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INTRODUCTION: Distal radius fractures (DRF) are associated with increased risk of subsequent fractures and physical decline in older adults. This study aims to evaluate the risk cognitive decline following DRF and potential for timely screening and intervention. METHODS: A cohort of 1046 individuals 50-75 years of age with DRF were identified between 1995 and 2015 (81.5% female; mean age 62.5 [± 7.1] years). A control group (N = 1044) without history of DRF was matched by age, sex, and fracture date (i.e., index). The incidence of neurocognitive disorders (NCD) in relation to DRF/index was determined. Group comparisons were adjusted by age and comorbidity measured by the Elixhauser index. RESULTS: The DRF group had a greater incidence of NCD compared to the control group (11.3% vs. 8.2%) with a 56% greater relative risk (HR = 1.56, 95% Cl: 1.18, 2.07; p = 0.002) after adjusting for age and comorbidity. For every 10-year age increase, the DRF group was over three times more likely to develop a NCD (HR = 3.23, 95% Cl: 2.57, 4.04; p < 0.001). CONCLUSION: DRF in adults ages 50 to 75 are associated with increased risk of developing neurocognitive disorders. DRF may represent a sentinel opportunity for cognitive screening and early intervention. Distal radius fractures (DRF) have been associated with greater risk of future fractures and physical decline. This study reports that DRF are also associated with greater risk of developing neurocognitive disorders in older adults. Timely intervention may improve early recognition and long-term outcomes for older adults at risk of cognitive decline.
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Fraturas do Rádio , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Transtornos Neurocognitivos/complicações , Fraturas do Rádio/complicações , Fraturas do Rádio/epidemiologia , Estudos RetrospectivosRESUMO
OBJECTIVE: Schizophrenia is a severe and persistent mental illness with profound effects on patients, families, and communities. It causes immense suffering on personal, emotional, and socioeconomic levels. Individuals with schizophrenia have poorer health outcomes and die 10-20 years younger than the general population. Economic costs associated with schizophrenia are substantial and comprise 2.5% of healthcare expenditures worldwide. Despite psychosocioeconomic impacts, individuals with schizophrenia are subject to inequitable care, particularly at end of life. A systematic review was conducted to examine disparities in end-of-life care in schizophrenia and identify factors that can be targeted to enhance end-of-life care in this vulnerable population. DESIGN: A comprehensive search was conducted using the databases Ovid MEDLINE(R), Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from 2008-2018. Keywords included schizophrenia, palliative, end-of-life, and hospice. Two authors independently reviewed titles and abstracts; disagreements were resolved by consensus. RESULTS: The search identified 123 articles; 33 met criteria: 13 case reports, 12 retrospective studies, 5 literature reviews, and 3 prospective studies. Articles were divided into major themes including healthcare disparities, ethics, and palliative care. Palliative care was the most frequent theme comprising >50% of the articles, and there was considerable thematic overlap with ethics and palliative care. Almost half the articles (45%) were related to schizophrenia and comorbid cancer. CONCLUSIONS: Increased awareness of potential healthcare disparities in this population, creative approaches in multidisciplinary care, and provision of adequate palliative services and resources can enhance end-of-life care in schizophrenia.
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Esquizofrenia/terapia , Assistência Terminal , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Psicologia do EsquizofrênicoRESUMO
PURPOSE OF REVIEW: Dementia is a progressive and life-limiting condition that can be described in three stages: early, middle, and late. This article reviews current literature on late-stage dementia. RECENT FINDINGS: Survival times may vary across dementia subtypes. Yet, the overall trajectory is characterized by progressive decline until death. Ideally, as people with dementia approach the end of life, care should focus on comfort, dignity, and quality of life. However, barriers prevent optimal end-of-life care in the final stages of dementia. Improved and earlier advanced care planning for persons with dementia and their caregivers can help delineate goals of care and prepare for the inevitable complications of end-stage dementia. This allows for timely access to palliative and hospice care, which ultimately improves dementia end-of-life care.
