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Brain Stimulation

○ Elsevier BV

Preprints posted in the last 7 days, ranked by how well they match Brain Stimulation's content profile, based on 125 papers previously published here. The average preprint has a 0.09% match score for this journal, so anything above that is already an above-average fit.

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Interictal functional ultrasound imaging in human epilepsy resection and responsive neurostimulation surgery

Agyeman, K. A.; Lee, D.; Lee, B. P.; McGinn, R. J.; Abedi, A.; Russin, J.; Wu, K.; Choi, w.; Liu, C.; Christopoulos, V. N.

2026-10-20 neurology 10.64898/2026.10.15.26365563 medRxiv
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Over 30% of patients with epilepsy are refractory to medication and may require surgical or neuromodulation-based intervention. Accurate localization of seizure-onset zones (SOZ) and assessment of treatment-associated brain responses remain major clinical challenges. Current workflows may involve invasive intracranial monitoring, prolonged hospitalization, adjustment of anti-seizure medications, and seizure capture to localize the SOZ, while opportunities for complementary intraoperative functional assessment remain limited. We used intraoperative functional ultrasound imaging (fUSI) to characterize interictal (i.e., non-seizure) cortical activity in nine patients with drug-resistant focal epilepsy and to assess treatment-associated brain responses following SOZ resection and responsive neurostimulation (RNS). fUSI signals were acquired directly from the exposed cortex during standard-of-care surgery. We developed six ultrafast power Doppler-based interictal activity markers (IaMs) to distinguish SOZ from peri-resection zone (PRZ) cortex and to quantify treatment-associated changes. The IaMs revealed distinct interictal hemodynamic dynamics between SOZ and PRZ cortex. Following SOZ resection, all six markers changed significantly within the surrounding PRZ. RNS also induced robust, stimulation paradigm-dependent modulation of cortical hemodynamic dynamics. Notably, RNS and surgical resection produced concordant directional changes across five of the six IaMs, despite representing fundamentally different therapeutic interventions. Together, these findings demonstrate the feasibility of intraoperative fUSI for characterizing and distinguishing interictal dynamics within SOZ and PRZ cortex and assessing treatment-associated cortical responses during human epilepsy surgery. Furthermore, fUSI could provide a complementary high-resolution functional imaging approach alongside established clinical methods for SOZ localization and intraoperative functional assessment.

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High Intensity Focused Ultrasound (HIFU) Thalamotomy as a Safe and Effective Treatment of Essential Tremor (ET) in Older Populations and those with Comorbidities

Farmer, A. J.; Young, W.; Young, W.; Neer, J.; Chang, F.-L.

2026-10-15 neurology 10.64898/2026.10.14.26365548 medRxiv
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Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) has been demonstrated to be a safe and effective minimally invasive therapy for essential tremor (ET). However, it is not clear whether older adults ([&ge;]70 years old) or individuals with comorbidities exhibit similar safety and efficacy. This IRB approved project collected EPIC EMR data on patients that underwent MRgHIFU at Parkview Regional Medical Center from January 2023 to November 2025. 68 patients were assessed for tremor severity using Clinical Rating Scale for Tremor (CRST), quality of life using Quality of life in ET Questionnaire (QUEST), and safety profile via reported post-procedure side effects. CRST and QUEST scores improved up to 1 year from baseline in our patient cohort and efficacies in older ([&ge;]70 years of age) and younger (<70 years of age) patients up to 3 months post MRgHIFU were not statistically different. Effects of comorbidities on CRST or QUEST scores improvements were all transient or did not affect endpoints. Older patients showed fewer total side effects at 3 months (1.17 (95% CI: 0.47-1.87) vs 0.21 (95% CI: -0.09-0.51), p=0.017) as did patients with pulmonary disease at 1 month (1.9 (95% CI: 1.6-2.2) vs 1.1 (95% CI: 0.9-1.3), p=0.036) while patients with family history of tremor showed more side effects at day 1 (1.5 (95% CI: 0.8-2.2) vs 2.5 (95% CI: 2.1-2.9), p=0.025). Age and comorbidities were not detected to adversely affect safety or efficacy following MRgHIFU in ET patients.

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Patient-specific subnetwork connectivity predicts deep brain stimulation response in obsessive-compulsive disorder

Seilheimer, R.; Vardalakis, N.; Choi, W.; Qiu, L.; Campos, G.; Nho, Y.; Chen, H.; Shuvaev, S.; Scangos, K.; Chang, A.; McIntyre, C.; Oathes, D. J.; Ganguly, T.; Cristancho, M.; Brown, L.; Barbosa, D. A.; Pesaran, B.; Halpern, C.; Scangos, K.

2026-10-21 psychiatry and clinical psychology 10.64898/2026.10.19.26365556 medRxiv
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Deep brain stimulation (DBS) can be an effective treatment for severe obsessive-compulsive disorder (OCD), but response is variable, and objective, reliable predictors of who will respond positively are absent. In three individuals with OCD, we implanted intracranial electrodes across the cortico-striato-limbic network before DBS. Prefrontal gamma activity, most prominently in the orbitofrontal cortex (OFC), distinguished high- from low-symptom OCD states reproducibly across days. Acute stimulation of the ventral capsule/ventral striatum relieved OCD symptoms and, in one patient, significantly shifted this OFC gamma signal. Effective connectivity from therapeutic stimulation sites to these prefrontal regions defined three patient-specific OCD subnetworks; the baseline strength of the nucleus accumbens/ventral pallidum-OFC subnetwork predicted acute and long-term DBS response. Imaging-based modeling of current propagation in stimulation-activated ventral capsule to the OFC tracked acute response, suggesting that this prediction could be approximated from imaging alone. These findings outline a predictive, subnetwork-level framework for personalized DBS in OCD.

