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BACKGROUND: Research using latent variable models demonstrates that pre-attentive measures of early auditory processing (EAP) and cognition may initiate a cascading effect on daily functioning in schizophrenia. However, such models fail to account for relationships among individual measures of cognition and EAP, thereby limiting their utility. Hence, EAP and cognition may function as complementary and interacting measures of brain function rather than independent stages of information processing. Here, we apply a data-driven approach to identifying directional relationships among neurophysiologic and cognitive variables. METHODS: Using data from the Consortium on the Genetics of Schizophrenia 2, we estimated Gaussian Graphical Models and Bayesian networks to examine undirected and directed connections between measures of EAP, including mismatch negativity and P3a, and cognition in 663 outpatients with schizophrenia and 630 control participants. RESULTS: Chain structures emerged among EAP and attention/vigilance measures in schizophrenia and control groups. Concerning differences between the groups, object memory was an influential variable in schizophrenia upon which other cognitive domains depended, and working memory was an influential variable in controls. CONCLUSIONS: Measures of EAP and attention/vigilance are conditionally independent of other cognitive domains that were used in this study. Findings also revealed additional causal assumptions among measures of cognition that could help guide statistical control and ultimately help identify early-stage targets or surrogate endpoints in schizophrenia.
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BACKGROUND: Auditory system plasticity is a promising target for neuromodulation, cognitive rehabilitation and therapeutic development in schizophrenia (SZ). Auditory-based targeted cognitive training (TCT) is a 'bottom up' intervention designed to enhance the speed and accuracy of auditory information processing, which has been shown to improve neurocognition in certain SZ patients. However, the dynamics of TCT learning as a function of training exercises and their impact on neurocognitive functioning and therapeutic outcomes are unknown. METHODS: Forty subjects (SZ, n = 21; healthy subjects (HS), n = 19) underwent comprehensive clinical, cognitive, and auditory assessments, including measurements of auditory processing speed (APS) at baseline and after 1-h of TCT. SZ patients additionally completed 30-hours of TCT and repeated assessments ~10-12 weeks later. RESULTS: SZ patients were deficient in APS at baseline (d = 0.96, p < 0.005) relative to HS. After 1-h of TCT, analyses revealed significant main effects of diagnosis (d = 1.75, p = 0.002) and time (d = 1.04, p < 0.001), and a diagnosis × time interaction (d = 0.85, p = 0.02) on APS. APS learning effects were robust after 1-h in SZ patients (d = 1.47, p < 0.001) and persisted throughout the 30-h of training. Baseline APS was associated with verbal learning gains after 30-h of TCT (r = 0.51, p = 0.02) in SZ. CONCLUSIONS: TCT learning metrics may have prognostic utility and aid in the prospective identification of individuals likely to benefit from TCT. Future experimental medicine studies may advance predictive algorithms that enhance TCT-related clinical, cognitive and functional outcomes.
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AIM: Gamma-band auditory steady-state response (ASSR) is a neurophysiologic index that is increasingly used as a translational biomarker in the development of treatments of neuropsychiatric disorders. While gamma-band ASSR is generated by distributed networks of highly interactive temporal and frontal cortical sources, the majority of human gamma-band ASSR studies using electroencephalography (EEG) highlight activity from only a single frontocentral scalp site, Fz, where responses tend to be largest and reductions in schizophrenia patients are most evident. However, no previous study has characterized the relative source contributions to Fz, which is a necessary step to improve the concordance of preclinical and clinical EEG studies. METHODS: A novel method to back-project the contributions of independent cortical source components was applied to assess the independent sources and their proportional contributions to Fz as well as source-resolved responses in 432 schizophrenia patients and 294 healthy subjects. RESULTS: Independent contributions of gamma-band ASSR to Fz were detected from orbitofrontal, bilateral superior/middle/inferior temporal, bilateral middle frontal, and posterior cingulate gyri in both groups. In contrast to expectations, the groups showed comparable source contribution weight to gamma-band ASSR at Fz. While gamma-band ASSR reductions at Fz were present in schizophrenia patients consistent with previous studies, no group differences in individual source-level responses to Fz were detected. CONCLUSION: Small differences in multiple independent sources summate to produce scalp-level differences at Fz. The identification of independent source contributions to a single scalp sensor represents a promising methodology for measuring dissociable and homologous biomarker targets in future translational studies.
