Thalamic stereoelectroencephalography for neuromodulation target selection: Proof of concept and review of literature of pulvinar direct electrical stimulation.

In patients with drug-resistant epilepsy (DRE) who are not candidates for resective surgery, various thalamic nuclei, including the anterior, centromedian, and pulvinar nuclei, have been extensively investigated as targets for neuromodulation. However, the therapeutic effects of different targets for thalamic neuromodulation on various types of epilepsy are not well understood. Here, we present a 32-year-old patient with multifocal bilateral temporoparieto-occipital epilepsy and bilateral malformations of cortical development (MCDs) who underwent bilateral stereoelectroencephalographic (SEEG) recordings of the aforementioned three thalamic nuclei bilaterally. The change in the rate of interictal epileptiform discharges (IEDs) from baseline were compared in temporal, central, parietal, and occipital regions after direct electrical stimulation (DES) of each thalamic nucleus. A significant decrease in the rate of IEDs (33% from baseline) in the posterior quadrant regions was noted in the ipsilateral as well as contralateral hemisphere following DES of the pulvinar. A scoping review was also performed to better understand the current standpoint of pulvinar thalamic stimulation in the treatment of DRE. The therapeutic effect of neuromodulation can differ among thalamic nuclei targets and epileptogenic zones (EZs). In patients with multifocal EZs with extensive MCDs, personalized thalamic targeting could be achieved through DES with thalamic SEEG electrodes.

Safety of Concomitant Cortical and Thalamic Stereoencephalography Explorations in Patients With Drug-Resistant Epilepsies.

BACKGROUND AND OBJECTIVES: Intracranial electrophysiology of thalamic nuclei has demonstrated involvement of thalamic areas in the propagation of seizures in focal drug-resistant epilepsy. Recent studies have argued that thalamus stereoencephalography (sEEG) may aid in understanding the epileptogenic zone and treatment options. However, the study of thalamic sEEG-associated hemorrhage incidence has not been investigated in a cohort study design. In this article, we present the largest retrospective cohort study of sEEG patients and compare hemorrhage rates between those with and without thalamic sEEG monitoring. METHODS: Retrospective chart review of clinical and epilepsy history, electrode implantation, rationale, and outcomes was performed for 76 patients (age 20-69 years) with drug-resistant epilepsy who underwent sEEG monitoring at our institution (2019-2022). A subset of 38% of patients (n = 30) underwent thalamic monitoring of the anterior thalamic nucleus (n = 14), pulvinar nucleus (n = 25), or both (n = 10). Planned perisylvian orthogonal sEEG trajectories were extended to 2- to 3-cm intraparenchymally access thalamic area(s).The decision to incorporate thalamic monitoring was made by the multidisciplinary epilepsy team. Statistical comparison of hemorrhage rate, type, and severity between patients with and without thalamic sEEG monitoring was made. RESULTS: Our approach for thalamic monitoring was not associated with local intraparenchymal hemorrhage of thalamic areas or found along extended cortical trajectories, and symptomatic hemorrhage rates were greater for patients with thalamic coverage (10% vs 0%, P = .056), although this was not found to be significant. Importantly, patients with perisylvian electrode trajectories, with or without thalamic coverage, did not experience a higher incidence of hemorrhage (P = .34). CONCLUSION: sEEG of the thalamus is a safe and valuable tool that can be used to interrogate the efficacy of thalamic neuromodulation for drug-resistant epilepsy. While patients with thalamic sEEG did have higher incidence of hemorrhage at any monitoring site, this finding was apparently not related to the method of perisylvian implantation and did not involve any trajectories targeting the thalamus.

Functional profile of perilesional gray matter in focal cortical dysplasia: an fMRI study.

