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1.
Epilepsia ; 64(12): 3155-3159, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37728519

RESUMEN

One of the major challenges of modern epileptology is the underutilization of epilepsy surgery for treatment of patients with focal, medication resistant epilepsy (MRE). Aggravating this distressing failure to deliver optimum care to these patients is the underuse of proven localizing tools, such as magnetoencephalography (MEG), a clinically validated, non-invasive, neurophysiological method used to directly measure and localize brain activity. A sizable mass of published evidence indicates that MEG can improve identification of surgical candidates and guide pre-surgical planning, increasing the yield of SEEG and improving operative outcomes. However, despite at least 10 common, evidence supported, clinical scenarios in MRE patients where MEG can offer non-redundant information and improve the pre-surgical evaluation, it is regularly used by only a minority of USA epilepsy centers. The current state of the art in MEG sensors employs SQUIDs, which require cooling with liquid helium to achieve superconductivity. This sensor technology has undergone significant generational improvement since whole head MEG scanners were introduced around in 1990s, but still has limitations. Further advances in sensor technology which may make ME G more easily accessible and affordable have been eagerly awaited, and development of new techniques should be encouraged. Of late, optically pumped magnetometers (OPMs) have received considerable attention, even prompting some potential acquisitions of new MEG systems to be put on hold, based on a hope that OPMs will usher in a new generation of MEG equipment and procedures. The development of any new clinical test used to guide intracranial EEG monitoring and/or surgical planning must address several specific issues. The goal of this commentary is to recognize the current state of OPM technology and to suggest a framework for it to advance in the clinical realm where it can eventually be deemed clinically valuable to physicians and patients. The American Clinical MEG Society (ACMEGS) strongly supports more advanced and less expensive technology and looks forward to continuing work with researchers to develop new sensors and clinical devices which will improve the experience and outcome for patients, and perhaps extend the role of MEG. However, currently, there are no OPM devices ready for practical clinical use. Based on the engineering obstacles and the clinical tradeoffs to be resolved, the assessment of experts suggests that there will most likely be another decade relying solely on "frozen SQUIDs" in the clinical MEG field.


Asunto(s)
Epilepsia , Magnetoencefalografía , Humanos , Magnetoencefalografía/métodos , Encéfalo/cirugía , Encéfalo/fisiología , Electrocorticografía , Epilepsia/diagnóstico , Epilepsia/cirugía
2.
J Policy Model ; 45(1): 90-102, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36532102

RESUMEN

Many countries have imposed a set of non-pharmaceutical health policy interventions in an effort to slow the spread of the COVID-19 pandemic. The objective of this paper is to examine the effects of the interventions, drawing on evidence from the OECD countries. A special feature here is the mechanism that underlies the impact of the containment policies. To this end, a causal mediation analysis decomposing the total effect into a direct and an indirect effect is conducted. The key finding is a dual cause-effect channel. On the one hand, there is a direct effect of the non-pharmaceutical interventions on the various health variables. Beyond this, a quantitatively dominant indirect impact of non-pharmaceutical interventions operating via voluntary changes in social distancing is shown.

3.
J Policy Model ; 44(2): 450-473, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35370327

RESUMEN

On 3 June 2020, the German government announced a EUR 130 billion fiscal stimulus package to stimulate market demand and jumpstart the economy in the wake of the COVID-19 pandemic lockdown in the spring of 2020. The most prominent measure of this package is an unconventional fiscal policy in the form of a temporary VAT rates cut for six months, from 1 July to 31 December 2020. Employing a dynamic stochastic general equilibrium (DSGE) framework, we study the efficiency of the VAT tax rates cut for ameliorating the consequences of the pandemic recession. The simulation of the calibrated DSGE model yields a tax policy-induced real GDP increase of about 0.3% points for 2020.

4.
Econ Model ; 93: 465-473, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32904582

RESUMEN

The People's Bank of China (PBoC) has implemented numerous measures to cushion the impacts of the COVID-19 health crisis on the Chinese economy. Since the current monetary policy framework features a multi-instrument mix of liquidity tools and pricing signals, we employ a dynamic-factor modelling approach to derive a composite indicator of China's monetary policy stance. Our quantitative assessment shows that the PBoC's policy response to the outbreak of the COVID-19 pandemic has been swift and decisive. Specifically, our estimates reveal that the PBoC has implemented novel policy measures to ensure that commercial banks maintain liquidity access and credit provision during the COVID-19 crisis.

