Magnetoencephalography for Epilepsy Presurgical Evaluation.

PURPOSE OF THE REVIEW: Magnetoencephalography (MEG) is a functional neuroimaging technique that records neurophysiology data with millisecond temporal resolution and localizes it with subcentimeter accuracy. Its capability to provide high resolution in both of these domains makes it a powerful tool both in basic neuroscience as well as clinical applications. In neurology, it has proven useful in its ability to record and localize epileptiform activity. Epilepsy workup typically begins with scalp electroencephalography (EEG), but in many situations, EEG-based localization of the epileptogenic zone is inadequate. The complementary sensitivity of MEG can be crucial in such cases, and MEG has been adopted at many centers as an important resource in building a surgical hypothesis. In this paper, we review recent work evaluating the extent of MEG influence of presurgical evaluations, novel analyses of MEG data employed in surgical workup, and new MEG instrumentation that will likely affect the field of clinical MEG. RECENT FINDINGS: MEG consistently contributes to presurgical evaluation and these contributions often change the plan for epilepsy surgery. Extensive work has been done to develop new analytic methods for localizing the source of epileptiform activity with MEG. Systems using optically pumped magnetometry (OPM) have been successfully deployed to record and localize epileptiform activity. MEG remains an important noninvasive tool for epilepsy presurgical evaluation. Continued improvements in analytic methodology will likely increase the diagnostic yield of the test. Novel instrumentation with OPM may contribute to this as well, and may increase accessibility of MEG by decreasing cost.

Enhanced clinical decisions for management of benign prostatic hyperplasia using patient-reported outcomes: protocol for a prospective observational study.

BACKGROUND: Lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) significantly impact quality of life among older men. Despite the prevalent use of the American Urological Association Symptom Index (AUA-SI) for BPH, this measure overlooks key symptoms such as pain and incontinence, underscoring the need for more comprehensive patient-reported outcome (PRO) tools. This study aims to integrate enhanced PROs into routine clinical practice to better capture the spectrum of LUTS, thereby improving clinical outcomes and patient care. METHODS: This prospective observational study will recruit men with LUTS secondary to BPH aged ≥ 50 years from urology clinics. Participants will be stratified into medical and surgical management groups, with PRO assessments scheduled at regular intervals to monitor LUTS and other health outcomes. The study will employ the LURN Symptom Index (SI)-29 alongside the traditional AUA-SI and other non-urologic PROs to evaluate a broad range of symptoms. Data on comorbidities, symptom severity, and treatment efficacy will be collected through a combination of electronic health records and PROs. Analyses will focus on the predictive power of these tools in relation to symptom trajectories and treatment responses. Aims are to: (1) integrate routine clinical tests with PRO assessment to enhance screening, diagnosis, and management of patients with BPH; (2) examine psychometric properties of the LURN SIs, including test-retest reliability and establishment of clinically meaningful differences; and (3) create care-coordination recommendations to facilitate management of persistent symptoms and common comorbidities measured by PROs. DISCUSSION: By employing comprehensive PRO measures, this study expects to refine symptom assessment and enhance treatment monitoring, potentially leading to improved personalized care strategies. The integration of these tools into clinical settings could revolutionize the management of LUTS/BPH by providing more nuanced insights into patient experiences and outcomes. The findings could have significant implications for clinical practices, potentially leading to updates in clinical guidelines and better health management strategies for men with LUTS/BPH. TRIAL REGISTRATION: This study is registered in ClinicalTrials.gov (NCT05898932).

Formation of new stellar populations from gas accreted by massive young star clusters.

