RESUMEN
Hiatus hernias (HH) are a common cause of symptoms and complications, with considerable variation in anatomy, function, diagnosis and treatment. We undertook the first systematic review to appraise how HH are diagnosed and classified in the literature, using randomized controlled trials as a sample. A search was performed in July 2021of the PubMed, EMBASE and Cochrane Central Register of Controlled Trials, and 2832 articles were identified and 64 were included. Median Jadad score was 2. Studies demonstrated considerable variation in diagnosis, classification and minimum surgical steps. The commonest classifications before surgery were axial length and the Type I-IV classification, variably assessed by endoscopy and contrast swallow. Intra-operatively, the commonest classification was type I-IV. A minority used more than one classification, or alternatives such as defect size and Hill classification. Most studies reported minimum steps, but these varied. Only a minority reported criteria for diagnosing recurrence. Using randomized controlled trials to appraise the highest quality evidence in the literature, we found considerable variation and inconsistency in the way HH are diagnosed and classified. This lack of a 'common language' has significant impacts for the generalizability of evidence, study synthesis and design. We propose the development of an internationally accepted classification. We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.
RESUMEN
BACKGROUND: There are a variety of surgical and endoscopic interventions available to treat gastroesophageal reflux disease. There is, however, no consensus on which approach is best.The aim of this national audit is to describe the current variation in the UK clinical practice in relation to anti-reflux surgery (ARS) and to report adherence to available clinical guidelines. METHODS: This national audit will be conducted at centers across the UK using the secure online web platform ALEA. The study will comprise two parts: a registration questionnaire and a prospective multicenter audit of ARS. All participating centers will be required to complete the registration questionnaire comprising details regarding pre-, peri-, and post-operative care pathways and whether or not these are standardized within each center. Following this, a 12-month multicenter prospective audit will be undertaken to capture data including patient demographics, predominant symptoms, preoperative investigations, surgery indication, intraoperative details, and postoperative outcomes within the first 90 days.Local teams will retain access to their own data to facilitate local quality improvement. The full dataset will be reported at national and international scientific congresses and will contribute to peer-reviewed publications and national quality improvement initiatives. CONCLUSIONS: This study will identify and explore variation in the processes and outcomes following ARS within the UK using a collaborative cohort methodology. The results generated by this audit will facilitate local and national quality improvement initiatives and generate new possibilities for future research in anti-reflux interventions.
Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo , Reflujo Gastroesofágico , Hernia Hiatal , Laparoscopía , Fundoplicación , Reflujo Gastroesofágico/cirugía , Hernia Hiatal/cirugía , Humanos , Resultado del Tratamiento , Reino UnidoRESUMEN
OBJECTIVES: We recently described metabolic nodal stage (mN) and response (mNR) of cancer of the esophagus and gastro-esophageal junction (GEJ) to neoadjuvant chemotherapy (NAC) using 18F-FDG PET-CT as new markers of disease progression, recurrence, and death. We aimed to validate our findings. METHODS: Our validation cohort comprised all patients consecutive to our discovery cohort, staged before and after NAC using PET-CT from 2014 to 2017. Multivariate binary logistic and Cox regression were performed. RESULTS: Fifty-one of the 200 patients had FDG-avid nodes after NAC (25.5%; i.e., lack of complete mNR), and were more likely to progress during NAC to incurable disease on PET-CT or at surgery: odds ratio 3.84 (1.46-10.1; p = 0.006). In 176 patients undergoing successful resection, patients without complete mNR had a worse prognosis: disease-free survival hazard ratio 2.46 (1.34-4.50); p = 0.004. These associations were independent of primary tumor metabolic, pathological response, and stage. In a hybrid pathological/metabolic nodal stage, avid nodal metastases conferred a worse prognosis than non-avid metastases. Lack of complete mNR predicted recurrence or death at 1 and 2 years: positive predictive values 44.4% (31.7-57.8) and 74.1% (56.6-86.3) respectively. CONCLUSIONS: This study provides temporal validation for mNR as a new and independent predictive and prognostic marker of esophageal and GEJ cancer treated with NAC and surgery, although external validation is required to assess generalizability. mNR may provide surrogate information regarding the phenotype of metastatic cancer clones beyond the mere presence of nodal metastases, and might be used to better inform patients, risk stratify, and personalize management, including adjuvant therapy. KEY POINTS: ⢠We previously described metabolic nodal response (mNR) of esophageal cancer to neoadjuvant chemotherapy using 18 F-FDG PET-CT as a predictor of unresectable disease, early recurrence, and death. ⢠We report the first validation of these findings. In an immediately consecutive cohort, we found consistent proportions of patients with and without mNR, and associations with abandoned resection, early recurrence, and death. ⢠This supports mNR as a new and actionable biomarker in esophageal cancer. Although external validation is required, mNR may provide surrogate information about the chemosensitivity of metastatic subclones, and the means to predict treatment success, guide personalized therapy, and follow-up.