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Levodopa Preferentially Reorganizes Dorsal Subthalamic Activity in Parkinsons Disease

Nair, S.; Joshi, P.; Filyushkina, V.; Sayfulina, K.; Guha, A.; Sedov, A.; Shaikh, A. G.

2026-10-15 neurology 10.64898/2026.10.13.26365259 medRxiv
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Background: Dopamine replacement reshapes subthalamic activity in Parkinson's disease, but whether this response reflects anatomically organized network reconfiguration remains unclear. Objectives: To determine whether levodopa preferentially reorganizes dorsal subthalamic spectral activity and cortico-subthalamic directionality. Methods: Twelve participants undergoing bilateral subthalamic deep brain stimulation contributed 30 contacts (14 dorsal, 16 ventral). Recordings obtained OFF and ON medication underwent spectral parameterization and multiband state-space analysis. Simultaneous electroencephalography in six participants enabled assessment of directional cortico-subthalamic coupling using the phase slope index. Results: Levodopa suppressed beta power more strongly dorsally than ventrally (-2.473 versus -0.120 dB; p=0.0438). Dorsal theta power increased, with a trend toward an increase after baseline normalization (p=0.07). Dorsal contacts exhibited greater theta-beta (+5.904 versus +1.610 dB; p=0.006) and gamma-beta (+2.516 versus +0.384 dB; p=0.0188) state-space shifts, principally driven by beta suppression. Gamma changes did not differ regionally. Concurrently, dorsal low-beta and beta interactions shifted toward cortical leading at selected electrodes, whereas ventral responses were less consistent. Conclusions: Levodopa produces a topographically organized subthalamic response, combining preferential dorsal beta suppression with altered cortico-subthalamic directionality. These findings position contact anatomy as a key consideration in characterizing dopaminergic network responses and motivate clinical validation of spatially informed multiband biomarkers for adaptive stimulation.

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Sensorimotor cortex activity during cued gait differs in Parkinson's freezers and non-freezers

Ma, L.; Miura, M.; Talu, I.; Cross, K. A.

2026-10-21 neurology 10.64898/2026.10.19.26365651 medRxiv
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Gait impairments are a major contributor to disability in patients with Parkinson's disease despite dopaminergic and neuromodulation therapies. External cues (e.g., visual targets, rhythmic auditory sounds) are commonly used to improve gait quality and reduce freezing of gait (FOG), yet their effectiveness varies across patients and contexts. Improved understanding of the neural mechanisms of cueing benefits is essential to personalize rehabilitation strategies and improve outcomes. We use mobile electroencephalography (EEG) to test the hypothesis that cues improve gait through engagement of voluntary motor control mechanisms to compensate for impaired gait automaticity. In addition, we investigate whether this mechanism is related to cueing benefits or freezing status. Eighteen PD patients with a history of freezing (PD-F), 21 patients without freezing (PD-NF) and 19 age-matched healthy controls (HC) walked overground under three conditions: normal walking, synchronizing to auditory cues, and stepping over visual cues. Stride-locked beta band (13-30 Hz) power dynamics in sensorimotor cortex were used to measure cortical control of stepping. Spatiotemporal gait parameters improved with cues in all groups. However, PD-F had smaller cue-related gains in speed and stride length when compared with PD-NF for both cue types, and did not improve gait speed with visual cues. EEG revealed greater contralateral sensorimotor cortex swing-phase beta suppression in PD-F than PD-NF patients, with visual cues eliciting the most robust response. In contrast, beta suppression with cues was less pronounced in PD-NF and HC, despite greater behavioral gains. In addition, engagement of sensorimotor cortex during visual cueing was associated with divergent gait effects across PD subgroups: In PD-NF greater beta suppression was associated with less gait improvement, whereas in PD-F the opposite was observed. These findings suggest distinct sensorimotor control mechanisms for cue utilization in PD-F and PD-NF, and indicate that engagement of voluntary motor control circuits may underlie cueing benefits primarily in PD-F.

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Functional and Organic Pseudo-Orthostatic Tremor: Clinical Features, Electrophysiology, and Treatment Outcomes in a Retrospective Cohort

Querejeta-Coma, A.; Yupanqui-Guerra, L. M.; Santos-Sanchez-de-las-Matas, L.; Gomez-Dominguez, A.; Canfield-Medina, H.; Cano-de-la-Cuerda, R.; Ordas-Bandera, C. M.

