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OBJECTIVE: We measured how long distraction by a smartphone affects simulated driving behaviors after the tasks are completed (i.e., the distraction hangover). BACKGROUND: Most drivers know that smartphones distract. Trying to limit distraction, drivers can use hands-free devices, where they only briefly glance at the smartphone. However, the cognitive cost of switching tasks from driving to communicating and back to driving adds an underappreciated, potentially long period to the total distraction time. METHOD: Ninety-seven 21- to 78-year-old individuals who self-identified as active drivers and smartphone users engaged in a simulated driving scenario that included smartphone distractions. Peripheral-cue and car-following tasks were used to assess driving behavior, along with synchronized eye tracking. RESULTS: The participants' lateral speed was larger than baseline for 15 s after the end of a voice distraction and for up to 25 s after a text distraction. Correct identification of peripheral cues dropped about 5% per decade of age, and participants from the 71+ age group missed seeing about 50% of peripheral cues within 4 s of the distraction. During distraction, coherence with the lead car in a following task dropped from 0.54 to 0.045, and seven participants rear-ended the lead car. Breadth of scanning contracted by 50% after distraction. CONCLUSION: Simulated driving performance drops dramatically after smartphone distraction for all ages and for both voice and texting. APPLICATION: Public education should include the dangers of any smartphone use during driving, including hands-free.
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Conducción de Automóvil , Envío de Mensajes de Texto , Humanos , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Teléfono Inteligente , Asunción de Riesgos , Simulación por Computador , Accidentes de TránsitoRESUMEN
EEG microstates represent transient electrocortical events that reflect synchronized activities of large-scale networks, which allows investigations of brain dynamics with sub-second resolution. We recorded resting EEG from 38 children and adolescents with Autism Spectrum Development (ASD) and 48 age, IQ, sex, and handedness-matched typically developing (TD) participants. The EEG was segmented into a time series of microstates using modified k-means clustering of scalp voltage topographies. The frequency and global explained variance (GEV) of a specific microstate (type C) were significantly lower in the ASD group compared to the TD group while the duration of the same microstate was correlated with the presence of ASD-related behaviors. The duration of this microstate was also positively correlated with participant age in the TD group, but not in the ASD group. Further, the frequency and duration of the microstate were significantly correlated with the overall alpha power only in the TD group. The signal strength and GEV for another microstate (type G) was greater in the ASD group than the TD group, and the associated topographical pattern differed between groups with greater variations in the ASD group. While more work is needed to clarify the underlying neural sources, the existing literature supports associations between the two microstates and the default mode and salience networks. The current study suggests specific alterations of temporal dynamics of the resting cortical network activities as well as their developmental trajectories and relationships to alpha power, which has been proposed to reflect reduced neural inhibition in ASD.
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Trastorno del Espectro Autista , Trastorno Autístico , Adolescente , Encéfalo/fisiología , Mapeo Encefálico , Niño , Electroencefalografía , Humanos , DescansoRESUMEN
There is substantial evidence of age-related declines in anatomical connectivity during adulthood, with associated alterations in functional connectivity. But the relation of those functional alterations to the structural reductions is unclear. The complexities of both the structural and the functional connectomes make it difficult to determine such relationships. We pursue this question with methods, based on animal research, that specifically target the interhemispheric connections between the visual cortices. We collect t1- and diffusion-weighted imaging data from which we assess the integrity of the white matter interconnecting the bilateral visual cortices. Functional connectivity between the visual cortices is measured with electroencephalography during the presentation of drifting sinusoidal gratings that agree or conflict across hemifields. Our results show age-related reductions in the integrity of the white matter interconnecting the visual cortices, and age-related increases in the difference in functional interhemispheric lagged coherence between agreeing versus disagreeing visual stimuli. We show that integrity of the white matter in the splenium of the corpus callosum predicts the differences in lagged coherence for the agreeing versus disagreeing stimuli; and that this relationship is mediated by age. These results give new insight into the causal relationship between age and functional connectivity.
