The use of simultaneous stereo-electroencephalography and magnetoencephalography in localising the epileptogenic focus in refractory focal epilepsy

Abstract Both magnetoencephalography and stereo-electroencephalography are used in presurgical epilepsy assessment, with contrasting advantages and limitations. It is not known whether simultaneous stereo-electroencephalography-magnetoencephalography recording confers an advantage over both individual modalities, in particular whether magnetoencephalography can provide spatial context to epileptiform activity seen on stereo-electroencephalography. 24 adult and paediatric patients who underwent stereo-electroencephalography study for pre-surgical evaluation of drug-resistant focal epilepsy, were recorded using simultaneous stereo-electroencephalography-magnetoencephalography, of which 14 had abnormal interictal activity during recording. The 14 patients were divided into two groups; those with detected superficial (n = 7) and deep (n = 7) brain interictal activity. Interictal spikes were independently identified in stereo-electroencephalography and magnetoencephalography. Magnetoencephalography dipoles were derived using a distributed inverse method. There was no significant difference between stereo-electroencephalography and magnetoencephalography in detecting superficial spikes (p = 0.135) and stereo-electroencephalography was significantly better at detecting deep spikes (p = 0.002). Mean distance across patients between stereo-electroencephalography channel with highest average spike amplitude and magnetoencephalography dipole was 20.7+/- 4.4 mm. for superficial sources, and 17.8 +/- 3.7 mm. for deep sources, even though for some of the latter (n = 4) no magnetoencephalography spikes were detected and magnetoencephalography dipole was fitted to a stereo-electroencephalography interictal activity triggered average. Removal of magnetoencephalography dipole was associated with 1 year seizure freedom in 6/7 patients with superficial source, and 5/6 patients with deep source. Although stereo-electroencephalography has greater sensitivity in identifying interictal activity from deeper sources, a magnetoencephalography source can be localised using stereo-electroencephalography information, thereby providing useful whole brain context to stereo-electroencephalography and potential role in epilepsy surgery planning.In the largest case series to date, Vivekananda et al. perform simultaneous magnetoencephalography and stereo-electroencephalography in refractory focal epilepsy patients. They demonstrate that for deep brain epileptogenic foci, magnetoencephalography dipoles could be derived from average stereo-electroencephalography data, thereby overcoming a traditional limitation of magnetoencephalography of reduced sensitivity for deep sources.

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The use of simultaneous SEEG and MEG in localising seizure onset zone

10.1101/2020.01.31.20019505 ◽

2020 ◽

Author(s):

Umesh Vivekananda ◽

Chunyan Cao ◽

Wei Liu ◽

Jing Zhang ◽

Fergus Rugg-Gunn ◽

...

Keyword(s):

Potential Role ◽

Seizure Freedom ◽

Good Spatial Resolution ◽

Seizure Onset Zone ◽

Significant Difference ◽

Surgical Evaluation ◽

Deep Source ◽

Drug Resistant Epilepsy ◽

Deep Sources ◽

Deep Brain

AbstractObjectivesBoth 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-resistant epilepsy, were recorded using simultaneous SEEG-MEG, of which 14 had abnormal interictal activity during recording. The 14 patients were divided into two groups; those with presumed superficial (n=7) and deep (n=7) brain interictal activity.ResultsThere was no significant difference between SEEG and MEG in identifying superficial spikes (p=0.135) and SEEG was significantly better at detecting deep spikes (p=0.002). Mean distance across patients between SEEG channel with highest average spike amplitude and MEG dipole was 26.6+/-3.6 mm for superficial sources, and 21.5 +/- 2.04 mm for deep sources, even though for some of the latter (n=4) no MEG spikes were detected and MEG dipole was fitted to a SEEG interictal activity triggered average. Removal of MEG dipole was associated with 1 year seizure freedom in 5/6 patients with superficial source, and 4/6 patients with deep source.ConclusionsAlthough SEEG has greater sensitivity in identifying interictal activity from deeper sources, an MEG source can be localised using SEEG information, thereby providing useful whole brain context to SEEG and potential role in epilepsy surgery planning.

