Presurgical Evaluation Of Patients Research Articles

Evaluation of function and limiting factors of gait disorder treatment in cerebral palsy: development of the Walking Abilities Levels Classification System

The Gross Motor Function Classification System has allowed us to stratificate cerebral palsy patients, according to their walking abilities. The lack of sensitivity about detecting changes and the absence of a global patient evaluation, justify the search of new pre-operative evaluation tools. To present the Walking Abilities Levels Classification System (WALCS) and to show the first inter-observer agreement study that has been carried out. This system uses first a different pattern for ordering gait functional skills, and after that, evaluates the reversibility of the contextual factors that may limit the result of a gait disorder treatment. A new evaluation frame was built by an interdisciplinary team with an average professional experience of more than 15 years, initially focused as part of the pre-surgical patient evaluation. An inter-observer agreement study was held to gain the first insight of it. 14 participants studied the medical reports and gait lab video images of 10 cases. The kappa index was 0.76 for the walking ability level, 0.79 for the biological type, 0.69 psychological type and 0.64 social type of limiting factors. The WALCS offers a new evaluation frame gathering patient walking skills and limiting factors treatment. The initial inter-observer agreement rate endorsed more intra- and inter-studies in order to achieve a more robust validation.

Epilepsy Presurgical Evaluation of Patients with Complex Source Localization by a Novel Component-Based EEG-fMRI Approach

E: <: <: <: <: <: <: <: <: <: <: <: <: <: Background: The precise localization of epileptic foci is an unavoidable prerequisite for epilepsy surgery. Simultaneous EEG-fMRI recording has recently created new horizons to locate foci in patients with epilepsy and, in comparison with single-modality methods, has yielded promising results although it is still subject to a few limitations such as the lack of access to information between interictal events. This study assessed its potential added value in the presurgical evaluation of patients with complex source localization. Adult candidates considered ineligible for surgery on account of an unclear focus and/or presumed multifocality based on EEG underwent EEG-fMRI. Objectives: Adopting a component-based approach, this study attempted to identify the neural behavior of the epileptic generators and detect the components of interest to be later used as inputs in the GLM model, substituting the classical linear regressor. Methods: Nine IED sets from five patients were analyzed. These patients were rejected for surgery because of an unclear focus in two, presumed multifocality in one, and a combination of both in two of them. Results: Component-based EEG-fMRI improved localization in three out of four patients with unclear foci. In patients with presumed multifocality, component-based EEG-fMRI advocated one of the foci in five patients and confirmed multifocality in one out of five patients. In two patients, component-based EEG-fMRI opened new prospects for surgery. In these complex cases, component-based EEG-fMRI either improved source localization or corroborated a negative decision regarding surgical candidacy. Conclusion: As supported by the statistical findings, the developed EEG-fMRI method led to a more realistic estimation of localization than the conventional EEG-fMRI approach, making it a tool of high value in the presurgical evaluation of patients with refractory epilepsy.

Determining the dose of amobarbital in Wada test for the presurgical evaluation of patients with temporal lobe epilepsy

The standard use of amobarbital in Wada test varied between epilepsy centres, with no unified dosing or protocols available in epilepsy centres. We aimed to determine the dose of amobarbital in the presurgical evaluations of patients with temporal lobe epilepsy (TLE).

