Clinical Neurophysiology

IntroductionSleep spindles are electroencephalographic elements characteristic of non-rapid eye movement sleep generated by thalamo-cortical interactions. Spindles have been linked to some of the cognitive benefits afforded by sleep and high spindle activity is associated with increased arousal threshold (deeper sleep). Here, we demonstrate that targeting the thalamus with Transcranial Electrical Stimulation with Temporal Interference (TES-TI) can enhance spindle activity. Methods24 participant...

About half of patients who undergo epilepsy surgery for drug-resistant epilepsy have seizure recurrence, supporting the need for approaches that more accurately identify the epileptogenic zone, defined as the brain areas whose removal causes cessation of seizures. Altered network connectivity has emerged as a candidate biomarker of the epileptogenic zone, but how connectivity is altered in the epileptogenic zone remains uncertain, with prior studies reporting inconsistent results. We hypothesize...

Epilepsy diagnosis and treatment monitoring are hindered by the episodic, heterogeneous expression of seizures and by normal-appearing scalp EEG in many patients. We previously described paroxysmal slow-wave events (PSWEs)--brief epochs of broadband slowing detectable on EEG. Here, using intracerebral and epidural recordings in a paraoxon rat model of temporal lobe epilepsy, we show that PSWEs arise preferentially in temporo-frontal networks, co-occur with global slowing, and increase during bot...

BackgroundPrevious studies have suggested that social cognition abilities do not change following surgical treatment for temporal lobe epilepsy (TLE). However, the follow-up period in these studies was no longer than 14 months. The present study investigated the long-term effects of epilepsy surgery on social cognition, extending the follow-up period to an average of 12 years (range 7-15 years). MethodsWe assessed 24 patients with drug-resistant TLE (mean age = 37 {+/-} 11 years; 14 males) who ...

Even mild SARS-CoV-2 infection can lead to post-COVID syndrome, 70% of such patients have post-COVID fatigue (pCF). Many physiological abnormalities observed in pCF could be explained by reduced vagus nerve activity. The vagus nerve, central to metabolic and inflammatory homeostasis, can be activated non-invasively by transcutaneous auricular vagus nerve stimulation (taVNS). Can taVNS improve symptoms in pCF? Data were collected from a randomized study including 114 individuals with pCF. They c...

In this study, we subject the conventional physiological interpretation of independent component analysis (ICA) applied to EEG, the small-patch model, to systematic falsification, and propose an alternative large-patch model. The small-patch model assumes that ICs correspond to localized cortical patches with < 1 cm{superscript 2}. However, this assumption has remained unvalidated. The small-patch model predicts that approximately 70% of sources are localized within sulci up to 15 mm deep, with ...

Type 1 narcolepsy (NT1), a disorder caused by the loss of hypocretin/orexin transmission, is characterized by daytime sleepiness and symptoms where Rapid Eye Movement (REM) sleep, a state normally occurring from middle to late in the night, can intermingle with wakefulness. This results in cataplexy and sleep paralysis, episodes of muscle paralysis when awake, or in the generation of dream-like hallucinations and vivid dreaming, periods of visual imagery or sensory experiences that occur while a...

ObjectiveDetecting epileptic seizures in real-world environments remains challenging, as electroencephalography (EEG) is often impractical in chronic ambulatory monitoring. Heart rate and accelerometry, measurable from wearable devices, provide a less obtrusive alternative. Although some studies explored multimodal wearable-based seizure detection, few have been validated on long-term ambulatory datasets reflecting real-world variability. This study investigated the added value of accelerometry ...

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) can reduce seizures in patients with drug-resistant epilepsy. However, seizure freedom is rare, and there is no early response biomarker to predict long-term seizure suppression. To evaluate a short-term biomarker of therapeutic response to DBS, we studied 18-minute trials of ANT stimulation in patients with drug-resistant epilepsy undergoing intracranial electroencephalography. We compared a standard high-frequency perio...

Neuromodulation targeting thalamic nuclei is increasingly used to treat drug-resistant focal epilepsy, yet human intracranial EEG studies describing how thalamocortical interactions evolve across seizures remain limited. We aimed to define frequency-specific thalamocortical network dynamics from seizure onset to termination, compare thalamocortical and cortico-cortical network activation, and test whether thalamic EEG features can classify seizure state to inform closed-loop or adaptive thalamic...

