Aberrant oscillatory activity in neurofibromatosis type 1: an EEG study of resting state and working memory.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a genetic neurodevelopmental disorder commonly associated with impaired cognitive function. Despite the well-explored functional roles of neural oscillations in neurotypical populations, only a limited number of studies have investigated oscillatory activity in the NF1 population. METHODS: We compared oscillatory spectral power and theta phase coherence in a paediatric sample with NF1 (N = 16; mean age: 13.03 years; female: n = 7) to an age/sex-matched typically developing control group (N = 16; mean age: 13.34 years; female: n = 7) using electroencephalography measured during rest and during working memory task performance. RESULTS: Relative to typically developing children, the NF1 group displayed higher resting state slow wave power and a lower peak alpha frequency. Moreover, higher theta power and frontoparietal theta phase coherence were observed in the NF1 group during working memory task performance, but these differences disappeared when controlling for baseline (resting state) activity. CONCLUSIONS: Overall, results suggest that NF1 is characterised by aberrant resting state oscillatory activity that may contribute towards the cognitive impairments experienced in this population. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03310996 (first posted: October 16, 2017).

Endoscopic Imaging of Pancreatic Cysts.

Pancreatic cystic lesions (PCLs) have been diagnosed with increasing frequency likely due to the widespread use of cross-sectional imaging. A precise diagnosis of the PCL is important because it helps identify patients in need of surgical resection and those who can undergo surveillance imaging. A combination of clinical and imaging findings as well as cyst fluid markers can help classify PCLs and guide management. This review focuses on endoscopic imaging of PCLs including endoscopic and endosonographic features and fine needle aspiration. We then review the role of adjunct techniques, such as microforceps, contrast-enhanced endoscopic ultrasound, pancreatoscopy, and confocal laser endomicroscopy.

Experimental investigation of training schedule on home-based working memory training in healthy older adults.

Introduction: The efficacy of working memory training (WMT) for cognitive enhancement in healthy older adults has been extensively investigated. Typically, WMT results in improved performance on the training task, but limited or no transfer of improvement to other cognitive tasks. Accordingly, there is a need to identify optimal intervention parameters to maximize training and transfer task effects of WMT. The current study aimed to investigate the effect of training schedule on training and transfer task performance of WMT in healthy older adults. A secondary aim was to examine the feasibility of participants performing the intervention online at home, unsupervised, and using their personal devices. Methods: Participants (N = 71; mean age: 66 years) completed sixteen WMT or active-control sessions over eight (distributed) or four (intensive) weeks. Adaptive verbal and spatial n-back tasks were used as the WMT tasks. We tested near transfer effects to a digit-span task and far transfer effects to an abstract relational reasoning task. Results: Participants successfully performed the cognitively demanding intervention using their own devices, online at home, and with minimal contact with the researcher. We observed a significant improvement in WMT task performance in the WMT group relative to active-controls, but no evidence of near or far transfer. Similar training effects were observed irrespective of the intensity of the training schedule. Discussion: Our results suggest that comparable benefits could be observed when using less intensive schedules that may be more easily accommodated into everyday life.

Attentional Features of Mindfulness are Better Predictors of Face Recognition than Empathy and Compassion-Based Constructs.

Recent research has employed measures of either empathy, compassion or mindfulness and linked better face recognition memory to higher scores of identification with all humanity and mindfulness but not empathy or compassion. Additionally, empathy, compassion and mindfulness have been suggested as concepts that intertwine, but research has not yet examined how their respective personality questionnaires map onto latent concepts. We employed these measures together to explore their factor structure and, using structural equation modelling, we investigated if the suggested latent variables predict recognition memory performance for face and non-face stimuli. Attentional notions of mindfulness described a latent factor that predicted face recognition. All self-compassion facets and the non-react mindfulness facet described a latent factor, which predicted false alarms in face recognition. Finally, empathy and compassion-based notions described one latent factor, which did not predict recognition performance. None of the latent variables predicted performance in either object or voice recognition. Collectively, findings indicate attention-based mindfulness to benefit face recognition, prompting further research into the potential of mindfulness to support the face recognition process.

The effects of transcranial alternating current stimulation on memory performance in healthy adults: A systematic review.