Objectives: We aim to investigate the functional profiles of perilesional gray matter (GM) in epileptic patients with focal cortical dysplasia (FCD) and to correlate these profiles with FCD II subtypes, surgical outcomes, and different antiseizure medications (ASMs) treatment response patterns. Methods: Nine patients with drug-responsive epilepsy and 30 patients with drug-resistant epilepsy (11 were histologically confirmed FCD type IIa, 19 were FCD type IIb) were included. Individual-specific perilesional GM and contralateral homotopic GM layer masks were generated. These masks underwent a two-voxel (2 mm) dilation from the FCD lesion and contralateral homotopic region, resulting in 10 GM layers (20 mm). Layer 1, the innermost, progressed to Layer 10, the outermost. Amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) analyses were conducted to assess the functional characteristics of ipsilateral perilesional GM and contralateral homotopic GM. Results: Compared to the contralateral homotopic GM, a significant reduction of ALFF was detected at ipsilateral perilesional GM layer 1 to 6 in FCD type IIa (after Bonferroni correction p < 0.005, paired t-test), whereas a significant decrease was observed at ipsilateral perilesional GM layer 1 to 2 in FCD type IIb (after Bonferroni correction p < 0.005, paired t-test). Additionally, a significant decrease of the ReHo was detected at ipsilateral perilesional GM layer 1 compared to the CHRs in FCD type IIb. Notably, complete resection of functional perilesional GM alterations did not correlate with surgical outcomes. Compared to the contralateral homotopic GM, a decreased ALFF in the ipsilateral perilesional GM layer was detected in drug-responsive patients, whereas decreased ALFF in the ipsilateral perilesional GM layer 1-6 and decreased ReHo at ipsilateral perilesional GM layer 1 were observed in drug-resistant patients (after Bonferroni correction p < 0.005, paired t-test). Conclusion: Our findings indicate distinct functional profiles of perilesional GM based on FCD histological subtypes and ASMs' response patterns. Importantly, our study illustrates that the identified functional alterations in perilesional GM may not provide sufficient evidence to determine the epileptogenic boundary required for surgical resection.

Challenging Cortical Explorations in Difficult-to-Localize Seizures: The Rationale and Usefulness of Perisylvian Paralimbic Explorations With Orthogonal Stereoelectroencephalography Depth Electrodes.

BACKGROUND AND OBJECTIVE: Stereoelectroencephalography (SEEG) is an invasive monitoring method designed to define and localize the epileptogenic zone (EZ) and explore the putative network responsible for the electroclinical seizures using anatomo-functional-electroclinical correlations. When indicated by semiology in selected patients, exploration of both limbic and paralimbic (PL) regions is indispensable. However, the PL cortex is located in deep and highly vascularized areas in proximity to the anterior Sylvian fissure and middle cerebral artery branches. Thus, those explorations are considered surgically challenging because of the multilobar location and fear of hemorrhagic events. Here, we discuss and illustrate the rationale and SEEG methodology approach in usefulness of exploring the PL regions using standard orthogonal SEEG depth electrode trajectories with the Talariach reference system. METHODS: We retrospectively studied PL exploration from a cohort of 71 consecutive SEEG procedures from Nov 2019 to Nov 2022 and identified 31 patients who underwent PL trajectories. RESULTS: In 31 patients, there were 32 SEEG trajectories, and no major complications were observed. PL electrodes were consistently implanted in the C10/D10 coordinates of the Talariach reference coordinates. The most common confirmed EZ in our cohort was mesio-temporal (45%), followed by temporo-perisylvian regions (16%), ventromedial frontal (13%), and mesio-lateral temporal regions (13%). The PL contacts were involved in the EZ in 10 patients (32%). Of 31 patients, 25 underwent resective surgery, and 19 obtained Engel 1 outcome with a mean follow-up of 25 months (range 12-41 months) after surgery. CONCLUSION: The orthogonal perisylvian PL trajectories are feasible and useful in sampling multiple PL regions with single-electrode trajectories. In patients with perisylvian seizures, sampling PL structures may contribute to an improved understanding of seizure propagation and the optimal anatomic demarcation of the EZs in this surgically challenging region.

Validation of different predictive scoring scales in patients with new-onset epileptic seizures or epilepsy related to neuronal surface antibody-mediated autoimmune encephalitis.