Stars in clusters are thought to form in a single burst from a common progenitor cloud of molecular gas. However, massive, old 'globular' clusters--those with ages greater than ten billion years and masses several hundred thousand times that of the Sun--often harbour multiple stellar populations, indicating that more than one star-forming event occurred during their lifetimes. Colliding stellar winds from late-stage, asymptotic-giant-branch stars are often suggested to be triggers of second-generation star formation. For this to occur, the initial cluster masses need to be greater than a few million solar masses. Here we report observations of three massive relatively young star clusters (1-2 billion years old) in the Magellanic Clouds that show clear evidence of burst-like star formation that occurred a few hundred million years after their initial formation era. We show that such clusters could have accreted sufficient gas to form new stars if they had orbited in their host galaxies' gaseous disks throughout the period between their initial formation and the more recent bursts of star formation. This process may eventually give rise to the ubiquitous multiple stellar populations in globular clusters.

A mass transfer origin for blue stragglers in NGC 188 as revealed by half-solar-mass companions.

In open star clusters, where all members formed at about the same time, blue straggler stars are typically observed to be brighter and bluer than hydrogen-burning main-sequence stars, and therefore should already have evolved into giant stars and stellar remnants. Correlations between blue straggler frequency and cluster binary star fraction, core mass and radial position suggest that mass transfer or mergers in binary stars dominates the production of blue stragglers in open clusters. Analytic models, detailed observations and sophisticated N-body simulations, however, argue in favour of stellar collisions. Here we report that the blue stragglers in long-period binaries in the old (7 × 10(9)-year) open cluster NGC 188 have companions with masses of about half a solar mass, with a surprisingly narrow mass distribution. This conclusively rules out a collisional origin, as the collision hypothesis predicts a companion mass distribution with significantly higher masses. Mergers in hierarchical triple stars are marginally permitted by the data, but the observations do not favour this hypothesis. The data are highly consistent with a mass transfer origin for the long-period blue straggler binaries in NGC 188, in which the companions would be white dwarfs of about half a solar mass.

A binary star fraction of 76 per cent and unusual orbit parameters for the blue stragglers of NGC 188.

Blue straggler stars lie on or near the main sequences of star clusters (all members of which formed around the same time), but typically are more luminous than the turn-off stars and therefore long ago should have evolved off the main sequence to become giants and white dwarfs. They are thought to derive from normal main-sequence stars that have undergone a recent increase in mass. Statistical evidence indicates that in globular star clusters the blue stragglers probably form from binary stars. The specific formation processes, such as mass transfer, mergers or stellar collisions during dynamical encounters of binary stars, remain unresolved. Here we report that 16 of the 21 blue stragglers (76 per cent) in the old (7-Gyr; ref. 2) open cluster NGC 188 are currently in binary systems, a frequency three times that found among normal solar-type main-sequence stars. These blue straggler binaries have a remarkable period-eccentricity distribution, with all but three having orbital periods of approximately 1,000 days. Moreover, these stars are rotating faster than normal main-sequence stars of the same surface temperatures. These data show that most, and possibly all, blue stragglers derive from multiple-star systems, and indicate that the several formation processes operate simultaneously. We suggest that rapid rotation of blue stragglers may place upper limits on their ages.

CO2 activation and carbonate intermediates: an operando AP-XPS study of CO2 electrolysis reactions on solid oxide electrochemical cells.

Through the use of ambient pressure X-ray photoelectron spectroscopy and specially designed ceria-based solid oxide electrochemical cells, carbon dioxide (CO2) electrolysis reactions (CO2 + 2e(-)→ CO + O(2-)) and carbon monoxide (CO) electro-oxidation reactions (CO + O(2-)→ CO2 + 2e(-)) over cerium oxide electrodes have been investigated in the presence of 0.5 Torr CO-CO2 gas mixtures at ∼600 °C. Carbonate species (CO3(2-)) are identified on the ceria surface as reaction intermediates. When CO2 electrolysis is promoted on ceria electrodes at +2.0 V applied bias, we observe a higher concentration of CO3(2-) over a 400 µm-wide active region on the ceria surface, accompanied by Ce(3+)/Ce(4+) redox changes. This increase in the CO3(2-) steady-state concentration suggests that the process of pre-coordination of CO2 to the ceria surface to form a CO3(2-) intermediate (CO2(g) + O(2-)(surface)→ CO3(2-)(surface)) precedes a rate-limiting electron transfer process involving CO3(2-) reduction to give CO and oxide ions (CO3(2-)(surface) + 2Ce(3+)→ CO(g) + 2O(2-)(surface) + 2Ce(4+)). When the applied bias is switched to -1.5 V to promote CO electro-oxidation on ceria, the surface CO3(2-) concentration slightly decreases from the equilibrium value, suggesting that the electron transfer process is also a rate-limiting process in the reverse direction.

