Craniofaringioma/radioterapia , Craniofaringioma/cirurgia , Adulto , Pessoa de Meia-Idade , Neoplasias Hipofisárias/radioterapia , Neoplasias Hipofisárias/cirurgia , Feminino , Masculino , Estudos Retrospectivos , Idoso , Adulto Jovem , Resultado do Tratamento , Radiocirurgia/métodos , Radioterapia Adjuvante/métodos , Procedimentos Neurocirúrgicos/métodos , SeguimentosRESUMO
To systematically review the reported outcomes and complications of different treatment options for choroid plexus arteriovenous malformations (AVMs), specifically focusing on surgical resection and endovascular embolization. A systematic literature review was performed using a PubMed query for studies published between January 1975 and July 2021. All studies describing the clinical presentation, management, and outcome of confirmed choroid plexus AVM cases were included. A total of 20 studies were included in the final analysis. Of these, 18 were singlepatient case reports, one article contained two patients, and a single study was a cohort of 24 patients. Patient age ranged from one day to 61 years, with a mean of 31.8±20.4 years. Most choroid plexus AVMs were located in the lateral ventricles (14 patients, 70.0%), while there were four (20.0%) located in the third ventricle, and two in the fourth ventricle (10.0%). Almost all patients were treated with surgical resection (18 patients, 90%). In 14 patients (77.8%), complete resection of the AVM was achieved. A residual AVM was reported in one case (5.6%). Most patients were reported to have improved from their presentation status over time (14 patients, 70.0%). Presence or absence of long-term sequelae (e.g., neurologic deficits) were reported for 14 patients (70%). Eleven of these patients (78.6%) were reported to have no neurological sequelae. While data on choroid plexus AVMs remains limited, the available evidence suggests gross total resection of lesions in this location can be safely achieved with subsequent reduction in preoperative symptoms.
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BACKGROUND: Though women now comprise approximately 21.5% of all neurosurgery residents in the United States, women only represent 10% of practicing neurosurgeons nationally. Serving as a journal editor is 1 measure of academic success. We investigated characteristics of editorial boards for top neurosurgical journals to identify factors influencing membership on editorial boards. We sought to identify gender differences to explain the paucity of women on editorial boards. METHODS: This is a cross-sectional study of editorial boards for the top 10 English-language neurosurgical journals. Data were obtained from journal websites, program faculty lists, or physician online profiles. Gender differences were compared using Student t test and χ2 analysis. RESULTS: Seven hundred twenty-two editorial board members were examined (female n = 65; male n = 650; unidentified n = 7). Overall, women had fewer years in practice (P = 0.002) and more often had additional advanced degrees (P = 0.009) while men had higher h-indices (P < 0.0001). Within the boards of Neurosurgery and Acta Neurochirurgica, men had been in practice longer (P = 0.014; P = 0.023) and had higher h-indices (P = 0.003; P = 0.025). Male editors for Journal of Neurosurgery: Spine and World Neurosurgery had higher h-indices (P = 0.007; P = 0.018). CONCLUSIONS: Women constitute â¼9% of editorial boards for top neurosurgical journals, a percentage comparable to the amount of practicing female academic neurosurgeons. This finding is encouraging as in that there appears to be no readily identifiable bias in the selection of editorial board members. The differences in years in practice and h-index suggest that gender distribution may equalize with time as more women enter practice and produce scientific literature. Efforts to recruit and retain women in neurosurgery should be pursued to rectify this discrepancy.