2026-10-20 neurology 10.64898/2026.10.18.26365840 medRxiv
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Background: Pseudo-orthostatic tremor (psOT) is a rare form of tremor of the lower body, triggered by standing, at frequencies lower than 13 Hz. It is believed to be secondary to other neurological disorders in a large proportion of cases. Surface electromyography (sEMG) can identify its core characteristics and differentiate it from other similar disorders such as primary orthostatic tremor (POT) and orthostatic myoclonus (OM). Objectives: Our study aims to illustrate the clinical and neurophysiological features as well as the outcomes and final diagnoses of patients with psOT in a retrospective two-centre cohort. Methods: We retrospectively examined the available clinical and neurophysiological records of 35 consecutive patients with a diagnosis of psOT in the 2022-2026 period. Data on demographics, clinical characteristics, sEMG findings, pharmacological treatments, ancillary investigations and patient reported outcomes were collected. Results: 35 patients with psOT were identified, of which 6 (17%) displayed features consistent with a functional neurological disorder (FND). Among the 29 patients with organic psOT, 21 (72.4%) fulfilled the diagnostic criteria for essential tremor (ET), while an identifiable neurological cause was established in four (13.8%). sEMG findings differed between functional and organic psOT, with the latter often displaying features consistent with weight-bearing hyperkinesias. Conclusions: Our retrospective study suggests that psOT is most often associated with ET, while an identifiable neurological cause was found in a relatively small proportion of patients. We also describe functional psOT as a previously unrecognized clinical presentation of FND.

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Predictors of methadone response in chronic neuropathic pain

Barbosa, M. M.; Pentiado, J. A. M.; Kubota, G.; Martins, P. N.; Moreira, L. I.; Fernandes, A. M.; da Silva, V. A.; Junior, J. R.; Figueiredo, E. G.; Yeng, L. T.; Teixeira, M. J.; de Andrade, D. C.

2026-10-21 pain medicine 10.64898/2026.10.16.26365778 medRxiv
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Background: Although opioids are frequently prescribed for refractory chronic neuropathic pain, few data are available on baseline factors that may identify individuals more likely to respond and inform individually tailored practice. Methods: This was a post hoc, exploratory analysis of individual-level data from a placebo-controlled trial of methadone for chronic neuropathic pain (NCT05235191). Baseline clinical, psychological, psychophysical and radiological variables were tested for association with 30% or more pain reduction in the methadone group. The correlation between expectation of improvement and pain reduction was examined in both groups. Results: Of the 81 participants completing the 8-week follow-up, 28 (70%) on methadone and 14 (34.1%) on placebo achieved 30% or more pain reduction. In the methadone group, responders had higher baseline expectation of improvement (median 100 [80-100] vs. 55 [50-81]; p=0.004), which correlated moderately with percentage pain reduction (rs=0.508; p<0.001). Neither finding was observed in the placebo group (p=0.211 and p=0.161, respectively), although the correlation did not differ significantly between groups (p for interaction=0.728). Other clinical, sociodemographic, psychological and psychophysical variables were not associated with response. In the subsample with peripheral neuropathic pain and structural MRI (n=37), lower left precentral cortex volume was associated with response to methadone (p=0.041), and lower right paracentral volume with response to placebo (p=0.003). Conclusions: Baseline expectation may influence treatment outcomes, supporting its inclusion as a covariate to improve the precision of treatment effect estimates in trials, and its use in clinical practice to help tailor treatment to individual patients. These exploratory findings require confirmation in larger studies.

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Effects of Cannabidiol on Auditory Mismatch Negativity in Autistic Children

Budhiraja, K.; Parrella, N.-F.; Hill, A. T.; Catchlove, S.; Downey, L. A.; Enticott, P. G.; Ford, T. C.

2026-10-16 psychiatry and clinical psychology 10.64898/2026.10.14.26365371 medRxiv
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Pharmacological treatments targeting core autistic features remain limited. In neurotypical adults, cannabidiol (CBD) alters mismatch negativity (MMN), an electrophysiological marker of automatic auditory deviance detection that has been associated with autistic traits. The effects of CBD on MMN, as measured using electroencephalography (EEG), in autistic children remain unknown. This secondary analysis of a pilot randomised, double-blind, placebo-controlled crossover trial examined the effects of 12 weeks of oral CBD oil on MMN during a duration-deviant auditory oddball task. We hypothesised that CBD would produce more negative MMN amplitudes and shorter peak latencies relative to placebo. Nineteen autistic children (6-12 years, 8 female) received CBD (dose) and placebo in randomised order, separated by an 8-week washout. Age-adjusted linear mixed-effects models tested Time (baseline, follow-up) x Treatment (CBD, placebo) effects on mean MMN amplitude and peak latency separately at Fz and FCz. Exploratory Spearman correlations examined baseline associations between MMN and Developmental Behaviour Checklist-2 (DBC-2) Social Relating scores. At FCz, latency decreased following CBD but increased following placebo but did not survive FDR correction (p = .029, pFDR = .058) and no other interactions were significant. Higher baseline DBC-2 Social Relating scores were associated with more negative MMN amplitude at FCz (rho = -.58, pFDR = .028) and Fz (rho = -.59, pFDR = .028). These findings provide tentative evidence that CBD may modulate MMN latency in autistic children. Larger trials should clarify CBDs effects on MMN and further examine the association between MMN amplitude and social-relating difficulties.

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Intraoperative Very High-Frequency Activity for Localization of the Epileptogenic Zone: An International Multicenter Study

Uda, H.; Kuroda, N.; Usui, N.; Ogawa, H.; Okumura, T.; Hashiguchi, M.; Kawaguchi, N.; Hatano, K.; Erder, E.; Fujioka, K.; Choromanski, D.; Mahmood, N.; Figueroa, M.; Kuwabara, N.; Luat, A. F.; Cools, M.; ASANO, E.