Predictors of Pain Recurrence After Lumbar Facet Joint Injections

IntroductionFacet joint injections (FJIs) of anesthetic and corticosteroids are useful for the diagnosis and treatment of low back pain (LBP). In the current study, we evaluated the efficacy of FJI on LBP treatment and the predictive variables of pain recurrence after FJI.MethodsWe included and followed prospectively forty-three consecutive patients with chronic LBP treated with FJI. Clinical assessments were carried out at a baseline 1 week before FJIs and after a 6-month follow-up visit using the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI) for disability-specific measure and MacNab criteria for global effectiveness, and compared through analysis using paired-samples “t” tests. Multiple cox-regression analysis was used to identify the presurgical variables independently associated with pain recurrence anytime during the follow-up. In addition to the demographic, clinical, and surgical data, we also analyzed psychometric scales: Pain Catastrophizing Scale (PCS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI).ResultsAfter a 6-month follow-up, thirty-two patients (74.4%) showed a clinically significant reduction of pain and twenty-seven (62.8%) reported a clinically significant improvement of disability. Presurgical catastrophizing (PCS score ≥ 5, adjusted HR 4.4, CI 95% 1.7–11.3, p = 0.002) and smoking (Adjusted HR 12.5, CI 95% 1.1–138.9, p = 0.04) remains associated with pain recurrence.ConclusionFJI reduces LBP and disability of patients with unresponsive LBP. Pain-related cognitive and behavioral factors determined by pain catastrophizing and smoking were independently associated with pain recurrence after lumbar FJI. The results support the need of a multidisciplinary approach for presurgical evaluation of patients with chronic pain.

Value of stereoelectroencephalography (SEEG)-guided radiofrequency thermocoagulation in treating drug-resistant focal epilepsy

Stereoelectroencephalography (SEEG) has been widely used in the presurgical evaluation of patients with medically intractable epilepsy. In the past, SEEG was commonly used as a method for mapping and localizing the epileptogenic zone (EZ). Since 2004, several studies have been conducted to examine the effectiveness of SEEG-guided radiofrequency thermocoagulation (RF-TC) in treating refractory epilepsy. However, the seizure-free and responder rates varied greatly across studies. We aimed to analyze the outcome of 56 patients who were treated with SEEG-guided RF-TC to evaluate the effectiveness of this treatment. SEEG-guided RF-TC can be considered as a treatment for refractory epilepsy. However, due to its limited efficacy, SEEG-guided RF-TC might be regarded as a temporary treatment performed under SEEG rather than a promising treatment for refractory epilepsy.

Intranasal Dexmedetomidine for Sedation During Magnetoencephalography.

Magnetoencephalography (MEG) is a noninvasive tool used clinically for presurgical evaluation of patients with medically intractable epilepsy. These recordings require patients to lie still for prolonged periods of time in a magnetically shielded room. Children or uncooperative adults with epilepsy may require sedation to reduce movement artefact and obtain high-quality recordings. Potential challenges related to the use of total intravenous anesthesia in the MEG environment include limited access to the patient's airway, remote location, suppression of cortical activity, and increased patient care expenses. We report our experience with intranasal dexmedetomidine as sedation for intractable epilepsy patients undergoing MEG. Sleep deprivation occurred the night before MEG testing. Intranasal dexmedetomidine (2 μg/kg) was administered and oxygen saturation, blood pressure, and pulse rate were recorded continuously on a monitor outside the magnetically shielded room. A recording of spontaneous neuromagnetic activity was immediately followed by median nerve electrical stimulation. Twenty-six patients (mean age 12.2 ± 4.2 years) with medically intractable epilepsy were recorded using this protocol. There were no failures of sedation, and although patients experienced transient bradycardia, none required intervention and the recording did not need to be stopped. In all cases, artefact-free MEG recordings were obtained with sufficient interictal discharges available for source analysis. Our experience suggests that intranasal dexmedetomidine is an advantageous sedation option for children and adults with intractable epilepsy who are undergoing MEG. Further research is needed to determine the best ways to apply these methods to younger children and those with developmental disabilities.