The recent introduction of Transcranial Alternating Current stimulation (tACS) in research on memory modulation has yielded some exciting findings. Whilst evidence suggests small but significant modulatory effects of tACS on perception and cognition, it is unclear how effective tACS is at modulating memory, and the neural oscillations underlying memory. The aim of this systematic review was to determine the efficacy with which tACS, compared to sham stimulation, can modify working memory (WM) and long-term memory (LTM) performance in healthy adults. We examined how these effects may be moderated by specific tACS parameters and study/participant characteristics. Our secondary goal was to investigate the neural correlates of tACS' effects on memory performance in healthy adults. A systematic search of eight databases yielded 11,413 records, resulting in 34 papers that included 104 eligible studies. The results were synthesised by memory type (WM/LTM) and according to the specific parameters of frequency band, stimulation montage, individual variability, cognitive demand, and phase. A second synthesis examined the correspondence between tACS' effects on memory performance and the oscillatory features of electroencephalography (EEG) and magnetencephalography (MEG) recordings in a subset of 26 studies. The results showed a small-to-medium effect of tACS on WM and LTM performance overall. There was strong evidence to suggest that posterior theta-tACS modulates WM performance, whilst the modulation of LTM is achieved by anterior gamma-tACS. Moreover, there was a correspondence between tACS effects on memory performance and oscillatory outcomes at the stimulation frequency. We discuss limitations in the field and suggest ways to improve our understanding of tACS efficacy to ensure a transition of tACS from an investigative method to a therapeutic tool.

Morning and evening salivary cortisol levels in patients with chronic widespread pain and those at high risk.

BACKGROUND: Hypothalamic-Pituitary-Adrenal (HPA) axis dysregulation has been implicated in chronic widespread pain (CWP); the hallmark of fibromyalgia (FM). This is the first study to compare HPA axis changes in individuals with CWP and those at high risk of symptom development. METHODS: We sought to determine differences in morning and evening salivary cortisol levels in FM (n = 19), those at-risk (n = 20) and pain-free controls (n = 17). Risk factors included non-CWP pain, somatic symptoms, illness behaviour and sleep disturbance. We conducted the study in the absence of centrally acting medication, to address limitations of previous research. RESULTS: Repeated measures ANOVA revealed significant main effects of group (p = 0.003), and time of day (p = 0.002), with no significant interaction. Cortisol levels were higher in FM (p = 0.027) and at-risk (p = 0.003) groups, compared to controls, but there was no significant difference between FM and at-risk groups. The main effect of group remained significant with sleep problems (p = 0.021) and life events (p = 0.007), but was not significant with anxiety (p = 0.076) or depression (p = 0.098) scores as covariates. With sleep problems as a covariate, cortisol levels remained significantly higher only in the at-risk group (p = 0.017). CONCLUSIONS: This study indicates elevated salivary cortisol in FM and those at high risk, and identifies anxiety, depression and sleep problems as potential contributing factors. The results shed light on the dynamic relationship between stress, mood and sleep disorders and the brain's resilience to pain. SIGNIFICANCE: This study examines neurobiological changes in chronic widespread pain and high risk individuals. One strength of the study is the absence of centrally acting medication. We found high salivary cortisol common to Fibromyalgia and those at risk and identified contributing factors. Our results offer insight into the early mechanistic changes underlying Fibromyalgia development and open up possibilities for early diagnosis and prevention.

Cognitive and Electrophysiological Correlates of Working Memory Impairments in Neurofibromatosis Type 1.

Neurofibromatosis 1 (NF1) is a single gene disorder associated with working Memory (WM) impairments. The aim of this study was to investigate P300 event-related potential (ERP) associated with WM in NF1. Sixteen adolescents with NF1 were compared with controls on measures of WM and EEG was recorded during a WM nback task. The NF1 group showed poorer performance on measures of WM as compared to the control group. No group differences were observed in P300 amplitude at Pz, but P300 latency was shorter in the NF1 group. Topographic analyses of P300 amplitude showed group differences indicating neural processing differences in the NF1 group relative to controls, which possibly contribute to the cognitive deficits seen in this population.

Abdominal Actinomycosis Abscess Presenting as an Isolated Gastrointestinal Pseudotumor.

Actinomyces is a gram-positive anaerobic bacterium that is ubiquitous in nature. It typically presents as respiratory, cervicofacial, or abdominopelvic abscesses. We present a 66-year-old man with a progressive enlarging abdominal wall nodule concerning for malignancy. The patient had a negative workup, including an ultrasound-guided fine-needle aspiration and colonoscopy, with biopsy for a possible extension to the colonic wall. Diagnosis of an Actinomyces abscess was obtained through surgical resection with right hemicolectomy. He was successfully treated with a prolonged course of intravenous antibiotics. This is a rare case of an isolated abdominal wall Actinomyces abscess mimicking a gastrointestinal malignancy.

Functional network topology in drug resistant and well-controlled idiopathic generalized epilepsy: a resting state functional MRI study.