Asunto(s)
Neoplasias Esofágicas/diagnóstico por imagen , Neoplasias Esofágicas/tratamiento farmacológico , Fluorodesoxiglucosa F18/farmacocinética , Ganglios Linfáticos/metabolismo , Terapia Neoadyuvante/métodos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Anciano , Supervivencia sin Enfermedad , Neoplasias Esofágicas/metabolismo , Unión Esofagogástrica/diagnóstico por imagen , Unión Esofagogástrica/metabolismo , Femenino , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Radiofármacos/farmacocinética , Reproducibilidad de los Resultados , Resultado del TratamientoRESUMEN
OBJECTIVES: Fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is typically considered to have minimal yield in gastric cancer, and so is not consistently recommended by international guidelines. However, its yield is considerable in esophageal and junctional cancer, identifying unsuspected metastases and risk-stratifying patients using metabolic nodal stage (mN). We aimed to determine the contemporary utility of routine 18F-FDG PET-CT in gastric cancer. METHODS: We routinely stage patients with non-junctional gastric cancer with PET-CT, provided initial CT does not demonstrate unequivocal metastases. We performed a retrospective study of all such patients staged in our institution from January 2007 to July 2016. Our primary endpoint was detection of incurable disease. Our secondary endpoint was disease-free survival following gastrectomy. Decision theory, economic, and predictive models were generated. RESULTS: The primary tumor was FDG-avid in 225/279 patients (80.6%). Seventy-two (25.8%) had FDG-avid nodes (resectable by D2 lymphadenectomy). This was not influenced by the Lauren classification. Unsuspected metastases were identified in 20 patients (7.2%). In 13 (4.7%), these would not have been otherwise identified. Decision theory and economic modeling supported routine PET-CT. Patients with FDG-avid nodes were more likely to have incurable disease (51.4% versus 15.5%; p < 0.001), and a worse prognosis if not: multivariate hazard ratio 2.19 (1.23-3.91; p = 0.008). Prognosis worsened with mN stage. CONCLUSIONS: PET-CT appears useful when used routinely for non-junctional gastric cancer, and should be considered in international recommendations. Any extra costs appear small and offset by avoiding futile investigations and radical treatment. mN stage identifies patients at risk of early recurrence and death. KEY POINTS: ⢠PET-CT is typically not considered useful when staging gastric cancer. We describe a retrospective study of 279 patients routinely staged with PET-CT in the absence of metastases on CT. ⢠The primary tumor was avid in 80% of patients. Twenty-five percent had resectable avid nodes. PET-CT identified previously unsuspected metastases in 7% of patients, which would likely not have been identified by conventional staging without PET-CT in 5%. These patients were much more likely to have avid nodes. ⢠Beyond avoiding futile investigations and radical treatment in this 5%, we found patients with FDG-avid nodes (metabolic nodal stage, mN) to have a worse disease-free survival after gastrectomy.