2026-10-15 neurology 10.64898/2026.10.14.26365543 medRxiv
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Background and Objectives Interictal spikes on intraoperative electrocorticography have been used to localize the epileptogenic zone but have limited specificity. We hypothesized that identifying spatially distributed, spike-associated very high-frequency activity (vHFA; 500-2,000 Hz) would improve the ability of spikes to localize the epileptogenic zone. We aimed to characterize spike-associated vHFA and to determine whether a seizure outcome prediction model incorporating vHFA could be externally validated across independent centers. Methods This retrospective two-center cohort study included patients with drug-resistant focal epilepsy who underwent electrocorticography and subsequent resection between January 2016 and May 2025. Spikes occurring across contacts within 50 ms were classified as co-occurring; all others were classified as isolated. We determined whether vHFA was associated with co-occurring spikes. We then assessed whether contacts enriched in vHFA-positive co-occurring spikes were more likely to be located within the resected region among seizure-free patients. Finally, we determined whether the rate of such spikes remaining outside the resection predicted seizure outcomes across the two centers. Results Among 56 patients (mean age: 21.2 years; 26 females), we identified 132,359 spikes, of which 1,925 were vHFA-positive. The vHFA peak preceded the associated spike peak by 8.0 ms (95%CI: 5.0-16.0). vHFA-positive spikes were more likely to be classified as co-occurring, even after adjustment for anatomy and inter-electrode distance (OR: 3.43; 95%CI: 2.82-4.17). Among the 35 seizure-free patients, contacts with higher rates of vHFA-positive co-occurring spikes were more likely to be resected (OR: 11.92 per occurrence/min; 95%CI: 5.62-25.32). This association was stronger than that observed for all spikes (OR: 1.09 per occurrence/min; 95%CI: 1.06-1.11). Twenty patients experienced postoperative seizure recurrence; a higher proportion of vHFA-positive co-occurring spikes in preserved areas was associated with recurrence (OR: 3.22 per 0.01 increase in proportion; 95%CI: 1.14-9.12). In bidirectional cross-center validation, models incorporating vHFA-positive co-occurring spikes yielded areas under the receiver operating characteristic curves of 0.80 and 0.69, with better performance when the model was developed using the larger sample. Discussion Spike-associated vHFA may identify a biologically meaningful subset of interictal spikes involved in propagation across the epileptogenic zone. vHFA-positive co-occurring spikes may represent a generalizable intraoperative biomarker of the epileptogenic zone.

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Timing of Addiction Consultation and Alcohol Withdrawal Management in Hospitalized Adults

Reese, T.; Kast, K. A.; Marcovitz, D.; Stewart-Kast, L.; Tindle, H.; Wright, A.; Shah, M.; Menon, S.; von Horn, A.

2026-10-21 addiction medicine 10.64898/2026.10.18.26365824 medRxiv
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Objective To evaluate the association of early addiction consultation with withdrawal pharmacotherapy and complications in hospitalized patients with alcohol withdrawal. Methods Retrospective single-center cohort of adult hospitalizations with alcohol withdrawal (diagnosis code or CIWA-Ar [&ge;]10 within 24 hours) from July 2020 to January 2026. Exposure was an addiction consult service order within 24 hours of arrival, compared with no or later consultation. Primary outcomes were intensive care unit (ICU) transfer after the first 24 hours and delirium tremens or withdrawal seizure not present on admission. Process outcomes included phenobarbital and thiamine administration within 24 hours and benzodiazepine dose in the first 48 hours. Secondary outcomes included length of stay and 30-day death or return to hospital. Results Of 4,663 hospitalizations, 1,379 (29.6%) received early consultation. After adjustment, early consultation was associated with lower odds of ICU transfer (odds ratio [OR] 0.73; 95% CI 0.54-0.99) and fewer episodes of delirium tremens (risk difference -1.09 per 100; -1.45 to -0.73), with no significant difference in withdrawal seizure. Early consultation was associated with phenobarbital (OR 1.57; 1.32-1.86) and thiamine (OR 1.23; 1.07-1.41) within 24 hours, higher 48-hour lorazepam-equivalent dose (ratio of geometric means 1.44; 1.32-1.57), shorter stays (ratio 0.92; 0.88-0.97), and lower odds of 30-day death or return to hospital (OR 0.78; 0.66-0.91). Conclusions Early addiction consultation was associated with earlier, more intensive withdrawal pharmacotherapy, lower odds of ICU transfer, and fewer episodes of delirium tremens, although the complication associations were sensitive to cohort definition.

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Cardiac MRI at 3.0T in the presence of implantable cardioverter defibrillators (ICDs)

Reiter, T.; Weber, O. M.; Weiss, i.; Kraus, N.; Kress, S.; Bauer, W. R.