Despite an increasing number of drug treatment options for people with idiopathic generalized epilepsy (IGE), drug resistance remains a significant issue and the mechanisms underlying it remain poorly understood. Previous studies have largely focused on potential cellular or genetic explanations for drug resistance. However, epilepsy is understood to be a network disorder and there is a growing body of literature suggesting altered topology of large-scale resting networks in people with epilepsy compared with controls. We hypothesize that network alterations may also play a role in seizure control. The aim of this study was to compare resting state functional network structure between well-controlled IGE (WC-IGE), drug resistant IGE (DR-IGE) and healthy controls. Thirty-three participants with IGE (10 with WC-IGE and 23 with DR-IGE) and 34 controls were included. Resting state functional MRI networks were constructed using the Functional Connectivity Toolbox (CONN). Global graph theoretic network measures of average node strength (an equivalent measure to mean degree in a network that is fully connected), node strength distribution variance, characteristic path length, average clustering coefficient, small-world index and average betweenness centrality were computed. Graphs were constructed separately for positively weighted connections and for absolute values. Individual nodal values of strength and betweenness centrality were also measured and 'hub nodes' were compared between groups. Outcome measures were assessed across the three groups and between both groups with IGE and controls. The IGE group as a whole had a higher average node strength, characteristic path length and average betweenness centrality. There were no clear differences between groups according to seizure control. Outcome metrics were sensitive to whether negatively correlated connections were included in network construction. There were no clear differences in the location of 'hub nodes' between groups. The results suggest that, irrespective of seizure control, IGE interictal network topology is more regular and has a higher global connectivity compared to controls, with no alteration in hub node locations. These alterations may produce a resting state network that is more vulnerable to transitioning to the seizure state. It is possible that the lack of apparent influence of seizure control on network topology is limited by challenges in classifying drug response. It is also demonstrated that network topological features are influenced by the sign of connectivity weights and therefore future methodological work is warranted to account for anticorrelations in graph theoretic studies.

Reading direct speech quotes increases theta phase-locking: Evidence for cortical tracking of inner speech?

Growing evidence shows that theta-band (4-7 Hz) activity in the auditory cortex phase-locks to rhythms of overt speech. Does theta activity also encode the rhythmic dynamics of inner speech? Previous research established that silent reading of direct speech quotes (e.g., Mary said: "This dress is lovely!") elicits more vivid inner speech than indirect speech quotes (e.g., Mary said that the dress was lovely). As we cannot directly track the phase alignment between theta activity and inner speech over time, we used EEG to measure the brain's phase-locked responses to the onset of speech quote reading. We found that direct (vs. indirect) quote reading was associated with increased theta phase synchrony over trials at 250-500 ms post-reading onset, with sources of the evoked activity estimated in the speech processing network. An eye-tracking control experiment confirmed that increased theta phase synchrony in direct quote reading was not driven by eye movement patterns, and more likely reflects synchronous phase resetting at the onset of inner speech. These findings suggest a functional role of theta phase modulation in reading-induced inner speech.

Advanced endoscopy fellowship training in the United States: recent trends in American Society for Gastrointestinal Endoscopy advanced endoscopy fellowship match, trainee experience, and postfellowship employment.

BACKGROUND AND AIMS: The American Society for Gastrointestinal Endoscopy (ASGE) advanced endoscopy fellowship (AEF) match offers a structured application process for AEF training in the United States. Our aim was to describe recent trends in AEF match, trainee experience, and postfellowship employment. METHODS: ASGE AEF match data from 2012 to 2020 were reviewed. Online surveys were sent to advanced endoscopy trainees in 2019 and 2020 to explore their perceptions about AEF training and postfellowship jobs. RESULTS: Data for 2020 showed 19% of matched applicants were women, 55% foreign medical graduates, and 17.5% U.S. visa holders. The number of AEF match applicants increased by 15.6% (90 in 2012 to 104 in 2020) and number of AEF programs increased by 23.5% (51 in 2012 to 63 in 2020). The average applicant match rate was 57% (range, 52.8%-60.6%) and position match rate 87.9% (range, 79.1%-94.6%). Ninety-one percent of trainees (n = 58) rated the quality of their training as very good/excellent; 75% of trainees participated in >300 ERCPs and 64.1% in >300 EUS cases. Seventy percent of trainees reported that advanced endoscopic procedures comprised ≤50% of their procedure volume in their first job, and 71.9% believed it was not easy to find a job after fellowship; however, 97% believed they would make the same decision to pursue AEF training again. CONCLUSIONS: There has been a steady increase in the number of advanced endoscopy applicants and training positions over recent years. Most graduating fellows reported 50% or less of their upcoming clinical practice would involve advanced endoscopic procedures. Future studies are needed to further clarify employment opportunities and personnel needs for advanced endoscopists.

Alpha entrainment drives pain relief using visual stimulation in a sample of chronic pain patients: a proof-of-concept controlled study.

