Functional changes in the pediatric brain following neural injuries attest to remarkable feats of plasticity. Investigations of the neurobiological mechanisms that underlie this plasticity have largely focused on activation in the penumbra of the lesion or in contralesional, homotopic regions. Here, we adopt a whole-brain approach to evaluate the plasticity of the cortex in patients with large unilateral cortical resections due to drug-resistant childhood epilepsy. We compared the functional connectivity (FC) in patients\' preserved hemisphere with the corresponding hemisphere of matched controls as they viewed and listened to a movie excerpt in a functional magnetic resonance imaging (fMRI) scanner. The preserved hemisphere was segmented into 180 and 200 parcels using two different anatomical atlases. We calculated all pairwise multivariate statistical dependencies between parcels, or parcel edges, and between 22 and 7 larger-scale functional networks, or network edges, aggregated from the smaller parcel edges. Both the left and right hemisphere-preserved patient groups had widespread reductions in FC relative to matched controls, particularly for within-network edges. A case series analysis further uncovered subclusters of patients with distinctive edgewise changes relative to controls, illustrating individual postoperative connectivity profiles. The large-scale differences in networks of the preserved hemisphere potentially reflect plasticity in the service of maintained and/or retained cognitive function.

CONCLUSIONS: Although the role of sleep in modulating epileptic activity is well established, many epileptologists overlook the significance of considering sleep during presurgical epilepsy evaluations in cases of drug-resistant epilepsy. Here, we conducted a comprehensive literature review from January 2000 to May 2023 using the PubMed electronic database and compiled evidence to highlight the need to revise the current clinical approach. All articles were assessed for eligibility by two independent reviewers. Our aim was to shed light on the clinical value of incorporating sleep monitoring into presurgical evaluations with stereo-electroencephalography. We present the latest developments on the important bidirectional interactions between sleep and various forms of epileptic activity observed in stereo-electroencephalography recordings. Specifically, epileptic activity is modulated by different sleep stages, peaking in non-rapid eye movement sleep, while being suppressed in rapid eye movement sleep. However, this modulation can vary across different brain regions, underlining the need to account for sleep to accurately pinpoint the epileptogenic zone during presurgical assessments. Finally, we offer practical solutions, such as automated sleep scoring algorithms using stereo-electroencephalography data alone, to seamlessly integrate sleep monitoring into routine clinical practice. It is hoped that this review will provide clinicians with a readily accessible roadmap to the latest evidence concerning the clinical utility of sleep monitoring in the context of stereo-electroencephalography and aid the development of therapeutic and diagnostic strategies to improve patient surgical outcomes.

CONCLUSIONS: Stereoelectroencephalography is an established, hypothesis-driven method for investigating refractory epilepsy. There are special considerations and some limitations that apply to children who undergo stereoelectroencephalography. A key principle in stereoelectroencephalography is taking an individualized approach to investigating refractory epilepsy. A crucial factor for success in a personalized pediatric epilepsy surgery is understanding some of the fundamental and unique aspects of it, including, but not limited to, diverse etiology, epilepsy syndromes, maturation, and age-related characteristics as well as neural plasticity. Such features are reflected in the ontogeny of semiology and electrophysiology. In addition, special considerations are taken into account during cortical stimulation in children. Stereoelectroencephalography can guide a tailored surgical intervention where it is sufficient to render the patient seizure-free but it also lessens collateral damage with a minimum or no functional deficit. Epilepsy surgery outcomes remain stagnant despite advances in noninvasive testing modalities. A stereoelectroencephalography \"way of thinking\" and guided mentorship may influence outcomes positively.