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Cuerpo Calloso , Sustancia Blanca , Envejecimiento , Animales , Cuerpo Calloso/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética , Electroencefalografía , Sustancia Blanca/diagnóstico por imagenRESUMEN
Spatial neglect is a common feature of right hemisphere damage in adults, but less is known about spatial inattention following early brain damage. We used a Posner-based cueing task to examine hemispatial neglect and aspects of attention in children with perinatal stroke in either left (LH) or right hemisphere (RH) and controls. A visual perception task assessed the speed of visual perception. A spatial attention cueing task (the E-task) measured the ability to discriminate the direction of a target stimulus ("E"), when presented on the left or right side of the screen. This task provided indices of performance for attention orienting, disengagement and reorienting. Children with LH lesions had slowed visual perception compared to controls. Children with RH lesions did not demonstrate similar deficits. On the E-task, groups with both LH and RH lesions demonstrated lower accuracy on both left and right sides compared to controls. Children with LH lesions also showed impaired attention orienting and disengagement on left and right sides compared to controls, while children with RH lesions were most impaired in orienting and disengagement on their contralesional side. Children with LH lesions demonstrated more extensive attentional deficits than children with RH lesions. These results suggest that development of spatial attention may require different neural networks than maintenance of attention.
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Trastornos de la Percepción/patología , Tiempo de Reacción/fisiología , Percepción Espacial/fisiología , Accidente Cerebrovascular/complicaciones , Percepción Visual/fisiología , Adolescente , Niño , Señales (Psicología) , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Pruebas NeuropsicológicasRESUMEN
Autism spectrum disorders (ASDs) have been linked to atypical communication among distributed brain networks. However, despite decades of research, the exact nature of these differences between typically developing (TD) individuals and those with ASDs remains unclear. ASDs have been widely studied using resting-state neuroimaging methods, including both functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). However, little is known about how fMRI and EEG measures of spontaneous brain activity are related in ASDs. In the present study, two cohorts of children and adolescents underwent resting-state EEG (n = 38 per group) or fMRI (n = 66 ASD, 57 TD), with a subset of individuals in both the EEG and fMRI cohorts (n = 17 per group). In the EEG cohort, parieto-occipital EEG alpha power was found to be reduced in ASDs. In the fMRI cohort, blood oxygen level-dependent (BOLD) power was regionally increased in right temporal regions and there was widespread overconnectivity between the thalamus and cortical regions in the ASD group relative to the TD group. Finally, multimodal analyses indicated that while TD children showed consistently positive relationships between EEG alpha power and regional BOLD power, these associations were weak or negative in ASDs. These findings suggest atypical links between alpha rhythms and regional BOLD activity in ASDs, possibly implicating neural substrates and processes that coordinate thalamocortical regulation of the alpha rhythm.
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Trastorno del Espectro Autista/diagnóstico por imagen , Trastorno del Espectro Autista/fisiopatología , Adolescente , Ritmo alfa/fisiología , Trastorno del Espectro Autista/metabolismo , Trastorno Autístico/diagnóstico por imagen , Trastorno Autístico/fisiopatología , Encéfalo/fisiopatología , Mapeo Encefálico/métodos , Niño , Electroencefalografía/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Tálamo/fisiopatologíaRESUMEN
Attentional impairments are among the earliest identifiable features of autism spectrum disorders (ASDs). Three attention networks have been extensively studied using the attention network test (ANT), but this long and repetitive task may pose challenges for individuals with ASDs. The AttentionTrip was developed as a more engaging measure of attention network efficiency. In 20 adults with ASDs and 20 typically developing controls, both tasks produced typical network scores (all p < .003, all Cohen's d > 0.78). Reaction time was less variable in the AttentionTrip than the ANT, possibly reflecting improved task engagement. Although the AttentionTrip elicited more consistent responses throughout an experimental session, anomalously low split-half reliability for its executive control network suggests that some changes may be needed.