5.
Epidemiology ; 30(1): 154-159, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30299405

RESUMEN

BACKGROUND: The 2003 revision of the US Standard Certificate of Live Birth (birth certificate) and Pregnancy Risk Assessment Monitoring System (PRAMS) are important for maternal weight research and surveillance. We examined quality of prepregnancy body mass index (BMI), gestational weight gain, and component variables from these sources. METHODS: Data are from a PRAMS data quality improvement study among a subset of New York City and Vermont respondents in 2009. We calculated mean differences comparing prepregnancy BMI data from the birth certificate and PRAMS (n = 734), and gestational weight gain data from the birth certificate (n = 678) to the medical record, considered the gold standard. We compared BMI categories (underweight, normal weight, overweight, obese) and gestational weight gain categories (below, within, above recommendations), classified by different sources, using percent agreement and the simple κ statistic. RESULTS: For most maternal weight variables, mean differences between the birth certificate and PRAMS compared with the medical record were less than 1 kg. Compared with the medical record, the birth certificate classified similar proportions into prepregnancy BMI categories (agreement = 89%, κ = 0.83); PRAMS slightly underestimated overweight and obesity (agreement = 84%, κ = 0.73). Compared with the medical record, the birth certificate overestimated gestational weight gain below recommendations and underestimated weight gain within recommendations (agreement = 81%, κ = 0.69). Agreement varied by maternal and pregnancy-related characteristics. CONCLUSIONS: Classification of prepregnancy BMI and gestational weight gain from the birth certificate or PRAMS was mostly similar to the medical record but varied by maternal and pregnancy-related characteristics. Efforts to understand how misclassification influences epidemiologic associations are needed.


Asunto(s)
Estatura , Peso Corporal , Exactitud de los Datos , Monitoreo Epidemiológico , Ganancia de Peso Gestacional , Registros Médicos/normas , Resultado del Embarazo/epidemiología , Adulto , Certificado de Nacimiento , Índice de Masa Corporal , Femenino , Humanos , Recién Nacido , Ciudad de Nueva York , Embarazo , Medición de Riesgo , Vermont/epidemiología
6.
Matern Child Health J ; 19(9): 1916-24, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25676044

RESUMEN

Maternal smoking is captured on the 2003 US Standard Birth Certificate based on self-reported tobacco use before and during pregnancy collected on post-delivery maternal worksheets. Study objectives were to compare smoking reported on the birth certificate to maternal worksheets and prenatal and hospital medical records. The authors analyzed a sample of New York City (NYC) and Vermont women (n = 1,037) with a live birth from January to August 2009 whose responses to the Pregnancy Risk Assessment Monitoring System survey were linked with birth certificates and abstracted medical records and maternal worksheets. We calculated smoking prevalence and agreement (kappa) between sources overall and by maternal and hospital characteristics. Smoking before and during pregnancy was 13.7 and 10.4% using birth certificates, 15.2 and 10.7% using maternal worksheets, 18.1 and 14.1% using medical records, and 20.5 and 15.0% using either maternal worksheets or medical records. Birth certificates had "almost perfect" agreement with maternal worksheets for smoking before and during pregnancy (κ = 0.92 and 0.89) and "substantial" agreement with medical records (κ = 0.70 and 0.74), with variation by education, insurance, and parity. Smoking information on NYC and Vermont birth certificates closely agreed with maternal worksheets but was underestimated compared with medical records, with variation by select maternal characteristics. Opportunities exist to improve birth certificate smoking data, such as reducing the stigma of smoking, and improving the collection, transcription, and source of information.