2026-10-21 cardiovascular medicine 10.64898/2026.10.16.26364740 medRxiv
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Patients with implantable cardioverter-defibrillators (ICDs) often are excluded from receiving CMR scans at 3.0T due to ICD-induced image artifacts. This work aims to transfer sequence protocols established for CMR imaging in the presence of ICDs at 1.5T to a first human application at 3.0T. All measurements were performed on a clinical 3T MRI scanner. Phantom measurements were used to establish and optimize wideband PSIR LGE imaging at 3.0T. Volunteer measurements with externally placed ICDs were used for optimization of CINE imaging and wideband PSIR imaging. Thirdly, patients with implanted ICD were examined with the optimized protocols. Human measurements showed that SA stacks obtained with spoiled GRE after contrast agent showed a markedly lower artifact burden than the conventional approach. For scar imaging, a wideband PSIR with a bandwidth of 3kHz and a frequency offset of +750Hz allowed a sufficient suppression of relevant artifacts in the majority of scans. No strong correlation between the image quality and the distance between the cardiac silhouette and the device was detected. The presented work shows the feasibility of clinical cardiac MRI at 3.0T including GRE-CINE and wideband PSIR-LGE for patients with ICDs.

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Microstructural phenotyping and clinical relevance of multiple sclerosis lesions using quantitative susceptibility source separation

Martinez-Heras, E.; Alberich, M.; Shin, H.-G.; Sampedro, F.; GUZMAN, E. G.; del Agua, E.; Ochoa, N. M.; Garriga, J. S.; Rovira, A.; Pareto, D.

2026-10-16 neurology 10.64898/2026.10.15.26365462 medRxiv
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Background: Quantitative susceptibility mapping (QSM) exhibits phase cancellation between paramagnetic (e.g. iron) and diamagnetic (e.g. myelin/protein) sources, obscuring microstructural lesion heterogeneity in multiple sclerosis (MS). We evaluated whether biophysical {chi}-separation identifies clinically meaningful lesion phenotypes and whether reduced echo sampling preserves microstructural sensitivity. Methods: In this cross-sectional study of 183 people with multiple sclerosis (PwMS), we analyzed 3327 quality-controlled white matter lesions using 3T MRI with a five-echo gradient-recalled echo sequence (GRE5) and a subsampled two-echo dataset (GRE2). A hybrid framework combining unsupervised clustering on whole-lesion paramagnetic ({chi}para) and diamagnetic ({chi}dia) features with rule-based compartmental edge-core gradient assignment resolved MS lesion phenotypes. Intralesional microstructural properties were evaluated using linear mixed-effects models. Multivariable linear regressions assessed associations with physical disability (Expanded Disability Status Scale, EDSS; n = 158), cognitive processing speed (Symbol Digit Modalities Test, SDMT; n = 79), and disease duration (DD; n = 161), with sensitivity models adjusting for total lesion volume, count, or DD. Results: The framework identified four reproducible lesion phenotypes (Adjusted Rand Index = 0.924): Type 1 (22.7%; preserved {chi}dia), Type 2 (32.9%; high {chi}para without positive edge-core gradient), Type 3 (35.8%; attenuated {chi}dia), and Type 4 (8.6%; high {chi}para with a positive edge-core paramagnetic gradient). Higher EDSS was selectively associated with more negative signed {chi}dia within Type 4 lesions (whole: {beta} = -0.37, q = 0.020; core: {beta} = -0.37, q = 0.006; edge: {beta} = -0.34, q = 0.030) and Type 2 edge ({beta} = -0.33, q = 0.044). Type 4 core associations remained robust across sensitivity models adjusting for total lesion volume ({beta} = -0.35, q = 0.004), total lesion count ({beta} = -0.37, q = 0.008), and DD ({beta} = -0.32, q = 0.033). Abbreviated GRE2 attenuated Type 4 compartmental associations to non-significance (all q greater than 0.05; core: {beta} = -0.20, q = 0.215). Conclusions: Quantitative {chi}-separation identified four internally stable susceptibility-defined MS lesion phenotypes, revealing disability-associated tissue heterogeneity beyond total lesion burden. Higher EDSS was associated with more negative diamagnetic measures within Type 4 cores after adjustment for lesion burden, pointing toward complex intralesional non-myelin tissue remodeling or reactive astrogliosis. Two-echo subsampling may influence compartment-specific clinical associations. By uncoupling susceptibility sources, {chi}-separation provides a quantitative framework for characterizing disability-associated lesion heterogeneity.

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AI Tools to Assist with Management of Patient Portal Messages: Auto-Categorization and Routing

Brooks, J. D.; Donahue, M. A.; Rayapureddy, J. A.; Molyneaux, B.; Sylvia, L. G.; Park, E. R.; Mishuris, R. G.; Thurler, A. H.; Moura, L. M. V. R.

2026-10-21 neurology 10.64898/2026.10.19.26365557 medRxiv
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Background and Objective: The volume of patient portal messages has grown substantially and artificial intelligence (AI) can support clinical staff and improve the timeliness of patient care. Our objective is to test if an AI tool for managing the electronic inbox In-Basket reduces response times to patient portal messages in neurology. Methods: We conducted an implementation study from January to May 2026 in the neurology department at two clinical sites within a regional medical system. A single AI tool was implemented to auto-categorize and auto-route all patient messages received in the electronic inbox. The tool also generates optional draft replies to messages. Primary process measures were the median weekly time (hours) from message creation to the first action and to closure. Impact was analyzed using a controlled interrupted time-series (ITS) design, comparing message-volume-matched control divisions. Results: Among 24,142 messages analyzed, pre-intervention median weekly time to first action was 11.3 hours [IQR: 5.6, 15.1] (Site A) and 16.1 hours [IQR: 13.8, 19.0] (Site B), falling post-intervention to 1.0 hour [IQR: 0, 3.1] (Site A) and 0.6 hours [IQR: 0.2, 2.4] (Site B). Controlled interrupted time-series analysis showed a significant immediate differential level change in median weekly hours to first action at Site A (-92.5%, 95% CI: -97.5% to -78.0%), and a significant downward trend at Site B (-43.5%, 95% CI: -65.2% to -8.2%). Changes in time to closure were directionally favorable but not statistically significant at either site. There was low use of the generated draft replies, only 0.5% at Site A and 3% at Site B. Discussion: Implementation of AI-assisted message categorization and routing was associated with a substantially reduced initial action time for patient In-Basket messages in Epilepsy. The utilization of AI-generated draft-replies to messages was low. These findings support the feasibility and effectiveness of AI-augmented workflows to improve inbox management.