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Demência/terapia , Assistência Terminal/métodos , Cuidadores , Humanos , Cuidados Paliativos , Qualidade de VidaRESUMO
OBJECTIVES: The aim of the present study was to examine N-acetylaspartate (NAA), a general marker of neuronal viability, and total NAA (tNAA), the combined signal of NAA and N-acetylaspartylglutamate, in bipolar depression before and after lamotrigine treatment. Given that NAA is synthesized through direct acetylation of aspartate by acetyl-coenzyme A-l-aspartate-N-acetyltransferase, we hypothesized that treatment with lamotrigine would be associated with an increase in NAA level. METHODS: Patients with bipolar depression underwent two-dimensional proton magnetic resonance spectroscopy of the anterior cingulate at baseline (n = 15) and after 12 weeks of lamotrigine treatment (n = 10). A group of age-matched healthy controls (n = 9) underwent scanning at baseline for comparison. RESULTS: At baseline, patients with bipolar depression had significantly lower NAA [mean standard deviation (SD) = 1.13 (0.21); p = 0.02] than controls [mean (SD) = 1.37 (0.27)]. Significant increases in NAA [mean (SD) = 1.39 (0.21); p = 0.01] and tNAA [mean (SD) = 1.61 (0.25); p = 0.02] levels were found after 12 weeks of lamotrigine treatment. CONCLUSIONS: These data suggest an NAA deficit in bipolar depression that is normalized after lamotrigine treatment. Future research is warranted to evaluate whether baseline NAA level is a potential biomarker for identifying lamotrigine response patterns and whether this functional brain change has an associated clinical response.
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Ácido Aspártico/análogos & derivados , Transtorno Bipolar/tratamento farmacológico , Espectroscopia de Ressonância Magnética , Triazinas/uso terapêutico , Adulto , Idoso , Ácido Aspártico/metabolismo , Biomarcadores/metabolismo , Encéfalo/efeitos dos fármacos , Dipeptídeos , Feminino , Giro do Cíngulo/efeitos dos fármacos , Humanos , Lamotrigina , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
Schizophrenia is associated with early mortality of 15 to 20 years, and 80 % of deaths are due to cardiovascular disease with a three-times greater risk of sudden-cardiac-death. While lifestyle, medications, genetics, and healthcare disparities are contributing factors, the etiology of this complex process is not fully understood. The aim of this study is to examine cardiac-related healthcare utilization and electrocardiogram (ECG) outcomes in schizophrenia at the end of life (EOL). A cohort of individuals with schizophrenia (SG) (n = 610, ≥50 years) were identified retrospectively from a unified clinical data platform and measures of cardiovascular healthcare utilization were evaluated within a 12-month period prior to death. Similarly, a control group (n = 610) was randomly identified and matched by gender (53 % females) and age of death (72.8 ± 12.4 years). Statistical methods included Cochran-Mantel-Haenszel and mixed-effects logistic & linear regression tests with adjustments for match strata and marital status, race, age, and gender as covariates. Results indicate that SG was more likely to be unmarried, unemployed, or from minority groups (all p < 0.001), and more likely to have diabetes and/or cardiovascular disease (p < 0.001). SG was less likely to receive an ECG (p = 0.001) or cardiac catheterization procedure (p < 0.001). SG had a greater mean QTc (447.2 ms vs. 434.6 ms; p = 0.001) and were twice as likely to have "prolonged QT" on ECG report (p = 0.006). In conclusion, SG had reduced likelihood of cardiac-related healthcare interventions, and despite greater likelihood of prolonged QTc, a recognized biomarker of cardiac risk, ECG was less likely at EOL. Given greater cardiac comorbidity and risk of sudden cardiac death in schizophrenia, improved practice guidelines are needed.