Diagnostic added value of electrical source imaging in presurgical evaluation of patients with epilepsy: A prospective study

ObjectiveTo investigate the diagnostic added value of electrical source imaging (ESI) in presurgical evaluation of patients with drug resistant focal epilepsy. MethodsEighty-two consecutive patients were included. We analyzed both low density (LD) and high density (HD) EEG recordings. LD ESI was done on interictal and ictal signals recorded during long-term video-EEG monitoring (LTM), with standard 25 electrodes and age-matched template head models. HD ESI was done on shorter recordings (90–120 min), with 256 electrodes, using individual head model. The multidisciplinary team made decisions first blinded to ESI (based on all other modalities) and then discussed the results of the ESI. We considered that ESI had diagnostic added value, when it provided non-redundant information that changed the patientś management plan. ResultsESI had diagnostic added value in 28 patients (34%). In most cases (85.7%), these changes were related to planning of the invasive recordings. In nine out of 13 patients, invasive recordings confirmed the localization. Out of eight patients in whom the ESI source was resected, six became seizure-free. ConclusionsESI provides non-redundant information in one third of the patients undergoing presurgical evaluation. SignificanceThis study provides evidence for the diagnostic added value of ESI in presurgical evaluation.

A Novel Noninvasive Approach Based on SPECT and EEG for the Location of the Epileptogenic Zone in Pharmacoresistant Non-Lesional Epilepsy.

Background and objectives: The aim of this study is to propose a methodology that combines non-invasive functional modalities electroencephalography (EEG) and single photon emission computed tomography (SPECT) to estimate the location of the epileptogenic zone (EZ) for the presurgical evaluation of patients with drug-resistant non-lesional epilepsy. Materials and Methods: This methodology consists of: (i) Estimation of ictal EEG source imaging (ESI); (ii) application of the subtraction of ictal and interictal SPECT co-registered with MRI (SISCOM) methodology; and (iii) estimation of ESI but using the output of the SISCOM as a priori information for the estimation of the sources. The methodology was implemented in a case series as an example of the application of this novel approach for the presurgical evaluation. A gold standard and a coincidence analysis based on measures of sensitivity and specificity were used as a preliminary assessment of the proposed methodology to localize EZ. Results: In patients with good postoperative evolution, the estimated EZ presented a spatial coincidence with the resection site represented by high values of sensitivity and specificity. For the patient with poor postoperative evolution, the methodology showed a partial incoherence between the estimated EZ and the resection site. In cases of multifocal epilepsy, the method proposed spatially extensive epileptogenic zones. Conclusions: The results of the case series provide preliminary evidence of the methodology’s potential to epileptogenic zone localization in non-lesion drug-resistant epilepsy. The novelty of the article consists in estimating the sources of ictal EEG using SISCOM result as a prior for the inverse solution. Future studies are necessary in order to validate the described methodology. The results constitute a starting point for further studies in order to support the clinical reliability of the proposed methodology and advocate for their implementation in the presurgical evaluation of patients with intractable non-lesional epilepsy.

Electroclinical features of insulo-opercular epilepsy: an SEEG and PET study.

ObjectiveTo report clinical experience with presurgical evaluation in patients with insulo‐opercular epilepsy. Quantitative analysis on PET imaging and stereoelectroencephalography (SEEG) signals was used to summarize their electroclinical features.MethodsTwenty‐two patients with focal epilepsy arising from the insular and/or opercular cortex according to SEEG were retrospectively analyzed. Presurgical noninvasive data were analyzed in detail. Interictal PET data of patients were then statistically compared with those of healthy controls to identify the interictal hypometabolic network. The epileptogenicity index (EI) of ictal SEEG signal was computed to identify areas of spread at the beginning of seizure onset.ResultsFocal tonic seizures of the face and/or neck (16/22, 73%) were the most prevalent early objective signs. Epileptic discharges in the interictal and ictal scalp‐EEG mostly showed an ipsilateral perisylvian distribution. Statistical analysis of interictal PET showed significant hypometabolism in the insular lobe, central operculum, supplementary motor area, middle cingulate cortex, bilateral caudate nuclei, and putamen. According to the EI analysis, insulo‐opercular epilepsy could be classified as insulo‐opercular epilepsy (50%), opercular epilepsy (41%), and insular cortex epilepsy (9%).SignificanceClinical diagnosis of insulo‐opercular epilepsy is challenging because of its complex seizure semiology and nonlocalizing discharges on scalp‐EEG. A common hypometabolic network involving the insulo‐opercular cortex, mesial frontal cortex and subcortical nuclei may be involved in the organization of the insulo‐opercular epilepsy network. Furthermore, quantified SEEG analysis suggested that pure insular epilepsy is rare, and the close connection between insular and opercular cortex necessitates SEEG implantation to define the epileptogenic zone.