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Neurocirurgia , Publicações Periódicas como Assunto , Humanos , Masculino , Feminino , Estados Unidos , Estudos Transversais , Fatores Sexuais , Procedimentos NeurocirúrgicosRESUMO
BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) has emerged as a precise, incisionless approach to cerebral lesioning and an alternative to neuromodulation in movement disorders. Despite rigorous clinical trials, long-term patient-centered outcome data after MRgFUS for tremor-predominant Parkinson's Disease (TPPD) are relatively lacking. OBJECTIVE: To report long-term data on patient satisfaction and quality of life after MRgFUS thalamotomy for TPPD. METHODS: In a retrospective study of patients who underwent MRgFUS thalamotomy for TPPD at our institution between 2015 and 2022, a patient survey was administered to collect self-reported measures of tremor improvement, recurrence, Patients' Global Impression of Change (PGIC), and side effects. Patient demographics, FUS parameters, and lesion characteristics were analyzed. RESULTS: A total of 29 patients were included with a median follow-up of 16 months. Immediate tremor improvement was achieved in 96% of patients. Sustained improvement was achieved in 63% of patients at last follow-up. Complete tremor recurrence to baseline occurred for 17% of patients. Life quality improvement denoted by a PGIC of 1 to 2 was reported by 69% of patients. Long-term side effects were reported by 38% of patients and were mostly mild. Performing a secondary anteromedial lesion to target the ventralis oralis anterior/posterior nucleus was associated with higher rates of speech-related side effects (56% vs 12%), without significant improvement in tremor outcomes. CONCLUSION: Patient satisfaction with FUS thalamotomy for tremor-predominant PD was very high, even at longer term. Extended lesioning to target the motor thalamus did not improve tremor control and may contribute to greater frequency of postoperative motor- and speech-related side effects.
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Tremor Essencial , Doença de Parkinson , Humanos , Tremor , Doença de Parkinson/complicações , Doença de Parkinson/cirurgia , Qualidade de Vida , Estudos Retrospectivos , Tremor Essencial/cirurgia , Resultado do Tratamento , Tálamo/diagnóstico por imagem , Tálamo/cirurgia , Imageamento por Ressonância Magnética , Medidas de Resultados Relatados pelo PacienteRESUMO
Stroke remains a major burden on patients, families, and healthcare professionals, despite major advances in prevention, acute treatment, and rehabilitation. Preclinical basic research can help to better define mechanisms contributing to stroke pathology, and identify therapeutic interventions that can decrease ischemic injury and improve outcomes. Animal models play an essential role in this process, and mouse models are particularly well-suited due to their genetic accessibility and relatively low cost. Here, we review the focal cerebral ischemia models with an emphasis on the middle cerebral artery occlusion technique, a "gold standard" in surgical ischemic stroke models. Also, we highlight several histologic, genetic, and in vivo imaging approaches, including mouse stroke MRI techniques, that have the potential to enhance the rigor of preclinical stroke evaluation. Together, these efforts will pave the way for clinical interventions that can mitigate the negative impact of this devastating disease.
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BACKGROUND: Women have historically been underrepresented in academic medicine, particularly in surgical subspecialties. This study investigated potential associations between gender and promoting practices in academic neurosurgery. METHODS: Faculty data, including time from residency, professorship, specialty, and h-index, were obtained from websites of the institutions listed in the American Association of Neurological Surgeons Neurosurgical Residency Training Program Directory. Demographics, training, and appointments were compared between male and female neurosurgeons. Predictors of professorship, chair, directorship, and division leadership were identified using multivariable models. RESULTS: The study examined 1629 faculty members. Women were more likely to be assistant professors (P < 0.0001), while men were more likely to be full professors (P < 0.0001), hold chair positions (P = 0.007), lead subspecialty divisions (P = 0.008), and have a higher Scopus h-index (P < 0.0001). In a multivariable analysis, years from training (P < 0.001), fellowship (P = 0.009), h-index (P < 0.001), and chair/program director/division leadership position (P < 0.001) were significant positive predictors of full professorship. Holding additional advanced degrees (P = 0.010), leading a subspecialty division (P = 0.005), and having a higher h-index (P = 0.002) positively predicted chair position. However, when accounting for all other factors, gender was not a significant predictor of full professorship, division leadership, chair, or program directorship. CONCLUSIONS: While significantly more men hold leadership positions in U.S. academic institutions, after controlling for contributing variables, there did not appear to be an association between gender and full professorship, division leadership, chair, or program directorship in academic neurosurgery. While the field still has significant work to do to achieve gender equity, these results may serve as encouragement to women who are looking to advance their careers in academic neurosurgery.