Asunto(s)
Registros Médicos/estadística & datos numéricos , Atención Prenatal/estadística & datos numéricos , Fumar/epidemiología , Adolescente , Adulto , Femenino , Humanos , Ciudad de Nueva York/epidemiología , Embarazo , Autoinforme , Fumar/psicología , Vermont/epidemiología , Estadísticas Vitales
7.
Matern Child Health J ; 18(10): 2489-98, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24770954

RESUMEN

To assess the validity of self-reported maternal and infant health indicators reported by mothers an average of 4 months after delivery. Three validity measures-sensitivity, specificity and positive predictive value (PPV)-were calculated for pregnancy history, pregnancy complications, health care utilization, and infant health indicators self-reported on the Pregnancy Risk Assessment Monitoring System (PRAMS) questionnaire by a representative sample of mothers delivering live births in New York City (NYC) (n = 603) and Vermont (n = 664) in 2009. Data abstracted from hospital records served as gold standards. All data were weighted to be representative of women delivering live births in NYC or Vermont during the study period. Most PRAMS indicators had >90 % specificity. Indicators with >90 % sensitivity and PPV for both sites included prior live birth, any diabetes, and Medicaid insurance at delivery, and for Vermont only, infant admission to the NICU and breastfeeding in the hospital. Indicators with poor sensitivity and PPV (<70 %) for both sites (i.e., NYC and Vermont) included placenta previa and/or placental abruption, urinary tract infection or kidney infection, and for NYC only, preterm labor, prior low-birth-weight birth, and prior preterm birth. For Vermont only, receipt of an HIV test during pregnancy had poor sensitivity and PPV. Mothers accurately reported information on prior live births and Medicaid insurance at delivery; however, mothers' recall of certain pregnancy complications and pregnancy history was poor. These findings could be used to prioritize data collection of indicators with high validity.


Asunto(s)
Lactancia Materna/estadística & datos numéricos , Indicadores de Salud , Nacimiento Vivo/epidemiología , Complicaciones del Embarazo/epidemiología , Atención Prenatal/estadística & datos numéricos , Adulto , Parto Obstétrico , Femenino , Humanos , Lactante , Bienestar del Lactante , Recién Nacido , Edad Materna , New York/epidemiología , Vigilancia de la Población , Embarazo , Nacimiento Prematuro , Prevalencia , Reproducibilidad de los Resultados , Medición de Riesgo , Autoinforme , Sensibilidad y Especificidad , Vermont/epidemiología , Adulto Joven
8.
Artículo en Inglés | MEDLINE | ID: mdl-38896525

RESUMEN

An expansive area of research focuses on discerning patterns of alterations in functional brain networks from the early stages of Alzheimer's disease, even at the subjective cognitive decline (SCD) stage. Here, we developed a novel hyperbolic MEG brain network embedding framework for transforming high-dimensional complex MEG brain networks into lower-dimensional hyperbolic representations. Using this model, we computed hyperbolic embeddings of the MEG brain networks of two distinct participant groups: individuals with SCD and healthy controls. We demonstrated that these embeddings preserve both local and global geometric information, presenting reduced distortion compared to rival models, even when brain networks are mapped into low-dimensional spaces. In addition, our findings showed that the hyperbolic embeddings encompass unique SCD-related information that improves the discriminatory power above and beyond that of connectivity features alone. Notably, we introduced a unique metric-the radius of the node embeddings-which effectively proxies the hierarchical organization of the brain. Using this metric, we identified subtle hierarchy organizational differences between the two participant groups, suggesting increased hierarchy in the dorsal attention, frontoparietal, and ventral attention subnetworks among the SCD group. Last, we assessed the correlation between these hierarchical variations and cognitive assessment scores, revealing associations with diminished performance across multiple cognitive evaluations in the SCD group. Overall, this study presents the first evaluation of hyperbolic embeddings of MEG brain networks, offering novel insights into brain organization, cognitive decline, and potential diagnostic avenues of Alzheimer's disease.