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Operative Technique and Lessons Learned From Surgical Implantation of the NeuroPace Responsive Neurostimulation® System in 57 Consecutive Patients

Operative Neurosurgery ◽

10.1093/ons/opaa300 ◽

2020 ◽

Author(s):

Max O Krucoff ◽

Thomas A Wozny ◽

Anthony T Lee ◽

Vikram R Rao ◽

Edward F Chang

Keyword(s):

Operative Technique ◽

Focal Epilepsy ◽

Intraoperative Imaging ◽

Case Series ◽

Lessons Learned ◽

Seizure Freedom ◽

Operative Techniques ◽

Surgical Positioning ◽

Intracerebral Hemorrhages

Abstract BACKGROUND The Responsive Neurostimulation (RNS)® System (NeuroPace, Inc) is an implantable device designed to improve seizure control in patients with medically refractory focal epilepsy. Because it is relatively new, surgical pearls and operative techniques optimized from experience beyond a small case series have yet to be described. OBJECTIVE To provide a detailed description of our operative technique and surgical pearls learned from implantation of the RNS System in 57 patients at our institution. We describe our method for frame-based placement of amygdalo-hippocampal depth leads, open implantation of cortical strip leads, and open installation of the neurostimulator. METHODS We outline considerations for patient selection, preoperative planning, surgical positioning, incision planning, stereotactic depth lead implantation, cortical strip lead implantation, craniotomy for neurostimulator implantation, device testing, closure, and intraoperative imaging. RESULTS The median reduction in clinical seizure frequency was 60% (standard deviation 63.1) with 27% of patients achieving seizure freedom at last follow up (median 23.1 mo). No infections, intracerebral hemorrhages, or lead migrations were encountered. Two patients experienced lead fractures, and four lead exchanges have been performed. CONCLUSION The techniques set forth here will help with the safe and efficient implantation of these new devices.

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Epilepsy surgery

Practical Neurology ◽

10.1136/practneurol-2019-002192 ◽

2019 ◽

pp. practneurol-2019-002192 ◽

Cited By ~ 1

Author(s):

Fergus Rugg-Gunn ◽

Anna Miserocchi ◽

Andrew McEvoy

Keyword(s):

Epilepsy Surgery ◽

Focal Epilepsy ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Nuclear Medicine Imaging ◽

Co Morbidity ◽

Surgical Evaluation ◽

Clonic Seizures ◽

Eeg Recordings ◽

Electroencephalogram Eeg

Epilepsy surgery offers the chance of seizure remission for the 30%–40% of patients with focal epilepsy whose seizures continue despite anti-epileptic medications. Epilepsy surgery encompasses curative resective procedures, palliative techniques such as corpus callosotomy and implantation of stimulation devices. Pre-surgical evaluation aims to identify the epileptogenic zone and to prevent post-operative neurological and cognitive deficits. This entails optimal imaging, prolonged video-electroencephalogram (EEG) recordings, and neuropsychological and psychiatric assessments; some patients may then require nuclear medicine imaging and intracranial EEG recording. The best outcomes are in those with an electro-clinically concordant structural lesion on MRI (60%–70% seizure freedom). Lower rates of seizure freedom are expected in people with extra-temporal lobe foci, focal-to-bilateral tonic-clonic seizures, normal structural imaging, psychiatric co-morbidity and learning disability. Nevertheless, surgery for epilepsy is under-used and should be considered for all patients with refractory focal epilepsy in whom two or three anti-epileptic medications have been ineffective.