OBJECTIVE: Stereoelectroencephalography (SEEG) is widely performed on individuals with medically refractory epilepsy for whom invasive seizure localization is desired. Despite increasing adoption in many centers across the world, no standardized electrode naming convention exists, generating confusion among both clinical and research teams.
METHODS: We have developed a novel nomenclature, named the Standardized Electrode Nomenclature for SEEG Applications system. Concise, unique, informative, and unambiguous labels provide information about entry point, deep targets, and relationships between electrodes. Inter-rater agreement was evaluated by comparing original electrode names from 10 randomly sampled cases (including 136 electrodes) with those prospectively assigned by four additional blinded raters.
RESULTS: The Standardized Electrode Nomenclature for SEEG Application system was prospectively implemented in 40 consecutive patients undergoing SEEG monitoring at our institution, creating unique electrode names in all cases, and facilitating implantation design, SEEG recording and mapping interpretation, and treatment planning among neurosurgeons, neurologists, and neurophysiologists. The inter-rater percent agreement for electrode names among two neurosurgeons, two epilepsy neurologists, and one neurosurgical fellow was 97.5%.
CONCLUSIONS: This standardized naming convention, Standardized Electrode Nomenclature for SEEG Application, provides a simple, concise, reproducible, and informative method for specifying the target(s) and relative position of each SEEG electrode in each patient, allowing for successful sharing of information in both the clinical and research settings. General adoption of this nomenclature could pave the way for improved communication and collaboration between institutions.

OBJECTIVE: Stereotactic EEG (SEEG) is being increasingly used in the intracranial evaluation of refractory epilepsy in the United States. A 2022 survey of SEEG practices among National Association of Epilepsy Centers tertiary referral (NAEC level IV) centers found largely similar practices across institutions. However, a few significant differences were noted in technical and patient care practice, and in the level of SEEG background training. In the year since publication, we review the identified challenges facing SEEG practice and suggest specific corrective action.
CONCLUSIONS: Stereotactic EEG has rapidly become the principal method for intracranial EEG monitoring in epilepsy surgery centers in the United States. The rate of adoption of SEEG is currently higher than the growth of invasive monitoring overall. Most report similar indications for SEEG, although significant variability exists in personnel expertise and technical and patient care practice. Consensus statements, guidelines, and review of postgraduate training curricula are urgently needed to benchmark SEEG practice and develop appropriate skillsets in the next generation of practitioners in the United States.

A central role for neuroinflammation in epileptogenesis has recently been suggested by several investigations. This systematic review explores the role of inflammatory mediators in epileptogenesis, its association with seizure severity, and its correlation with drug-resistant epilepsy (DRE). The study analysed articles published in JCR journals from 2019 to 2024. The search strategy comprised the MESH, free terms of \"Neuroinflammation\", and selective searches for the following single biomarkers that had previously been selected from the relevant literature: \"High mobility group box 1/HMGB1\", \"Toll-Like-Receptor 4/TLR-4\", \"Interleukin-1/IL-1\", \"Interleukin-6/IL-6\", \"Transforming growth factor beta/TGF-β\", and \"Tumour necrosis factor-alpha/TNF-α\". These queries were all combined with the MESH terms \"Epileptogenesis\" and \"Epilepsy\". We found 243 articles related to epileptogenesis and neuroinflammation, with 356 articles from selective searches by biomarker type. After eliminating duplicates, 324 articles were evaluated, with 272 excluded and 55 evaluated by the authors. A total of 21 articles were included in the qualitative evaluation, including 18 case-control studies, 2 case series, and 1 prospective study. As conclusion, this systematic review provides acceptable support for five biomarkers, including TNF-α and some of its soluble receptors (sTNFr2), HMGB1, TLR-4, CCL2 and IL-33. Certain receptors, cytokines, and chemokines are examples of neuroinflammation-related biomarkers that may be crucial for the early diagnosis of refractory epilepsy or may be connected to the control of epileptic seizures. Their value will be better defined by future studies.