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Eletroencefalografia/métodos , Potenciais Evocados Auditivos/fisiologia , Lobo Frontal/fisiologia , Ritmo Gama/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Although the initial events of Alzheimer's disease (AD) are still not known, it is clear that the disease in its sporadic form results from the combination of genetic and environmental risk factors. Among the latter, behavioral stress has been increasingly recognized as an important factor in the propagation of AD. However, the mechanisms underlying this modulation remain to be fully investigated. Since stress up-regulates the ALOX5 gene product, 5-lipoxygenase (5LO), herein we investigated its role in modulating stress-dependent development of the AD phenotype. To reach this goal, triple transgenic (3xTg) mice and 3xTg genetically deficient for 5LO were investigated after undergoing a restraint/isolation paradigm. In the present paper, we found that 28 days of restraint/isolation stress worsened tau phosphorylation and solubility, increased glycogen synthase kinase 3ß activity, compromised long-term potentiation and impaired fear-conditioned memory recall in 3xTg animals, but not in 3xTg animals lacking 5LO (3xTg/5LO-/-). These results highlight the novel functional role that the ALOX5 gene plays in the development of the biochemical, electrophysiological and behavioral sequelae of stress in the AD context. They provide critical support that this gene and its expressed protein are viable therapeutic targets to prevent the onset or delay the progression of AD in individuals exposed to this risk factor.
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Doença de Alzheimer/genética , Araquidonato 5-Lipoxigenase/genética , Estresse Psicológico/genética , Proteínas tau/genética , Doença de Alzheimer/complicações , Doença de Alzheimer/patologia , Doença de Alzheimer/psicologia , Animais , Araquidonato 5-Lipoxigenase/deficiência , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Quinase 3 da Glicogênio Sintase/genética , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Imobilização/psicologia , Potenciação de Longa Duração/genética , Masculino , Rememoração Mental , Camundongos , Camundongos Transgênicos , Fosforilação , Isolamento Social/psicologia , Estresse Psicológico/complicações , Estresse Psicológico/patologia , Estresse Psicológico/psicologia , Transmissão Sináptica , Proteínas tau/química , Proteínas tau/metabolismoRESUMO
BACKGROUND: Click trains elicit an auditory steady-state response (ASSR) at the driving frequency (1F) and its integer multiple frequencies (2F, 3F, etc.) called harmonics; we call this harmonic response the steady-state harmonic response (SSHR). We describe the 40 Hz ASSR (1F) and 80 Hz SSHR (2F) in humans and rats and their sensitivity to the uncompetitive NMDA antagonist memantine. METHODS: In humans (healthy control participants, n = 25; patients with schizophrenia, n = 28), electroencephalography was recorded after placebo or 20 mg memantine in a within-participant crossover design. ASSR used 1 ms, 85-dB clicks presented in 250 40/s 500-ms trains. In freely moving rats (n = 9), electroencephalography was acquired after memantine (0, 0.3, 1, 3 mg/kg) in a within-participant crossover design; 65-dB click trains used 5-mV monophasic, 1-ms square waves (40/s). RESULTS: Across species, ASSR at 1F generated greater evoked power (EP) than the 2F SSHR. 1F > 2F intertrial coherence (ITC) was also detected in humans, but the opposite relationship (ITC: 2F > 1F) was seen in rats. EP and ITC at 1F were deficient in patients and were enhanced by memantine across species. EP and ITC at 2F were deficient in patients. Measures at 2F were generally insensitive to memantine across species, although in humans the ITC harmonic ratio (1F:2F) was modestly enhanced by memantine, and in rats, both the EP and ITC harmonic ratios were significantly enhanced by memantine. CONCLUSIONS: ASSR and SSHR are robust, nonredundant electroencephalography signals that are suitable for cross-species analyses that reveal potentially meaningful differences across species, diagnoses, and drugs.
