A 6-month follow-up of an RCT on behavioral and neurocognitive effects of neurofeedback in children with ADHD

To assess the long-term effects of neurofeedback (NFB) in children with attention deficit hyperactivity disorder (ADHD), we compared behavioral and neurocognitive outcomes at a 6-month naturalistic follow-up of a randomized controlled trial on NFB, methylphenidate (MPH), and physical activity (PA). Ninety-two children with a DSM-IV-TR ADHD diagnosis, aged 7–13, receiving NFB (n = 33), MPH (n = 28), or PA (n = 31), were re-assessed 6-months after the interventions. NFB comprised theta/beta training on the vertex (cortical zero). PA comprised moderate to vigorous intensity exercises. Outcome measures included parent and teacher behavioral reports, and neurocognitive measures (auditory oddball, stop-signal, and visual spatial working memory tasks). At follow-up, longitudinal hierarchical multilevel model analyses revealed no significant group differences for parent reports and neurocognitive measures (p = .058–.997), except for improved inhibition in MPH compared to NFB (p = .040) and faster response speed in NFB compared to PA (p = .012) during the stop-signal task. These effects, however, disappeared after controlling for medication use at follow-up. Interestingly, teacher reports showed less inattention and hyperactivity/impulsivity at follow-up for NFB than PA (p = .004–.010), even after controlling for medication use (p = .013–.036). Our findings indicate that the superior results previously found for parent reports and neurocognitive outcome measures obtained with MPH compared to NFB and PA post intervention became smaller or non-significant at follow-up. Teacher reports suggested superior effects of NFB over PA; however, some children had different teachers at follow-up. Therefore, this finding should be interpreted with caution. Clinical trial registration Train your brain and exercise your heart? Advancing the treatment for Attention Deficit Hyperactivity Disorder (ADHD), Ref. no. NCT01363544, https://clinicaltrials.gov/show/NCT01363544.     

EEG-heart rate connectivity changes after sensorimotor rhythm neurofeedback training: Ancillary study

ObjectivesNeurofeedback can induce long-term changes in brain functional connectivity, but its influence on the connectivity between different physiological systems is unknown. The present paper is an ancillary study of a previous paper that confirmed the effect of neurofeedback on brain connectivity associated with chronic pain. We analysed the influence of neurofeedback on the connectivity between the electroencephalograph (EEG) and heart rate (HR).MethodsSeventeen patients diagnosed with fibromyalgia were divided into three groups: good sensorimotor rhythm (SMR) training responders (n = 4), bad SMR responders (n = 5) and fake training (SHAM, n = 8). Training consisted of six sessions in which participants learned to synchronize and desynchronize SMR power. Before the first training (pre-resting state) and sixth training (post-resting state) session, open-eye resting-state EEG and electrocardiograph signals were recorded.ResultsGood responders reduced pain ratings after SMR neurofeedback training. This improvement in fibromyalgia symptoms was associated with a reduction of the connectivity between the central area and HR, between central and frontal areas, within the central area itself, and between central and occipital areas. The sham group and poor responders experienced no changes in their fibromyalgia symptoms.ConclusionsOur results provide new evidence that neurofeedback is a promising tool that can be used to treat of chronic pain syndromes and to obtain a better understanding of the interactions between physiological networks. These findings are preliminary, but they may pave the way for future studies that are more methodologically robust. In addition, new research questions are raised: what is the role of the central-peripheral network in chronic pain and what is the effect of neurofeedback on this network.     

Effects of Neurofeedback Training on Attention in Children with Intellectual Disability

This study investigated effects of neurofeedback (NFB) training on attention in children with intellectual disability (ID). Twenty-one children with ID were assigned to an NFB training group (n = 7), to a visual perception (VP) training group (n = 7), or to a no-treatment group (n = 7). Two groups received 36 sessions of NFB or VP training, respectively, over 12 weeks. Children's Color Trails Test–2, Stroop Color and Word Test, and Digit Span were administered to all participants before and after training. The follow-up study was conducted with both the NFB and VP groups in the same way after 3 months. The EEGs of the NFB group also were measured. The NFB group showed significantly improved scores on the all tests compared to the 2 control groups. The brainwaves of the frontal lobes of the NFB group declined significantly in theta wave amplitude and theta-to-beta ratio. The NFB results were maintained in the follow-up study. Beta/SMR uptraining seemed to be an effective way to enhance attention in children with ID.     