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Concussion, Attention, and Mental Health: A Brain Network Study in Youth (CAMBY) - Study Protocol

Scratch, S.; Gill, P. K.; Hickling, A.; Irvin, A.; Zamyadi, R.; Parimoo, S.; Johnston, P. R.; Davis, A. L.; Ibrahim, G. M.; Dunkley, B. T.; Wheeler, A. L.

2026-10-20 neurology 10.64898/2026.10.14.26365111 medRxiv
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BACKGROUND: One in three adolescents with a concussion history report experiencing long-lasting somatic, sleep, emotional, and/or cognitive disturbances (persisting symptoms after concussion (PSaC)). Cognitive difficulties, such as attentional problems, are common symptoms and can interfere with ongoing development. Clinically, psychiatric symptoms also present in youth with PSaC. A concussion causes diffuse functional and microstructural alterations to neural networks. To develop targeted treatments for PSaC (e.g., neurostimulation), we need to understand how and where structural alterations and neural dysfunction intersect to cause long-lasting symptoms. OBJECTIVES: 1) Identify functional and microstructural properties in intrinsic connectivity networks, as well as neuropsychological outcomes, that differentiate adolescents with concussion with PSaC from those who do not have PSaC. 2) Determine whether neural activity within intrinsic connectivity networks mediates the relationship between network microstructure and specific neuropsychological features in adolescents with concussion. METHODS: CAMBY is a prospective study of adolescents aged 12 to 18 years with a history of concussion. Participants are allocated based on recovery status (PSaC vs. No-PSaC (recovered controls)). Advanced structural (magnetic resonance imaging; MRI) and functional (magnetoencephalography; MEG) neuroimaging and neuropsychological measures will be collected one month or more after concussion. Microstructural and functional features will be computed within intrinsic connectivity networks, then compared between PSaC and recovered control groups and related to symptom domains and neuropsychological profiles. IMPACT: This will be the first study to integrate MRI, MEG, and neuropsychology in adolescents with PSaC to identify disrupted networks underlying PSaC. This observational study is a necessary step towards future clinical trials that accurately target promising therapeutic neurostimulation protocols.

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Spectral power and functional connectivity of resting EEG in people exposed to armed conflict and controls

Nitola-Pulido, L.; Bonilla, D. S.; Herrera Murcia, E.; Reyes Gavilan, P. A.; Santamaria-Garcia, H.

2026-10-19 psychiatry and clinical psychology 10.64898/2026.10.15.26365676 medRxiv
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Exposure to armed conflict can leave persistent effects on mental health, yet its neurophysiological correlates remain poorly characterized, particularly in populations exposed to prolonged violence outside narrowly defined post traumatic stress disorder samples. Here we examined resting state electroencephalographic activity in 122 Colombian adults, including 74 participants exposed to armed conflict and 48 controls. Eyes closed EEG was analysed for 240 seconds per participant. We quantified absolute and relative spectral power across delta, theta, alpha and beta bands and regional functional connectivity using weighted phase lag index in theta, alpha and beta. Group comparisons were adjusted for age, education, sex and assessment year, with correction across 78 EEG contrasts. Median occipital and global alpha power was lower in exposed participants, although adjusted estimates were close to the null and confidence intervals were broad. Temporal theta relative power was lower in exposed participants at nominal significance, but this association did not survive Holm correction. No spectral power or regional connectivity contrast remained significant after multiple testing correction. Exploratory associations between EEG measures and MoCA performance were modest in participants with confirmed scores. These findings provide a systematic characterization of resting EEG after exposure to armed conflict in a population shaped by prolonged violence and displacement. They also indicate that large or widespread alterations in resting spectral power and connectivity were not detectable with the current sample and analytical framework, while defining candidate signals and methodological priorities for larger studies of conflict related brain health.

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Focus or Feeding: A Quantitative Analysis of Prescribed Amphetamines in Human Milk

Yamada, E.; Stark, A.; Burdine, J.; Donikini, L.; Datta, P.; Krutsch, K.