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Síndrome do QT Longo , Esquizofrenia , Feminino , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Masculino , Estudos Retrospectivos , Esquizofrenia/epidemiologia , Esquizofrenia/tratamento farmacológico , Disparidades em Assistência à Saúde , Morte Súbita Cardíaca , Eletrocardiografia , Fatores de RiscoRESUMO
One important executive function known to be compromised in autism spectrum disorder (ASD) is related to response error monitoring and post-error response correction. Several reports indicate that children with ASD show reduced error processing and deficient behavioral correction after an error is committed. Error sensitivity can be readily examined by measuring event-related potentials (ERP) associated with responses to errors, the fronto-central error-related negativity (ERN), and the error-related positivity (Pe). The goal of our study was to investigate whether reaction time (RT), error rate, post-error RT change, ERN, and Pe will show positive changes following 12-week long slow frequency repetitive TMS (rTMS) over dorsolateral prefrontal cortex (DLPFC) in high functioning children with ASD. We hypothesized that 12 sessions of 1 Hz rTMS bilaterally applied over the DLPFC will result in improvements reflected in both behavioral and ERP measures. Participants were randomly assigned to either active rTMS treatment or wait-list (WTL) groups. Baseline and post-TMS/or WTL EEG was collected using 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. ERN in TMS treatment group became significantly more negative. The number of omission errors decreased post-TMS. The RT did not change, but post-error RT became slower. There were no changes in RT, error rate, post-error RT slowing, nor in ERN/Pe measures in the wait-list group. Our results show significant post-TMS differences in the response-locked ERP such as ERN, as well as behavioral response monitoring measures indicative of improved error monitoring and correction function. The ERN and Pe, along with behavioral performance measures, can be used as functional outcome measures to assess the effectiveness of neuromodulation (e.g., rTMS) in children with autism and thus may have important practical implications.
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Transtorno Autístico/psicologia , Transtorno Autístico/reabilitação , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Autoimagem , Estimulação Magnética Transcraniana , Adolescente , Criança , Comportamento Infantil , Interpretação Estatística de Dados , Manual Diagnóstico e Estatístico de Transtornos Mentais , Eletroencefalografia , Eletroculografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Testes de Inteligência , Masculino , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Estimulação Magnética Transcraniana/instrumentação , Estimulação Magnética Transcraniana/métodos , Adulto JovemRESUMO
In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to be an important research tool or treatment modality in addressing the stimulus hypersensitivity characteristic of autism spectrum disorders.
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Transtorno Autístico/psicologia , Potenciais Evocados/fisiologia , Processos Mentais/fisiologia , Estimulação Magnética Transcraniana , Adolescente , Adulto , Comportamento , Córtex Cerebral/fisiopatologia , Criança , Eletroencefalografia , Feminino , Humanos , Hipercinese/psicologia , Interneurônios/fisiologia , Masculino , Estimulação Luminosa , Escalas de Graduação Psiquiátrica , Tempo de Reação/fisiologia , Comportamento Social , Adulto JovemRESUMO
Patients over the age 65 are a quickly expanding segment of the US population and represent a large percentage of patients requiring inpatient care. Older adults are more likely to experience polypharmacy and adverse drug effects. This review explains the risks of polypharmacy and potentially inappropriate medications in the elderly. Specific classes of medications frequently used in older adults in acute care settings are examined, including anticholinergic, sedative hypnotics, and antipsychotic medications. We discuss strategies aimed at addressing polypharmacy in this population including a drug regimen review (which is distinct from medication reconciliation), screening tools, pharmacist-led interventions, and computer-based strategies in the context of current literature and research findings. We provide a summary of general guidelines that may be helpful for geriatricians and hospitalists in improving patient care and clinical outcomes.