EEG Neurofeedback in the Treatment of Adults with Binge-Eating Disorder: a Randomized Controlled Pilot Study

Specific alterations in electroencephalography (EEG)-based brain activity have recently been linked to binge-eating disorder (BED), generating interest in treatment options targeting these neuronal processes. This randomized-controlled pilot study examined the effectiveness and feasibility of two EEG neurofeedback paradigms in the reduction of binge eating, eating disorder and general psychopathology, executive functioning, and EEG activity. Adults with BED and overweight (N = 39) were randomly assigned to either a food-specific EEG neurofeedback paradigm, aiming at reducing fronto-central beta activity and enhancing theta activity after viewing highly palatable food pictures, or a general EEG neurofeedback paradigm training the regulation of slow cortical potentials. In both conditions, the study design included a waiting period of 6 weeks, followed by 6 weeks EEG neurofeedback (10 sessions à 30 min) and a 3-month follow-up period. Both EEG neurofeedback paradigms significantly reduced objective binge-eating episodes, global eating disorder psychopathology, and food craving. Approximately one third of participants achieved abstinence from objective binge-eating episodes after treatment without any differences between treatments. These results were stable at 3-month follow-up. Among six measured executive functions, only decision making improved at posttreatment in both paradigms, and cognitive flexibility was significantly improved after food-specific neurofeedback only. Both EEG neurofeedback paradigms were equally successful in reducing relative beta and enhancing relative theta power over fronto-central regions. The results highlight EEG neurofeedback as a promising treatment option for individuals with BED. Future studies in larger samples are needed to determine efficacy and treatment mechanisms.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13311-021-01149-9.     

Hearing Safety of Long-Term Treatment with Theta Burst Stimulation

BackgroundRepetitive transcranial magnetic stimulation (rTMS) for the experimental treatment of tinnitus or auditory hallucinations aims at a modulation of cortical activity in areas of auditory perception and processing. Continuous theta burst stimulation (cTBS) is a patterned rTMS paradigm with lower stimulation intensity and shorter stimulus duration that is increasingly used for the optimization of rTMS-treatment paradigms. Possible interference with physiological brain function and the noise emitted by the rTMS device might induce relevant unwanted impairment of hearing and speech perception.Objective/HypothesisHere, we investigate the audiological safety of long-term, bilateral cTBS for the treatment of auditory phantom perception.MethodsForty-eight patients with chronic tinnitus were treated for four weeks with bilateral continuous theta burst stimulation to the temporal (n = 16), temporoparietal (n = 16) or a non-cortical control (n = 16) site. Measurements in these patients were obtained before and four weeks after treatment. The rTMS-induced noise was measured at various frequency levels.ResultsNo evidence was found for auditory threshold shifts or alterations in the perception of speech in quiet or in background noise by bilateral, long-term theta burst stimulation to the temporal or temporoparietal cortex with a loudness of up to 84 dB SPL (A).ConclusionsTheta burst stimulation of the temporal and temporoparietal cortex appears to be safe with respect to hearing and speech perception. These data provide evidence for the audiological safety of rTMS in the experimental treatment of auditory phantom perception.     