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Internato e Residência , Neurocirurgia , Docentes de Medicina , Bolsas de Estudo , Feminino , Equidade de Gênero , Humanos , Liderança , Masculino , Neurocirurgia/educação , Estados UnidosRESUMO
Intra-operative ultrasound has become a relevant imaging modality in neurosurgical procedures. While B-mode, with its intrinsic limitations, is still considered the primary ultrasound modality, intra-operative contrast-enhanced ultrasound (ioCEUS) has more recently emerged as a powerful tool in neurosurgery. Though still not used on a large scale, ioCEUS has proven its utility in defining tumor boundaries, identifying lesion vascular supply and mapping neurovascular architecture. Here we propose a step-by-step procedure for performing ioCEUS analysis of the brain, highlighting its neurosurgical applications. Moreover, we provide practical advice on the use of ultrasound contrast agents and review technical ultrasound parameters influencing ioCEUS imaging.
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Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Meios de Contraste , Procedimentos Neurocirúrgicos , Humanos , Período Intraoperatório , Ultrassonografia/métodosRESUMO
BACKGROUND: Pediatric brain arteriovenous malformations (AVMs) are a significant cause of morbidity but the role of multimodal therapy in the treatment of these lesions is not well understood. OBJECTIVE: To compare the outcomes of stereotactic radiosurgery (SRS) with and without prior embolization for pediatric AVMs. METHODS: We retrospectively evaluated the International Radiosurgery Research Foundation pediatric AVM database. AVMs were categorized, based on use of pre-embolization (E + SRS) or lack thereof (SRS-only). Outcomes were compared in unadjusted and inverse probability weight (IPW)-adjusted models. Favorable outcome was defined as obliteration without post-SRS hemorrhage or permanent radiation-induced changes (RIC). RESULTS: The E + SRS and SRS-only cohorts comprised 91 and 448 patients, respectively. In unadjusted models, the SRS-only cohort had higher rates of obliteration (68.5% vs 43.3%, < .001) and favorable outcome (61.2% vs 36.3%, P < .001) but a lower rate of symptomatic RIC (9.0% vs 16.7%, P = .031). The IPW-adjusted rates of every outcome were similar between the 2 cohorts. However, cumulative obliteration rates at 3, 5, 8, and 10 yr remained higher in the absence of prior embolization (46.3%, 64.6%, 72.6%, and 77.4% for SRS-only vs 24.4%, 37.2%, 44.1%, and 48.7% for E + SRS cohorts, respectively; SHR = 0.449 [0.238-0.846], P = .013). CONCLUSION: Embolization appears to decrease cumulative obliteration rates after SRS for pediatric AVMs without affecting the risk of post-treatment hemorrhage or adverse radiation effects arguing against the routine use of pre-SRS embolization. While endovascular therapy can be considered for occlusion of high-risk angioarchitectural features prior to SRS, future studies are necessary to clarify its role.
Assuntos
Malformações Arteriovenosas Intracranianas , Radiocirurgia , Encéfalo , Criança , Seguimentos , Humanos , Malformações Arteriovenosas Intracranianas/cirurgia , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Prior comparisons of brain arteriovenous malformations (AVMs) treated using stereotactic radiosurgery (SRS) with or without embolization were inherently flawed, due to differences in the pretreatment nidus volumes. OBJECTIVE: To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Patients were categorized into the embolization and SRS (E + SRS) or SRS alone (SRS-only) cohorts. The 2 cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was defined as AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiologic and symptomatic radiation-induced changes (RIC), and cyst formation. RESULTS: The matched cohorts each comprised 101 patients. Crude AVM obliteration rates were similar between the matched E + SRS vs SRS-only cohorts (48.5% vs 54.5%; odds ratio = 0.788, P = .399). Cumulative probabilities of obliteration at 3, 4, 5, and 6 yr were also similar between the E + SRS (33.0%, 46.4%, 56.2%, and 60.8%, respectively) and SRS-only (32.9%, 46.2%, 56.0%, and 60.6%, respectively) cohorts (subhazard ratio (SHR) = 1.005, P = .981). Cumulative probabilities of radiologic RIC at 3, 4, 5, and 6 yr were lower in the E + SRS (25.0%, 25.7%, 26.7%, and 26.7%, respectively) vs SRS-only (45.3%, 46.2%, 47.8%, and 47.8%, respectively) cohort (SHR = 0.478, P = .004). Symptomatic and asymptomatic embolization-related complication rates were 8.3% and 18.6%, respectively. Rates of post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation were similar between the matched cohorts. CONCLUSION: This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.