Surprising dissimilarities in a newly formed pair of 'identical twin' stars.

The mass and chemical composition of a star are the primary determinants of its basic physical properties-radius, temperature and luminosity-and how those properties evolve with time. Accordingly, two stars born at the same time, from the same natal material and with the same mass, are 'identical twins,' and as such might be expected to possess identical physical attributes. We have discovered in the Orion nebula a pair of stellar twins in a newborn binary star system. Each star in the binary has a mass of 0.41 +/- 0.01 solar masses, identical to within 2 per cent. Here we report that these twin stars have surface temperatures differing by approximately 300 K ( approximately 10 per cent) and luminosities differing by approximately 50 per cent, both at high confidence level. Preliminary results indicate that the stars' radii also differ, by 5-10 per cent. These surprising dissimilarities suggest that one of the twins may have been delayed by several hundred thousand years in its formation relative to its sibling. Such a delay could only have been detected in a very young, definitively equal-mass binary system. Our findings reveal cosmic limits on the age synchronization of young binary stars, often used as tests for the age calibrations of star-formation models.

Enhanced Clinical Decisions for Management of Benign Prostatic Hyperplasia using Patient-Reported Outcomes: Protocol for a Prospective Observational Study.

Background: Lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) significantly impact quality of life among older men. Despite the prevalent use of the American Urological Association Symptom Index (AUA-SI) for BPH, this measure overlooks key symptoms such as pain and incontinence, underscoring the need for more comprehensive patient-reported outcome (PRO) tools. This study aims to integrate enhanced PROs into routine clinical practice to better capture the spectrum of LUTS, thereby improving clinical outcomes and patient care. Methods: This prospective observational study will recruit men with LUTS secondary to BPH aged ≥ 50 years from urology clinics. Participants will be stratified into medical and surgical management groups, with PRO assessments scheduled at regular intervals to monitor LUTS and other health outcomes. The study will employ the LURN Symptom Index (SI)-29 alongside the traditional AUA-SI and other non-urologic PROs to evaluate a broad range of symptoms. Data on comorbidities, symptom severity, and treatment efficacy will be collected through a combination of electronic health records and PROs. Analyses will focus on the predictive power of these tools in relation to symptom trajectories and treatment responses. Aims are to: (1) integrate routine clinical tests with PRO assessment to enhance screening, diagnosis, and management of patients with BPH; (2) examine psychometric properties of the LURN SIs, including test-retest reliability and establishment of clinically meaningful differences; and (3) create care-coordination recommendations to facilitate management of persistent symptoms and common comorbidities measured by PROs. Discussion: By employing comprehensive PRO measures, this study expects to refine symptom assessment and enhance treatment monitoring, potentially leading to improved personalized care strategies. The integration of these tools into clinical settings could revolutionize the management of LUTS/BPH by providing more nuanced insights into patient experiences and outcomes. The findings could have significant implications for clinical practices, potentially leading to updates in clinical guidelines and better health management strategies for men with LUTS/BPH. Trial registration: This study is registered in ClinicalTrials.gov (NCT05898932).

Corrigendum: The role of the piriform cortex in temporal lobe epilepsy: A current literature review.

[This corrects the article DOI: 10.3389/fneur.2022.1042887.].

The role of the piriform cortex in temporal lobe epilepsy: A current literature review.