Cortical source analysis of resting state EEG data in children with attention deficit hyperactivity disorder

ObjectiveThis study investigated age-dependent and subtype-related alterations in electroencephalography (EEG) power spectra and current source densities (CSD) in children with attention deficit and hyperactivity disorder (ADHD).MethodsWe performed spectral and cortical source (exact low-resolution electromagnetic tomography, eLORETA) analyses using resting state EEG recordings from 40 children (8–16 years) with combined and inattentive subtypes of ADHD and 41 age-matched healthy controls (HC). Group differences in EEG spectra and CSD were investigated at each scalp location, voxel and cortical region in delta, theta, alpha and beta bands. We also explored associations between topographic changes in EEG power and CSD and age.ResultsCompared to healthy controls, combined ADHD subtype was characterized with significantly increased diffuse theta/beta power ratios (TBR) with a widespread decrease in beta CSD. Inattentive ADHD subtype presented increased TBR in all brain regions except in posterior areas with a global increase in theta source power. In both ADHD and HC, older age groups showed significantly lower delta source power and TBR and higher alpha and beta source power than younger age groups. Compared to HC, ADHD was characterized with increases in theta fronto-central and temporal source power with increasing age.ConclusionsOur results confirm that TBR can be used as a neurophysiological biomarker to differentiate ADHD from healthy children at both the source and sensor levels.SignificanceOur findings emphasize the importance of performing the source imaging analysis in order to better characterize age-related changes in resting-state EEG activity in ADHD and controls.     

Neurofeedback in ADHD: a single-blind randomized controlled trial

Neurofeedback treatment has been demonstrated to reduce inattention, impulsivity and hyperactivity in children with attention deficit/hyperactivity disorder (ADHD). However, previous studies did not adequately control confounding variables or did not employ a randomized reinforcer-controlled design. This study addresses those methodological shortcomings by comparing the effects of the following two matched biofeedback training variants on the primary symptoms of ADHD: EEG neurofeedback (NF) aiming at theta/beta ratio reduction and EMG biofeedback (BF) aiming at forehead muscle relaxation. Thirty-five children with ADHD (26 boys, 9 girls; 6–14 years old) were randomly assigned to either the therapy group (NF; n = 18) or the control group (BF; n = 17). Treatment for both groups consisted of 30 sessions. Pre- and post-treatment assessment consisted of psychophysiological measures, behavioural rating scales completed by parents and teachers, as well as psychometric measures. Training effectively reduced theta/beta ratios and EMG levels in the NF and BF groups, respectively. Parents reported significant reductions in primary ADHD symptoms, and inattention improvements in the NF group were higher compared to the control intervention (BF, d _corr = −.94). NF training also improved attention and reaction times on the psychometric measures. The results indicate that NF effectively reduced inattention symptoms on parent rating scales and reaction time in neuropsychological tests. However, regarding hyperactivity and impulsivity symptoms, the results imply that non-specific factors, such as behavioural contingencies, self-efficacy, structured learning environment and feed-forward processes, may also contribute to the positive behavioural effects induced by neurofeedback training.     

A shared low-frequency oscillatory rhythm abnormality in resting and sensory gating in schizophrenia

ObjectivesWe hypothesized that an oscillatory abnormality that is consistently observed across various testing paradigms may index an elementary neuronal abnormality marking schizophrenia risk.MethodsCompared neural oscillations in resting EEG and sensory gating conditions in schizophrenia patients (n = 128), their first-degree relatives (n = 80), and controls (n = 110) and calculated phenotypic and/or genetic correlation of the abnormal measure across these conditions.ResultsUsing a uniform, single trial analytical approach, we identified two prominent oscillatory characteristics in schizophrenia: (1) augmented neural oscillatory power was pervasive in medicated schizophrenia patients in most frequencies, most prominent in the theta–alpha range (4–11 Hz) across the two paradigms (all p < 0.007); and (2) their first-degree relatives shared significantly augmented oscillatory energy in theta–alpha frequency in resting (p = 0.002) and insufficient suppression of theta–alpha in sensory gating (p = 0.01) compared with normal controls. Heritability estimates for theta–alpha related measures for resting and gating conditions ranged from 0.44 to 0.49 (p < 0.03). The theta–alpha measures were correlated genetically with each other (RhoG = 0.82 ± 0.43; p < 0.05).ConclusionsAugmented theta–alpha rhythm may be an elementary neurophysiological problem associated with genetic liability of schizophrenia.SignificanceThis finding helps to refine key electrophysiologic biomarkers for genetic and clinical studies of schizophrenia.     