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Desarrollo del Adolescente/fisiología , Atención/fisiología , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/psicología , Juegos de Video/psicología , Adolescente , Adulto , Cognición/fisiología , Función Ejecutiva/fisiología , Femenino , Humanos , Masculino , Tiempo de Reacción/fisiología , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
BACKGROUND: Prior studies using a variety of methodologies have reported inconsistent dopamine (DA) findings in individuals with autism spectrum disorder (ASD), ranging from dopaminergic hypo- to hyper-activity. Theta-band power derived from scalp-recorded electroencephalography (EEG), which may be associated with dopamine levels in frontal cortex, has also been shown to be atypical in ASD. The present study examined spontaneous eye-blink rate (EBR), an indirect, non-invasive measure of central dopaminergic activity, and theta power in children with ASD to determine: 1) whether ASD may be associated with atypical DA levels, and 2) whether dopaminergic dysfunction may be associated with aberrant theta-band activation. METHOD: Participants included thirty-two children with ASD and thirty-two age-, IQ-, and sex-matched typically developing (TD) children. Electroencephalography and eye-tracking data were acquired while participants completed an eyes-open resting-state session. Blinks were counted and EBR was determined by dividing blink frequency by session duration and theta power (4-7.5â¯Hz) was extracted from midline leads. RESULTS: Eye-blink rate and theta-band activity were significantly reduced in children with ASD as compared to their TD peers. For all participants, greater midline theta power was associated with increased EBR (related to higher DA levels). CONCLUSIONS: These results suggest that ASD may be associated with dopaminergic hypo-activity, and that this may contribute to atypical theta-band power. Lastly, EBR may be a useful tool to non-invasively index dopamine levels in ASD and could potentially have many clinical applications, including selecting treatment options and monitoring treatment response.
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Trastorno del Espectro Autista/metabolismo , Parpadeo/fisiología , Dopamina/metabolismo , Descanso/fisiología , Ritmo Teta/fisiología , Adolescente , Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/psicología , Mapeo Encefálico/métodos , Niño , Electroencefalografía/métodos , Femenino , Humanos , Masculino , Descanso/psicologíaRESUMEN
This study investigates how task-irrelevant auditory information is processed in children with autism spectrum disorder (ASD). Eighteen children with ASD and 19 age- and IQ-matched typically developing (TD) children were presented with semantically-congruent and incongruent picture-sound pairs, and in separate tasks were instructed to attend to only visual or both audio-visual sensory channels. Preliminary results showed that when required to attend to both modalities, both groups were equally slowed for semantically-incongruent compared to congruent pairs. However, when asked to attend to only visual information, children with ASD were disproportionally slowed by incongruent auditory information, suggesting that they may have more difficulty filtering task-irrelevant cross-modal information. Correlational analyses showed that this inefficient cross-modal attentional filtering was related to greater sociocommunicative impairment.
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Trastorno del Espectro Autista/fisiopatología , Filtrado Sensorial , Atención , Percepción Auditiva , Niño , Femenino , Humanos , Masculino , Percepción VisualRESUMEN
This letter makes scientific and methodological contributions. Scientifically, it demonstrates a new and behaviorally relevant effect of temporal expectation on the phase coherence of the electroencephalogram (EEG). Methodologically, it introduces novel methods to characterize EEG recordings at the single-trial level. Expecting events in time can lead to more efficient behavior. A remarkable finding in the study of temporal expectation is the foreperiod effect on reaction time, that is, the influence on reaction time of the delay between a warning signal and a succeeding imperative stimulus to which subjects are instructed to respond as quickly as possible. Here we study a new foreperiod effect in an audiovisual attention-shifting oddball task in which attention-shift cues directed the attention of subjects to impendent deviant stimuli of a given modality and therefore acted as warning signals for these deviants. Standard stimuli, to which subjects did not respond, were interspersed between warning signals and deviants. We hypothesized that foreperiod durations modulated intertrial phase coherence (ITPC, the degree of phase alignment across multiple trials) evoked by behaviorally irrelevant standards and that these modulations are behaviorally meaningful. Using averaged data, we first observed that ITPC evoked by standards closer to the warning signal was significantly different from that evoked by standards further away from it, establishing a new foreperiod effect on ITPC evoked by standards. We call this effect the standard foreperiod (SFP) effect on ITPC. We reasoned that if the SFP influences ITPC evoked by standards, it should be possible to decode the former from the latter on a trial-by-trial basis. We were able to do so showing that this effect can be observed in single trials. We demonstrated the behavioral relevance of the SFP effect on ITPC by showing significant correlations between its strength and subjects' behavioral performance.