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Imaging the Extent and Location of Spatiotemporally Distributed Epileptiform Sources from MEG Measurements

10.1101/2021.11.09.467915 ◽

2021 ◽

Author(s):

Xiyuan Jiang ◽

Shuai Ye ◽

Abbas Sohrabpour ◽

Anto Bagic ◽

Bin He

Keyword(s):

Focal Epilepsy ◽

Real Data ◽

Drug Resistant ◽

Interictal Spikes ◽

Source Imaging ◽

Non Invasive ◽

Eeg Source Imaging ◽

Surgical Evaluation ◽

Extended Sources ◽

Drug Resistant Epilepsy

Non-invasive MEG/EEG source imaging provides valuable information about the epileptogenic brain areas which can be used to aid presurgical planning in focal epilepsy patients suffering from drug-resistant seizures. However, the source extent estimation for electrophysiological source imaging remains to be a challenge and is usually largely dependent on subjective choice. Our recently developed algorithm, fast spatiotemporal iteratively reweighted edge sparsity minimization (FAST-IRES) strategy, has been shown to objectively estimate extended sources from EEG recording, while it has not been applied to MEG recordings. In this work, through extensive numerical experiments and real data analysis in a group of focal drug-resistant epilepsy patients interictal spikes, we demonstrated the ability of FAST-IRES algorithm to image the location and extent of underlying epilepsy sources from MEG measurements. Our results indicate the merits of FAST-IRES in imaging the location and extent of epilepsy sources for pre-surgical evaluation from MEG measurements.

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Sequential motor task (Luria's Fist-Edge-Palm Test) in children with benign focal epilepsy of childhood with centrotemporal spikes

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20130043 ◽

2013 ◽

Vol 71 (6) ◽

pp. 380-384 ◽

Cited By ~ 2

Author(s):

Carmen Silvia Molleis Galego Miziara ◽

Maria Luiza Giraldes de Manreza ◽

Leticia Mansur ◽

Umbertina Conti Reed ◽

Carlos Alberto Buchpiguel

Keyword(s):

School Performance ◽

Performance Test ◽

Single Photon ◽

Focal Epilepsy ◽

Epileptiform Activity ◽

Photon Emission ◽

Control Group ◽

Emission Computed Tomography ◽

Functional Changes ◽

Significant Difference

This study evaluated the sequential motor manual actions in children with benign focal epilepsy of childhood with centrotemporal spikes (BECTS) and compares the results with matched control group, through the application of Luria's fist-edge-palm test. The children with BECTS underwent interictal single photon emission computed tomography (SPECT) and School Performance Test (SPT). Significant difference occurred between the study and control groups for manual motor action through three equal and three different movements. Children with lower school performance had higher error rate in the imitation of hand gestures. Another factor significantly associated with the failure was the abnormality in SPECT. Children with BECTS showed abnormalities in the test that evaluated manual motor programming/planning. This study may suggest that the functional changes related to epileptiform activity in rolandic region interfere with the executive function in children with BECTS.

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Functional Connectivity of the Anterior Nucleus of the Thalamus in Pediatric Focal Epilepsy

Frontiers in Neurology ◽

10.3389/fneur.2021.670881 ◽

2021 ◽

Vol 12 ◽

Author(s):

Rory J. Piper ◽

Chayanin Tangwiriyasakul ◽

Elhum A. Shamshiri ◽

Maria Centeno ◽

Xiaosong He ◽

...

Keyword(s):