Germline variants in the phosphatidylinositol glycan class A (PIGA) gene, which is involved in glycosylphosphatidylinositol (GPI) biosynthesis, cause multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2) with X-linked recessive inheritance. The available literature has described a pattern of almost 100% X-chromosome inactivation in mothers carrying PIGA variants. Here, we report a male infant with MCAHS2 caused by a novel PIGA variant inherited from his mother, who has a non-skewed pattern of X inactivation. Phenotypic evidence supporting the pathogenicity of the variant was obtained by flow-cytometry tests. We propose that the assessment in neutrophils of the expression of GPI-anchored proteins (GPI-APs), especially CD16, should be considered in cases with variants of unknown significance with random X-inactivation in carrier mothers in order to clarify the pathogenic role of PIGA or other gene variants linked to the synthesis of GPI-APs.

About 40 % of new-onset epilepsy is drug refractory. If epilepsy surgery is not an option or fails, vagal nerve stimulation (VNS) can be considered. VNS efficacy is reported as more than 50 % seizure frequency reduction in 50-56 % of patients. Features in the newer models offer additional treatment optimization possibilities. Side effects include hoarseness, cough, and dyspnoea. Caution is advised for patients with sleep apnoea or lung disease. VNS has specific limitations concerning MRI. This review presents an overview of VNS treatment in Denmark and discusses future challenges.

OBJECTIVE: Despite the benefits of anterior temporal lobectomy with amygdalohippocampectomy (ATL+AH) in patients with temporal lobe epilepsy (TLE), approximately up to 5% may have hemiparesis as its postoperative complication. This paper aims to describe which step/s of the ATL with AH have the highest probability of having greatest decrease in MEP amplitude.
METHODS: This study utilized a cross-sectional design of obtaining data from TLE patients who underwent ATL+AH with TcMEP monitoring. Each of the following steps were evaluated for reduction in MEP amplitude: 1) Dural Opening, 2) Opening the inferior horn, 2) Vertical temporal lobe resection 3) Subpial dissection, 4) Temporal lobe stem resection, 5) Lateral temporal lobe resection, 6) Hippocampal Resection, 7) Amygdala Resection, 8) Uncus resection and 9) Dural Closure.
RESULTS: Nineteen patients were included in the study. Based on Friedman Test, one or more steps had significantly different average MEP amplitude reductions (Friedman=50.7, p=0.0001). When compared to baseline (100%, cut off p=0.005), hippocampal resection (z=-3.81, p<0.0001), T1 subpial dissection (z=-3.2, p=0.0010), uncus resection (z=-3.48, p=0.0002), temporal stem resection (z=-3.26, p=0.001), lateral temporal lobe resection (z=-3.13, p=0.002) and amygdalectomy (-z=-3.37, p=0.0005) were significantly lower. Of these, hippocampal resection, uncus resection and amygdalectomy were deemed highly significant.
CONCLUSIONS: MEP amplitude tends to decrease during amygdala, hippocampal and uncal resection because of surgical manipulation of choroidal arteries which can potentially cause hemiparesis so careful attention should be paid to changes in MEP during these steps.

Stereo-electroencephalography (SEEG) is the gold standard to delineate surgical targets in focal drug-resistant epilepsy. SEEG uses electrodes placed directly into the brain to identify the seizure-onset zone (SOZ). However, its major constraint is limited brain coverage, potentially leading to misidentification of the \'true\' SOZ. Here, we propose a framework to assess adequate SEEG sampling by coupling epileptic biomarkers with their spatial distribution and measuring the system\'s response to a perturbation of this coupling. We demonstrate that the system\'s response is strongest in well-sampled patients when virtually removing the measured SOZ. We then introduce the spatial perturbation map, a tool that enables qualitative assessment of the implantation coverage. Probability modelling reveals a higher likelihood of well-implanted SOZs in seizure-free patients or non-seizure free patients with incomplete SOZ resections, compared to non-seizure-free patients with complete resections. This highlights the framework\'s value in sparing patients from unsuccessful surgeries resulting from poor SEEG coverage.