9.
World Neurosurg ; 182: e486-e492, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38042289

RESUMEN

BACKGROUND: Stereoelectroencephalography (SEEG) remains critical in guiding epilepsy surgery. Robot-assisted techniques have shown promise in improving SEEG implantation outcomes but have not been directly compared. In this single-institution series, we compared ROSA and Stealth AutoGuide robots in pediatric SEEG implantation. METHODS: We retrospectively reviewed 21 sequential pediatric SEEG implantations consisting of 6 ROSA and 15 AutoGuide procedures. We determined mean operative time, time per electrode, root mean square (RMS) registration error, and surgical complications. Three-dimensional radial distances were calculated between each electrode's measured entry and target points with respective errors from the planned trajectory line. RESULTS: Mean overall/per electrode operating time was 73.5/7.5 minutes for ROSA and 126.1/10.9 minutes for AutoGuide (P = 0.030 overall, P = 0.082 per electrode). Mean RMS registration error was 0.77 mm (0.55-0.93 mm) for ROSA and 0.6 mm (0.2-1.0 mm) for AutoGuide (P = 0.26). No procedures experienced complications. The mean radial (entry point error was 1.23 ± 0.11 mm for ROSA and 2.65 ± 0.12 mm for AutoGuide (P < 0.001), while the mean radial target point error was 1.86 ± 0.15 mm for ROSA and 3.25 ± 0.16 mm for AutoGuide (P < 0.001). CONCLUSIONS: Overall operative time was greater for AutoGuide procedures, although there was no statistically significant difference in time per electrode. Both systems are highly accurate with no significant RMS error difference. While the ROSA robot yielded significantly lower entry and target point errors, both robots are safe and reliable for deep electrode insertion in pediatric epilepsy.


Asunto(s)
Epilepsia Refractaria , Epilepsia , Procedimientos Quirúrgicos Robotizados , Niño , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Estudios Retrospectivos , Electroencefalografía/métodos , Técnicas Estereotáxicas , Epilepsia/cirugía , Electrodos Implantados , Epilepsia Refractaria/cirugía
10.
PLoS One ; 18(2): e0280822, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36800392

RESUMEN

The cognitive performance of the crew has a major impact on mission safety and success in space flight. Monitoring of cognitive performance during long-duration space flight therefore is of paramount importance and can be performed using compact state-of-the-art mobile EEG. However, signal quality of EEG may be compromised due to the vicinity to various electronic devices and constant movements. We compare noise characteristics between in-flight extraterrestrial microgravity and ground-level terrestrial electroencephalography (EEG) recordings. EEG data recordings from either aboard International Space Station (ISS) or on earth's surface, utilizing three EEG amplifiers and two electrode types, were compared. In-flight recordings showed noise level of an order of magnitude lower when compared to pre- and post-flight ground-level recordings with the same EEG system. Noise levels between ground-level recordings with actively shielded cables, and in-flight recordings without shielded cables, were similar. Furthermore, noise level characteristics of shielded ground-level EEG recordings, using wet and dry electrodes, and in-flight EEG recordings were similar. Actively shielded mobile dry EEG systems will support neuroscientific research and neurocognitive monitoring during spaceflight, especially during long-duration space missions.


Asunto(s)
Vuelo Espacial , Ingravidez , Electroencefalografía , Electrodos
11.
Brain Commun ; 5(3): fcad168, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37274829

RESUMEN

Epilepsy surgery continues to be a recommended treatment for intractable (medication-resistant) epilepsy; however, 30-70% of epilepsy surgery patients can continue to have seizures. Surgical failures are often associated with incomplete resection or inaccurate localization of the epileptogenic zone. This retrospective study aims to improve surgical outcome through in silico testing of surgical hypotheses through a personalized computational neurosurgery model created from individualized patient's magnetoencephalography recording and MRI. The framework assesses the extent of the epileptic network and evaluates underlying spike dynamics, resulting in identification of one single brain volume as a candidate for resection. Dynamic-locked networks were utilized for virtual cortical resection. This in silico protocol was tested in a cohort of 24 paediatric patients with focal drug-resistant epilepsy who underwent epilepsy surgery. Of 24 patients who were included in the analysis, 79% (19 of 24) of the models agreed with the patient's clinical surgery outcome and 21% (5 of 24) were considered as model failures (accuracy 0.79, sensitivity 0.77, specificity 0.82). Patients with unsuccessful surgery outcome typically showed a model cluster outside of the resected cavity, while those with successful surgery showed the cluster model within the cavity. Two of the model failures showed the cluster in the vicinity of the resected tissue and either a functional disconnection or lack of precision of the magnetoencephalography-MRI overlapping could explain the results. Two other cases were seizure free for 1 year but developed late recurrence. This is the first study that provides in silico personalized protocol for epilepsy surgery planning using magnetoencephalography spike network analysis. This model could provide complementary information to the traditional pre-surgical assessment methods and increase the proportion of patients achieving seizure-free outcome from surgery.