Theta EEG source localization using LORETA in partial epilepsy patients with and without medication

ObjectiveTo investigate and localize the sources of spontaneous, scalp-recorded theta activity in patients with partial epilepsy (PE).MethodsNine patients with beginning, untreated PE (Group 1), 31 patients with already treated PE (Group 2), and 14 healthy persons were investigated by means of spectral analysis and LORETA, low resolution electromagnetic tomography (1 Hz very narrow band analysis, age-adjusted, Z-scored values). The frequency of main interest was 4–8 Hz.ResultsGroup analysis: Group 1 displayed bilateral theta maxima in the temporal theta area (TTA), parietal theta area (PTA), and frontal theta area (FTA). In Group 2, theta activity increased all over the scalp as compared to the normative mean (Z = 0) and also to Group 1. Maximum activity was found in the TTA, PTA, and FTA. However, in the PTA and FTA the centers of the abnormality shifted towards the medial cortex. Individual analysis: all the patients showed preferential activation (maximum Z-values) within one of the three theta areas.ConclusionsEEG activity in the theta band is increased in anatomically meaningful patterns in PE patients, which differs from the anatomical distribution of theta in healthy persons.SignificanceThe findings contribute to our understanding of the sources of theta rhythms and the pathophysiology of PE.     

Independent component approach to the analysis of EEG recordings at early stages of depressive disorders

ObjectiveA modern approach for blind source separation of electrical activity represented by Independent Components Analysis (ICA) was used for QEEG analysis in depression.MethodsThe spectral characteristics of the resting EEG in 111 adults in the early stages of depression and 526 non-depressed subjects were compared between groups of patients and healthy controls using a combination of ICA and sLORETA methods.ResultsComparison of the power of independent components in depressed patients and healthy controls have revealed significant differences between groups for three frequency bands: theta (4–7.5 Hz), alpha (7.5–14 Hz), and beta (14–20 Hz) both in Eyes closed and Eyes open conditions. An increase in slow (theta and alpha) activity in depressed patients at parietal and occipital sites may reflect a decreased cortical activation in these brain regions, and a diffuse enhancement of beta power may correlate with anxiety symptoms playing an important role on the onset of depressive disorder.ConclusionsICA approach used in the present study allowed us to localize the EEG spectra differences between the two groups.SignificanceA relatively rare approach which uses the ICA spectra for comparison of the quantitative parameters of EEG in different groups of patients/subjects allows to improve an accuracy of measurement.     

Vagus Nerve Stimulation Modulates Phase-Amplitude Coupling in Thalamic Local Field Potentials

ObjectiveThe antiseizure effects of vagus nerve stimulation (VNS) are thought to be mediated by the modulation of afferent thalamocortical circuitry. Cross-frequency phase-amplitude coupling (PAC) is a mechanism of hierarchical network coordination across multiple spatiotemporal scales. In this study, we leverage local field potential (LFP) recordings from the centromedian (CM) (n = 3) and anterior (ATN) (n = 2) nuclei in five patients with tandem thalamic deep brain stimulation and VNS to study neurophysiological changes in the thalamus in response to VNS.Materials and MethodsBipolar LFP data were recorded from contact pairs spanning target nuclei in VNS “on” and “off” states.ResultsActive VNS was associated with increased PAC between theta, alpha, and beta phase and gamma amplitude in CM (q < 0.05). Within the ATN, PAC changes also were observed, although these were less robust. In both nuclei, active VNS also modulated interhemispheric bithalamic functional connectivity.ConclusionsWe report that VNS is associated with enhanced PAC and coordinated interhemispheric interactions within and between thalamic nuclei, respectively. These findings advance understanding of putative neurophysiological effects of acute VNS and contextualize previous animal and human studies showing distributed cortical synchronization after VNS.     