Functional Connectivity ◽

Focal Epilepsy ◽

Epileptiform Activity ◽

Epileptogenic Zone ◽

Healthy Children ◽

Anterior Nucleus ◽

Epileptiform Discharges ◽

Significant Difference ◽

Before And After ◽

Drug Resistant Epilepsy

Objective: Whilst stimulation of the anterior nucleus of the thalamus has shown efficacy for reducing seizure frequency in adults, alterations in thalamic connectivity have not been explored in children. We tested the hypotheses that (a) the anterior thalamus has increased functional connectivity in children with focal epilepsy, and (b) this alteration in the connectome is a persistent effect of the disease rather than due to transient epileptiform activity.Methods: Data from 35 children (7–18 years) with focal, drug-resistant epilepsy and 20 healthy children (7–17 years) were analyzed. All subjects underwent functional magnetic resonance imaging (fMRI) whilst resting and were simultaneously monitored with scalp electroencephalography (EEG). The fMRI timeseries were extracted for each Automated Anatomical Labeling brain region and thalamic subregion. Graph theory metrics [degree (DC) and eigenvector (EC) centrality] were used to summarize the connectivity profile of the ipsilateral thalamus, and its thalamic parcellations. The effect of interictal epileptiform discharges (IEDs) captured on EEG was used to determine their effect on DC and EC.Results: DC was significantly higher in the anterior nucleus (p = 0.04) of the thalamus ipsilateral to the epileptogenic zone in children with epilepsy compared to controls. On exploratory analyses, we similarly found a higher DC in the lateral dorsal nucleus (p = 0.02), but not any other thalamic subregion. No differences in EC measures were found between patients and controls. We did not find any significant difference in DC or EC in any thalamic subregion when comparing the results of children with epilepsy before, and after the removal of the effects of IEDs.Conclusions: Our data suggest that the anterior and lateral dorsal nuclei of the thalamus are more highly functionally connected in children with poorly controlled focal epilepsy. We did not detect a convincing change in thalamic connectivity caused by transient epileptiform activity, suggesting that it represents a persistent alteration to network dynamics.

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Criteria positive and criteria negative anaphylaxis, with a focus on undifferentiated somatoform idiopathic anaphylaxis: A review and case series

Allergy and Asthma Proceedings ◽

10.2500/aap.2020.41.200076 ◽

2020 ◽

Vol 41 (6) ◽

pp. 436-441 ◽

Cited By ~ 1

Author(s):

Daniel A. Rosloff ◽

Kunal Patel ◽

Paul J. Feustel ◽

Jocelyn Celestin

Keyword(s):

Diagnostic Criteria ◽

Statistical Significance ◽

Case Series ◽

Poor Response ◽

Response To Treatment ◽

Fisher Exact Test ◽

Subjective Symptoms ◽

Significant Difference ◽

Physical Findings ◽

Idiopathic Anaphylaxis

Background: Undifferentiated somatoform (US) idiopathic anaphylaxis (IA) is considered a psychogenic disorder characterized by a lack of observable physical findings and poor response to treatment. Although failure to diagnose true anaphylaxis can have disastrous consequences, identification of US-IA is crucial to limit unnecessary expenses and use of health care resources. Objective: To better define the presentation and understand the potential relationship between US-IA and underlying psychiatric comorbidities. Methods: We retrospectively reviewed 110 visits by 107 patients to our institution for evaluation and management of anaphylaxis over a 1-year period. The patients were classified as having either criteria positive (CP) or criteria negative (CN) anaphylaxis based on whether they met Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium criteria for the clinical diagnosis of anaphylaxis. Patient characteristics, including objective and subjective signs and symptoms, and the presence of psychiatric diagnoses were collected and analyzed. Statistical significance was assessed by using the Fisher exact test. A literature review of US-IA and other psychogenic forms of anaphylaxis was performed. Results: Patients with CP anaphylaxis were more likely to present with hypotension, wheezing, urticaria, and vomiting than were patients with CN anaphylaxis. The patients with CN anaphylaxis were more likely to present with subjective symptoms of sensory throat tightness or swelling compared with patients with CP anaphylaxis. No significant difference was detected in the prevalence of psychiatric conditions between the two groups. Conclusion: Patients who met previously established diagnostic criteria for anaphylaxis were more likely to present with objective physical findings than those who did not meet criteria for true anaphylaxis. CN patients who presented for treatment of anaphylaxis were more likely to present with subjective symptoms. Formal diagnostic criteria should be used by clinicians when evaluating patients with suspected anaphylaxis.