2026-10-20 psychiatry and clinical psychology 10.64898/2026.10.14.26365136 medRxiv
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Objective: Amphetamine (AMP) and its derivates are commonly prescribed for the management of attention-deficit/hyperactivity disorder (ADHD). This study aimed to 1) quantify AMP's transfer into human milk in lactating women receiving therapeutic doses and 2) contextualize infant exposure. Methods: Milk samples and dyad health histories of thirteen lactating women treated with varying doses of either mixed AMP, dextroamphetamine, or lisdexamfetamine were released for this study from the InfantRisk Human Milk Biorepository. Milk drug concentrations were quantified by validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) and used to calculate standard relative infant dose (RIDmat) and RID standardized to the defined daily dose (RIDDDD) of 15 mg AMP base. Results: Average milk concentrations (Cavg) of AMP base ranged from 23.3 to 297.0 ng/mL and increased linearly (R^2 = 0.92) with maternal daily dose. The RIDmat ranged 3.6-10.8% and RIDDDD ranged 1.4-21.8%. The fitted regression line crossed the 10% RIDDDD threshold at 1.17x DDD, with the upper 95% prediction limit crossing at 0.84x DDD. No adverse event reported by the mother-infant dyads were attributed to AMP exposure, notably including absence of reduced milk supply. Conclusions:The levels of AMP observed in human milk followed a dose predictable manner. The average patient was predicted to remain below the 10% RID DDD safety threshold at total daily doses at or below approximately 28 mg of mixed AMP salts or 59 mg of lisdexamfetamine. Ninety-five percent of patients were predicted to remain below the threshold at or below approximately 20 mg and 40 mg, respectively.

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T-cell dysregulation is implicated in the encephalopathy of prematurity

Smikle-Bernard, R.; Blesa Cabez, M.; Vaher, K.; Amir, R.; Mckinnon, K.; Murphy, L.; Thrippleton, M. J.; Quigley, A. J.; Bastin, M. E.; Reynolds, R. M.; Whalley, H. C.; Marioni, R. E.; Cox, S. R.; Boardman, J. P.

2026-10-16 neurology 10.64898/2026.10.15.26365621 medRxiv
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Preterm birth is strongly linked to systemic inflammation and encephalopathy of prematurity, which underlies subsequent cognitive impairment. T-cell immunity contributes to brain-immune crosstalk across the life course but its role in the pathogenesis of encephalopathy of prematurity is unknown. Protein epigenetic scores are DNA methylation (DNAm)-based proxies of circulating proteins. We tested the hypothesis that T-cell dysregulation has a specific role in child neurodevelopment following preterm birth. Multimodal data were collected from 144 preterm infants (median gestational age at birth 29+5 weeks [range 23+3 to 32+6]) recruited to a prospective cohort study: saliva DNAm for protein epigenetic score derivation and brain MRI, both at term-equivalent age, and the Mullen Scales of Early Learning Composite score at 5 years from a subset. We investigated associations of the epigenetic scores for cytotoxic and regulatory T cell-associated molecule (DNAm CRTAM) and C-reactive protein (DNAm CRP; a non-specific marker of inflammation) with MRI metrics of encephalopathy of prematurity: global and regional brain volumes, and general factors of diffusion tensor imaging and neurite orientation dispersion and density imaging metrics averaged across 42 white matter tracts. We tested whether DNAm CRTAM explains more variance than DNAm CRP in MRI metrics of the encephalopathy of prematurity and cognitive scores in childhood. Higher neonatal DNAm CRTAM was associated with lower general factor of fractional anisotropy ({beta} = -0.252, q = 0.011) and higher general factors of radial diffusivity ({beta} = 0.215, q = 0.039), mean diffusivity ({beta} = 0.198, q = 0.047) and orientation dispersion index ({beta} = 0.201, q = 0.048), independent of inflammatory morbidities and other biological covariates after false discovery rate correction. DNAm CRTAM explained more variance than DNAm CRP (maximum incremental R2 = 4.2% vs 1.5%) in diffusion MRI metrics. Higher neonatal DNAm CRTAM was associated with lower cognitive scores at 5 years, independent of DNAm CRP and other covariates ({beta} = -0.332, P = 0.008), and explained more variance in cognitive scores than DNAm CRP (incremental R2 = 9.4% vs 1.2%). An epigenetic proxy of CRTAM in preterm infants is associated with both encephalopathy of prematurity in the neonatal period and lower cognitive performance at 5 years, explaining greater incremental variance than a non-specific marker of inflammation. The data implicate T-cell dysregulation in the pathophysiology of atypical neurodevelopment following preterm birth.

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Maternal body mass index in early pregnancy and offspring risk of multiple sclerosis: A population-based cohort study

Xu, H.; Razaz, N.; Remaeus, K.; Lee, J.; Fink, K.; McKay, K. A.

2026-10-16 neurology 10.64898/2026.10.15.26365617 medRxiv
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Objective To examine whether prospectively recorded maternal BMI in early pregnancy is associated with offspring multiple sclerosis (MS) risk, including childhood-onset and adult-onset MS. Design Nationwide population-based cohort study. Setting Swedish national health and demographic registers. Participants 1,524,863 singleton children born in Sweden from 1992 to 2007 and followed through 2025. Exposures Maternal BMI recorded at the first antenatal visit, categorised as underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9), and obesity ([&ge;]30.0), and also modelled continuously. Main outcome measures MS in offspring, identified as at least three ICD-10 G35 codes recorded on separate dates. Cox models estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) adjusting for confounders. Results During follow-up, 1539 offspring (0.1%) were diagnosed with MS at a median age of 24 years (interquartile range, 20-27 years). MS incidence rates by maternal BMI category were 0.37 per 10,000 person-years for both underweight, and normal weight, 0.42 for overweight, and 0.45 for obesity. Compared with normal weight women, maternal overweight and obesity were associated with higher hazards of offspring MS, with adjusted HRs of 1.20 (95% CI, 1.05 to 1.37) and 1.35 (95% CI, 1.11 to 1.64), respectively. Onset-specific analyses showed similar findings for adult-onset MS and less precise but directionally consistent estimates for paediatric-onset MS. Each 1-unit increase in maternal BMI was associated with a 3%, 4%, and 3% higher hazard of overall, paediatric-onset, and adult-onset offspring MS, respectively. Conclusions In this population-based cohort study, higher maternal BMI were associated with an increased rate of MS in offspring. The findings provide large-scale prospective evidence that maternal adiposity may be related to offspring MS risk and support further investigation of the prenatal metabolic environment in the early-life origins of MS.