Asunto(s)
Adenocarcinoma/secundario , Fluorodesoxiglucosa F18/farmacología , Gastrectomía , Recurrencia Local de Neoplasia/epidemiología , Estadificación de Neoplasias/métodos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias Gástricas/patología , Adenocarcinoma/diagnóstico , Adenocarcinoma/mortalidad , Anciano , Supervivencia sin Enfermedad , Femenino , Humanos , Incidencia , Escisión del Ganglio Linfático , Metástasis Linfática , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Periodo Posoperatorio , Valor Predictivo de las Pruebas , Pronóstico , Radiofármacos/farmacología , Estudios Retrospectivos , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/cirugía , Tasa de Supervivencia/tendencias , Reino Unido/epidemiologíaRESUMEN
BACKGROUND & AIMS: Barrett's esophagus (BE) increases the risk of esophageal adenocarcinoma (EAC). We found the risk to be BE has been associated with single nucleotide polymorphisms (SNPs) on chromosome 6p21 (within the HLA region) and on 16q23, where the closest protein-coding gene is FOXF1. Subsequently, the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON) identified risk loci for BE and esophageal adenocarcinoma near CRTC1 and BARX1, and within 100 kb of FOXP1. We aimed to identify further SNPs that increased BE risk and to validate previously reported associations. METHODS: We performed a genome-wide association study (GWAS) to identify variants associated with BE and further analyzed promising variants identified by BEACON by genotyping 10,158 patients with BE and 21,062 controls. RESULTS: We identified 2 SNPs not previously associated with BE: rs3072 (2p24.1; odds ratio [OR] = 1.14; 95% CI: 1.09-1.18; P = 1.8 × 10(-11)) and rs2701108 (12q24.21; OR = 0.90; 95% CI: 0.86-0.93; P = 7.5 × 10(-9)). The closest protein-coding genes were respectively GDF7 (rs3072), which encodes a ligand in the bone morphogenetic protein pathway, and TBX5 (rs2701108), which encodes a transcription factor that regulates esophageal and cardiac development. Our data also supported in BE cases 3 risk SNPs identified by BEACON (rs2687201, rs11789015, and rs10423674). Meta-analysis of all data identified another SNP associated with BE and esophageal adenocarcinoma: rs3784262, within ALDH1A2 (OR = 0.90; 95% CI: 0.87-0.93; P = 3.72 × 10(-9)). CONCLUSIONS: We identified 2 loci associated with risk of BE and provided data to support a further locus. The genes we found to be associated with risk for BE encode transcription factors involved in thoracic, diaphragmatic, and esophageal development or proteins involved in the inflammatory response.
Asunto(s)
Esófago de Barrett/genética , Proteínas Morfogenéticas Óseas/genética , Predisposición Genética a la Enfermedad , Factores de Diferenciación de Crecimiento/genética , Polimorfismo de Nucleótido Simple , Proteínas de Dominio T Box/genética , Esófago de Barrett/etiología , Neoplasias Esofágicas/genética , Estudio de Asociación del Genoma Completo , Humanos , RiesgoRESUMEN
OBJECTIVES: It is unknown whether restaging oesophageal cancer after neoadjuvant therapy with positron emission tomography-computed tomography (PET-CT) is more sensitive than contrast-enhanced CT for disease progression. We aimed to determine this and stratify risk. METHODS: This was a retrospective study of patients staged before neoadjuvant chemotherapy (NAC) by (18)F-FDG PET-CT and restaged with CT or PET-CT in a single centre (2006-2014). RESULTS: Three hundred and eighty-three patients were restaged (103 CT, 280 PET-CT). Incurable disease was detected by CT in 3 (2.91 %) and PET-CT in 17 (6.07 %). Despite restaging unsuspected incurable disease was encountered at surgery in 34/336 patients (10.1 %). PET-CT was more sensitive than CT (p = 0.005, McNemar's test). A new classification of FDG-avid nodal stage (mN) before NAC (plus tumour FDG-avid length) predicted subsequent progression, independent of conventional nodal stage. The presence of FDG-avid nodes after NAC and an impassable tumour stratified risk of incurable disease at surgery into high (75.0 %; both risk factors), medium (22.4 %; either), and low risk (3.87 %; neither) groups (p < 0.001). Decision theory supported restaging PET-CT. CONCLUSIONS: PET-CT is more sensitive than CT for detecting interval progression; however, it is insufficient in at least higher risk patients. mN stage and response (mNR) plus primary tumour characteristics can stratify this risk simply. KEY POINTS: ⢠Restaging (18) F-FDG-PET-CT after neoadjuvant chemotherapy identifies metastases in 6 % of patients ⢠Restaging (18) F-FDG-PET-CT is more sensitive than CT for detecting interval progression ⢠Despite this, at surgery 10 % of patients had unsuspected incurable disease ⢠New concepts (FDG-avid nodal stage and response) plus tumour impassability stratify risk ⢠Higher risk (if not all) patients may benefit from additional restaging modalities.