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Memantina , Esquizofrenia , Humanos , Ratos , Animais , Memantina/farmacologia , Potenciais Evocados Auditivos/fisiologia , Estimulação Acústica , EletroencefalografiaRESUMO
Acetylcholine (ACh) signaling is critical for central nervous function and is known to be abnormal in schizophrenia (SZ), a chronic neuropsychiatric disorder in which cognitive deficits persist, despite treatment. This review provides a summary of the clinical evidence linking ACh abnormalities to SZ-associated cognitive deficits, an overview of ACh-based pro-cognitive strategies attempted in SZ, and a survey of recent studies that describe the impact of anticholinergic medication burden on cognitive outcomes in SZ. Methodological challenges that currently limit more substantial investigation of ACh in SZ patients and future directions are also discussed.
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Transtornos Cognitivos , Disfunção Cognitiva , Esquizofrenia , Humanos , Esquizofrenia/tratamento farmacológico , Antagonistas Colinérgicos/uso terapêutico , Cognição , Transtornos Cognitivos/tratamento farmacológico , AcetilcolinaRESUMO
BACKGROUND: The uncompetitive NMDA antagonist, memantine (MEM), enhances prepulse inhibition of startle (PPI) across species. MEM is used to treat Alzheimer's disease (AD); conceivably, its acute impact on PPI might be used to predict a patient's sensitivity to MEM's therapeutic effects. OBJECTIVE: To begin to test this possibility, we studied MEM effects on PPI and related measures in AD patients. METHODS: 18 carefully screened individuals with AD (mean ageâ=â72.8 y; M:F=9â:â9) completed double-blind order-balanced testing with MEM (placebo versus 20âmg), assessing acoustic startle magnitude, habituation, PPI, and latency. RESULTS: Fifteen out of 18 participants exhibited reliable startle responses. MEM did not significantly impact startle magnitude or habituation. Compared to placebo responses, PPI was significantly increased after MEM (pâ<â0.04; dâ=â0.40); this comparison reached a large effect size for the 60âms interval (dâ=â0.62), where maximal MEM effects on PPI were previously detected. Prepulses reduced peak startle latency ("latency facilitation") and this effect was amplified after MEM (pâ=â0.03; dâ=â0.41; for 60âms intervals, dâ=â0.69). No effects of MEM were detected on cognition, nor were MEM effects on startle associated with cognitive or clinical measures. CONCLUSION: MEM enhances prepulse effects on startle magnitude and latency in AD; these changes in PPI and latency facilitation with MEM suggest that these measures can be used to detect an AD patient's neural sensitivity to acute MEM challenge. Studies in progress will determine whether such a "biomarker" measured at the outset on treatment can predict sensitivity to MEM's therapeutic effects.