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Atención/fisiología , Ondas Encefálicas/fisiología , Conducta de Elección , Percepción/fisiología , Detección de Señal Psicológica/fisiología , Estimulación Acústica , Adulto , Animales , Mapeo Encefálico , Señales (Psicología) , Electroencefalografía , Femenino , Humanos , Masculino , Estimulación Luminosa , Análisis de Componente Principal , Desempeño Psicomotor , Tiempo de Reacción , Estadísticas no Paramétricas , Adulto JovenRESUMEN
In addition to the social, communicative and behavioral symptoms that define the disorder, individuals with ASD have difficulty re-orienting attention quickly and accurately. Similarly, fast re-orienting saccadic eye movements are also inaccurate and more variable in both endpoint and timing. Atypical gaze and attention are among the earliest symptoms observed in ASD. Disruption of these foundation skills critically affects the development of higher level cognitive and social behavior. We propose that interventions aimed at these early deficits that support social and cognitive skills will be broadly effective. We conducted a pilot clinical trial designed to demonstrate the feasibility and preliminary efficacy of using gaze-contingent video games for low-cost in-home training of attention and eye movement. Eight adolescents with ASD participated in an 8-week training, with pre-, mid- and post-testing of eye movement and attention control. Six of the eight adolescents completed the 8 weeks of training and all six showed improvement in attention (orienting, disengagement) and eye movement control or both. All game systems remained intact for the duration of training and all participants could use the system independently. We delivered a robust, low-cost, gaze-contingent game system for home use that, in our pilot training sample, improved the attention orienting and eye movement performance of adolescent participants in 8 weeks of training. We are currently conducting a clinical trial to replicate these results and to examine what, if any, aspects of training transfer to more real-world tasks. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 546-554, 2018.
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Atención , Trastorno del Espectro Autista/rehabilitación , Movimientos Oculares , Terapia Asistida por Computador , Juegos de Video , Adolescente , Niño , Estudios de Factibilidad , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Proyectos Piloto , Conducta Social , Conducta Espacial , Resultado del TratamientoRESUMEN
Atypical functional connectivity has been implicated in autism spectrum disorders (ASDs). However, the literature to date has been largely inconsistent, with mixed and conflicting reports of hypo- and hyper-connectivity. These discrepancies are partly due to differences between various neuroimaging modalities. Functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG) measure distinct indices of functional connectivity (e.g., blood-oxygenation level-dependent [BOLD] signal vs. electrical activity). Furthermore, each method has unique benefits and disadvantages with respect to spatial and temporal resolution, vulnerability to specific artifacts, and practical implementation. Thus far, functional connectivity research on ASDs has remained almost exclusively unimodal; therefore, interpreting findings across modalities remains a challenge. Multimodal integration of fMRI, EEG, and MEG data is critical in resolving discrepancies in the literature, and working toward a unifying framework for interpreting past and future findings. This review aims to provide a theoretical foundation for future multimodal research on ASDs. First, we will discuss the merits and shortcomings of several popular theories in ASD functional connectivity research, using examples from the literature to date. Next, the neurophysiological relationships between imaging modalities, including their relationship with invasive neural recordings, will be reviewed. Finally, methodological approaches to multimodal data integration will be presented, and their future application to ASDs will be discussed. Analyses relating transient patterns of neural activity ("states") are particularly promising. This strategy provides a comparable measure across modalities, captures complex spatiotemporal patterns, and is a natural extension of recent dynamic fMRI research in ASDs. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 456-473, 2018.