Temporal lobe epilepsy is the most common form of focal epilepsy and can have various detrimental consequences within many neurologic domains. Recent evidence suggests that the piriform cortex may also be implicated in seizure physiology. The piriform cortex is a primary component of the olfactory network and is located at the junction of the frontal and temporal lobes, wrapping around the entorhinal sulcus. Similar to the hippocampus, it is a tri-layered allocortical structure, with connections to many adjacent regions including the orbitofrontal cortex, amygdala, peri- and entorhinal cortices, and insula. Both animal and human studies have implicated the piriform cortex as a critical node in the temporal lobe epilepsy network. It has additionally been shown that resection of greater than half of the piriform cortex may significantly increase the odds of achieving seizure freedom. Laser interstitial thermal therapy has also been shown to be an effective treatment strategy with recent evidence hinting that ablation of the piriform cortex may be important for seizure control as well. We propose that sampling piriform cortex in intracranial stereoelectroencephalography (sEEG) procedures with the use of a temporal pole or amygdalar electrode would be beneficial for further understanding the role of the piriform cortex in temporal lobe epilepsy.

PyParse: a semiautomated system for scoring spoken recall data.

Studies of human memory often generate data on the sequence and timing of recalled items, but scoring such data using conventional methods is difficult or impossible. We describe a Python-based semiautomated system that greatly simplifies this task. This software, called PyParse, can easily be used in conjunction with many common experiment authoring systems. Scored data is output in a simple ASCII format and can be accessed with the programming language of choice, allowing for the identification of features such as correct responses, prior-list intrusions, extra-list intrusions, and repetitions.

Temporal associative processes revealed by intrusions in paired-associate recall.

Although much is known about the factors that influence the acquisition and retention of individual paired associates, the existence of temporally defined associations spanning multiple pairs has not been demonstrated. We report two experiments in which subjects studied randomly paired nouns for a subsequent cued recall test. When subjects recalled nontarget items, their intrusions tended to come from nearby pairs. This across-pair contiguity effect was graded, spanning noncontiguously studied word pairs. The existence of such long-range temporally defined associations lends further support to contextual-retrieval models of episodic association.

Running-down phenomenon captured with chronic electrocorticography.

The running-down phenomenon refers to 2 analogous but distinct entities that may be seen after epilepsy surgery. The first is clinical, and denotes a progressive diminution in seizures after epilepsy surgery in which the epileptogenic zone could not be completely removed (Modern Problems of Psychopharmacology 1970;4:306, Brain 1996:989). The second is electrographic, and refers to a progressive deactivation of a secondary seizure focus after removal of the primary epileptogenic zone. This progressive decrease in epileptiform activity may represent a reversal of secondary epileptogenesis, where a primary epileptogenic zone is postulated to activate epileptiform discharges at a second site and may become independent.3 The electrographic running-down phenomenon has been reported in only limited numbers of patients, using serial postoperative routine scalp electroencephalography (EEG) (Arch Neurol 1985;42:318). We present what is, to our knowledge, the most detailed demonstration of the electrographic running-down phenomenon in humans, made possible by chronic electrocorticography (ECoG). Our patient's left temporal seizure focus overlapped with language areas, limiting the resection to a portion of the epileptogenic zone, followed by implantation of a direct brain-responsive neurostimulator (RNS System, NeuroPace Inc.) to treat residual epileptogenic tissue. Despite the limited extent of the resection, the patient remains seizure-free more than 2 years after surgery, with the RNS System recording ECoG without delivering stimulation. We reviewed the chronic recordings with automated spike detection and inspection of electrographic episodes marked by the neurostimulator. These recordings demonstrate progressive diminution in spiking and rhythmic discharges, consistent with an electrographic running-down phenomenon.

Assessing Substitution Effects on Surface Chemistry by in Situ Ambient Pressure X-ray Photoelectron Spectroscopy on Perovskite Thin Films, BaCe xZr0.9- xY0.1O2.95 ( x = 0; 0.2; 0.9).