ObjectiveWe developed and validated a detection-guided artifact removal framework for clinical electroencephalography (EEG). It corrects only the contaminated segments and preserves artifact-free data. ApproachThe framework employs convolutional neural network (CNN) detectors trained on the Temple University Hospital (TUH) Artifact Corpus of 150 recordings from 105 patients. For eye movement artifacts (20 second windows), it uses independent component analysis (ICA) and canonical correlation an...

BackgroundEpilepsy affects around 50 million people worldwide and remains a major diagnostic challenge, particularly in resource-limited settings. Electroencephalography (EEG) is essential for diagnosis but relies heavily on expert interpretation, often limited by workforce shortages. Artificial intelligence (AI) offers a promising solution to automate EEG interpretation, enhance diagnostic accuracy, and improving diagnostic efficiency. MethodsThis retrospective diagnostic validation study was ...

ImportanceTracking and predicting seizure frequency in patients with epilepsy is important for prognostication and therapy management. Interictal spikes have been proposed as a biomarker of seizure burden, but their association with seizure frequency has not been well quantified across epilepsy subtypes. ObjectiveTo measure the association between spike rate and seizure frequency and how this varies by epilepsy subtype. Design, Setting and ParticipantsWe studied 3,614 consecutive routine outpa...

BackgroundAssessing consciousness at the bedside in the neurocritical care unit is complicated by sedation and other treatment effects. While EEG is commonly used, it offers a limited view of the neurovascular unit. We evaluated whether combining cerebral blood flow (CBF) features with EEG improves binary classification of consciousness in patients with severe brain injury. MethodsWe retrospectively analyzed 35 adults who underwent multimodal neuromonitoring. Signals were segmented into 30-min ...

BackgroundInvasive intracranial pressure (ICP) monitoring is the reference standard for detecting intracranial hypertension but requires neurosurgical expertise and carries procedural risks. Non-invasive methods with high negative predictive value (NPV) could serve as screening tools to rule out dangerous ICP elevations and guide decisions about invasive monitoring. We conducted a pilot evaluation to assess whether a smartphone-based, lighting-invariant quantitative pupillometry platform achieve...

BackgroundDifferentiating between motor functional dissociative seizures (FDS) and motor epileptic seizures (ES) is a common diagnostic challenge, requiring video electroencephalography (vEEG) as gold standard. However, vEEG requires specialized technicians and clinical experts to set up and interpret and oftentimes fails to capture events. We sought to develop machine-learning (ML) tools to carry out this diagnostic task independently of vEEG or human review by a neurologist. MethodsIn this re...

BackgroundEpilepsy affects approximately 50 million individuals worldwide, with nearly one-third developing drug-resistant epilepsy (DRE). The centromedian nucleus of the thalamus (CM) and the brainstem are integral components of seizure-modulating networks and represent promising targets for neuromodulation. This study aimed to map structural connectivity between CM and specific brainstem nuclei using probabilistic tractography and to evaluate whether connectivity patterns correlate with seizur...

Sensory organization at the spinal segment level is commonly inferred from dermatomal maps that assume a fixed correspondence between cutaneous regions and spinal segments. However, based on the complexities of spinal neuroanatomy and neurophysiology, the distribution of sensory signals within the cord may be broader and less segment-specific than dermatomal maps suggest, leaving the segment-level localization of sensory-evoked activity in humans uncertain. Spinal cord functional magnetic resona...

BackgroundChildren with epilepsy are rarely included in clinical drug trials, delaying approval and introduction of new antiseizure medications (ASMs). To circumvent this we used population-wide register data to study retention, an intergrated meassure of effect and tolerability, of newer ASMs used in children in Sweden; brivaracetam, cenobamate, lacosamide, and perampanel. MethodsAll cases of incident epilepsy and subsequent ASM treatment 2007-2021 were identified using national registers. Ret...

Effective connectivity of the human insula, mainly assessed at rest using cortico-cortical evoked potentials (CCEPs), is not yet fully characterized at high-resolution. Here, we significantly extend prior CCEP studies of the insula by leveraging an extensive multicenter CCEP database and fine-grained anatomical atlases of the insula. We analyzed CCEP datasets from 897 patients with refractory focal epilepsy (459 females, age: 26{+/-}14 years) explored by stereo electroencephalography and with a...