Assuntos
Embolização Terapêutica/métodos , Malformações Arteriovenosas Intracranianas/terapia , Radiocirurgia/métodos , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Embolization of brain arteriovenous malformations (AVMs) using ethylene-vinyl alcohol copolymer (Onyx) embolization may influence the treatment effects of stereotactic radiosurgery (SRS) differently than other embolysates. OBJECTIVE: To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Embolized AVMs treated with SRS were selected and categorized based on embolysate usage into Onyx embolization (OE + SRS) or non-Onyx embolization (NOE + SRS) cohorts. The 2 cohorts were matched in a 1:1 ratio using de novo AVM features for comparative analysis of outcomes. RESULTS: The matched cohorts each comprised 45 patients. Crude AVM obliteration rates were similar between the matched OE + SRS vs NOE + SRS cohorts (47% vs 51%; odds ratio [OR] = 0.837, P = .673). Cumulative probabilities of obliteration were also similar between the OE + SRS vs NOE + SRS cohorts (subhazard ratio = 0.992, P = .980). Rates of post-SRS hemorrhage, all-cause mortality, radiation-induced changes, cyst formation, and embolization-associated complications were similar between the matched cohorts. Sensitivity analysis for AVMs in the OE + SRS cohort embolized with Onyx alone revealed a higher rate of asymptomatic embolization-associated complications in this subgroup compared to the NOE + SRS cohort (36% vs 15%; OR = 3.297, P = .034), but the symptomatic complication rates were similar. CONCLUSION: Nidal embolization using Onyx does not appear to differentially impact the outcomes of AVM SRS compared with non-Onyx embolysates. The embolic agent selected for pre-SRS AVM embolization should reflect both the experience of the neurointerventionalist and target of endovascular intervention.
Assuntos
Embolização Terapêutica/métodos , Malformações Arteriovenosas Intracranianas/terapia , Polivinil/uso terapêutico , Radiocirurgia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Background Compensation has historically been unequal for men versus women in medical fields, particularly in surgical subspecialties. Objective We analyzed associations between gender and compensation and identified factors associated with compensation among male and female academic neurosurgeons in the United States (US) public institutions. Methods This is a cross-sectional study of available data for the 2016-2017 fiscal years associated with male and female neurosurgical faculty from public, academic institutions within the US. The data used for analysis included total annual salary, which consisted of the base salary and additional compensation. Other gleaned data included faculty demographics, training, and academic appointments. The male and female neurosurgeons' data were separated into two respective gender groups and then were compared. Predictors of compensation were identified using univariable and non-imputed and multiply-imputed multivariable statistical models. Results The cohort was comprised of 460 neurosurgery faculty members (female n=34; male n=426). Total annual salaries were comparable between the genders. Females were more likely to be younger (p=0.001), to have completed neurosurgery training recently (p=0.003), to have had fellowship training (p=0.011), and to have lower h--indices (p=0.003) compared to males. Males and females differed in academic ranks (p=0.035) and neurosurgical subspecialties (p=0.038). Midwest (a[Formula: see text])=-US$337,516.7, p=0.002), South (a[Formula: see text]=-US$302,500.5, p=0.003), and West (a[Formula: see text]=-US$276,848.8, p=0.005) practices were independent predictors of lower annual compensation. Chair position (a[Formula: see text]=US$174,180.3, p=0.019) and associate professorship (a[Formula: see text]=US$126,633.4, p=0.037) were independent predictors of higher annual compensation. Gender was not a significant predictor of total annual compensation. Conclusions Total salaries were not different between male and female neurosurgeons in public, academic institutions in the US. Gender was not a significant predictor of total annual compensation. This study is applicable to public institutions in states with Freedom of Information Act reporting requirements.