The localizing and lateralizing value of palpitation aura in patients with focal epilepsy

The semiology of auras is essential to presurgical evaluation of patients with focal epilepsy. To assess the localizing and lateralizing value of palpitation aura in focal epilepsy, we retrospectively analyzed the demography, electroclinical, neuroimaging, surgical, pathology data, and outcomes of 114 patients with focal epilepsy and the palpitation aura occurrence in relation to epileptogenic (temporal vs extratemporal, left vs right) origin. Out of 114 patients (mean age, 23.44 ± 9.69 years), 17 (14.9%) patients experienced palpitation as the first aura. Twelve had temporal, one had parietal, one had occipital lobe, and three had multiple lobes junction onset seizures. Palpitation aura was observed more frequently in temporal epilepsy: 22.2% of temporal lobe epilepsy (TLE) and 8.3% of extratemporal lobe epilepsy (EX-TLE) exhibited palpitation aura (p = 0.038). However, palpitation aura had no difference between the left or right side: 16.4% with right-sided epilepsy and 13.2% with left-sided epilepsy exhibited palpitation aura (p = 0.634). Thus, our study suggested that palpitation was a frequent aura in patients with focal epilepsy. It is more commonly seen with temporal lobe origin, but it has no lateralizing value.

Multimodal noninvasive evaluation in MRI-negative operculoinsular epilepsy.

Presurgical evaluation of patients with operculoinsular epilepsy and negative MRI presents major challenges. Here the authors examined the yield of noninvasive modalities such as voxel-based morphometric MRI postprocessing, FDG-PET, subtraction ictal SPECT coregistered to MRI (SISCOM), and magnetoencephalography (MEG) in a cohort of patients with operculoinsular epilepsy and negative MRI. Twenty-two MRI-negative patients were included who had focal ictal onset from the operculoinsular cortex on intracranial EEG, and underwent focal resection limited to the operculoinsular cortex. MRI postprocessing was applied to presurgical T1-weighted volumetric MRI using a morphometric analysis program (MAP). Individual and combined localization yields of MAP, FDG-PET, MEG, and SISCOM were compared with the ictal onset location on intracranial EEG. Seizure outcomes were reported at 1 year and 2 years (when available) using the Engel classification. Ten patients (45.5%, 10/22) had operculoinsular abnormalities on MAP; 5 (23.8%, 5/21) had operculoinsular hypometabolism on FDG-PET; 4 (26.7%, 4/15) had operculoinsular hyperperfusion on SISCOM; and 6 (30.0%, 6/20) had an MEG cluster (3 tight, 3 loose) within the operculoinsular cortex. The highest yield of a 2-test combination was 59.1%, seen with MAP and SISCOM, followed by 54.5% with MAP and FDG-PET, and also 54.5% with MAP and MEG. The highest yield of a 3-test combination was 68.2%, seen with MAP, MEG, and SISCOM. The yield of the 4-test combination remained at 68.2%. When all other tests were negative or nonlocalizing, unique information was provided by MAP in 5, MEG in 1, SISCOM in 2, and FDG-PET in none of the patients. One-year follow-up was available in all patients, and showed 11 Engel class IA, 4 class IB, 4 class II, and 3 class III/IV. Two-year follow-up was available in 19 patients, and showed 9 class IA, 3 class IB, 1 class ID, 3 class II, and 3 class III/IV. This study highlights the individual and combined values of multiple noninvasive modalities for the evaluation of nonlesional operculoinsular epilepsy. The 3-test combination of MAP, MEG, and SISCOM represented structural, interictal, and ictal localization information, and constituted the highest yield. MAP showed the highest yield of unique information when other tests were negative or nonlocalizing.