OBJECTIVE: To validate the different predictive scoring scales in the Chinese population with new-onset epileptic seizures or epilepsy of unknown etiology related to neuronal surface antibody (Ab)-mediated autoimmune encephalitis (AE). METHODS: We retrospectively reviewed the charts of 174 consecutive patients from October 2018 to December 2022, whose serum and cerebrospinal fluid samples were tested for neuronal surface Abs. The antibody prevalence in epilepsy and encephalopathy (APE2), antibodies contributing to focal epilepsy signs and symptoms (ACES), "obvious" indications for neural antibody testing in epilepsy or seizures (ONES) checklist, and the combinations were used to validate the predictive models of neuronal surface Ab-mediated AE. RESULTS: A total of 139 patients with new-onset epileptic seizures or epilepsy of unknown etiology were enrolled. Abs were detected in 37 patients (26.6%). The APE2/ONES reflex score had the highest sensitivity (89.2%) and lowest specificity (41.7%). The ACES score had the lowest sensitivity (67.5%) and highest specificity (64.7%). Variations in the performance were observed in the different types of AE. 100% of patients with anti-γ-aminobutyric acid B-B receptor encephalitis were predicted by ONES, APE2/ONES reflex, and ACES/ONES reflex scores. Only 75% of patients with anti-N-methyl-D-aspartate receptor encephalitis were predicted by the APE2/ONES and ACES/ONES reflex scores. CONCLUSION: Our study was the first to validate various predictive scoring scales in the Chinese cohort of patients with new-onset epileptic seizures or epilepsy of unknown etiology related to neuronal surface Ab-mediated AE. Based upon clinical suspicion, more than one scoring scale should be performed to predict the chance of AE in those patients.

Stereoelectroencephalography-guided laser ablation in neocortical epilepsy: Electrophysiological correlations and outcome.

OBJECTIVE: We aimed to study the correlation between seizure outcomes in patients with drug-resistant epilepsy (DRE) who underwent laser interstitial thermal therapy (LITT) and stereoelectroencephalographic electrophysiologic patterns with respect to the extent of laser ablation. METHODS: We retrospectively analyzed 16 consecutive DRE patients who underwent LITT. A seizure onset zone (SOZ) was obtained from multidisciplinary patient management conferences and again was confirmed independently by two epileptologists based on conventional analysis. SOZs were retrospectively divided into localized, lobar and multilobar, and nonlocalized onset types. A posteriori-predicted epileptogenic zone (PEZ) was identified using the previously developed "EZ fingerprint" pipeline. The completeness of the SOZ and PEZ ablation was compared and correlated with the duration of seizure freedom (SF). RESULTS: Of 16 patients, 11 had an a posteriori-identified PEZ. Three patients underwent complete ablation of SOZ with curative intent, and the other 13 with palliative intent. Of three patients with complete ablation of the SOZ, two had concordant PEZ and SOZ and achieved 40- and 46-month SF without seizure recurrence. The remaining patient, without any PEZ identified, had seizure recurrence within 1 month. Six of 13 patients with partial ablation of the SOZ and PEZ achieved mean seizure freedom of 19.8 months (range = 1-44) with subsequent seizure recurrence. The remaining seven patients had partial ablation of the SOZ without the PEZ identified or ablation outside the PEZ with seizure recurrence within 1-2 months, except one patient who had 40-month seizure freedom after ablation of periventricular heterotopia. SIGNIFICANCE: Only complete ablation of the well-restricted SOZ concordant with the PEZ was associated with long-term SF, whereas partial ablation of the PEZ might lead to SF with eventual seizure recurrence. Failure to identify PEZ and ablation limited to the SOZ often led to 1-2 months of SF.

Trans-Interhemispheric Stereoelectroencephalography Depth Electrode Placement for Mesial Frontal Lobe Explorations in Medically Refractory Epilepsy: A Technical Note and Case Series.

BACKGROUND: Stereoelectroencephalography (SEEG) is an established and safe methodology for extra-operative invasive monitoring in patients with medical refractory epilepsy. SEEG has several advantages such as the ability to record deep cortical structures, mapping the epileptogenic zone in a three-dimensional manner, and analyze bihemispheric regions without the need for bilateral craniotomies. In patients with bilateral hemispheric hypotheses, especially the mesial surface of frontal lobes, bilateral lead placement is compulsory to further define and localize the epileptogenic zone. In this particular cohort of patients, bilateral monitoring may be accomplished from a single entry point using trans-interhemispheric placement of the electrodes. The use of trans-interhemispheric monitoring offers several advantages including sparing the need for additional leads. OBJECTIVE: To test the hypothesis that, given the lack of the falx as a limiting structure in the ventral and mesial frontal lobe regions, trans-interhemispheric SEEG placement is feasible and a potential benefit for the SEEG method. METHODS: We report on 6 patients who underwent bilateral monitoring using trans-interhemispheric SEEG lead placement and discuss the operative technique. RESULTS: Six patients underwent trans-interhemispheric monitoring, with a median of 3 leads per patient (19 total). Trajectory error was minimal (<0.3 mm), and operating room time was comparable with that in previous reports. All leads were placed without adverse events, mislocalization, electrode hemorrhages, or any other complications. All patients had successful localization of the epileptogenic zone. CONCLUSION: Trans-interhemispheric SEEG to monitor the mesial wall of frontal lobe regions is technically feasible. No adverse events were observed, suggesting a favorable safety profile.