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Drug exposure during oxycodone-S-ketamine patient-controlled analgesia reflects pain-related dosing behaviour after lumbar fusion surgery

Virtanen, T.; Brinck, E. C. V.; Engstrom, M.; Kurkela, M. J.; Tarkkila, P.; Backman, J.; Tornio, A.; Kontinen, V.; Peltoniemi, M.; Saari, T. I.

2026-10-21 pain medicine 10.64898/2026.10.20.26365979 medRxiv
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Background: Opioids remain the cornerstone of acute postoperative pain management but are associated with potentially serious adverse effects. We aimed to investigate the effect of oxycodone patient-controlled analgesia with adjunctive S-ketamine on pain after lumbar fusion surgery. Methods: In this secondary analysis, we examined oxycodone and S-ketamine exposure and PCA behaviour during the first 24 h. We assessed current pain versus subsequent PCA activity and whether the association between plasma oxycodone and adequate analgesia changed with postoperative time. Results: Plasma concentrations of administered drugs rose rapidly after PCA initiation, but variation was large. Metabolite concentrations accumulated over time. PCA attempt and delivered-dose rates decreased over postoperative time (RR 0.965 and 0.966 per hour, respectively; both P<0.001). Older age was associated with a lower delivered-dose rate (RR 0.905 per 10 years, 95% CI 0.829-0.987). Each 1-point higher current pain score was associated with more subsequent PCA attempts (RR 1.09, 95% CI 1.04-1.14) and delivered doses (RR 1.07, 95% CI 1.03-1.11). The oxycodone-analgesia association weakened over time [interaction P <0.001; odds ratios (Ors) per 10 ng/mL 1.16, 1.13, and 1.00 at 1, 4, and 24 h, respectively]. In active S-ketamine groups, including S-ketamine, norketamine, and 6-hydroxynorketamine concentrations left the pain-PCA association unchanged (RR 1.09 and 1.07) and preserved the time-dependent oxycodone association (ORs 1.30, 1.26, and 1.02). Conclusions: During PCA, drug exposure develops from patient-generated dosing histories while pain and recovery change. Current pain was associated with subsequent PCA activity, and the oxycodone-analgesia association was time-dependent.

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Event-related potential signatures of auditory predictive processing in first-episode psychosis: a passive pattern-based study

Munoz-Caracuel, M.; Munoz, V.; Angulo, B.; Ruiz-Martinez, F. J.; Perona-Garcelan, S.; Garrido, M. I.; Romero-Garcia, R.; Vazquez Morejon, A. J.; Crespo-Facorro, B.; Gomez, C. M.

2026-10-20 psychiatry and clinical psychology 10.64898/2026.10.19.26365874 medRxiv
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Background: Predictive-processing accounts propose altered prediction-error signaling in psychosis. However, event-related potential (ERP) findings in first-episode psychosis (FEP) are inconsistent and focused predominantly on mismatch negativity (MMN). Examining anticipatory and later post-stimulus ERP responses alongside MMN within a single passive paradigm may broaden the assessment of predictive processing in FEP. Methods: 34 participants with non-affective FEP and 34 healthy controls (HC) underwent EEG during a passive auditory pattern-based paradigm. Mean amplitudes of contingent negative variation (CNV), MMN, and post-imperative negative variation (PINV) were quantified at five frontocentral electrodes. Exploratory analyses examined N1 and P2 mean amplitudes. Mixed models tested group, electrode, and group-by- electrode effects adjusting for age, sex and years of education. Regressions examined ERP associations with psychotic-like experiences, neurocognition, and social cognition across groups, and with symptoms, functioning, and antipsychotic dose within FEP. Results: FEP participants reported more psychotic-like experiences and showed poorer global and social cognition than HC (all p-FDR [&le;] .042). Standardized adjusted FEP-HC differences at FCz were nonsignificant for CNV ({beta} = -0.46), MMN ({beta} = -0.30), and PINV ({beta} = -0.10; all p-FDR [&ge;] .265). Exploratory analyses identified lower P2 amplitude in FEP at FCz ({beta} = -0.73; p-FDR = .019) and in the averaged frontocentral ROI ({beta} = -0.64; p-FDR = .027). No ERP-phenotype associations survived FDR correction. Conclusions: Despite phenotypic differences between FEP and HC, no significant differences emerged in the primary ERP indices of predictive processing examined. The exploratory P2 finding and its possible relationship to predictive processing and frontal dysfunction in FEP warrant further investigation.