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Avaliação Geriátrica/métodos , Equipe de Assistência ao Paciente/organização & administração , Polimedicação , Lista de Medicamentos Potencialmente Inapropriados/estatística & dados numéricos , Papel Profissional , Idoso , Idoso de 80 Anos ou mais , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Antipsicóticos/administração & dosagem , Antipsicóticos/efeitos adversos , Antagonistas Colinérgicos/administração & dosagem , Antagonistas Colinérgicos/efeitos adversos , Humanos , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/efeitos adversos , Reconciliação de Medicamentos/métodos , Farmacêuticos/organização & administração , Fatores de RiscoRESUMO
To better understand visual processing abnormalities in autism we studied the attention orienting related frontal event potentials (ERP) and the sustained attention related centro-parietal ERPs in a three stimulus oddball experiment. The three stimulus oddball paradigm was aimed to test the hypothesis that individuals with autism abnormally orient their attention to novel distracters as compared to controls. A dense-array 128 channel EGI electroencephalographic (EEG) system was used on 11 high-functioning children and young adults with autism spectrum disorder (ASD) and 11 age-matched, typically developing control subjects. Patients with ASD showed slower reaction times but did not differ in response accuracy. At the anterior (frontal) topography the ASD group showed significantly higher amplitudes and longer latencies of early ERP components (e.g., P100, N100) to novel distracter stimuli in both hemispheres. The ASD group also showed prolonged latencies of late ERP components (e.g., P2a, N200, P3a) to novel distracter stimuli in both hemispheres. However, differences were more profound in the right hemisphere for both early and late ERP components. Our results indicate augmented and prolonged early frontal potentials and a delayed P3a component to novel stimuli, which suggest low selectivity in pre-processing and later-stage under-activation of integrative regions in the prefrontal cortices. Also, at the posterior (centro-parietal) topography the ASD group showed significantly prolonged N100 latencies and reduced amplitudes of the N2b component to target stimuli. In addition, the latency of the P3b component was prolonged to novel distracters in the ASD group. In general, the autistic group showed prolonged latencies to novel stimuli especially in the right hemisphere. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. We propose the potential application of ERP evaluations in a novelty task as outcome measurements in the biobehavioral treatment (e.g., EEG biofeedback, TMS) of autism.
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Transtorno Autístico/fisiopatologia , Transtorno Autístico/psicologia , Potenciais Evocados/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Criança , Eletroencefalografia , Feminino , Humanos , Masculino , Lobo Parietal/fisiopatologia , Estimulação Luminosa , Córtex Pré-Frontal/fisiopatologia , Tempo de Reação/fisiologia , Córtex Somatossensorial/fisiologia , Córtex Somatossensorial/fisiopatologia , Adulto JovemRESUMO
How psychiatric symptoms affect patients' decision making in practice can inform how we think-theoretically and conceptually-about what it means for those patients to have decision-making capacity. Assessment of a patient's decisional capacity allows those with adequate capacity to make choices regarding treatment and protects those who lack capacity from potential harm caused by impaired decision making. In analyzing a case in which a patient with stage II breast cancer refuses further treatment, we review the conceptual model of informed consent and approaches to assessing decision-making capacity that are in accordance with the American Medical Association Code of Medical Ethics as well as tools to assess decisional capacity.
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Tomada de Decisões , Consentimento Livre e Esclarecido , Competência Mental , Transtornos Mentais/psicologia , Recusa do Paciente ao Tratamento/psicologia , HumanosRESUMO
OBJECTIVE: Preliminary studies suggest that repetitive transcranial magnetic stimulation (rTMS) may be an effective and tolerable intervention for adolescents with treatment-resistant depression. There is limited rationale to inform coil placement for rTMS dosing in this population. We sought to examine and compare three localization techniques for coil placement in the context of an open-label trial of high-frequency rTMS for adolescents with treatment-resistant depression. METHODS: Ten adolescents with treatment-resistant depression were enrolled in an open-label trial of high-frequency rTMS. Participants were offered 30 rTMS sessions (10 Hz, 120% motor threshold, left 3000 pulses applied to the dorsolateral prefrontal cortex) over 6-8 weeks. Coil placement for treatment was MRI guided. The scalp location for treatment was compared with the locations identified with standard 5 cm rule and Beam F3 methods. RESULTS: Seven adolescents completed 30 rTMS sessions. No safety or tolerability concerns were identified. Depression severity as assessed with the Children's Depression Rating Scale Revised improved from baseline to treatment 10, treatment 20, and treatment 30. Gains in depressive symptom improvement were maintained at 6 month follow-up visits. An MRI-guided approach for coil localization was feasible and efficient. Our results suggest that the 5 cm rule, Beam F3, and the MRI-guided localization approaches provided variable scalp targets for rTMS treatment. CONCLUSIONS: Open-label, high-frequency rTMS was feasible, tolerable, and effective for adolescents with treatment-resistant depression. Larger, blinded, sham-controlled trials are needed for definitive safety and efficacy data. Further efforts to understand optimal delivery, dosing, and biomarker development for rTMS treatments of adolescent depression are warranted.