Spectral analysis of the sleep onset period in primary insomnia

ObjectiveTo compare the EEG power spectra characteristics of the sleep onset period (SOP) in patients with sleep onset insomnia (SOI), sleep maintenance insomnia (SMI) and good sleepers (GS).MethodsThe time course of EEG power density (1–40 Hz) during the SOP was examined in thirty subjects (SOI patients: N = 10, SMI patients: N = 10, GS: N = 10).ResultsThe EEG power of the beta2 frequency band (18–29.75 Hz) was significantly lower in SOI than in SMI in the period preceding sleep onset. The alpha power was significantly higher for the SMI group compared to GS before sleep onset. Despite the lack of statistical significance, several differences in EEG dynamics were observed in SOI compared to two other groups: delta power increased slower after sleep onset; beta2 and 3 (18–29.75 and 30–39.75 Hz) power decrease less abruptly before sleep onset; beta1 (15–17.75 Hz) power increase through the whole SOP.ConclusionsThe lower level of beta2 frequency band in SOI and the differences in dynamics in delta and beta bands may suggest that a mechanism other than hyperarousal participates in etiology of SOI.SignificanceSOI and SMI patients have different spectral characteristics in SOP, thus future studies should avoid the inclusion of mixed insomnia samples.     

Electroencephalographic correlates of working memory deficits in children with Fetal Alcohol Spectrum Disorder using a single-electrode pair recording device

ObjectiveChildren with Fetal Alcohol Spectrum Disorder (FASD) exhibit cognitive deficits that can be probed using eye movement tasks. We employed a recently developed, single-sensor electroencephalographic (EEG) recording device in measuring EEG activity during the performance of an eye movement task probing working memory in this population.MethodsChildren with FASD (n = 18) and typically developing children (n = 19) performed a memory-guided saccade task requiring the participant to remember the spatial location of one, two or three stimuli. We hypothesized that children with FASD would (i) exhibit performance deficits, particularly at greater mnemonic loads; and (ii) display differences in theta (4–8 Hz) and alpha (8–12 Hz) frequency band power compared with controls.ResultsChildren with FASD failed to perform the task correctly more often than controls when presented with two or three stimuli, and demonstrated related reductions in alpha and theta power.ConclusionThese data suggest that the memory-guided task is sensitive to working memory deficits in children with FASD.SignificanceSimultaneous recording of EEG activity suggest differing patterns of underlying neural recruitment in the clinical group, consistent with previous literature indicating more cognitive resources are required by children with FASD in order to complete complex tasks correctly.     

Correspondence of optimal stimulation and beta power varies regionally in STN DBS for Parkinson disease

IntroductionSubthalamic nucleus deep brain stimulation (STN DBS) for Parkinson disease (PD) normalizes neuronal hypersynchrony in the beta frequency range (13–30 Hz). The spatial correspondence of maximal beta power to the site of optimal stimulation along the DBS lead trajectory has been debated.MethodsWe determined the trajectory locations of the active contact, maximal beta power, and the dorsal border of the STN (DB-STN) in DBS patients. Beta power profiles were measured during intraoperative microelectrode recording (MER). Active contact locations were assigned during blinded, postoperative DBS programming. The DB-STN was identified both electrophysiologically during MER and anatomically on MRI. After grouping DBS trajectories into quadrants relative to the anatomic STN midpoint, we examined regional variations in the relative trajectory locations of the three entities.ResultsSTN DBS significantly improved motor performance for all 13 DBS patients, with active contacts at the DB-STN. Along trajectories passing posterior-medial to the STN midpoint, maximal beta power co-localized with active contacts at the DB-STN (difference Δ = 0.4 ± 1.6 mm, p = 0.57). By contrast, in posterior-lateral trajectories, maximal beta arose within the STN, ventral to active contacts (Δ = 1.9 ± 1.3 mm, p = 0.002). For trajectories anterior to the STN midpoint, maximal beta power co-localized with the DB-STN, while active contacts were ventral to peak beta power (p = 0.05).ConclusionOur findings indicate that co-localization of optimal stimulation and beta power varies by anatomical region in STN DBS for Parkinson disease.     