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Trastorno del Espectro Autista/diagnóstico por imagen , Trastorno del Espectro Autista/fisiopatología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Imagen Multimodal/métodos , Animales , Humanos , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiopatologíaRESUMEN
BACKGROUND: Autism spectrum disorder (ASD) is associated with deficits in adaptively orienting attention to behaviorally-relevant information. Neural oscillatory activity plays a key role in brain function and provides a high-resolution temporal marker of attention dynamics. Alpha band (8-12 Hz) activity is associated with both selecting task-relevant stimuli and filtering task-irrelevant information. METHODS: The present study used electroencephalography (EEG) to examine alpha-band oscillatory activity associated with attentional capture in nineteen children with ASD and twenty-one age- and IQ-matched typically developing (TD) children. Participants completed a rapid serial visual presentation paradigm designed to investigate responses to behaviorally-relevant targets and contingent attention capture by task-irrelevant distractors, which either did or did not share a behaviorally-relevant feature. Participants also completed six minutes of eyes-open resting EEG. RESULTS: In contrast to their TD peers, children with ASD did not evidence posterior alpha desynchronization to behaviorally-relevant targets. Additionally, reduced target-related desynchronization and poorer target detection were associated with increased ASD symptomatology. TD children also showed behavioral and electrophysiological evidence of contingent attention capture, whereas children with ASD showed no behavioral facilitation or alpha desynchronization to distractors that shared a task-relevant feature. Lastly, children with ASD had significantly decreased resting alpha power, and for all participants increased resting alpha levels were associated with greater task-related alpha desynchronization. CONCLUSIONS: These results suggest that in ASD under-responsivity and impairments in orienting to salient events within their environment are reflected by atypical EEG oscillatory neurodynamics, which may signify atypical arousal levels and/or an excitatory/inhibitory imbalance.
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OBJECTIVE: No drug is yet approved to treat the core symptoms of autism spectrum disorder (ASD). Low-dose suramin was effective in the maternal immune activation and Fragile X mouse models of ASD. The Suramin Autism Treatment-1 (SAT-1) trial was a double-blind, placebo-controlled, translational pilot study to examine the safety and activity of low-dose suramin in children with ASD. METHODS: Ten male subjects with ASD, ages 5-14 years, were matched by age, IQ, and autism severity into five pairs, then randomized to receive a single, intravenous infusion of suramin (20 mg/kg) or saline. The primary outcomes were ADOS-2 comparison scores and Expressive One-Word Picture Vocabulary Test (EOWPVT). Secondary outcomes were the aberrant behavior checklist, autism treatment evaluation checklist, repetitive behavior questionnaire, and clinical global impression questionnaire. RESULTS: Blood levels of suramin were 12 ± 1.5 µmol/L (mean ± SD) at 2 days and 1.5 ± 0.5 µmol/L after 6 weeks. The terminal half-life was 14.7 ± 0.7 days. A self-limited, asymptomatic rash was seen, but there were no serious adverse events. ADOS-2 comparison scores improved by -1.6 ± 0.55 points (n = 5; 95% CI = -2.3 to -0.9; Cohen's d = 2.9; P = 0.0028) in the suramin group and did not change in the placebo group. EOWPVT scores did not change. Secondary outcomes also showed improvements in language, social interaction, and decreased restricted or repetitive behaviors. INTERPRETATION: The safety and activity of low-dose suramin showed promise as a novel approach to treatment of ASD in this small study.
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For individuals with autism spectrum disorder (ASD), salient behaviorally-relevant information often fails to capture attention, while subtle behaviorally-irrelevant details commonly induce a state of distraction. The present study used functional magnetic resonance imaging (fMRI) to investigate the neurocognitive networks underlying attentional capture in sixteen high-functioning children and adolescents with ASD and twenty-one typically developing (TD) individuals. Participants completed a rapid serial visual presentation paradigm designed to investigate activation of attentional networks to behaviorally-relevant targets and contingent attention capture by task-irrelevant distractors. In individuals with ASD, target stimuli failed to trigger bottom-up activation of the ventral attentional network and the cerebellum. Additionally, the ASD group showed no differences in behavior or occipital activation associated with contingent attentional capture. Rather, results suggest that to-be-ignored distractors that shared either task-relevant or irrelevant features captured attention in ASD. Results indicate that individuals with ASD may be under-reactive to behaviorally-relevant stimuli, unable to filter irrelevant information, and that both top-down and bottom-up attention networks function atypically in ASD. Lastly, deficits in target-related processing were associated with autism symptomatology, providing further support for the hypothesis that non-social attentional processes and their neurofunctional underpinnings may play a significant role in the development of sociocommunicative impairments in ASD.