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Transtorno Depressivo Maior/terapia , Transtorno Depressivo Resistente a Tratamento/terapia , Imageamento por Ressonância Magnética/métodos , Estimulação Magnética Transcraniana/métodos , Adolescente , Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Estimulação Magnética Transcraniana/efeitos adversos , Resultado do TratamentoRESUMO
Proton magnetic resonance spectroscopy ((1) H-MRS) is a safe, noninvasive way of quantifying in vivo biochemical and metabolite concentration levels in individuals with Autism Spectrum Disorders (ASD). Findings to date suggest ASD is associated with widespread reduction in N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol (mI), and glutamate plus glutamine plus gamma-Aminobutyric Acid (Glx); however, variable findings, and even substantial increases, are not uncommon depending on the study and/or region-of-interest. Widespread reduction of NAA, Cr, Cho, mI, and Glx in ASD likely reflects impaired neuronal function and/or metabolism related to abnormal neurodevelopmental processes. Future studies should attempt to relate (1) H-MRS findings to histological findings and control for variability in subject age and functioning level; this would assist in evaluating the relationship between (1) H-MRS metabolic levels and neuronal and glial cell densities, as well as neurodevelopmental process associated with ASD. Furthermore, more longitudinal (1) H-MRS studies are needed in both control and ASD subjects to attempt to standardize metabolite levels across different developmental periods in well-defined endophenotypes. This will provide for a standard rubric for which metabolic aberrations (as well as treatment responses) can be measured. With higher magnetic field strengths and spectral-editing techniques capable of quantifying less-concentrated metabolites, (1) H-MRS will continue to be an important tool in ASD research.
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Encéfalo/metabolismo , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Colina/metabolismo , Creatina/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Inositol/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
Autism spectrum disorders (ASD) and attention deficit/hyperactivity disorder (ADHD) are very common developmental disorders which share some similar symptoms of social, emotional, and attentional deficits. This study is aimed to help understand the differences and similarities of these deficits using analysis of dense-array event-related potentials (ERP) during an illusory figure recognition task. Although ADHD and ASD seem very distinct, they have been shown to share some similarities in their symptoms. Our hypothesis was that children with ASD will show less pronounced differences in ERP responses to target and non-target stimuli as compared to typical children, and to a lesser extent, ADHD. Participants were children with ASD (N=16), ADHD (N=16), and controls (N=16). EEG was collected using a 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. There were no between group differences in reaction time (RT) to target stimuli, but both ASD and ADHD committed more errors, specifically the ASD group had statistically higher commission error rate than controls. Post-error RT in ASD group was exhibited in a post-error speeding rather than corrective RT slowing typical for the controls. The ASD group also demonstrated an attenuated error-related negativity (ERN) as compared to ADHD and controls. The fronto-central P200, N200, and P300 were enhanced and less differentiated in response to target and non-target figures in the ASD group. The same ERP components were marked by more prolonged latencies in the ADHD group as compared to both ASD and typical controls. The findings are interpreted according to the "minicolumnar" hypothesis proposing existence of neuropathological differences in ASD and ADHD, specifically minicolumnar number/width morphometry spectrum differences. In autism, a model of local hyperconnectivity and long-range hypoconnectivity explains many of the behavioral and cognitive deficits present in the condition, while the inverse arrangement of local hypoconnectivity and long-range hyperconnectivity in ADHD explains some deficits typical for this disorder. The current ERP study supports the proposed suggestion that some between group differences could be manifested in the frontal ERP indices of executive functions during performance on an illusory figure categorization task.
