Clinical EEG and neuroscience最新文献

Mismatch negativity (MMN) event-related potential (ERP) component reduction, indexing N-methyl-D-aspartate receptor (NMDAR)-dependent auditory echoic memory and short-term plasticity, is a well-established biomarker of schizophrenia that is sensitive to psychosis risk among individuals at clinical high-risk (CHR-P). Based on the NMDAR-hypofunction model of schizophrenia, NMDAR-dependent plasticity is predicted to contribute to aberrant neurodevelopmental processes involved in the pathogenesis of schizophrenia during late adolescence or young adulthood, including gray matter loss. Moreover, stress and inflammation disrupt plasticity. Therefore, using data collected during the 8-center North American Prodrome Longitudinal Study (NAPLS-2), we explored relationships between MMN amplitudes and salivary cortisol, gray matter volumes, and inflammatory cytokines. Participants included 303 CHR-P individuals with baseline electroencephalography (EEG) data recorded during an MMN paradigm as well as structural magnetic resonance imaging (MRI) and salivary cortisol, of which a subsample (n = 57) also completed blood draws. More deficient MMN amplitudes were associated with greater salivary cortisol and pro-inflammatory cytokine levels in future CHR-Converters, but not among those who did not convert to psychosis within the next two years. More deficient MMN amplitude was also associated with smaller total gray matter volume across participants regardless of future clinical outcomes, and with subcortical gray matter volumes among future CHR-Converters only. These findings are consistent with the theory that deficient NMDAR-dependent plasticity results in an overabundance of weak synapses that are subject to over-pruning during psychosis onset, contributing to gray matter loss. Further, MMN plasticity mechanisms may interact with stress, cortisol, and neuroinflammatory processes, representing a proximal influence of psychosis.

Objective: Face recognition is an important cognitive function of the human brain. Post stroke depression (PSD) is a common mental complication after stroke, which has a serious impact on individual physical function recovery and quality of life. This study aims to explore the face perception characteristics of PSD through electrophysiological indicators N170 and VPP, and provide an objective basis for the early evaluation of facial cognitive dysfunction in PSD. Methods: 58 patients in the cerebral small vessel disease (CSVD) with depressive symptoms (PSD) and 188 patients in the pure CSVD (NPSD). At the same time, 30 healthy subjects were selected as the healthy controls (HC). The differences of N170 and VPP components between the three groups were compared under the stimulation of inverted faces and upright faces. Results: PSD patients exhibited significantly longer peak latency and lower amplitude of N170 and VPP under both inverted and upright face stimulation compared to HC and NPSD. These results suggest that PSD patients have defects in early face recognition, there are abnormalities in the early perception and structural encoding of face information, and both the "overall mechanism" and "feature mechanism" of face recognition are damaged. Conclusions: These findings provide neuroelectrophysiological evidence for impaired emotionless face recognition in PSD patients.

Objective: Assessment of electroencephalographic (EEG) activity in depression has provided insights into neural profiles of the illness. However, there is limited understanding on how symptom severity and risk factors, such as childhood adversity, influence EEG features. Methods: Eyes-closed EEG was acquired in N = 28 depressed individuals being treated in a tertiary psychiatric setting. Absolute alpha, beta, theta, and delta power and inter-/intra-hemispheric coherence were examined. Relations between the Montgomery-Åsberg Depression Scale (MADRS) and Adverse Childhood Experience (ACE) Questionnaire and EEG features were assessed. Results: Individuals in the high (MADRS≥30) versus lower (MADRS ≤ 29) symptom severity group exhibited greater overall beta power, and lower Fp₁-Fp₂ delta and theta coherence. Those with high (≥3) versus lower (≤2) ACE scores exhibited greater T₇-T₈ beta coherence. Lowest F₃-F₄ beta coherence was observed in those with high ACE/high depression severity. A negative correlation existed between F₈-P₈ alpha coherence and symptom severity. Conclusions: Those with higher depression severity exhibit increased beta power, possibly reflecting a hyper-vigilant state. Depression severity and ACE history may produce subtle alterations in frontal delta/theta and temporal/frontal beta coherence regions. Significance: This is the first study to examine the neural impact of depression severity and ACE-assessed childhood trauma in depressed individuals receiving treatment in a tertiary setting, accounting for the clinical reality of the prevalence of their co-occurrence.