Clinical significance of ictal magnetoencephalography in patients undergoing epilepsy surgery.

OBJECTIVE: The significance of ictal magnetoencephalography (MEG) is not well appreciated. We evaluated the relationships between ictal MEG, MRI, intracranial electroencephalography (ICEEG), surgery and postoperative seizure outcome. METHODS: A total of 45 patients (46 cases) with ictal MEG who underwent epilepsy surgery was included. We examined the localization of each modality, surgical resection area and seizure freedom after surgery. RESULTS: Twenty-one (45.7%) out of 46 cases were seizure-free at more than 6 months follow-up. Median duration of postoperative follow-up was 16.5 months. The patients in whom ictal, interictal single equivalent current dipole (SECD) and MRI lesion localization were completely included in the resection had a higher chance of being seizure-free significantly (p < 0.05). Concordance between ictal and interictal SECD localizations was significantly associated with seizure-freedom. Concordance between MRI lesion and ictal SECD, concordance between ictal ICEEG and ictal and interictal SECD, as well as concordance between ictal ICEEG and MRI lesion were significantly associated with seizure freedom. CONCLUSIONS: Ictal MEG can contribute useful information for delineating the resection area in epilepsy surgery. SIGNIFICANCE: Resection should include ictal, interictal SECDs and MRI lesion localization, when feasible. Concordant ictal and interictal SECDs on MEG can be a favorable predictor of seizure freedom.

Epileptic seizures in patients with anti-IgLON5 disease.

BACKGROUND: Anti-IgLON5 is a rare neurologic disease that can present with epileptic seizures. However, epileptic seizures have not been characterized and are underreported. We aimed to investigate the clinical characteristics and demographics of epileptic seizures in patients with anti-IgLON5 disease. METHODS: We reported a case of anti-IgLON5 disease presenting with epileptic seizures and presented a comprehensive literature review on epileptic seizures in patients with the anti-IgLON5 disease. We searched the Medline, Pubmed, and Web of Science databases using the following search algorithm: "IgLON5" or "anti-IgLON5" or "IgLON5 antibody" limited to publications in English. RESULTS: We identified 183 cases from 66 publications. In addition to our case, nine (4.9%) patients with anti-IgLON5 disease had reported epileptic seizures, either focal or generalized. Of those, epileptic seizures were one of the main reasons for neurology consultation in six (3.2%). Patients with epileptic seizures affected both sexes similarly and usually developed in middle age. In addition to epileptic seizures, a majority of patients had sleep disorders and cognitive impairment. The frequency of epileptic seizures was reduced with the treatment of immunotherapy and antiseizure medication. CONCLUSION: Anti-IgLON5 disease can present with epileptic seizures, and our study expands the clinical spectrum of the anti-IgLON5 disease.

Contributions of Magnetoencephalography to Understanding Mechanisms of Generalized Epilepsies: Blurring the Boundary Between Focal and Generalized Epilepsies?