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Individuals with autism spectrum disorder (ASD) have previously been shown to have significantly augmented and prolonged event-related potentials (ERP) to irrelevant visual stimuli compared to controls at both early and later stages (e.g., N200, P300) of visual processing and evidence of an overall lack of stimulus discrimination. Abnormally large and indiscriminative cortical responses to sensory stimuli may reflect cortical inhibitory deficits and a disruption in the excitation/inhibition ratio. Low-frequency (≤1HZ) repetitive transcranial magnetic stimulation (rTMS) has been shown to increase inhibition of stimulated cortex by the activation of inhibitory circuits. It was our prediction that after 12 sessions of low-frequency rTMS applied bilaterally to the dorsolateral prefrontal cortices in individuals with ASD there would be a significant improvement in ERP indices of selective attention evoked at later (i.e., 200-600 ms) stages of attentional processing as well as an improvement in motor response error rate. We assessed 25 participants with ASD in a task of selective attention using illusory figures before and after 12 sessions of rTMS in a controlled design where a waiting-list group of 20 children with ASD performed the same task twice. We found a significant improvement in both N200 and P300 components as a result of rTMS as well as a significant reduction in response errors. We also found significant reductions in both repetitive behavior and irritability according to clinical behavioral questionnaires as a result of rTMS. We propose that rTMS has the potential to become an important therapeutic tool in ASD research and treatment.
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It has been reported that individuals with autism spectrum disorder (ASD) have abnormal responses to the sensory environment. For these individuals sensory overload can impair functioning, raise physiological stress, and adversely affect social interaction. Early-stage (i.e. within 200ms of stimulus onset) auditory processing abnormalities have been widely examined in ASD using event-related potentials (ERP), while ERP studies investigating early-stage visual processing in ASD are less frequent. We wanted to test the hypothesis of early-stage visual processing abnormalities in ASD by investigating ERPs elicited in a visual oddball task using illusory figures. Our results indicate that individuals with ASD have abnormally large cortical responses to task irrelevant stimuli over both parieto-occipital and frontal regions-of-interest (ROI) during early stages of visual processing compared to the control group. Furthermore, ASD patients showed signs of an overall disruption in stimulus discrimination, and had a significantly higher rate of motor response errors.
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INTRODUCTION: It has been reported that individuals with Autism Spectrum Disorder (ASD) have abnormal reactions to the sensory environment and visuo-perceptual abnormalities. Electrophysiological research has provided evidence that gamma band activity (30-80 Hz) is a physiological indicator of the co-activation of cortical cells engaged in processing visual stimuli and integrating different features of a stimulus. A number of studies have found augmented and indiscriminative gamma band power at early stages of visual processing in ASD; this may be related to decreased inhibitory processing and an increase in the ratio of cortical excitation to inhibition. Low frequency or 'slow' (≤1HZ) repetitive transcranial magnetic stimulation (rTMS) has been shown to increase inhibition of stimulated cortex by the activation of inhibitory circuits. METHODS: We wanted to test the hypothesis of gamma band abnormalities at early stages of visual processing in ASD by investigating relative evoked (i.e. ~ 100 ms) gamma power in 25 subjects with ASD and 20 age-matched controls using Kanizsa illusory figures. Additionally, we wanted to assess the effects of 12 sessions of bilateral 'slow' rTMS to the dorsolateral prefrontal cortex (DLPFC) on evoked gamma activity using a randomized controlled design. RESULTS: In individuals with ASD evoked gamma activity was not discriminative of stimulus type, whereas in controls early gamma power differences between target and non-target stimuli were highly significant. Following rTMS individuals with ASD showed significant improvement in discriminatory gamma activity between relevant and irrelevant visual stimuli. We also found significant improvement in the responses on behavioral questionnaires (i.e., irritability, repetitive behavior) as a result of rTMS. CONCLUSION: We proposed that 'slow' rTMS may have increased cortical inhibitory tone which improved discriminatory gamma activity at early stages of visual processing. rTMS has the potential to become an important therapeutic tool in ASD treatment and has shown significant benefits in treating core symptoms of ASD with few, if any side effects.
