Clinical EEG and neuroscience最新文献

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.

Background. The effect of antiseizure medications (ASMs) on cognition varies depending on the type of ASM. We aimed to investigate the effects of ASMs on patients with epilepsy based on the conflicting findings in the literature. Methods. Patients diagnosed with epilepsy who were taking ASMs were included. All patients underwent a neuropsychiatric assessment, Beck Depression and Anxiety Inventories, Positive and Negative Syndrome Scale, and general psychopathological tests. The patients were divided into polytherapy and monotherapy groups. Subgroups were categorized according to the type of ASMs, dosage, and duration of monotherapy. Results. Ninety-seven patients were included in this study. The polytherapy group showed a significant decrease in attention, total learning, and interpretation of proverbs compared to the monotherapy group. In the monotherapy group, carbamazepine use had a moderate positive correlation with working memory (r = .669; P = .034), and a strong negative correlation with maintaining attention (r = -.740; P = .014). The duration of levetiracetam monotherapy was negatively correlated with verbal memory (immediate recall r = -.436, P = .038; free recall r = .426, P = .043) and negatively weakly correlated with naming performance (r = -.488, P = .025). Conclusion. The study showed polytherapy may affect verbal and working memory. Carbamazepine may affect working memory and the maintenance of attention in a dose-dependent manner. Levetiracetam may cause impairments in verbal memory and naming, depending on the duration of usage.

Objective. Electroencephalographic neurofeedback (EEG NF) or its effects on event-related potentials (ERPs) in quantitative EEG have not yet been systematically studied in cancer patients. The aim of this study was to investigate the emotional arousal and valence effects on the event-related P300 in a visual oddball paradigm by an individualized EEG alpha and theta/beta NF intervention in cancer patients and survivors (N = 18, age between 31 and 73 years). Methods. ERPs to low and high arousal target stimuli with either emotional positive or negative content and depressive state were obtained in cancer patients before and after a five-week NF intervention in a waitlist paradigm, following the consensus on the reporting and experimental design of clinical and cognitive-behavioral NF studies (CRED-nf checklist). Results. Overall, P300 amplitudes decreased significantly (p < .05) from pre to post therapy. Effects concerning high arousal stimuli with negative and positive valences were on the border to significance. Moreover, patients achieved significant relief of depressive symptoms (p < .05). Especially younger participants (<55 yrs.) benefited. Conclusions. P300 observations could reflect a therapeutic effect on brain activity level. EEG NF alleviates depressive symptoms in cancer patients. Significance. Based on these findings, further studies are needed to investigate the effects on event-related potentials by NF therapy.

This study aimed to investigate the characteristics of resting-state electroencephalography (EEG) activity and brain networks in patients with mild traumatic brain injury (mTBI) and their association with neurocognitive function (NCF). We analyzed 26 patients with subacute mTBI and 21 healthy controls. The subacute mTBI group (9 females, 17 males) had a mean age of 29.9 ± 9.9 years, and the healthy controls (11 females, 10 males) had a mean age of 29.7 ± 11.5 years. Current source density, lagged phase synchronization, and resting-state network activity were analyzed using exact low-resolution electromagnetic tomography (eLORETA) with 60 s resting-state EEG data. In addition, a correlation analysis was performed between these EEG parameters and NCF in patients with mTBI. We used the statistical nonparametric mapping method in eLORETA to correct for multiple comparisons. There were no significant differences in EEG parameters between the patients with mTBI and healthy controls. However, in patients with mTBI, correlation analysis revealed negative correlations between theta activity in the anterior cingulate cortex and verbal short-term memory and between activity in the memory perception network and verbal memory. Our findings suggest that resting-state EEG may be clinically useful in investigating the mechanism of NCF decline in patients with mTBI.

Focal seizures (FS) have previously been described before or after infantile spasm (IS) clusters, but FS occurring simultaneously with an IS cluster has been rarely reported in the EEG literature. We present three cases where focal seizures (FS) occurred concurrently during an infantile spasm (IS) cluster on VEEG. On VEEG, onset of IS cluster preceded FS in all three patients; however, patient three was diagnosed with FS prior to the onset of IS. FS duration ranged from 10-90 s and was electrographic-only in two out of the three patients. Unfortunately, the first two patients are now deceased, and for patient two no etiology was ever identified. Currently, patient three is free of spasms as well as seizures but has global developmental delay; no definite etiology has been identified for their presentation. Concurrent FS with IS suggests that the seizure types may be generated in different brain areas with one seizure type potentially triggering the other and is generally reflective of multifocal or diffuse cerebral disease with a poor prognosis as was seen in at least two of our patients. Our three cases of IS where FS occurred concurrently contribute to the limited existing data describing this phenomenon on VEEG.

Miners working underground face some risk factors that affect the nervous system-such as high noise, dark environment, chronic stress, and exposure to toxic gases. However, it is not known whether these risk factors affect the cognition of miners. In this study, the cognitive changes of miners were examined through event-related oscillations via electroencephalogram (EEG). Twenty underground miners and control groups, equal to each other in age, education level, and working duration, participated in this study. Neuropsychological tests were applied to all participants to examine their cognitive characteristics. Then, 20-channel EEG was recorded for electrophysiological changes during visual oddball paradigm. Event-related power spectrum and phase locking were analyzed in delta (0.5-3.5), theta (4-7), and alpha (8-13 Hz) frequency bands. It was determined that the delta responses that emerged during the target stimulus differed between the two groups in terms of phase locking (p < 0.05). Considering event-related alpha responses, a statistical difference was found regarding power spectrum and phase locking (p < 0.05). Moreover, the alpha power spectrum in the miners was found to be negatively statistically correlated with working duration (p < 0.05). This study determined that the event-related electrophysiological responses of the miners were negatively affected depending on the working conditions. In addition, neuropsychological assessment determined miners had deficiencies in learning and memory skills and many other cognitive functions such as attention, behavioral inhibition, and visual perception.