According to the latest operational 2017 ILAE classification of epileptic seizures, the generalized epileptic seizure is still conceptualized as "originating at some point within and rapidly engaging, bilaterally distributed networks." In contrast, the focal epileptic seizure is defined as "originating within networks limited to one hemisphere." Hence, one of the main concepts of "generalized" and "focal" epilepsy comes from EEG descriptions before the era of source localization, and a presumed simultaneous bilateral onset and bi-synchrony of epileptiform discharges remains a hallmark for generalized seizures. Current literature on the pathophysiology of generalized epilepsy supports the concept of a cortical epileptogenic focus triggering rapidly generalized epileptic discharges involving intact corticothalamic and corticocortical networks, known as the cortical focus theory. Likewise, focal epilepsy with rich connectivity can give rise to generalized spike and wave discharges resulting from widespread bilateral synchronization. Therefore, making this key distinction between generalized and focal epilepsy may be challenging in some cases, and for the first time, a combined generalized and focal epilepsy is categorized in the 2017 ILAE classification. Nevertheless, treatment options, such as the choice of antiseizure medications or surgical treatment, are the reason behind the importance of accurate epilepsy classification. Over the past several decades, plentiful scientific research on the pathophysiology of generalized epilepsy has been conducted using non-invasive neuroimaging and postprocessing of the electromagnetic neural signal by measuring the spatiotemporal and interhemispheric latency of bi-synchronous or generalized epileptiform discharges as well as network analysis to identify diagnostic and prognostic biomarkers for accurate diagnosis of the two major types of epilepsy. Among all the advanced techniques, magnetoencephalography (MEG) and multiple other methods provide excellent temporal and spatial resolution, inherently suited to analyzing and visualizing the propagation of generalized EEG activities. This article aims to provide a comprehensive literature review of recent innovations in MEG methodology using source localization and network analysis techniques that contributed to the literature of idiopathic generalized epilepsy in terms of pathophysiology and clinical prognosis, thus further blurring the boundary between focal and generalized epilepsy.

Focal thalamocortical circuit abnormalities in sleep related epilepsy caused by focal cortical dysplasia type II.

Purpose To investigate the variations of the thalamocortical circuit between the focal cortical dysplasia (FCD) type II patients with sleep-related epilepsy (SRE) and those without SRE (non-SRE). Methods Patients with epilepsy who had histologically proven FCD type II were enrolled. Those without diffusion tensor image and 3-dimensional (3D) T1 MRI sequences were excluded. Thalamocortical structural connectivity to lesion and non-lesion regions was quantified using probabilistic tractography. Fractional anisotropy (FA) and mean diffusivity (MD) were computed. Results A total of 30 consecutive patients were included. Among them, 18 patients (60%) had SRE. Analysis of covariance showed that smaller lesion size was significantly associated with SRE (p=0.048). Compared to patients with non-SRE, patients with SRE showed a significant decrease in FA of thalamocortical projections to the lesion region (p=0.007). No difference was observed in the thalamocortical connectivity to the non-lesion region between patients with SRE and non-SRE. Among the patients with SRE, a significant decrease in FA of thalamocortical projections to the lesion region was noted compared with the contralateral homotopic non-lesion region (p=0.026). Conclusion The data provide evidence of disparity in thalamocortical projections to the lesion regions between SRE and non-SRE. This might indicate the underlying pathophysiology or neuroanatomical substrates of SRE related to the FCD type II.

Response to antiseizure medications in epileptic patients with malformation of cortical development.

BACKGROUND: Malformation of cortical development (MCD) is one of the most common causes of pharmacoresistant epilepsy. Improving the knowledge of antiseizure medications (ASMs) treatment response in epileptic patients with MCD is crucial for optimal treatment options, either pharmacological therapy or non-pharmacological intervention. AIM: To investigate the patterns of medical treatment outcome and the predictors for seizure freedom (SF) with ASM regimens in epilepsy caused by MCD. METHODS: The epileptic patients with MCD were consecutively enrolled from March 2013 to June 2019. SF was defined as no seizures for at least 12 months or three times the longest pretreatment inter-seizure interval, whichever was longer. Outcomes were classified into three patterns: pattern A: patients achieved SF at one point and remained so throughout follow-up; pattern B: patients' seizures fluctuated between periods of SF and relapse; pattern C: SF never attained. The terminal SF was defined if the patients remained SF at the last follow-up visit. RESULTS: A total of 164 epileptic patients with MCD were included. Pattern A was observed in 22, pattern B in 42, and pattern C in 100 patients. SF was ever achieved in 64 (pattern A and B) patients. Twenty-nine patients had terminal SF after a median follow-up time of 4.3 years. With continuing ASM treatment, seizure relapse risk was very low after a 5-year seizure-free period. The pretreatment seizure frequency was the only independent predictor for pattern A and seizure relapse. Sodium channel blockers monotherapy (33.8%) was more effective than levetiracetam (4.5%) in rendering SF in the initial ASM regimen. CONCLUSION: Medical treatment can be successful in a minority of epileptic patients with MCD, and pretreatment seizure frequency helps to predict the treatment outcome. An unequal efficacy of ASMs in epilepsy caused by MCD suggests etiological evaluation is vital in the management of focal epilepsy.