12.
Sci Rep ; 13(1): 9489, 2023 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-37303002

RESUMEN

Electroencephalography (EEG) can detect changes in cerebral activity during spaceflight. This study evaluates the effect of spaceflight on brain networks through analysis of the Default Mode Network (DMN)'s alpha frequency band power and functional connectivity (FC), and the persistence of these changes. Five astronauts' resting state EEGs under three conditions were analyzed (pre-flight, in-flight, and post-flight). DMN's alpha band power and FC were computed using eLORETA and phase-locking value. Eyes-opened (EO) and eyes-closed (EC) conditions were differentiated. We found a DMN alpha band power reduction during in-flight (EC: p < 0.001; EO: p < 0.05) and post-flight (EC: p < 0.001; EO: p < 0.01) when compared to pre-flight condition. FC strength decreased during in-flight (EC: p < 0.01; EO: p < 0.01) and post-flight (EC: ns; EO: p < 0.01) compared to pre-flight condition. The DMN alpha band power and FC strength reduction persisted until 20 days after landing. Spaceflight caused electrocerebral alterations that persisted after return to earth. Periodic assessment by EEG-derived DMN analysis has the potential to become a neurophysiologic marker of cerebral functional integrity during exploration missions to space.


Asunto(s)
Vuelo Espacial , Humanos , Astronautas , Ojo , Encéfalo , Electroencefalografía
13.
bioRxiv ; 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37961615

RESUMEN

An expansive area of research focuses on discerning patterns of alterations in functional brain networks from the early stages of Alzheimer's disease, even at the subjective cognitive decline (SCD) stage. Here, we developed a novel hyperbolic MEG brain network embedding framework for transforming high-dimensional complex MEG brain networks into lower-dimensional hyperbolic representations. Using this model, we computed hyperbolic embeddings of the MEG brain networks of two distinct participant groups: individuals with SCD and healthy controls. We demonstrated that these embeddings preserve both local and global geometric information, presenting reduced distortion compared to rival models, even when brain networks are mapped into low-dimensional spaces. In addition, our findings showed that the hyperbolic embeddings encompass unique SCD-related information that improves the discriminatory power above and beyond that of connectivity features alone. Notably, we introduced a unique metric-the radius of the node embeddings-which effectively proxies the hierarchical organization of the brain. Using this metric, we identified subtle hierarchy organizational differences between the two participant groups, suggesting increased hierarchy in the dorsal attention, frontoparietal, and ventral attention subnetworks among the SCD group. Last, we assessed the correlation between these hierarchical variations and cognitive assessment scores, revealing associations with diminished performance across multiple cognitive evaluations in the SCD group. Overall, this study presents the first evaluation of hyperbolic embeddings of MEG brain networks, offering novel insights into brain organization, cognitive decline, and potential diagnostic avenues of Alzheimer's disease.

14.
Neurocase ; 18(4): 323-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22060011

RESUMEN

We present a case of acquired auditory-visual synesthesia and its neurophysiological investigation in a healthy 42-year-old woman. She started experiencing persistent positive and intermittent negative visual phenomena at age 37 followed by auditory-visual synesthesia. Her neurophysiological investigation included video-EEG, fMRI, and MEG. Auditory stimuli (700 Hz, 50 ms duration, 0.5 s ISI) were presented binaurally at 60 db above the hearing threshold in a dark room. The patient had bilateral symmetrical auditory-evoked neuromagnetic responses followed by an occipital-evoked field 16.3 ms later. The activation of occipital cortex following auditory stimuli may represent recruitment of existing cross-modal sensory pathways.


Asunto(s)
Trastornos de la Percepción/fisiopatología , Trastornos de la Percepción/psicología , Estimulación Acústica , Adulto , Electroencefalografía , Potenciales Evocados Auditivos , Femenino , Humanos , Imagen por Resonancia Magnética , Magnetoencefalografía , Masculino , Lóbulo Occipital/fisiopatología , Trastornos de la Percepción/patología , Estimulación Luminosa , Sinestesia
15.
Surg Neurol Int ; 13: 585, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36600777