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Doença de Alzheimer , Memantina , Idoso , Humanos , Estimulação Acústica , Doença de Alzheimer/tratamento farmacológico , Cognição , Memantina/farmacologia , Memantina/uso terapêutico , Reflexo de Sobressalto/fisiologia , Masculino , Feminino , Método Duplo-CegoRESUMO
Auditory-based targeted cognitive training (ATCT) programs are emerging pro-cognitive therapeutic interventions which aim to improve auditory processing to attenuate cognitive impairment in a "bottom up" manner. Biomarkers of early auditory information processing (EAIP) like mismatch negativity (MMN) and P3a have been used successfully to predict gains from a full 40 h course of ATCT in schizophrenia (SZ). Here we investigated the ability of EAIP biomarkers to predict ATCT performance in a group of subjects (n = 26) across SZ, MDD, PTSD and GAD diagnoses. Cognition was assessed via the MATRICS Consensus Cognitive Battery (MCCB) and MMN/P3a were collected prior to completing 1 h of "Sound Sweeps," a representative ATCT exercise. Baseline and final performance over the first two levels of cognitive training served as the primary dependent variables. Groups had similar MMN, but the SZ group had attenuated P3a. MMN and MCCB cognitive domain t-scores, but not P3a, were strongly correlated with most ATCT performance measures, and explained up to 61% of variance in ATCT performance. Diagnosis was not a significant predictor for ATCT performance. These data suggest that MMN can predict ATCT performance in heterogeneous neuropsychiatric populations and should be considered in ATCT studies across diagnostically diverse cohorts.
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Disfunção Cognitiva , Esquizofrenia , Humanos , Treino Cognitivo , Eletroencefalografia , Esquizofrenia/terapia , Percepção Auditiva , Disfunção Cognitiva/diagnóstico , Potenciais Evocados Auditivos , Estimulação AcústicaAssuntos
Delírio/induzido quimicamente , Delírio/tratamento farmacológico , Agonistas GABAérgicos/efeitos adversos , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Ácido gama-Aminobutírico/análogos & derivados , Adulto , Baclofeno/uso terapêutico , Humanos , Masculino , Ácido gama-Aminobutírico/efeitos adversosRESUMO
Deficits in early auditory information processing contribute to cognitive and psychosocial disability; this has prompted development of interventions that target low-level auditory processing, which may alleviate these disabilities. The frequency following response (FFR) is a constellation of event-related potential and frequency characteristics that reflect the processing of acoustic stimuli at the level of the brainstem and ascending portions of the auditory pathway. While FFR is a promising candidate biomarker of response to auditory-based cognitive training interventions, the psychometric properties of FFR in schizophrenia patients have not been studied. Here we assessed the psychometric reliability and magnitude of group differences across 18 different FFR parameters to determine which of these parameters demonstrate adequate internal consistency. Electroencephalography from 40 schizophrenia patients and 40 nonpsychiatric comparison subjects was recorded during rapid presentation of an auditory speech stimulus (6000 trials). Patients showed normal response amplitudes but longer latencies for most FFR peaks and lower signal-to-noise ratios (SNRs) than healthy subjects. Analysis of amplitude and latency estimates of peaks, however, indicated a need for a substantial increase in task length to obtain internal consistency estimates above 0.80. In contrast, excellent internal consistency (>0.95) was shown for FFR sustained responses. Only SNR scores reflecting the FFR sustained response yielded significant group differences and excellent internal consistency, suggesting that this measure is a viable candidate for use in clinical treatment studies. The present study highlights the use of internal consistency estimates to select FFR characteristics for use in future intervention studies interested in individual differences among patients.
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Esquizofrenia , Percepção da Fala , Estimulação Acústica , Biomarcadores , Cognição , Eletroencefalografia , Humanos , Reprodutibilidade dos Testes , Esquizofrenia/terapia , Percepção da Fala/fisiologiaRESUMO
Neurophysiological biomarkers of auditory processing show promise predicting outcomes following auditory-based targeted cognitive training (TCT) in schizophrenia, but the viability of the frequency following response (FFR) as a biomarker has yet to be examined, despite its ecological and face validity for auditory-based interventions. FFR is an event-related potential (ERP) that reflects early auditory processing. We predicted that schizophrenia patients would show acute- and longer-term FFR malleability in the context of TCT. Patients were randomized to either TCT (n = 30) or treatment as usual (TAU; n = 22), and electroencephalography was recorded during rapid presentation of an auditory speech stimulus before treatment, after one hour of training, and after 30 h of training. Whereas patients in the TCT group did not show changes in FFR after training, amplitude reductions were observed in the TAU. FFR was positively associated with performance on a measure of single word-in-noise perception in the TCT group, and with a measure of sentence-in-noise perception in both groups. Psychometric reliability analyses of FFR scores indicated high internal consistency but low one-hour and 12-week test-rest reliability. These findings support the dissociation between measures of speech discriminability along the hierarchy of cortical and subcortical early auditory information processing in schizophrenia.