MEG Assessment of Expressive Language in Children Evaluated for Epilepsy Surgery

Establishing language dominance is an important step in the presurgical evaluation of patients with refractory epilepsy. In the absence of a universally accepted gold-standard non-invasive method to determine language dominance in the preoperative assessment, a range of tools and methodologies have recently received attention. When applied to pediatric age, many of the proposed methods, such as functional magnetic resonance imaging (fMRI), may present some challenges due to the time-varying effects of epileptogenic lesions and of on-going seizures on maturational phenomena. Magnetoencephalography (MEG) has the advantage of being insensitive to the distortive effects of anatomical lesions on brain microvasculature and to differences in the metabolism or vascularization of the developing brain and also provides a less intimidating recording environment for younger children. In this study we investigated the reliability of lateralized synchronous cortical activation during a verb generation task in a group of 28 children (10 males and 18 females, mean age 12 years) with refractory epilepsy who were evaluated for epilepsy surgery. The verb generation task was associated with significant decreases in beta oscillatory power (13–30 Hz) in frontal and temporal lobes. The MEG data were compared with other available presurgical non-invasive data including cortical stimulation, neuropsychological and fMRI data on language lateralization where available. We found that the lateralization of MEG beta power reduction was concordant with language dominance determined by one or more different assessment methods (i.e. cortical stimulation mapping, neuropsychological, fMRI or post-operative data) in 89% of patients. Our data suggest that qualitative hemispheric differences in task-related changes of spectral power could offer a promising insight into the contribution of dominant and non-dominant hemispheres in language processing and may help to characterize the specialization and lateralization of language processes in children.

Electromagnetic source imaging in presurgical workup of patients with epilepsy: A prospective study.

ObjectiveTo determine the diagnostic accuracy and clinical utility of electromagnetic source imaging (EMSI) in presurgical evaluation of patients with epilepsy.MethodsWe prospectively recorded magnetoencephalography (MEG) simultaneously with EEG and performed EMSI, comprising electric source imaging, magnetic source imaging, and analysis of combined MEG-EEG datasets, using 2 different software packages. As reference standard for irritative zone (IZ) and seizure onset zone (SOZ), we used intracranial recordings and for localization accuracy, outcome 1 year after operation.ResultsWe included 141 consecutive patients. EMSI showed localized epileptiform discharges in 94 patients (67%). Most of the epileptiform discharge clusters (72%) were identified by both modalities, 15% only by EEG, and 14% only by MEG. Agreement was substantial between inverse solutions and moderate between software packages. EMSI provided new information that changed the management plan in 34% of the patients, and these changes were useful in 80%. Depending on the method, EMSI had a concordance of 53% to 89% with IZ and 35% to 73% with SOZ. Localization accuracy of EMSI was between 44% and 57%, which was not significantly different from MRI (49%–76%) and PET (54%–85%). Combined EMSI achieved significantly higher odds ratio compared to electric source imaging and magnetic source imaging.ConclusionEMSI has accuracy similar to established imaging methods and provides clinically useful, new information in 34% of the patients.Classification of evidenceThis study provides Class IV evidence that EMSI had a concordance of 53%–89% and 35%–73% (depending on analysis) for the localization of epileptic focus as compared with intracranial recordings—IZ and SOZ, respectively.

The Role of Interictal Epileptiform Discharges in Epilepsy Surgery Outcome.