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INTRODUCTION: Preoccupation with drug and drug-related items is a typical characteristic of cocaine addicted individuals. It has been shown in multiple accounts that prolonged drug use has a profound effect on the EEG recordings of drug addicts when compared to controls during cue reactivity tests. Cue reactivity refers to a phenomenon in which individuals with a history of drug abuse exhibit excessive psychophysiological responses to cues associated with their drug of choice. One of the aims of this pilot study was to determine the presence of an attentional bias to preferentially process drug-related cues using evoked and induced gamma reactivity measures in cocaine addicts before and after biobehavioral treatment based on neurofeedback. Another aim was to show that central SMR amplitude increase and frontal theta control is possible in an experimental outpatient drug users group over 12 neurofeedback sessions. METHOD: Ten current cocaine abusers participated in this pilot research study using neurofeedback combined with Motivational Interviewing sessions. Eight of them completed all planned pre- and post -neurofeedback cue reactivity tests with event-related EEG recording and clinical evaluations. Cue reactivity test represented a visual oddball task with images from the International Affective Picture System and drug-related pictures. Evoked and induced gamma responses to target and non-target drug cues were analyzed using wavelet analysis. RESULTS: Outpatient subjects with cocaine addiction completed the biobehavioral intervention and successfully increased SMR while keeping theta practically unchanged in 12 sessions of neurofeedback training. The addition of Motivational Interviewing helped retain patients in the study. Clinical evaluations immediately after completion of the treatment showed decreased self-reports on depression and stress scores, and urine tests collaborated reports of decreased use of cocaine and marijuana. Effects of neurofeedback resulted in a lower EEG gamma reactivity to drug-related images in a post-neurofeedback cue reactivity test. In particular, evoked gamma showed decreases in power to non-target and to a lesser extent target drug-related cues at all topographies (left, right, frontal, parietal, medial, inferior); while induced gamma power decreased globally to both target and non-target drug cues. Our findings supported our hypothesis that gamma band cue reactivity measures are sufficiently sensitive functional outcomes of neurofeedback treatment. Both evoked and induced gamma measures were found capable to detect changes in responsiveness to both target and non-target drug cues. CONCLUSION: Our study emphasizes the utility of cognitive neuroscience methods based on EEG gamma band measures for the assessment of the functional outcomes of neurofeedback-based biobehavioral interventions for cocaine use disorders. This approach may have significant potential for identifying both physiological and clinical markers of treatment progress. The results confirmed our prediction that EEG changes achieved with neurofeedback training will be accompanied by positive EEG outcomes in a cue reactivity and clinical improvements.
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INTRODUCTION: Error monitoring and correction is one of the executive functions and is important for effective goal directed behavior. Deficient executive functioning, including reduced error monitoring ability, is one of the typical features of such neurodevelopmental disorders as autism, probably related to perseverative responding, stereotyped repetitive behaviors, and an inability to accurately monitor ongoing behavior. Our prior studies of behavioral and event-related potential (ERP) measures during performance on visual oddball tasks in high-functioning autistic (HFA) children showed that despite only minor differences in reaction times HFA children committed significantly more errors. METHODS: This study investigated error monitoring in children with autism spectrum disorder (ASD) with response-locked event-related potentials - the Error-related Negativity (ERN) and Error-related Positivity (Pe) recorded at fronto-central sites. The ERN reflects early error detection processes, while the Pe has been associated with later conscious error evaluation and attention re-allocation. Reaction times (RT) in correct trials and post-error slowing in reaction times were measured. In this study fourteen subjects with ASD and 14 age- and IQ- matched controls received a three-category visual oddball task with novel distracters. RESULTS: ERN had a lower amplitude and longer latency in the ASD group but was localized in the caudal part of anterior cingulate cortex (ACC) in both groups. The Pe component was significantly prolonged in the ASD group but did not reach significance in amplitude differences compared to controls. We found significant post-error slowing in RTs in controls, and post-error acceleration in RTs in the ASD group. CONCLUSIONS: The reduced ERN and altered Pe along with a lack of post-error RT slowing in autism might be interpreted as insensitivity in the detection and monitoring of response errors and a reduced ability of execute corrective actions. This might result in reduced error awareness and failure in adjustment when dealing with situations where erroneous responses may occur. This deficit might be manifested in the perseverative behaviors often seen in individuals with ASD. The results are discussed in terms of a general impairment in self-monitoring and other executive functions underlying behavioral and social disturbances in ASD.