Mismatch negativity (MMN) has gained attention as a biomarker for psychosis and a translational intermediate phenotype in animal models of psychosis, including rodents and non-human primates. MMN has been linked to global functioning (Global Assessment of Functioning [GAF] score) and prognosis (psychosis onset or remission), suggesting that MMN reflects activities beyond auditory processing alone. This review examines the 45-year history of MMN from the perspective of psychiatric researchers and discusses current advances in computational and translational research on MMN, summarizing the current understanding of the MMN generation mechanism. We then address the essential question, "What do we observe through MMN?" Currently, we regard the relationship between global functioning in the real world and MMN as the key to answering this question. As a preliminary investigation, we analyzed the relationship between GAF as an objective variable and MMN, diagnosis, and basic epidemiological factors (age, sex, premorbid intelligence quotient) as explanatory variables (total n = 201, healthy controls: n = 41, patients with psychiatric disorders: n = 160) without assuming diagnostic categories. The relationship between functional outcomes and MMN was confirmed without a case-control design. Finally, we propose that new neurophysiological studies should acknowledge psychophysiological responses such as emotion, intention, and autonomic responses, as well as behavioral differences among participants beyond the dichotomy between healthy controls and patients. Measurements could be conducted in various settings from the participant's perspective. We discuss the potential for research investigating psychosis based on the interaction between individuals and the environment, using MMN as an illustrative model.

Auditory verbal hallucinations (AVH) are experienced by many individuals with schizophrenia (SZ), a neurodevelopmental disease that encumbers the quality of life and psychosocial outcome of those afflicted by it. While many hypotheses attempt to better define the etiology of AVHs in SZ, their neural profile and its moderation by current neuroleptics remains limited. The Mismatch Negativity (MMN) is an event related potential (ERP) measured from electroencephalographic (EEG) activity during the presentation of a deviance detection auditory paradigm. The neural regions and activity underlying the generation of the MMN include the primary auditory cortex and the prefrontal cortex which are regions also found to be activated during the experience of AVHs. Decreased MMN amplitudes have been robustly noted in SZ patients during the presentation of MMN tasks using auditory tones. However, the MMN generation to speech stimuli has not been extensively examined in SZ nor in relation to AVHs. The primary objective of this study was to examine the MMN to five speech-based deviants in SZ patients and healthy controls. Second, we assessed MMN features with AVH characteristics in 19 SZ patients and 21 HC. While AVH features did not correlate with measures of MMN, we found decreased MMN amplitudes to speech-based frequency and vowel change deviants in SZ patients compared to HC potentially reflecting deficiencies in basic speech processing mechanisms.

Artifacts on an electroencephalogram (EEG) - whether physiologic or non-physiologic - can be common and are important to recognize to prevent errors in interpretation. One such EEG artifact is an electroretinogram (ERG) artifact which occurs during photic stimulation. Typically, of a low amplitude, its presence is usually obscured by normal EEG activity over the frontopolar channels but it can appear prominent in very suppressed or EEG recordings showing electrocerebral inactivity. Overall, rarely reported in the literature, the purpose of this case report is to highlight the presence of an ERG artifact in a teenage boy where EEG was obtained after a cerebral anoxic event. It is important that EEG readers identify this to be a non-cerebral waveform in order to provide an accurate assessment of neurologic prognosis.

Aim: This study aims to investigate the effects of a neurofeedback system on cognitive skills, as measured by the Wechsler Intelligence Scale for Children-Revised (WISC-R), in a cohort of 100 children aged 8 to 12 who were diagnosed with attention deficit.Materials and Methods: A randomized single-blind sham control group design was employed, with 50 participants assigned to the experimental group receiving neurofeedback training and 50 participants assigned to the sham group receiving simulated training. Participants were selected through random sampling from individuals seeking assistance at a specialized education center over the course of one year (May 2021-2022). Pre- and post-test WISC-R assessments were administered to both groups to evaluate participants' mental performance. The experimental group underwent a total of 60 sessions of quantitative electroencephalography-based infralow frequency neurofeedback training, with half-hour sessions conducted three days a week over a five-month period. The post-test WISC-R was administered at the end of the sixth month.Results: The results revealed significant differences between the pre- and post-training test scores, specifically in terms of verbal IQ, picture arrangement, performance IQ, and total IQ (p = 0.016, p = 0.001, p < 0.001, and p = 0.002, respectively), when comparing the differences between the two groups.Conclusion: These findings indicate a notable improvement in performance IQ, total IQ, and a reduction in attention deficits among the neurofeedback group based on the WISC-R assessments. Future studies should consider employing larger sample sizes, including appropriate control groups, and conducting long-term follow-ups to further elucidate the clinical significance of these results.