Effects of nitrous oxide sedation on resting electroencephalogram topography

ObjectiveTo quantify the effects of nitrous oxide (N₂O) gas on electroencephalogram (EEG) topography in healthy male participants.MethodsHealthy male participants were administered 20% (n = 8) or 40% (n = 8) N₂O while having high-density (modified 10–20) noise minimized EEG recordings.ResultsNitrous oxide was found to produce clear reductions in resting total power, particularly at frontal-vertex sites. These reductions were found to principally reflect reductions in band-limited delta power. Following the termination of N₂O inhalation, during N₂O washout, selective increases in frontal theta power were observed that increased above baseline values.ConclusionsNitrous oxide does not produce the classical anteriorization of slow wave activity typically seen during anesthetic induction. Instead N₂O reduces frontal slow wave (delta) activity, which during gas washout produces a withdrawal response of enhanced frontal slow wave (theta) activity.SignificanceAttempts to characterize a unitary mechanism of loss of consciousness during anesthesia on the basis of the topographic electroencephalographic changes is challenged by the distinct EEG effects that N₂O has when compared to other well known anesthetic agents that include propofol and sevoflurane.     

Modulation of motorcortical excitability by methylphenidate in adult voluntary test persons performing a go/nogo task

This study investigated the interaction between motorcortical excitability (short interval cortical inhibition, intracortical facilitation and long interval cortical inhibition), different requirement conditions [choice reaction test (CRT), attention/go/nogo], and their pharmacological modulation by methylphenidate (MPH) in normal healthy adults (n = 31) using a transcranial magnetic stimulation paradigm. MPH was administered in a dosage of 1 mg/kg body weight, maximum 60 mg. Additionally, serum level and clearance of MPH were controlled. The statistical analysis of variance revealed a significant three-way interaction of 2 (MPH) × 3 (CRT) × 6 (ISI) predicting motor evoked potential amplitudes (P = 0.032, MPH none and full dose, n = 31). In order to compare effects of dosage an additional between-subjects factor (half vs. full MPH dose) was introduced. None of the interactions involving this between-subject factor reached statistical significance. Exploring interactions with MPH only, a 3 (MPH none, half and full dose) × 3 (CRT) × 6 (ISI) analysis of variance revealed significant two-way interactions for MPH × ISI (P = 0.040) and condition × ISI (P < 0.001, n = 18). Effects observed for MPH were strongest on facilitatory processes, weaker for intracortical inhibition. In sum, MPH seems to interact via striato–thalamo–cortical pathways with original motorcortical processes (ISI), to a lesser extent with task-dependent or behavioral parameters (CRT).     

The 5:36 Express from Paddington Station

ABSTRACT

A pre-post design including 22 females was used to evaluate the effectiveness of neurofeedback in the treatment of adolescent anorexia nervosa. Resting EEG measures and a psychological test-battery assessing eating behavior traits, clinical symptoms, emotionality, and mood were obtained. While both the experimental (n = 10) and control group (n = 12) received their usual maintenance treatment, the experimental group received 10 sessions of individual alpha frequency training over a period of 5 weeks as additional treatment. Significant training effects were shown in eating behavior traits, emotion regulation, and in relative theta power in the eyes closed condition. Although the results are limited due to the small sample size, these are the first empirical data demonstrating the benefits of neurofeedback as a treatment adjunct in individuals with anorexia nervosa.     