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Atención/fisiología , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/fisiopatología , Encéfalo/metabolismo , Imagen por Resonancia Magnética , Estimulación Luminosa/métodos , Tiempo de Reacción/fisiología , Adolescente , Niño , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Desempeño Psicomotor/fisiologíaRESUMEN
We recorded visual event-related brain potentials from 32 adult male participants (16 high-functioning participants diagnosed with autism spectrum disorder (ASD) and 16 control participants, ranging in age from 18 to 53 years) during a three-stimulus oddball paradigm. Target and non-target stimulus probability was varied across three probability conditions, whereas the probability of a third non-target stimulus was held constant in all conditions. P3 amplitude to target stimuli was more sensitive to probability in ASD than in typically developing participants, whereas P3 amplitude to non-target stimuli was less responsive to probability in ASD participants. This suggests that neural responses to changes in event probability are attention-dependant in high-functioning ASD. The implications of these findings for higher-level behaviors such as prediction and planning are discussed.
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Trastornos Generalizados del Desarrollo Infantil/fisiopatología , Potenciales Evocados Visuales/fisiología , Adolescente , Adulto , Atención/fisiología , Encéfalo/fisiología , Estudios de Casos y Controles , Electroencefalografía , Humanos , Masculino , Persona de Mediana Edad , Probabilidad , Tiempo de Reacción/fisiología , Adulto JovenRESUMEN
The EEG reflects the activation of large populations of neurons that act in synchrony and propagate to the scalp surface. This activity reflects both the brain's background electrical activity and when the brain is being challenged by a task. Despite strong theoretical and methodological arguments for the use of EEG in understanding the neural correlates of autism, the practice of collecting, processing and evaluating EEG data is complex. Scientists should take into consideration both the nature of development in autism given the life-long, pervasive course of the disorder and the disability of altered or atypical social, communicative, and motor behaviors, all of which require accommodations to traditional EEG environments and paradigms. This paper presents guidelines for the recording, analyzing, and interpreting of EEG data with participants with autism. The goal is to articulate a set of scientific standards as well as methodological considerations that will increase the general field's understanding of EEG methods, provide support for collaborative projects, and contribute to the evaluation of results and conclusions.
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Trastorno Autístico/fisiopatología , Encéfalo/fisiopatología , Recolección de Datos/normas , Electroencefalografía , Electrofisiología , HumanosRESUMEN
OBJECTIVE: To investigate the usefulness of point-of-care hand and wrist joint ultrasound (US) examination in patients with established rheumatoid arthritis (RA). METHODS: Fifty-one RA patients were evaluated using clinical disease activity measures and gray-scale and power Doppler (PD) US. Agreement between US and clinical findings and its impact on physicians' confidence and clinical decision were assessed. RESULTS: Agreement between intraarticular PD signal and joint swelling (JS) was moderate (82%; κ = 0.44). Agreement between PD signal and joint tenderness to palpation (TTP) was fair (75%; κ = 0.24). The greatest agreement between PD signal and clinical findings was seen in the 5th metacarpophalangeal (MCP) joint (96% JS, 88% TTP) and the poorest agreement was seen in the wrist (69% JS, 65% TTP) and 2nd (75% JS, 72% TTP) and 3rd (82% JS, 72% TTP) MCP joints. The presence of PD signal in nonswollen and/or nontender joints accounted for most of the disagreement in the wrists, while the opposite was true for the 2nd/3rd MCP joints. Agreement between sonographic synovial thickening and clinical findings was poor. Total sonographic synovial hypertrophy or PD score correlated significantly with physician-recorded, but not patient-recorded, clinical outcomes. US increased both physicians' confidence in their clinical decision (P < 0.0005, irrespective of Clinical Disease Activity Index score) and patients' confidence in physicians' medical decisions (88.4% of the cases). US modified biologic agent and/or disease-modifying antirheumatic drug (DMARD) use in 7 individual cases, but it did not affect the overall treatment plan (P > 0.15) or DMARD (P < 0.062) or biologic agent (P > 1.0) use in this group of RA patients. CONCLUSION: PD examination of the wrist and 2nd/3rd MCP joints might be feasible and clinically meaningful in evaluation of disease activity in patients with established RA. US examination of the hand/wrist joints in RA increases physicians' confidence in their clinical decision and can help to individualize DMARD and biologic agent use.