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Transtornos Cognitivos , Esquizofrenia , Percepção da Fala , Estimulação Acústica , Percepção Auditiva/fisiologia , Biomarcadores , Cognição , Transtornos Cognitivos/complicações , Eletroencefalografia , Humanos , Reprodutibilidade dos Testes , Esquizofrenia/complicações , Esquizofrenia/terapia , Percepção da Fala/fisiologiaRESUMO
BACKGROUND: Mismatch negativity (MMN) and P3a are event-related potential measures of early auditory information processing that are increasingly used as translational biomarkers in the development of treatments for neuropsychiatric disorders. These responses are reduced in schizophrenia patients over the frontocentral scalp electrodes and are associated with important domains of cognitive and psychosocial functioning. While MMN and P3a responses are generated by a dynamic network of cortical sources distributed across the temporal and frontal brain regions, it is not clear how these sources independently contribute to MMN and P3a at the primary frontocentral scalp electrode or to abnormalities observed in schizophrenia. This study aimed to determine the independent source contributions and characterize the magnitude of impairment in source-level MMN and P3a responses in schizophrenia patients. METHODS: A novel method was applied to back-project the contributions of 11 independent cortical source components to Fz, the primary scalp sensor that is used in clinical studies, in n = 589 schizophrenia patients and n = 449 healthy comparison subjects. RESULTS: The groups showed comparable individual source contributions underlying both MMN and P3a responses at Fz. Source-level responses revealed an increasing magnitude of impairment in schizophrenia patients from the temporal to more frontal sources. CONCLUSIONS: Schizophrenia patients have a normal architecture of source contributions that are accompanied by widespread abnormalities in source resolved mismatch and P3a responses, with more prominent deficits detected from the frontal sources. Quantification of source contributions and source-level responses accelerates clarification of the neural networks underlying MMN reduction at Fz in schizophrenia patients.
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Esquizofrenia , Encéfalo , Eletroencefalografia , Potenciais Evocados , Potenciais Evocados Auditivos , Lobo Frontal , HumanosRESUMO
BACKGROUND: Schizophrenia patients have abnormal electroencephalographic (EEG) power over multiple frequency bands, even at rest, though the primary neural generators and spatiotemporal dynamics of these abnormalities are largely unknown. Disturbances in the precise synchronization of oscillations within and across cortical sources may underlie abnormal resting-state EEG activity in schizophrenia patients. METHODS: A novel assessment method was applied to identify the independent contributing sources of resting-state EEG and assess the phase discontinuity in schizophrenia patients (N = 148) and healthy subjects (N = 143). RESULTS: A network of 11 primary contributing sources of scalp EEG was identified in both groups. Schizophrenia patients showed abnormal elevations of EEG power in the temporal region in the theta, beta, and gamma-bands, as well as the posterior cingulate gyrus in the delta, theta, alpha, and beta-bands. The higher theta-band power in the middle temporal gyrus was significantly correlated with verbal memory impairment in patients. The peak frequency of alpha was lower in patients in the cingulate and temporal regions. Furthermore, patients showed a higher rate of alpha phase discontinuity in the temporal region as well as a lower rate of theta phase discontinuity in the temporal and posterior cingulate regions. CONCLUSIONS: Abnormal rates of phase discontinuity of alpha- and theta-band, abnormal elevations of EEG power in multiple bands, and a lower peak frequency of alpha were identified in schizophrenia patients at rest. Clarification of the mechanistic substrates of abnormal phase discontinuity may clarify core pathophysiologic abnormalities of schizophrenia and contribute to the development of novel biomarkers for therapeutic interventions.