Performance of proton-solid oxide fuel cells (H+-SOFC) is governed by ion transport through solid/gas interfaces. Major breakthroughs are then intrinsically linked to a detailed understanding of how parameters tailoring bulk proton conductivity affect surface chemistry in situ, at an early stage. In this work, we studied proton and oxygen transport at the interface between H+-SOFC electrolyte BaCe xZr0.9- xY0.1O2.95 ( x = 0; 0.2; 0.9) thin films and the gas (100 mTorr of H2O and O2) by using synchrotron-based ambient pressure X-ray photoelectron spectroscopy at operating temperature (>400 °C). We developed highly textured BaCe xZr0.9- xY0.1O2.95 epitaxial thin films, which exhibit high level of in-plane proton conductivity, that is, up to 0.08 S cm-1 at 500 °C for x = 0.9. Upon applying 100 mTorr water partial pressure above 300 °C, major changes are observed only in the O 1s and Y 3d core level spectra, with a clear Zr/Ce ratio dependency. OH- formation is favored by Ce content while initiated near Y. Hydration is also associated with surface secondary phase growth comprising oxygen-under-coordinated yttrium and/or yttrium hydroxide. With BaCe0.2Zr0.7Y0.1O2.95, high levels of ionic conductivities and chemical stability are obtained as a result of the optimized surface reaction kinetics, with low activation energy barrier for proton transport while restraining formation of OH-/SO42- adsorb species.

EEG correlates of verbal and nonverbal working memory.

BACKGROUND: Distinct cognitive processes support verbal and nonverbal working memory, with verbal memory depending specifically on the subvocal rehearsal of items. METHODS: We recorded scalp EEG while subjects performed a Sternberg task. In each trial, subjects judged whether a probe item was one of the three items in a study list. Lists were composed of stimuli from one of five pools whose items either were verbally rehearsable (letters, words, pictures of common objects) or resistant to verbal rehearsal (sinusoidal grating patterns, single dot locations). RESULTS: We found oscillatory correlates unique to verbal stimuli in the theta (4-8 Hz), alpha (9-12 Hz), beta (14-28 Hz), and gamma (30-50 Hz) frequency bands. Verbal stimuli generally elicited greater power than did nonverbal stimuli. Enhanced verbal power was found bilaterally in the theta band, over frontal and occipital areas in the alpha and beta bands, and centrally in the gamma band. When we looked specifically for cases where oscillatory power in the time interval between item presentations was greater than oscillatory power during item presentation, we found enhanced beta activity in the frontal and occipital regions. CONCLUSION: These results implicate stimulus-induced oscillatory activity in verbal working memory and beta activity in the process of subvocal rehearsal.

Eye closure causes widespread low-frequency power increase and focal gamma attenuation in the human electrocorticogram.

OBJECTIVE: We sought to characterize the effects of eye closure on EEG power using electrocorticography (ECoG). Specifically, we sought to elucidate the anatomical areas demonstrating an eye closure effect, and at which frequencies this effect occurs. METHODS: ECoG was recorded from 32 patients undergoing invasive monitoring for seizure focus localization. Patients were instructed to close and open their eyes repeatedly. ECoG power was compared in the epochs following eye closure and opening, for various frequency bands and brain regions. RESULTS: We found that at low frequencies, eye closure causes widespread power increases involving all lobes of the brain. This effect was significant not only in the α (8-12 Hz) band but in the δ (2-4 Hz), θ (4-8 Hz), and ß (15-30 Hz) bands as well. At high frequencies, eye closure causes comparatively focal power decreases over occipital cortex and frontal Brodmann areas 8 and 9. CONCLUSIONS: Eye closure (1) affects a broad range of frequencies outside the α band and (2) involves a distributed network of neural activity in anatomical areas outside visual cortex. SIGNIFICANCE: This study constitutes the first large-scale, systematic application of ECoG to study eye closure, which is shown to influence a broad range of frequencies and brain regions.