Clinical Neurophysiology

Scalp electroencephalography (EEG) may reveal bilateral independent or unclear (BI/U) ictal onset patterns in patients with focal drug-resistant epilepsy, presenting a challenge to surgical decision-making. The utility of stereo-electroencephalography (SEEG) in this subgroup, particularly the probability of delineating a single seizure onset zone (SOZ) that would permit curative resection, remains poorly understood. This study examined whether BI/U scalp EEG findings could predict SEEG outcomes ...

IntroductionOne third of children with epilepsy develop drug-resistant epilepsy (DRE). Epilepsy surgery is the treatment for DRE, and selecting the surgical target typically requires recording spontaneous seizures during intracranial monitoring with stereoelectroencephalography (sEEG). In adults, induced seizures have been shown to help define surgical targets and are associated with superior surgical outcomes. No published studies focus on the safety, tolerability, and yield of electrical stimu...

RationaleFocal cortical dysplasia (FCD) is associated with increased seizure-risk during sleep, yet the underlying mechanisms remain unclear. Previous studies report increased oscillatory patterns during sleep in focal epilepsy patients with FCD. We investigated whether fast oscillations (FOs, 14-250 Hz) within the epileptic focus significantly change during sleep compared to wake, hypothesizing that analyzing broad frequency bands provides more comprehensive information than narrow bands alone....

Music engages sensory, motor, cognitive, and emotional systems, making it a powerful model for studying experience-dependent neuroplasticity. Although research on music-related brain changes is expanding, integration of structural, functional, and cerebrovascular findings remains limited, and effects on higher-order cognitive processes remain unclear. This systematic review will synthesize evidence on music-induced cortical adaptations, including structural changes (e.g., gray and white matter a...

Functional seizures (FS) are common, and distinguishing FS from epileptic seizures (ES) can be challenging despite video telemetry (VT), and the pathophysiology is not well-understood. The heartbeat evoked potential (HEP) reflects the central processing of cardiac signals and bodily attention. Our group previously demonstrated that HEP amplitude may differentiate FS from ES. Here, we sought to replicate these HEP findings in an independent sample and test if HEP can characterise semiological sub...

The neuronal circuit disturbances that drive interictal and ictal epileptiform discharges remains elusive. Using a combination of extraoperative macro- and micro-electrode interictal recordings in six presurgical patients during non-rapid eye movement (REM) sleep we found that, exclusively in the seizure onset zone, fast ripples (FR; 200-600Hz), but not ripples (80-200 Hz), frequently occur <300 msec before an interictal intracranial EEG (iEEG) spike with a probability exceeding chance (bootstra...

BackgroundAnimal studies have demonstrated that sleep is crucial for physiological synaptic pruning, and that this pruning is primarily regulated at a local, cellular level. We hypothesized that local alterations in sleep homeostatic regulation may constitute an interictal biomarker of the seizure onset zone (SOZ), and that sleep homeostasis abnormalities may also be present in areas beyond the SOZ, proportional to their secondary recruitment during seizures. MethodsOvernight intracranial EEG (...

BackgroundIntractable or drug-resistant epilepsy (DRE) is a condition where seizures cannot be adequately controlled through antiepileptic medications. In the setting where resective surgery is ineffective, neuromodulation therapy, or vagus nerve stimulation (VNS), is a safe and approved solution. Nonetheless, the efficacy has yet to be clear. We conducted this systematic review and meta-analysis to evaluate the clinical benefit and response of VNS on seizure frequency reduction in intractable e...

ObjectivesBoth Magnetoencephalography (MEG) and stereo-electroencephalography (SEEG) are used in presurgical epilepsy assessment, with contrasting advantages and limitations. It is not known whether combined recording using both modalities can maintain inherent advantages whilst overcoming these limitations e.g. recording from deep brain sources whilst preserving good spatial resolution. Methods24 adult and paediatric patients who underwent SEEG study for pre-surgical evaluation of focal drug-r...

The goal of this study was to determine resting state fMRI effective connectivity (RSEC) capacity, agnostic of epileptogenic events, in distinguishing seizure onset zones (SOZ) from propagation zones (pZ). Consecutive patients (2.1-18.2 years old), with epilepsy and hypothalamic hamartoma, pre-operative rs-fMRI-directed surgery, post-operative imaging, and Engel class I outcomes were collected. Cross-spectral dynamic causal modelling (DCM) was used to estimate RSEC between the ablated rs-fMRI-SO...