Asunto(s)
Neoplasias Esofágicas/diagnóstico por imagen , Neoplasias Esofágicas/patología , Adulto , Anciano , Quimioterapia Adyuvante , Teoría de las Decisiones , Progresión de la Enfermedad , Neoplasias Esofágicas/terapia , Esofagectomía/métodos , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Metástasis de la Neoplasia , Estadificación de Neoplasias , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Pronóstico , Radiofármacos , Estudios Retrospectivos , Medición de Riesgo/métodos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodosRESUMEN
Barrett's esophagus (BE) is a common and important precursor lesion of esophageal adenocarcinoma (EAC). A third of patients with BE are asymptomatic, and our ability to predict the risk of progression of metaplasia to dysplasia and EAC (and therefore guide management) is limited. There is an urgent need for clinically useful biomarkers of susceptibility to both BE and risk of subsequent progression. This study aims to systematically identify, review, and meta-analyze genetic biomarkers reported to predict both. A systematic review of the PubMed and EMBASE databases was performed in May 2014. Study and evidence quality were appraised using the revised American Society of Clinical Oncology guidelines, and modified Recommendations for Tumor Marker Scores. Meta-analysis was performed for all markers assessed by more than one study. A total of 251 full-text articles were reviewed; 52 were included. A total of 33 germline markers of susceptibility were identified (level of evidence II-III); 17 were included. Five somatic markers of progression were identified; meta-analysis demonstrated significant associations for chromosomal instability (level of evidence II). One somatic marker of progression/relapse following photodynamic therapy was identified. However, a number of failings of methodology and reporting were identified. This is the first systematic review and meta-analysis to evaluate genetic biomarkers of BE susceptibility and risk of progression. While a number of limitations of study quality temper the utility of those markers identified, some-in particular, those identified by genome-wide association studies, and chromosomal instability for progression-appear plausible, although robust validation is required.
Asunto(s)
Adenocarcinoma/genética , Esófago de Barrett/genética , Neoplasias Esofágicas/genética , Esófago/patología , Variación Genética , Lesiones Precancerosas/genética , Adenocarcinoma/diagnóstico , Esófago de Barrett/diagnóstico , Esófago de Barrett/terapia , Progresión de la Enfermedad , Neoplasias Esofágicas/diagnóstico , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Fenotipo , Lesiones Precancerosas/diagnóstico , Lesiones Precancerosas/terapia , Pronóstico , Medición de Riesgo , Factores de Riesgo , Resultado del TratamientoRESUMEN
Eight loci have been identified by the two genome-wide association studies of Barrett's esophagus that have been conducted to date. Esophageal adenocarcinoma cases were included in the second study following evidence that predisposing genetic variants for this cancer overlap with those for Barrett's esophagus. Genes with roles in embryonic development of the foregut are adjacent to 6 of the loci identified (FOXF1, BARX1, FOXP1, GDF7, TBX5, and ALDH1A2). An additional locus maps to a gene with known oncogenic potential (CREB-regulated transcription coactivator 1), but expression quantitative trait data implicates yet another gene involved in esophageal development (PBX4). These results strongly support a model whereby dysregulation of genes involved in esophageal and thoracic development increases susceptibility to Barrett's esophagus and esophageal adenocarcinoma, probably by reducing anatomical antireflux mechanisms. An additional signal at 6p21 in the major histocompatibility complex also reinforces evidence that immune and inflammatory response to reflux is involved in the development of both diseases. All of the variants identified are intronic or intergenic rather than coding and are presumed to be or to mark regulatory variants. As with genome-wide association studies of other diseases, the functional variants at each locus are yet to be identified and the genes affected need confirming. In this chapter as well as discussing the biology behind each genome-wide association signal, we review the requirements for successfully conducting genome-wide association studies and discuss how progress in understanding the genetic variants that contribute to Barrett's esophagus/esophageal adenocarcinoma susceptibility compares to other cancers.