Electrophysiological correlates of improved executive function following EEG neurofeedback in adult attention deficit hyperactivity disorder

ObjectiveEvent-related potentials (ERPs) are reported to be altered in relation to cognitive processing deficits in attention deficit hyperactivity disorder (ADHD). However, this evidence is mostly limited to cross-sectional data. The current study utilized neurofeedback (NFB) as a neuromodulatory tool to examine the ERP correlates of attentional and inhibitory processes in adult ADHD using a single-session, within-subject design.MethodsWe recorded high-density EEG in 25 adult ADHD patients and 22 neurotypical controls during a Go/NoGo task, before and after a 30-minute NFB session designed to down-regulate the alpha (8–12 Hz) rhythm.ResultsAt baseline, ADHD patients demonstrated impaired Go/NoGo performance compared to controls, while Go-P3 amplitude inversely correlated with ADHD-associated symptomatology in childhood. Post NFB, task performance improved in both groups, significantly enhancing stimulus detectability (d-prime) and reducing reaction time variability, while increasing N1 and P3 ERP component amplitudes. Specifically for ADHD patients, the pre-to-post enhancement in Go-P3 amplitude correlated with measures of improved executive function, i.e., enhanced d-prime, reduced omission errors and reduced reaction time variability.ConclusionsA single-session of alpha down-regulation NFB was able to reverse the abnormal neurocognitive signatures of adult ADHD during a Go/NoGo task.SignificanceThe study demonstrates for the first time the beneficial neurobehavioral effect of a single NFB session in adult ADHD, and reinforces the notion that ERPs could serve as useful diagnostic/prognostic markers of executive dysfunction.     

Quantitative evaluation of the microstructure of rapid eye movement sleep in refractory epilepsy: a preliminary study using electroencephalography and heart rate variability analysis

IntroductionPatients with epilepsy have a disturbed sleep architecture. Polysomnographic studies have shown that patients with refractory epilepsy have decreased rapid eye movement (REM) sleep and longer REM latency than those with medically controlled epilepsy. However, little is known about the differences in the REM sleep microstructure between these patient groups.MethodsWe conducted a retrospective case–control study of 20 patients with refractory epilepsy (refractory group) and 28 patients with medically controlled epilepsy (medically controlled group). All patients completed sleep questionnaires and underwent overnight in-lab polysomnography. Five-minute electroencephalogram recordings at the C3 and C4 electrodes from each REM sleep were selected for spectral analysis, and 5-min electrocardiogram segments recorded during REM sleep were used for heart rate variability analysis. The groups’ scores on the sleep questionnaires, polysomnographic sleep parameters, indices of sleep-related breathing disorders, and REM sleep electroencephalogram spectra were compared.ResultsThe refractory group had decreased REM sleep (p < 0.001) and longer REM latency (p = 0.0357) than those of the medically controlled group. Moreover, electroencephalogram spectral analysis revealed that the refractory group had decreased absolute beta power (p = 0.0039) and relative beta power (p = 0.0035) as well as increased relative delta power (p = 0.0015) compared with the medically controlled group.ConclusionsDifferences in the polysomnographic macrostructure and REM sleep microstructure between the study groups suggest REM sleep dysregulation in patients with refractory epilepsy.     

Neurophysiological markers of cue reactivity and inhibition subtend a three-month period of complete alcohol abstinence

ObjectiveFinding new tools for conventional management of alcohol disorders is a challenge for psychiatrists. Brain indications related to cognitive functioning could represent such an add-on tool.MethodsForty alcohol-dependent inpatients undertook two cognitive event-related potential (ERP) tasks at the beginning and at the end of a 4-week detoxification program. These comprised a visual oddball task investigating cue reactivity and a Go/No-go task tagging inhibition using oddball P3d and No-go P3d ERP components. Three months after discharge, the patient group (N = 40) was split into two subgroups: patients who remained abstinent during this post-treatment period (90 days; n = 15), and patients who relapsed (mean time: 28.5 ± 26.2 days; n = 25). Pattern changes of both ERP markers (oddball P3d and No-go P3d) during the detoxification were compared to differentiate these populations.ResultsAbstinent patients exhibited similar P3d responses devoted to alcohol cues in Sessions 1 and 2, but an increased No-go P3d devoted to No-go trials in alcohol-related contexts in Session 2 compared to Session 1.ConclusionsSpecific cue-reactivity and inhibitory neurophysiological markers subtend a further three-months of complete abstinence.SignificanceMonitoring these ERP changes during detoxification may provide important clues regarding patients’ future abstinence vs. relapse.