RESUMEN

Background: Medically refractory epilepsy constitutes up to one-third of the epilepsy pediatric patients. Corpus callosotomy (CC) has been used for the treatment of medically refractory epilepsy in children with atonic seizures and generalized tonic-clonic (GTC) seizures. In this case series study, we are describing a novel technique for CC using the frameless navigation probe through a minicraniotomy. Methods: Thirteen pediatric patients with the diagnosis of medically refractory epilepsy predominantly GTC with drop attack who underwent extensive Phase I. An L-shape was done, then through a 4 × 3 cm craniotomy, we were able to open the interhemispheric fissure until the corpus callosum is visualized. The Stealth probe is then used to go down to the midline raphe which is followed anteriorly then traced posteriorly to the anterior border of the vein of Galen. Finally, the Stealth probe is used to confirm the completeness of the callosotomy. Results: The procedure was accomplished successfully with no intraoperative complications; mean surgical time is 3 h:07 m. The mean follow-up was 31.5 months. All patients achieved significant seizure control. No patients experienced worsening of their atonic seizures after surgery compared with their preoperative state; however, six patients achieved Engel Class I, four patients achieved Engel Class II, and three patients achieved Engel Class III. Conclusion: Complete CC using a frameless navigation probe is a novel and effective technique for the treatment of medically refractory epilepsy with a very good surgical and seizure outcomes, minimal neurological morbidity, minimal blood loss, and short OR time.

16.
Brain Commun ; 4(2): fcac012, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35282163

RESUMEN

There is growing evidence for neuronal hyperexcitability in Alzheimer's disease. Hyperexcitability is associated with an increase in epileptiform activity and the disruption of inhibitory activity of interneurons. Interneurons fire at a high rate and are frequently associated with high-frequency oscillations in the gamma frequency band (30-150 Hz). It is unclear how hyperexcitability affects the organization of functional brain networks. A sample of 63 amnestic mild cognitive impairment patients underwent a magnetoencephalography resting-state recording with eyes closed. Twenty (31.75%) mild cognitive impairment patients had epileptiform activity. A cluster-based analysis of the magnetoencephalography functional connectivity revealed a region within the right temporal cortex whose global connectivity in the gamma frequency band was significantly reduced in patients with epileptiform activity relative to those without epileptiform activity. A subsequent seed-based analysis showed that this was largely due to weaker gamma band connectivity of this region with ipsilateral frontal and medial regions, and the upper precuneus area. In addition, this reduced functional connectivity was associated with higher grey matter atrophy across several cortical regions in the patients with epileptiform activity. These functional network disruptions and changes in brain physiology and morphology have important clinical implications as they may contribute to cognitive decline in mild cognitive impairment and Alzheimer's disease.

17.
Epilepsia ; 52 Suppl 4: 10-4, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21732934

RESUMEN

The surgical management of neocortical epilepsy is challenging because many patients are without obvious structural lesions, or lesions are small and easily overlooked during routine clinical interpretation of magnetic resonance imaging (MRI) data. Even when functional imaging data suggest focal epileptiform pathology, in the absence of a concordant structural lesion, invasive monitoring is often required to confirm that an appropriate surgical target has been identified. This study sought to determine the extent to which knowledge of magnetoencephalography (MEG) data can augment the MRI-based detection of structural brain lesions. MRI and whole-head MEG data were obtained from 40 patients with neocortical epilepsy. As a result of MEG data, 29 cases were sent for MRI reevaluation. In seven of these cases, MEG-guided review led to specification of now clear, but previously unidentified, lesions. There were two additional cases for which follow-up high-resolution imaging did not confirm structural abnormalities. In patients with neocortical epilepsy, MEG is a useful adjunct to MRI for the identification of structural lesions.


Asunto(s)
Encéfalo/patología , Epilepsia/patología , Magnetoencefalografía , Adolescente , Adulto , Encéfalo/fisiopatología , Niño , Preescolar , Electroencefalografía , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Convulsiones/diagnóstico , Convulsiones/patología , Convulsiones/fisiopatología , Adulto Joven
18.
Front Neurol ; 12: 722986, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34721261

RESUMEN

Magnetoencephalography (MEG) is a neurophysiologic test that offers a functional localization of epileptic sources in patients considered for epilepsy surgery. The understanding of clinical MEG concepts, and the interpretation of these clinical studies, are very involving processes that demand both clinical and procedural expertise. One of the major obstacles in acquiring necessary proficiency is the scarcity of fundamental clinical literature. To fill this knowledge gap, this review aims to explain the basic practical concepts of clinical MEG relevant to epilepsy with an emphasis on single equivalent dipole (sECD), which is one the most clinically validated and ubiquitously used source localization method, and illustrate and explain the regional topology and source dynamics relevant for clinical interpretation of MEG-EEG.