Asunto(s)
Esófago de Barrett/genética , Predisposición Genética a la Enfermedad/genética , Variación Genética , Estudio de Asociación del Genoma Completo/métodos , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Esófago de Barrett/diagnóstico , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Progresión de la Enfermedad , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/genética , Regulación Neoplásica de la Expresión Génica , HumanosRESUMEN
OBJECTIVE: This article aims to provide the first systematic review of enhanced recovery after surgery (ERAS) programs for esophagectomy and generate guidelines. BACKGROUND: ERAS programs use multimodal approaches to reduce complications and accelerate recovery. Although ERAS is well established in colorectal surgery, experience after esophagectomy has been minimal. However, esophagectomy remains an extremely high-risk operation, commonly performed in patients with significant comorbidities. Consequently, ERAS may have a significant role to play in improving outcomes. No guidelines or reviews have been published in esophagectomy. METHODS: We undertook a systematic review of the PubMed, EMBASE, and the Cochrane databases in July 2012. The literature was searched for descriptions of ERAS in esophagectomy. Components of successful ERAS programs were determined, and when not directly available for esophagectomy, extrapolation from related evidence was made. Graded recommendations for each component were then generated. RESULTS: Six retrospective studies have assessed ERAS for esophagectomy, demonstrating favorable morbidity, mortality, and length of stay. Methodological quality is, however, low. Overall, there is little direct evidence for components of ERAS, with much derived from nonesophageal thoracoabdominal surgery. CONCLUSIONS: ERAS in principle seems logical and safe for esophagectomy. However, the underlying evidence is poor and lacking. Despite this, a number of recommendations for practice and research can be made.
Asunto(s)
Enfermedades del Esófago/cirugía , Esofagectomía , Medicina Basada en la Evidencia , Cuidados Posoperatorios/métodos , Guías de Práctica Clínica como Asunto , Recuperación de la Función , HumanosRESUMEN
Change blindness refers to the difficulty most people find in detecting a difference between two pictures when these are presented successively, with a brief interruption between. Attention at the site of the change is required for detection. A number of studies have investigated change blindness in adults and children with autism spectrum disorders (ASD). Some have produced evidence that people with ASD find changes to social stimuli harder to detect and changes to non-social stimuli easier to detect, relative to comparison participants. However, other studies have produced entirely contradictory findings. There is a need for consistency in methodology to aid understanding of change blindness and attentional processes in ASD. Here, we replicate a change blindness study previously carried out with typically developing (TD) children and adults and with adults with ASD. Results reveal attenuated change blindness for non-social stimuli in children with ASD relative to TD norms. Our results are interpreted, alongside others' findings, as potentially indicative of a complex relationship between different influences on attention over time.