Abnormalities in auditory processing are believed to play a major role in autism and attention-deficit hyperactivity disorder (ADHD). Both conditions often co-occur in children, causing difficulties in deciding the most promising intervention. Event-related potentials (ERPs) have been investigated and are showing promise to act as potential biomarkers for both conditions. This study investigated mismatch negativity (MMN) using a passive listening task and P3b in an active auditory go/no-go discrimination task. Recordings were available from 103 children (24 females): 35 with ADHD, 27 autistic, 15 autistic children with co-occurring ADHD, and 26 neurotypical (NT) children. The age range considered was between 4 and 17 years, but varied between groups. The results revealed increases in the MMN and P3b amplitudes with age. Older children with ADHD exhibited smaller P3b amplitudes, while younger autistic children showed reduced MMN amplitudes in response to phoneme changes compared to their NT counterparts. Notably, children diagnosed with autism and ADHD did not follow this pattern; instead, they exhibited more similarities to NT children. The reduced amplitudes of phonetically elicited MMN in children with autism and reduced P3b in children with ADHD suggest that the two respective ERPs can act as potential biomarkers for each condition. However, optimisation and standardisation of the testing protocol, as well as longitudinal studies are required in order to translate these findings into clinical practice.

Objective: We aimed to evaluate the occurrence of electroencephalogram (EEG) abnormalities in pediatric patients attending an outpatient psychiatry clinic at a tertiary center. We examined the rates of abnormalities and specific findings based on demographics, specific diagnoses, and clinical severity. Methods: This study included pediatric patients who underwent EEG at the outpatient psychiatry clinic. Patient demographics, psychiatric diagnosis, intellectual disability, intelligent quotient (IQ) score, family history of psychiatric disorders, and Clinical Global Impression-Severity (CGI-S) score were obtained through retrospective electronic health record analysis. The rate of EEG abnormalities was calculated, and specific abnormal findings were reviewed. Relationships between the rate of EEG abnormalities and diagnosis, severity, IQ, and age at EEG examination were analyzed. Results: Of 319 patients who underwent EEG, 21.3% (68 patients) of patients exhibited abnormalities, including background abnormalities (14.7%, 47 patients), interictal epileptiform discharges (IEDs) (10.3%, 33 patients), and a slow posterior dominant rhythm (3.8%, 10 patients). The frontal region was the most commonly affected area. Neurodevelopmental disorders (NDDs) had the most frequent abnormalities (29.8%), followed by anxiety (16.7%), sleep (14.3%), mood (11.7%), psychotic (5%), and conduct disorders (0%). Disease severity did not correlate with the rate of EEG abnormalities. Adjusted for age, sex, severity, and family history, patients with EEG abnormalities exhibited lower IQ scores. Conclusion: EEG abnormalities were common in pediatric patients with psychiatric disorders, with background abnormalities detected as frequently as IEDs. Disease severity was not associated with EEG abnormality, while IQ scores showed a negative correlation.

Objective. Current research on the effectiveness of neurofeedback (NFB) in children with attention-deficit/hyperactivity disorder (ADHD) is divided. Personalized NFB (pNFB), using pre-recorded individual electroencephalogram (EEG) features, is hypothesized to provide more reliable results. Our paper reviews available evidence on pNFB effectiveness and its methodological quality. Additionally, it explores whether other methodological features implying personalization are related to successful NFB. Methods. We conducted a systematic literature review on PubMed, PSYNDEX, PsycInfo and PsycArticles until November, 30, 2023. Studies that focused on pNFB in children with ADHD were selected, deviant studies excluded. Quality ratings by independent raters using Loney's¹ criteria were conducted. Pooled effect sizes for NFB effects and methodological features were calculated. Results. Three of 109 studies included personalization and were reviewed in the full-text. In two studies, theta/beta-NFB was personalized using individual alpha peak frequencies (iAPF), whereas in one study, individual beta rhythms were trained. All three studies demonstrated significant short- and long-term improvements in ADHD symptoms, as assessed by questionnaires and objective performance tests, when compared to standard protocols (SP), sham-NFB, and control conditions. Twelve of 111 studies reported methodological features consistently related to NFB effectiveness. These features, including self-control instructions, feedback animations, timing of feedback presentation, behavioral performance, pre-recorded individual ERP-components and stimulant medication dosage, can be used to personalize NFB and enhance training success. Conclusion. Personalizing NFB with iAPF appears promising based on the existing -albeit small- body of research. Future NFB studies should include iAPF and other personalized features facilitating implementation consistently associated with treatment success.