19.
Front Hum Neurosci ; 15: 667777, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34149382

RESUMEN

Magnetoencephalography (MEG) is recognized as a valuable non-invasive clinical method for localization of the epileptogenic zone and critical functional areas, as part of a pre-surgical evaluation for patients with pharmaco-resistant epilepsy. MEG is also useful in localizing functional areas as part of pre-surgical planning for tumor resection. MEG is usually performed in an outpatient setting, as one part of an evaluation that can include a variety of other testing modalities including 3-Tesla MRI and inpatient video-electroencephalography monitoring. In some clinical circumstances, however, completion of the MEG as an inpatient can provide crucial ictal or interictal localization data during an ongoing inpatient evaluation, in order to expedite medical or surgical planning. Despite well-established clinical indications for performing MEG in general, there are no current reports that discuss indications or considerations for completion of MEG on an inpatient basis. We conducted a retrospective institutional review of all pediatric MEGs performed between January 2012 and December 2020, and identified 34 cases where MEG was completed as an inpatient. We then reviewed all relevant medical records to determine clinical history, all associated diagnostic procedures, and subsequent treatment plans including epilepsy surgery and post-surgical outcomes. In doing so, we were able to identify five indications for completing the MEG on an inpatient basis: (1) super-refractory status epilepticus (SRSE), (2) intractable epilepsy with frequent electroclinical seizures, and/or frequent or repeated episodes of status epilepticus, (3) intractable epilepsy with infrequent epileptiform discharges on EEG or outpatient MEG, or other special circumstances necessitating inpatient monitoring for successful and safe MEG data acquisition, (4) MEG mapping of eloquent cortex or interictal spike localization in the setting of tumor resection or other urgent neurosurgical intervention, and (5) international or long-distance patients, where outpatient MEG is not possible or practical. MEG contributed to surgical decision-making in the majority of our cases (32 of 34). Our clinical experience suggests that MEG should be considered on an inpatient basis in certain clinical circumstances, where MEG data can provide essential information regarding the localization of epileptogenic activity or eloquent cortex, and be used to develop a treatment plan for surgical management of children with complicated or intractable epilepsy.

20.
World Neurosurg ; 149: e1112-e1122, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33418117

RESUMEN

OBJECTIVE: This study aims to evaluate the performance of convolutional neural networks (CNNs) trained with resting-state functional magnetic resonance imaging (rfMRI) latency data in the classification of patients with pediatric epilepsy from healthy controls. METHODS: Preoperative rfMRI and anatomic magnetic resonance imaging scans were obtained from 63 pediatric patients with refractory epilepsy and 259 pediatric healthy controls. Latency maps of the temporal difference between rfMRI and the global mean signal were calculated using voxel-wise cross-covariance. Healthy control and epilepsy latency z score maps were pseudorandomized and partitioned into training data (60%), validation data (20%), and test data (20%). Healthy control individuals and patients with epilepsy were labeled as negative and positive, respectively. CNN models were then trained with the designated training data. Model hyperparameters were evaluated with a grid-search method. The model with the highest sensitivity was evaluated using unseen test data. Accuracy, sensitivity, specificity, F1 score, and area under the receiver operating characteristic curve were used to evaluate the ability of the model to classify epilepsy in the test data set. RESULTS: The model with the highest validation sensitivity correctly classified 74% of unseen test patients with 85% sensitivity, 71% specificity, F1 score of 0.56, and an area under the receiver operating characteristic curve of 0.86. CONCLUSIONS: Using rfMRI latency data, we trained a CNN model to classify patients with pediatric epilepsy from healthy controls with good performance. CNN could serve as an adjunct in the diagnosis of pediatric epilepsy. Identification of pediatric epilepsy earlier in the disease course could decrease time to referral to specialized epilepsy centers and thus improve prognosis in this population.


Asunto(s)
Encéfalo/diagnóstico por imagen , Epilepsia Refractaria/diagnóstico por imagen , Neuroimagen Funcional , Imagen por Resonancia Magnética , Redes Neurales de la Computación , Adolescente , Área Bajo la Curva , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , Vías Nerviosas/diagnóstico por imagen , Curva ROC , Descanso
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