Asunto(s)
Trastornos Generalizados del Desarrollo Infantil/psicología , Percepción Visual , Adolescente , Adulto , Factores de Edad , Análisis de Varianza , Atención , Niño , Desarrollo Infantil , Femenino , Humanos , Masculino , Estimulación Luminosa/métodos , Tiempo de Reacción , Adulto JovenRESUMEN
PURPOSE: Faecal incontinence is a common and important multifactorial disorder with a range of treatment options. Over the last two decades, neuromodulation via sacral nerve stimulators has been shown to be effective for both faecal and urinary incontinence, although associated with complications. Peripheral neuromodulation, via the posterior tibial nerve, is widely used in urinary incontinence; however, its use in faecal incontinence, whilst evolving is limited to eight small heterogeneous studies. REVIEW: These eight studies are discussed in the context of the methodology and underlying neurophysiology of peripheral neuromodulation, as are thus far unanswered questions. The eight studies include a total of 129 patients with faecal incontinence (of variable aetiology), all of whom had failed conservative management. One study was prospective and controlled, six were uncontrolled and one was retrospective and uncontrolled. Five different neuromodulatory protocols were used over six different study periods. Outcome measures varied, but short term primary endpoint success ranged from 30.0% to 83.3%. The limitations to this early evidence, whilst encouraging, are significant, and it remains to be seen whether this novel treatment modality represents the minimally invasive, well-tolerated, cost-effective and flexible panacea hoped for this common and debilitating disease. Three upcoming multicentre placebo-controlled trials will better be able to delineate its role.
Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Incontinencia Fecal/fisiopatología , Incontinencia Fecal/terapia , Nervio Tibial/fisiología , HumanosRESUMEN
This article was originally published under a [CC BY NC 4.0] license.
RESUMEN
INTRODUCTION: The identification of tumour mutational burden (TMB) as a biomarker of response to programmed cell death protein 1 (PD-1) immunotherapy has necessitated the development of genomic assays to measure this. We carried out comprehensive molecular profiling of cancers using the Illumina TruSight Oncology 500 (TSO500) panel and compared these to whole-genome sequencing (WGS). METHODS: Cancer samples derived from formalin-fixed material were profiled on the TSO500 panel, sequenced on an Illumina NextSeq 500 instrument and processed through the TSO500 Docker pipeline. Either FASTQ files (PierianDx) or vcf files (OncoKDM) were processed to understand clinical actionability. RESULTS: In total, 108 samples (a mixture of colorectal, lung, oesophageal and control samples) were processed via the DNA panel. There was good correlation between TMB, single-nucleotide variants (SNVs), indels and copy-number variations as predicted by TSO500 and WGS (R2 > 0.9) and good reproducibility, with less than 5% variability between repeated controls. For the RNA panel, 13 samples were processed, with all known fusions observed via orthogonal techniques. For clinical actionability, 72 tier 1 variants and 297 tier 2 variants were detected, with clinical trials identified for all patients. CONCLUSIONS: The TSO500 assay accurately measures TMB, microsatellite instability, SNVs, indels, copy-number/structural variation and gene fusions when compared to WGS and orthogonal technologies. Coupled with a clinical annotation pipeline, this provides a powerful methodology for identification of clinically actionable variants.
Asunto(s)
Biomarcadores de Tumor , Secuenciación de Nucleótidos de Alto Rendimiento , Mutación , Neoplasias/diagnóstico , Neoplasias/genética , Niño , Preescolar , Biología Computacional/métodos , Variaciones en el Número de Copia de ADN , Análisis Mutacional de ADN , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Proteínas de Punto de Control Inmunitario/genética , Proteínas de Punto de Control Inmunitario/metabolismo , Lactante , Masculino , Inestabilidad de Microsatélites , Neoplasias/tratamiento farmacológico , Polimorfismo de Nucleótido Simple , Secuenciación Completa del GenomaRESUMEN
Saccadic eye movements and fixations are the behavioral means by which we visually sample text during reading. Human oculomotor control is governed by a complex neurophysiological system involving the brain stem, superior colliculus, and several cortical areas. A very widely held belief among researchers investigating primate vision is that the oculomotor system serves to orient the visual axes of both eyes to fixate the same target point in space. It is argued that such precise positioning of the eyes is necessary to place images on corresponding retinal locations, such that on each fixation a single, nondiplopic, visual representation is perceived. Vision works actively through a continual sampling process involving saccades and fixations. Here we report that during normal reading, the eyes do not always fixate the same letter within a word. We also demonstrate that saccadic targeting is yoked and based on a unified cyclopean percept of a whole word since it is unaffected if different word parts are delivered exclusively to each eye via a dichoptic presentation technique. These two findings together suggest that the visual signal from each eye is fused at a very early stage in the visual pathway, even when the fixation disparity is greater than one character (0.29 deg), and that saccade metrics for each eye are computed on the basis of that fused signal.