One-third of the population in the UK and worldwide struggle with chronic pain. Entraining brain alpha activity through noninvasive visual stimulation has been shown to reduce experimental pain in healthy volunteers. Neural oscillations entrainment offers a potential noninvasive and nonpharmacological intervention for patients with chronic pain, which can be delivered in the home setting and has the potential to reduce use of medications. However, evidence supporting its use in patients with chronic pain is lacking. This study explores whether (a) alpha entrainment increase alpha power in patients and (b) whether this increase in alpha correlates with analgesia. In total, 28 patients with chronic pain sat in a comfortable position and underwent 4-min visual stimulation using customised goggles at 10 Hz (alpha) and 7 Hz (control) frequency blocks in a randomised cross-over design. 64-channel electroencephalography and 11-point numeric rating scale pain intensity and pain unpleasantness scores were recorded before and after stimulation. Electroencephalography analysis revealed frontal alpha power was significantly higher when stimulating at 10 Hz when compared to 7 Hz. There was a significant positive correlation between increased frontal alpha and reduction in pain intensity (r = 0.33; P < 0.05) and pain unpleasantness (r = 0.40; P < 0.05) in the 10 Hz block. This study provides the first proof of concept that changes in alpha power resulting from entrainment correlate with an analgesic response in patients with chronic pain. Further studies are warranted to investigate dose-response parameters and equivalence to analgesia provided by medications.

Interictal electroencephalographic functional network topology in drug-resistant and well-controlled idiopathic generalized epilepsy.

OBJECTIVE: The study aim was to compare interictal encephalographic (EEG) functional network topology between people with well-controlled idiopathic generalized epilepsy (WC-IGE) and drug-resistant IGE (DR-IGE). METHODS: Nineteen participants with WC-IGE, 18 with DR-IGE, and 20 controls underwent a resting state, 64-channel EEG. An artifact-free epoch was bandpass filtered into the frequency range of high and low extended alpha. Weighted functional connectivity matrices were calculated. Mean degree, degree distribution variance, characteristic path length (L), clustering coefficient, small world index (SWI), and betweenness centrality were measured. A Kruskal-Wallis H-test assessed effects across groups. Where significant differences were found, Bonferroni-corrected Mann-Whitney pairwise comparisons were calculated. RESULTS: In the low alpha band (6-9 Hz), there was a significant difference in L at the three-group level (p < .0001). This was lower in controls than both WC-IGE and DR-IGE (p < .0001 for both), with no difference in L between WC-IGE and DR-IGE. Mean degree (p = .031), degree distribution variance (p = .032), and SWI (p = .023) differed across the three groups in the high alpha band (10-12 Hz). Mean degree and degree distribution variance were lower in WC-IGE than controls (p = .029 for both), and SWI was higher in WC-IGE compared with controls (p = .038), with no differences in other pairwise comparisons. SIGNIFICANCE: IGE network topology is more regular in the low alpha frequency band, potentially reflecting a more vulnerable structure. WC-IGE network topology is different from controls in the high alpha band. This may reflect drug-induced network changes that have stabilized the WC-IGE network by rendering it less likely to synchronize. These results are of potential importance in advancing the understanding of mechanisms of epilepsy drug resistance and as a possible basis for a biomarker of DR-IGE.

Digestive Manifestations in Patients Hospitalized With Coronavirus Disease 2019.

BACKGROUND & AIMS: The prevalence and significance of digestive manifestations in coronavirus disease 2019 (COVID-19) remain uncertain. We aimed to assess the prevalence, spectrum, severity, and significance of digestive manifestations in patients hospitalized with COVID-19. METHODS: Consecutive patients hospitalized with COVID-19 were identified across a geographically diverse alliance of medical centers in North America. Data pertaining to baseline characteristics, symptomatology, laboratory assessment, imaging, and endoscopic findings from the time of symptom onset until discharge or death were abstracted manually from electronic health records to characterize the prevalence, spectrum, and severity of digestive manifestations. Regression analyses were performed to evaluate the association between digestive manifestations and severe outcomes related to COVID-19. RESULTS: A total of 1992 patients across 36 centers met eligibility criteria and were included. Overall, 53% of patients experienced at least 1 gastrointestinal symptom at any time during their illness, most commonly diarrhea (34%), nausea (27%), vomiting (16%), and abdominal pain (11%). In 74% of cases, gastrointestinal symptoms were judged to be mild. In total, 35% of patients developed an abnormal alanine aminotransferase or total bilirubin level; these were increased to less than 5 times the upper limit of normal in 77% of cases. After adjusting for potential confounders, the presence of gastrointestinal symptoms at any time (odds ratio, 0.93; 95% CI, 0.76-1.15) or liver test abnormalities on admission (odds ratio, 1.31; 95% CI, 0.80-2.12) were not associated independently with mechanical ventilation or death. CONCLUSIONS: Among patients hospitalized with COVID-19, gastrointestinal symptoms and liver test abnormalities were common, but the majority were mild and their presence was not associated with a more severe clinical course.