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Esquizofrenia , Encéfalo , Eletroencefalografia , Humanos , Memória , Lobo TemporalRESUMO
Gamma-band (40-Hz) activity is critical for cortico-cortical transmission and the integration of information across neural networks during sensory and cognitive processing. Patients with schizophrenia show selective reductions in the capacity to support synchronized gamma-band oscillations in response to auditory stimulation presented 40-Hz. Despite widespread application of this 40-Hz auditory steady-state response (ASSR) as a translational electroencephalographic biomarker for therapeutic development for neuropsychiatric disorders, the spatiotemporal dynamics underlying the ASSR have not been fully characterized. In this study, a novel Granger causality analysis was applied to assess the propagation of gamma oscillations in response to 40-Hz steady-state stimulation across cortical sources in schizophrenia patients (n = 426) and healthy comparison subjects (n = 293). Both groups showed multiple ASSR source interactions that were broadly distributed across brain regions. Schizophrenia patients showed distinct, hierarchically sequenced connectivity abnormalities. During the response onset interval, patients exhibited abnormal increased connectivity from the inferior frontal gyrus to the superior temporal gyrus, followed by decreased connectivity from the superior temporal to the middle cingulate gyrus. In the later portion of the ASSR response (300-500 ms), patients showed significantly increased connectivity from the superior temporal to the middle frontal gyrus followed by decreased connectivity from the left superior frontal gyrus to the right superior and middle frontal gyri. These findings highlight both the orchestration of distributed multiple sources in response to simple gamma-frequency stimulation in healthy subjects as well as the patterns of deficits in the generation and maintenance of gamma-band oscillations across the temporo-frontal sources in schizophrenia patients.
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Estimulação Acústica/métodos , Córtex Auditivo/fisiopatologia , Potenciais Evocados Auditivos/fisiologia , Ritmo Gama/fisiologia , Rede Nervosa/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagemRESUMO
Cognitive impairment is a hallmark of schizophrenia and a robust predictor of functional outcomes. Impairments are found in all phases of the illness and are only moderately attenuated by currently approved therapeutics. Neurophysiological indices of sensory discrimination (ie, mismatch negativity (MMN) and P3a amplitudes) and gamma-band auditory steady-state response (ASSR; power and phase locking) are translational biomarkers widely used in the development of novel therapeutics for neuropsychiatric disorders. It is unclear whether laboratory-based EEG measures add explanatory power to well-established models that use only cognitive, clinical, and functional outcome measures. Moreover, it is unclear if measures of sensory discrimination and gamma-band ASSR uniquely contribute to putative causal pathways linking sensory discrimination, neurocognition, negative symptoms, and functional outcomes in schizophrenia. To answer these questions, hierarchical associations among sensory processing, neurocognition, clinical symptoms, and functional outcomes were assessed via structural equation modeling in a large sample of schizophrenia patients (n = 695) and healthy comparison subjects (n = 503). The results showed that the neurophysiologic indices of sensory discrimination and gamma-band ASSR both significantly contribute to and yield unique hierarchical, "bottom-up" effects on neurocognition, symptoms, and functioning. Measures of sensory discrimination showed direct effects on neurocognition and negative symptoms, while gamma-band ASSR had a direct effect on neurocognition in patients. Continued investigation of the neural mechanisms underlying abnormal networks of MMN/P3a and gamma-band ASSR is needed to clarify the pathophysiology of schizophrenia and the development of novel therapeutic interventions.