Asunto(s)
Fijación Ocular , Músculos Oculomotores/fisiología , Lectura , Movimientos Sacádicos , Visión Binocular/fisiología , HumanosRESUMEN
The relationship between attention and eye movements is explored by consideration of the variety of ways attention may affect saccade programming. Four forms of attention are distinguished: one exogenous and three endogenous through either locations or objects or features. Each of these can control or influence the saccadic generation process. Visual onsets generate a rapid transient signal with low resolution that travels from the visual system to the oculomotor system. Generation of an eye movement is associated with an attentional signal, probably also with low resolution, travelling from the oculomotor system to the visual system. A high-resolution attentional signal, which appears to require voluntary effort, can also select saccadic targets.
Asunto(s)
Atención/fisiología , Movimientos Sacádicos/fisiología , Percepción Visual/fisiología , Percepción de Forma/fisiología , Humanos , Nervio Oculomotor/fisiología , Tiempo de Reacción/fisiología , Percepción Espacial/fisiología , Campos Visuales/fisiología , Vías Visuales/fisiologíaRESUMEN
Other people's eye-gaze is a powerful social stimulus that captures and directs visual attention. There is evidence that this is not the case for children with autism spectrum disorder (ASD), although less is known about attention to eye-gaze in adults. We investigated whether young adults would detect a change to the direction of eye-gaze in another's face more efficiently than a control change (presence/absence of spectacles). A change blindness method was used in which images showed faces as part of a complex, naturalistic scene. Results showed that adults with ASD, like typically developing controls, were faster and more accurate at detecting eye-gaze than control changes. Results are considered in terms of a developmental account of the relationship between social attention and other skills.
Asunto(s)
Atención , Trastorno Autístico/psicología , Percepción Visual , Adolescente , Adulto , Trastorno Autístico/diagnóstico , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Masculino , Desarrollo de Programa , Escalas de WechslerRESUMEN
Only a minority of esophageal cancers demonstrates a pathologic tumor response (pTR) to neoadjuvant chemotherapy (NAC). 18F-FDG PET/CT is often used for restaging after NAC and to assess response. Increasingly, it is used during therapy to identify unresponsive tumors and predict pTR, using avidity of the primary tumor alone. However, definitions of such metabolic tumor response (mTR) vary. We aimed to comprehensively reevaluate metabolic response assessment using accepted parameters, as well as novel concepts of metabolic nodal stage (mN) and metabolic nodal response (mNR). METHODS: This was a single-center retrospective U.K. cohort study. All patients with esophageal cancer staged before NAC with PET/CT and after with CT or PET/CT and undergoing resection from 2006 to 2014 were identified. pTR was defined as Mandard tumor regression grade 1-3; imaging parameters included metrics of tumor avidity (SUVmax/mean/peak), composites of avidity and volume (including metabolic tumor volume), nodal SUVmax, and our new concepts of mN stage and mNR. RESULTS: Eighty-two (27.2%) of 301 patients demonstrated pTR. No pre-NAC PET parameters predicted pTR. In 220 patients restaged by PET/CT, the optimal tumor ΔSUVmax threshold was a 77.8% reduction. This was as sensitive as the current PERCIST 30% reduction, but more specific with a higher negative predictive value (P < 0.001). ΔSUVmax and Δlength independently predicted pTR, and composite avidity/spatial metrics outperformed avidity alone. Although both mTR and mNR were associated with pTR, in 82 patients with 18F-FDG-avid nodes before NAC we observed mNR in 10 (12.2%) not demonstrating mTR. CONCLUSION: Current definitions of metabolic response are suboptimal and too simplistic. Composite avidity/volume measures improve prediction. mNR may further improve response assessment, by specifically assessing metastatic tumor subpopulations, likely responsible for disease relapse, and should be urgently assessed when considering aborting therapy on the basis of mTR alone.