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Introduction of intraoperative neuromonitoring does not necessarily improve overall long-term outcome in elective aneurysm clipping

Journal of Neurosurgery ◽

10.3171/2018.12.jns182177 ◽

2020 ◽

Vol 132 (4) ◽

pp. 1188-1196 ◽

Cited By ~ 2

Author(s):

Tobias Greve ◽

Veit M. Stoecklein ◽

Franziska Dorn ◽

Sophia Laskowski ◽

Niklas Thon ◽

...

Keyword(s):

Evoked Potentials ◽

Predictive Value ◽

Neurological Outcome ◽

Positive Impact ◽

Case Series ◽

Intraoperative Neuromonitoring ◽

Neurosurgical Procedures ◽

Long Term Outcome ◽

Unruptured Intracranial Aneurysms ◽

Significant Difference

OBJECTIVEIntraoperative neuromonitoring (IOM), particularly of somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs), evolved as standard of care in a variety of neurosurgical procedures. Case series report a positive impact of IOM for elective microsurgical clipping of unruptured intracranial aneurysms (ECUIA), whereas systematic evaluation of its predictive value is lacking. Therefore, the authors analyzed the neurological outcome of patients undergoing ECUIA before and after IOM introduction to this procedure.METHODSThe dates of inclusion in the study were 2007–2014. In this period, ECUIA procedures before (n = 136, NIOM-group; 2007–2010) and after introduction of IOM (n = 138, IOM-group; 2011–2014) were included. The cutoff value for SSEP/MEP abnormality was chosen as an amplitude reduction ≥ 50%. SSEP/MEP changes were correlated with neurological outcome. IOM-undetectable deficits (bulbar, vision, ataxia) were not included in risk stratification.RESULTSThere was no significant difference in sex distribution, follow-up period, subarachnoid hemorrhage risk factors, aneurysm diameter, complexity, and location. Age was higher in the IOM-group (57 vs 54 years, p = 0.012). In the IOM group, there were 18 new postoperative deficits (13.0%, 5.8% permanent), 9 hemisyndromes, 2 comas, 4 bulbar symptoms, and 3 visual deficits. In the NIOM group there were 18 new deficits (13.2%; 7.3% permanent, including 7 hemisyndromes). The groups did not significantly differ in the number or nature of postoperative deficits, nor in their recovery rate. In the IOM group, SSEPs and MEPs were available in 99% of cases. Significant changes were noted in 18 cases, 4 of which exhibited postoperative hemisyndrome, and 1 suffered from prolonged comatose state (5 true-positive cases). Twelve patients showed no new detectable deficits (false positives), however 2 of these cases showed asymptomatic infarction. Five patients with new hemisyndrome and 1 comatose patient did not show significant SSEP/MEP alterations (false negatives). Overall sensitivity of SSEP/MEP monitoring was 45.5%, specificity 89.8%, positive predictive value 27.8%, and negative predictive value 95.0%.CONCLUSIONSThe assumed positive impact of introducing SSEP/MEP monitoring on overall neurological outcome in ECUIA did not reach significance. This study suggests that from a medicolegal point of view, IOM is not stringently required in all neurovascular procedures. However, future studies should carefully address high-risk patients with complex procedures who might benefit more clearly from IOM than others.

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Prediction accuracy of standard and total keratometry by swept-source optical biometer for multifocal intraocular lens power calculation

Scientific Reports ◽

10.1038/s41598-021-84238-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hun Lee ◽

Jae Lim Chung ◽

Young Jun Kim ◽

Jae Yong Kim ◽

Hungwon Tchah

Keyword(s):