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Disfunção Cognitiva/fisiopatologia , Discriminação Psicológica/fisiologia , Potenciais Evocados Auditivos/fisiologia , Ritmo Gama/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Atenção , Percepção Auditiva , Disfunção Cognitiva/etiologia , Potenciais Evocados P300/fisiologia , Humanos , Esquizofrenia/complicaçõesRESUMO
BACKGROUND: Sensory processing abnormalities are common in schizophrenia (SZ) and impact everyday functions, such as speech perception in noisy environments. Auditory-based targeted cognitive training (TCT) is a "bottom up" cognitive remediation intervention designed to enhance the speed and accuracy of low-level auditory information processing. However, the effects of TCT on behavioral measures of central auditory processing (CAP) and the role of CAP function on verbal learning outcomes in SZ are unknown. METHODS: SZ (n = 42) and healthy subjects (CTL; n = 18) underwent comprehensive clinical, neurocognitive, and auditory assessments, including tests of hearing sensitivity and speech recognition (Words-in-Noise (WIN), Quick Speech-in-Noise (SIN)). SZ patients were randomized to receive either treatment-as-usual (TAU); or 30-h of TCT + TAU using a stratified, parallel design. SZ patients repeated assessments ~10-12 weeks later. RESULTS: Patients exhibited deficits in both WIN (p < 0.05, d = 0.50) and SIN (p < 0.01, d = 0.63). A treatment × time interaction on WIN (p < 0.05, d = 0.74), but not SIN discriminability, was seen in the TCT group relative to TAU. Specific enhancements in the 4-dB over background range drove gains in WIN performance. Moreover, SZ patients with greater CAP deficits experienced robust gains in verbal learning after 30-h of TCT relative to SZ patients without CAP impairment (p < 0.01, d = 1.28). CONCLUSION: Findings demonstrate that intensive auditory training enhances the fidelity of auditory processing and perception, such that specific CAP deficits were 'normalized' and were predictive of gains in verbal learning after TCT. It is conceivable that patients with deficiencies in CAP measures may benefit most from TCT and other interventions targeting auditory dysfunction in SZ.
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Transtornos Cognitivos , Esquizofrenia , Percepção Auditiva , Cognição , Humanos , Esquizofrenia/complicações , Esquizofrenia/terapia , Aprendizagem VerbalRESUMO
Memantine's benefits in Alzheimer's disease (AD) are modest and heterogeneous. We tested the feasibility of using sensitivity to acute memantine challenge to predict an individual's clinical response. Eight participants completed a double-blind challenge study of memantine (placebo versus 20âmg) effects on autonomic, subjective, cognitive, and neurophysiological measures, followed by a 24-week unblinded active-dose therapeutic trial (10âmg bid). Study participation was well tolerated. Subgroups based on memantine sensitivity on specific laboratory measures differed in their clinical response to memantine, some by large effect sizes. It appears feasible to use biomarkers to predict clinical sensitivity to memantine.
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Doença de Alzheimer/tratamento farmacológico , Biomarcadores , Cognição/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Memantina/administração & dosagem , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Testes NeuropsicológicosRESUMO
BACKGROUND: Schizophrenia patients show widespread deficits in neurocognitive, clinical, and psychosocial functioning. Mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) are robust translational biomarkers associated with schizophrenia and associated with cognitive dysfunction, negative symptom severity, and psychosocial disability. Although these biomarkers are conceptually linked as measures of early auditory information processing, it is unclear whether MMN and gamma-band ASSR account for shared vs. non-shared variance in cognitive, clinical, and psychosocial functioning. METHODS: Multiple regression analyses with MMN, gamma-band ASSR, and clinical measures were performed in large cohorts of schizophrenia outpatients (N = 428) and healthy comparison subjects (N = 283). RESULTS: Reduced MMN (d = 0.67), gamma-band ASSR (d = -0.40), and lower cognitive function were confirmed in schizophrenia patients. Regression analyses revealed that reduced MMN amplitude showed unique associations with lower verbal learning and negative symptoms, reduced gamma-band ASSR showed a unique association with working memory deficits, and both reduced MMN amplitude and reduced gamma-band ASSR showed an association with daily functioning impairment in schizophrenia patients. CONCLUSION: MMN and ASSR measures are non-redundant and complementary measures of early auditory information processing that are associated with important domains of functioning. Studies are needed to clarify the neural substrates of MMN and gamma-band ASSR to improve our understanding of the pathophysiology of schizophrenia and accelerate their use in the development of novel therapeutic interventions.