Update on the Neuroimaging and Electroencephalographic Biomarkers of Epileptogenesis: A Literature Review.

Epilepsy is one of the most common debilitating neurological disorders that lead to severe socio-cognitive dysfunction. While there are currently more than 30 antiseizure medications available for the treatment and prevention of seizures, none address the prevention of epileptogenesis that leading to the development of epilepsy following a potential brain insult. Hence, there is a growing need for the identification of accurate biomarkers of epileptogenesis that enable the prediction of epilepsy following a known brain insult. Although recent studies using various neuroimages and electroencephalography have found promising biomarkers of epileptogenesis, their utility needs to be further validated in larger clinical trials. In this literature review, we searched the Medline, Pubmed, and Embase databases using the following search algorithm: "epileptogenesis" and "biomarker" and "EEG" or "electroencephalography" or "neuroimaging" limited to publications in English. We presented a comprehensive overview of recent innovations in the role of neuroimaging and EEG in identifying reliable biomarkers of epileptogenesis.

Perilesional white matter integrity in drug-resistant epilepsy related to focal cortical dysplasia.

PURPOSE: We aimed to investigate the differences of white matter (WM) between the focal cortical dysplasia (FCD) patients with drug-resistant epilepsy and those with drug-responsive epilepsy. METHODS: Thirty epileptic patients with MRI-identified or histologically proven FCD were consecutively enrolled. Fractional anisotropy (FA) and mean diffusivity (MD) of the ipsilateral perilesional WM and contralateral homotopic WM layer masks were computed and corrected by the FA/MD of the corresponding hemispheric WM. The difference was evaluated using paired t-tests. The FA, MD and volumes of hemispheric WM and corpus callosum were also calculated. RESULTS: Patients with drug-resistant epilepsy showed significantly decreased FA and increased MD among ipsilateral perilesional WM layer 1 and 2, while patients with drug-responsive epilepsy showed decreased FA in only ipsilateral perilesional WM layer l, compared to remaining ipsilateral perilesional WM layers and contralateral layers 1 through 6. The integrity and volumes of the hemispheric WM and corpus callosum were similar between the two groups. CONCLUSION: We demonstrated that the WM microstructural alterations differed between epileptic patients with FCD according to their antiepileptic drug responses. More extensive perilesional WM abnormality is observed in patients with drug-resistant epilepsy related to FCD.

Neurovascular networks in epilepsy: Correlating ictal blood perfusion with intracranial electrophysiology.

Perfusion patterns observed in Subtraction Ictal SPECT Co-registered to MRI (SISCOM) assist in focus localization and surgical planning for patients with medically intractable focal epilepsy. While the localizing value of SISCOM has been widely investigated, its relationship to the underlying electrophysiology has not been extensively studied and is therefore not well understood. In the present study, we set to investigate this relationship in a cohort of 70 consecutive patients who underwent ictal and interictal SPECT studies and subsequent stereo-electroencephalography (SEEG) monitoring for localization of the epileptogenic focus and surgical intervention. Seizures recorded during SEEG evaluation (SEEG seizures) were matched to semiologically-similar seizures during the preoperative ictal SPECT evaluation (SPECT seizures) by comparing the semiological changes in the course of each seizure. The spectral changes of the ictal SEEG with respect to interictal ones over 7 traditional frequency bands (0.1 to 150Hz) were analyzed at each SEEG site. Neurovascular (SEEG/SPECT) relations were assessed by comparing the estimated spectral power density changes of the SEEG at each site with the perfusion changes (SISCOM z-scores) estimated from the acquired SISCOM map at that site. Across patients, a significant correlation (p<0.05) was observed between spectral changes during the SEEG seizure and SISCOM perfusion z-scores. Brain sites with high perfusion z-score exhibited higher increased SEEG power in theta to ripple frequency bands with concurrent suppression in delta and theta frequency bands compared to regions with lower perfusion z-score. The dynamics of the correlation of SISCOM perfusion and SEEG spectral power from ictal onset to seizure end and immediate postictal period were also derived. Forty-six (46) of the 70 patients underwent resective epilepsy surgery. SISCOM z-score and power increase in beta to ripple frequency bands were significantly higher in resected than non-resected sites in the patients who were seizure-free following surgery. This study provides for the first time concrete evidence that both hyper-perfusion and hypo-perfusion patterns observed in SISCOM maps have strong electrophysiological underpinnings, and that integration of the information from SISCOM and SEEG can shed light on the location and dynamics of the underlying epileptic brain networks, and thus advance our anatomo-electro-clinical understanding and approaches to targeted diagnostic and therapeutic interventions.