1.ObjectivesImplanted cervical vagus nerve stimulation (VNS) is used to treat refractory epilepsy, depression, stroke sequelae and rheumatoid arthritis. The therapeutic efficacy of VNS is limited by stimulation- induced side effects, including hoarseness, coughing, and voice alteration. We quantified VNS-evoked laryngeal muscle activation (EMG; indicating side effects) and changes in heart rate (HR; proxy for activation of therapeutic fibers) in participants undergoing VNS implant surgery. Meth...

IntroductionThere is a lack of treatment options for individuals with drug resistant idiopathic generalized epilepsy (IGE). Small, limited case series suggest that centromedian thalamus deep brain stimulation (CM-DBS) may be an effective treatment option. The optimal CM-DBS target for IGE is underexamined. Here, we present a retrospective analysis of CM-DBS targeting and efficacy for five patients with drug-resistant IGE. MethodsThis single-center case series study included all patients with dr...

Temporal Lobe Epilepsy (TLE) is considered to be the most common form of epilepsy, and it has been seen that most patients are refractory to antiepileptic drugs. A strong association of this ailment has been established with psychiatric comorbidities, primarily mood and anxiety disorders. The side of epileptogenic may contribute to depressive and anxiety symptoms; thus, in this study, we performed a systematic review to evaluate the prevalence of depression in TLE in surgical patients. The liter...

ImportanceStereoelectroencephalography (SEEG) is more frequently being used in the pre-surgical evaluation of children with focal epilepsy. Many factors affect the rate of identification of a definable seizure onset zone (SOZ) and subsequent seizure freedom following SEEG-guided epilepsy surgery, which have not been systematically examined in multi-centre studies. ObjectivesDetermine the rates and factors that predict (a) whether or not a definable putative SOZ was identified on SEEG and (b) su...

ObjectiveThere is an unmet need to develop seizure detection algorithms from brain regions outside the epileptogenic cortex. The study aimed to demonstrate the feasibility of classifying seizures and interictal states from local field potentials (LFPs) recorded from the human thalamus-a subcortical region remote to the epileptogenic cortex. We tested the hypothesis that spectral and entropy-based features extracted from LFPs recorded from the anterior nucleus of the thalamus (ANT) can distinguis...

Timely and accurate diagnosis of Psychogenic Non-Epileptic Seizures (PNES) is crucial. Aside from potential diagnostic delays, patients with PNES often undergo unnecessary pharmacological or invasive treatments. Presently, effective bedside tools for distinguishing PNES from epileptic seizures (ES) remain elusive, and the gold standard diagnosis relies primarily on patient history and prolonged video EEG monitoring. In this study, we developed a simple clinical tool - the Mean Dynamic Index (MD...

BackgroundFragile X Syndrome (FXS) is a rare, neurodevelopmental disorder caused by a mutation to the Fragile X messenger ribonucleoprotein 1 (Fmr1) gene and characterized by sensory processing abnormalities and sensitivities, including neural auditory oscillatory disruptions and reduced neural entrainment to chirp stimuli. The present study aims to evaluate the 40 Hz auditory steady state response (ASSR) in FXS to evaluate stimulus representation maintenance in FXS. MethodsAdolescents and adul...

OBJECTIVESNoninvasive brain stimulation continues to grow as an effective, low-risk way of improving the symptoms of brain conditions. Transcranial direct current stimulation (tDCS) is particularly well-tolerated, with benefits including low cost and potential portability. Nevertheless, continued study of perceptual and cognitive side effects is warranted, given the complexity of functional brain organization. This paper describes the results of a brief battery of tablet-based tasks used in a re...

BackgroundStuttering is a speech disorder that affects more than 70 million people worldwide, limiting their ability to communicate and socialize. In recent decades, several studies have demonstrated a link between stuttering and a deficit of {beta} electroencephalographic (EEG) power. Aim and MethodsThis study investigates the efficacy of a novel auditory neuro modulating technology that leverages euphonic music tracks with broad-spectrum binaural beats to induce selective EEG spectral power c...

Epileptic nystagmus (EN) is a subtle seizure semiology, most commonly seen in seizures originating in the posterior cortical regions. EN is broadly categorized into type I and type II. Type I EN consists of contralateral repetitive saccadic eye movements alternating with post-saccadic slow drifts with an overall contralateral deviation. Type II EN is characterized by ipsilateral slow drift alternating with contralateral corrective saccades. In this article, we report a method to perform oculogra...