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Esquizofrenia , Estimulação Acústica , Percepção Auditiva , Cognição , Eletroencefalografia , Potenciais Evocados Auditivos , Humanos , Memória de Curto Prazo , Esquizofrenia/complicaçõesRESUMO
In clinical trials, standardized assessment conducted by research staff facilitates identification of treatment benefit. Narrative notes completed by clinicians offer a novel source to characterize and contextualize outcomes. In this study, we examine qualitative analysis of clinical notes as a method to augment quantitative outcome measures and supply meaningful context in clinical trials. Two hundred eighty-four clinical progress notes from 19 participants with schizophrenia or schizoaffective disorder assigned to receive either auditory-targeted cognitive training or treatment as usual were included. Qualitative analysis of weekly progress notes written by clinicians involved in ongoing care of the participants was used to identify overall outcome trajectories and specific changes in program participation, social functioning, and symptom severity. Trajectories were compared with the parent study's 2 primary outcome measures. Qualitative analysis identified personalized and complex trajectories for individual participants. Approximately half the participants improved overall. Most participants displayed improved program participation and social functioning, whereas most participants experienced symptom deterioration. Engagement in targeted cognitive training did not impact change in trajectories. Qualitative trajectories were congruent (e.g., both indicated improvement) with the 2 primary outcome measures for 26-36% of the participants depending on the comparison. Including qualitative analysis of clinician progress notes provides useful context and identifies underlying processes not captured in quantitative data. However, they cannot replace quantitative outcome measurement. Better alignment with clinician- and patient-targeted outcomes may strengthen clinical trials. Qualitative analysis of routinely collected data can benefit research and programmatic decision making in usual care settings. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Transtornos Cognitivos , Transtornos Psicóticos , Esquizofrenia , Humanos , Avaliação de Resultados em Cuidados de Saúde , Transtornos Psicóticos/terapia , Esquizofrenia/terapiaRESUMO
OBJECTIVE: Many psychotropic medications used to treat schizophrenia have significant anticholinergic properties, which are linked to cognitive impairment and dementia risk in healthy subjects. Clarifying the impact of cognitive impairment attributable to anticholinergic medication burden may help optimize cognitive outcomes in schizophrenia. The aim of this study was to comprehensively characterize how this burden affects functioning across multiple cognitive domains in schizophrenia outpatients. METHODS: Cross-sectional data were analyzed using inferential statistics and exploratory structural equation modeling to determine the relationship between anticholinergic medication burden and cognition. Patients with a diagnosis of schizophrenia or schizoaffective disorder (N=1,120) were recruited from the community at five U.S. universities as part of the Consortium on the Genetics of Schizophrenia-2. For each participant, prescribed medications were rated and summed according to a modified Anticholinergic Cognitive Burden (ACB) scale. Cognitive functioning was assessed by performance on domains of the Penn Computerized Neurocognitive Battery (PCNB). RESULTS: ACB score was significantly associated with cognitive performance, with higher ACB groups scoring worse than lower ACB groups on all domains tested on the PCNB. Similar effects were seen on other cognitive tests. Effects remained significant after controlling for demographic characteristics and potential proxies of illness severity, including clinical symptoms and chlorpromazine-equivalent antipsychotic dosage. CONCLUSIONS: Anticholinergic medication burden in schizophrenia is substantial, common, conferred by multiple medication classes, and associated with cognitive impairments across all cognitive domains. Anticholinergic medication burden from all medication classes-including psychotropics used in usual care-should be considered in treatment decisions and accounted for in studies of cognitive functioning in schizophrenia.