Rare but life-threatening aspiration pneumonia related to initiation of clobazam therapy.

Clobazam (CLB) was approved in October 2011 by the United States FDA as an adjunctive therapy for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients older than the age of 2. Due to its unique chemical design and selective binding to the alpha-2 GABA-receptor, CLB has a decreased tendency for sedation compared to other benzodiazepines. A recent literature review shows that sedation, hypersalivation (drooling), and behavior changes are the most common side effects of CLB. It has also been shown that a patient's level of consciousness is indirectly related to the risk of aspiration. Hypersalivation is too is a significant predisposing factor for aspiration. In this report, we present three adult patients with epilepsy who had aspiration pneumonia during treatment with CLB. We would like to raise awareness of increased drooling and somnolence in patients with predisposing factors for aspiration such as treatment with CLB and emphasize vigilance in this regard.

The feasibility and value of extraoperative and adjuvant intraoperative stereoelectroencephalography in rolandic and perirolandic epilepsies.

OBJECTIVE: The objective of this study was to illustrate the feasibility and value of extra- and intraoperative stereoelectroencephalography (SEEG) in patients who underwent resection in rolandic and perirolandic regions. METHODS: The authors retrospectively reviewed all consecutive patients with at least 1 year of postoperative follow-up who underwent extra- and intraoperative SEEG monitoring between January 2015 and January 2017. RESULTS: Four patients with pharmacoresistant rolandic and perirolandic focal epilepsy were identified, who underwent conventional extraoperative invasive SEEG evaluations followed by adjuvant intraoperative SEEG recordings. Conventional extraoperative SEEG evaluations demonstrated ictal and interictal epileptiform activities involving eloquent rolandic and perirolandic cortical areas in all patients. Following extraoperative monitoring, patients underwent preplanned staged resections guided by simultaneous and continuous adjuvant intraoperative SEEG monitoring. Resections, guided by electrode contacts of interest in 3D boundaries, were performed while continuous real-time electrographic data from SEEG recordings were obtained. Staged approaches of resections were performed until there was intraoperative resolution of synchronous rolandic/perirolandic cortex epileptic activities. All patients in the cohort achieved complete seizure freedom (Engel class IA) during the follow-up period ranging from 18 to 50 months. Resection resulted in minimal neurological deficit; 3 patients experienced transient, distal plantar flexion weakness (mild foot drop). CONCLUSIONS: The seizure and functional outcome results of this highly preselected group of patients testifies to the feasibility and demonstrates the value of the combined benefits of both intra- and extraoperative SEEG recordings when resecting the rolandic and perirolandic areas. The novel hybrid method allows a more refined and precise identification of the epileptogenic zone. Consequently, tailored resections can be performed to minimize morbidity as well as to achieve adequate seizure control.

Epilepsy imitator: tongue biting caused by sleep-related facio-mandibular myoclonus.

PURPOSE: Sleep-related facio-mandibular myoclonus(SRFMM) is a rare and under-recognized stereotyped parasomnia. SRFMM can present with isolated tongue biting, which can be misdiagnosed as epilepsy and sleep bruxism. We aimed to investigate the clinical characteristics and demographics of patients with SRFMM. METHODS: We reported a case of SRFMM and presented a literature review on SRFMM. We searched the Medline, Pubmed, and Web of Science database using the following search algorithm: "facio-mandibular myoclonus" or "masticatory myoclonus" or "tongue biting" limited to publications in English. RESULTS: In total, nine studies were included. In addition to our case, a total of 17 patients were analyzed. SRFMM was found to be more prevalent in males, with a mean age of 48.2 years old. Most of the patients experienced tongue biting during non-rapid eye movement sleep. A majority of the patients were misdiagnosed with epilepsy or sleep bruxism. The simultaneous video EEG and surface EMG was beneficial in confirming the diagnosis of SRFMM. In some patients, clonazepam was reported to ameliorate the tongue biting event. CONCLUSION: This study represents a comprehensive summary of SRFMM, which has unique clinical features. Extra-caution may be needed in these cases as it may puzzle neurologists in terms of management.