Cataract Surgery ◽

Case Series ◽

Intraocular Lenses ◽

Power Calculation ◽

Neutral Position ◽

Swept Source ◽

Refractive Outcomes ◽

Case Series Study ◽

Significant Difference ◽

Optical Biometer

AbstractWe aimed to compare the refractive outcomes of cataract surgery with diffractive multifocal intraocular lenses (IOLs) using standard keratometry (K) and total keratometry (TK). In this retrospective observational case series study, a total of 302 patients who underwent cataract surgery with multifocal IOL implantation were included. Predicted refractive outcomes were calculated based on the current standard formulas and a new formula developed for TK using K and TK, which were obtained from a swept-source optical biometer. At 2-month postoperatively, median absolute prediction errors (MedAEs) and proportion of eyes within ± 0.50 diopters (D) of predicted postoperative spherical equivalent (SE) refraction were analyzed. There was no significant difference between MedAEs or proportion of eyes within ± 0.50D of predicted refraction from K and TK in each formula. In TFNT00 and 839MP IOL cases, there was no difference between MedAEs from K and TK using any formula. In 829MP IOL cases, MedAE from TK was significantly larger than that from K in Barrett Universal II/Barrett TK Universal II (P = 0.033). In 677MY IOL cases, MedAE from TK was significantly larger than that from K in Haigis (P = 0.020) and Holladay 2 (P = 0.006) formulas. In the subgroup analysis for IOL, there was no difference between the proportion of eyes within ± 0.50 D of predicted refraction from K and TK using any formula. TFNT00 and 839MP IOLs were favorable with TK, with 677MY IOL with K and 829MP IOL being in a neutral position, which necessitates the study that investigates the accuracy of the new TK technology.

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Combining Microfractures, Autologous Bone Graft, and Autologous Matrix-Induced Chondrogenesis for the Treatment of Juvenile Osteochondral Talar Lesions

Foot & Ankle International ◽

10.1177/1071100716687367 ◽

2017 ◽

Vol 38 (5) ◽

pp. 485-495 ◽

Cited By ~ 17

Author(s):

Riccardo D’Ambrosi ◽

Camilla Maccario ◽

Chiara Ursino ◽

Nicola Serra ◽

Federico Giuseppe Usuelli

Keyword(s):

Bone Graft ◽

Repeated Measures ◽

Osteochondral Lesion ◽

Young Patients ◽

Case Series ◽

Autologous Bone Graft ◽

Lesion Size ◽

Level Of Evidence ◽

Significant Difference ◽

Autologous Bone

Background: The purpose of this study was to evaluate the clinical and radiologic outcomes of patients younger than 20 years, treated with the arthroscopic-talus autologous matrix-induced chondrogenesis (AT-AMIC) technique and autologous bone graft for osteochondral lesion of the talus (OLT). Methods: Eleven patients under 20 years (range 13.3-20.0) underwent the AT-AMIC procedure and autologous bone graft for OLTs. Patients were evaluated preoperatively (T0) and at 6 (T1), 12 (T2), and 24 (T3) months postoperatively, using the American Orthopaedic Foot & Ankle Society Ankle and Hindfoot (AOFAS) score, the visual analog scale and the SF-12 respectively in its Mental and Physical Component Scores. Radiologic assessment included computed tomographic (CT) scan, magnetic resonance imaging (MRI) and intraoperative measurement of the lesion. A multivariate statistical analysis was performed. Results: Mean lesion size measured during surgery was 1.1 cm3 ± 0.5 cm3. We found a significant difference in clinical and radiologic parameters with analysis of variance for repeated measures ( P < .001). All clinical scores significantly improved ( P < .05) from T0 to T3. Lesion area significantly reduced from 119.1 ± 29.1 mm2 preoperatively to 77.9 ± 15.8 mm2 ( P < .05) at final follow-up as assessed by CT, and from 132.2 ± 31.3 mm2 to 85.3 ± 14.5 mm2 ( P < .05) as assessed by MRI. Moreover, we noted an important correlation between intraoperative size of the lesion and body mass index (BMI) ( P = .011). Conclusions: The technique can be considered safe and effective with early good results in young patients. Moreover, we demonstrated a significant correlation between BMI and lesion size and a significant impact of OLTs on quality of life. Level of Evidence: Level IV, retrospective case series.

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