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico , Articulaciones de la Mano/efectos de los fármacos , Articulaciones de la Mano/diagnóstico por imagen , Ultrasonografía Doppler , Articulación de la Muñeca/efectos de los fármacos , Articulación de la Muñeca/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/patología , Estudios de Casos y Controles , Técnicas de Apoyo para la Decisión , Evaluación de la Discapacidad , Estudios de Factibilidad , Articulaciones de la Mano/patología , Humanos , Persona de Mediana Edad , Dimensión del Dolor , Satisfacción del Paciente , Selección de Paciente , Sistemas de Atención de Punto , Valor Predictivo de las Pruebas , Encuestas y Cuestionarios , Membrana Sinovial/diagnóstico por imagen , Membrana Sinovial/efectos de los fármacos , Sinovitis/diagnóstico por imagen , Sinovitis/tratamiento farmacológico , Resultado del Tratamiento , Articulación de la Muñeca/patologíaRESUMEN
A substantial body of evidence links differences in brain size to differences in brain organization. We have hypothesized that the developmental aspect of this relation plays a role in autism spectrum disorder (ASD), a neurodevelopmental disorder which involves abnormalities in brain growth. Children with ASD have abnormally large brains by the second year of life, and for several years thereafter their brain size can be multiple standard deviations above the norm. The greater conduction delays and cellular costs presumably associated with the longer long-distance connections in these larger brains is thought to influence developmental processes, giving rise to an altered brain organization with less communication between spatially distant regions. This has been supported by computational models and by findings linking greater intra-cranial volume, an index of maximum brain-size during development, to reduced inter-hemispheric connectivity in individuals with ASD. In this paper, we further assess this hypothesis via a whole-brain analysis of network efficiency. We utilize diffusion tractography to estimate the strength and length of the connections between all pairs of cortical regions. We compute the efficiency of communication between each network node and all others, and within local neighborhoods; we then assess the relation of these measures to intra-cranial volume, and the differences in these measures between adults with autism and typical controls. Intra-cranial volume is shown to be inversely related to efficiency for wide-spread regions of cortex. Moreover, the spatial patterns of reductions in efficiency in autism bear a striking resemblance to the regional relationships between efficiency and intra-cranial volume, particularly for local efficiency. The results thus provide further support for the hypothesized link between brain overgrowth in children with autism and the efficiency of the organization of the brain in adults with autism.
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The earliest observable symptoms of autism spectrum disorders (ASDs) involve motor behavior. There is a growing awareness of the developmental importance of impaired motor function in ASD and its association with social skill. Compromised motor function requires increased attention, leaving fewer resources available for processing environmental stimuli and learning. This knowledge suggests that the motor system-which we know to be trainable-may be a gateway to improving outcomes of individuals living with ASD. In this review, we suggest a framework borrowed from machine learning to examine where, why, and how motor skills are different in individuals with ASD.
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Encéfalo/patología , Trastornos Generalizados del Desarrollo Infantil/complicaciones , Trastornos Generalizados del Desarrollo Infantil/patología , Trastornos de la Destreza Motora/etiología , Encéfalo/fisiopatología , HumanosRESUMEN
Typical adults show an inverse relation between callosal fiber length and degree of interhemispheric connectivity. This has been hypothesized to be a consequence of the influence of conduction delays and cellular costs during development on axonal pruning, both of which increase with fiber length. Autism spectrum disorder (ASD) provides a test of this hypothesis: Children with ASD are known to have enlarged brains; thus, adults with ASD should show reductions in interhemispheric connectivity proportional to their degree of brain overgrowth during development. This prediction was tested by assessing the relation between both the size and structure of the corpus callosum and callosal fiber length, adjusting for intracranial volume, which is thought to reflect maximum brain size achieved during development. Using tractography to estimate the length of callosal fibers emanating from all areas of cortex, and through which region of the corpus callosum they pass, we show that adults with ASD show an inverse relation between callosal fiber length, adjusted for intracranial volume, and callosum size, and a positive relation between adjusted callosal fiber length and radial diffusivity. The results provide support for the hypothesized impact of fiber length during development.