Background:Epilepsy surgery is a fundamental treatment in refractory epilepsy. Video electroencephalographic (v-EEG) monitoring plays an essential role in presurgical evaluation of patients. However there are reports of favorable outcome based on interictal and magnetic resonance imaging (MRI) findings without any need for v-EEG monitoring in patients with temporal lobe epilepsy (TLE). This study aimed to investigate the prognostic effect of concordance between interictal findings and ictal and MRI data on postsurgical outcome of TLE and extratemporal lobe epilepsy (ETLE).Methods:A retrospective study was conducted on 199 patients with refractory focal epilepsy who were admitted for presurgical evaluation. The concordance between irritative zone (IZ) and seizure onset zone (SOZ) and also IZ and MRI lesion was registered, and subsequently the prognostic effect of relevancy on 1-year follow-up result based on Engel criteria was investigated.Results:In TLE and ETLE regarding relevancy between IZ and SOZ, 77.8% and 73.2% were concordant, 2.5% and 0% were discordant, and 19.6% and 26.8% had overlap, respectively. Concordance between IZ and MRI lesion was found in 76.6% and 51.2% of patients with TLE and ETLE while discordance was recorded in 2.5% and 12.2% and overlap registered in 20.9% and 36.6%, respectively. The concordance of interictal findings had no effect on postsurgical outcome of patients with TLE and ETLE.Conclusions:Our study showed that concordance of IZ with SOZ and MRI has no independent effect on postsurgical outcome of patients with TLE and ETLE. We suggest that excluding exceptional cases, v-EEG monitoring should be considered as the mainstay of presurgical evaluation.

Incorporating Optical Coherence Tomography in the Cataract Preoperative Armamentarium: Additional Need or Additional Burden?

To determine the usefulness of preoperative optical coherence tomography (OCT) examination to detect asymptomatic macular abnormalities in patients scheduled for cataract surgery. Design: Prospective, interventional case series. Iladevi Cataract and Visakha Eye Center, Ahmedabad, India. Patients undergoing cataract surgery and intraocular lens (IOL) implantation for senile cataracts. Preoperatively no retinal/macular pathology was identified on clinical evaluation. All eyes underwent macular 5-line raster evaluation using spectral-domain OCT before and after cataract surgery (monthly for 3months). Central subfield thickness (CST) analysis was done. The primary outcome measure was determining the incidence of asymptomatic retinal lesions on OCT examination in clinically "normal" maculas. Secondary outcome measures included documenting change in corrected distance visual acuity and OCT thickness postoperatively. A total of 1444 eyes were evaluated. OCT revealed asymptomatic lesions in 133 (9.21%) patients. At 3months, all eyes showed significant median visual improvement (from 0.45 ± 0.13 logMAR to 0.06 ± 0.08 logMAR; P= .015) and insignificant median CST change (from 223.34 ± 21.1μm to 249.12 ± 19.24μm; P= .19). One eye showed increased vitreomacular traction (3months). Patients with asymptomatic lesions did not have significantly worse postoperative visual outcomes at 3months (from 0.52 ± 0.16 logMAR to 0.14 ± 0.1 logMAR; P= .12). A total of 9.21% patients with clinically normal maculas had subtle pathology detected on OCT, but this subset of patients did not have worse postoperative visual outcomes compared to eyes with normal OCT scans. Thus, a careful pre-cataract surgery fundus examination remains an essential part of the presurgical patient evaluation.

Automated EEG source imaging: A retrospective, blinded clinical validation study

ObjectiveTo evaluate the accuracy of automated EEG source imaging (ESI) in localizing epileptogenic zone. MethodsLong-term EEG, recorded with the standard 25-electrode array of the IFCN, from 41 consecutive patients with focal epilepsy who underwent resective surgery, were analyzed blinded to the surgical outcome. The automated analysis comprised spike-detection, clustering and source imaging at the half-rising time and at the peak of each spike-cluster, using individual head-models with six tissue-layers and a distributed source model (sLORETA). The fully automated approach presented ESI of the cluster with the highest number of spikes, at the half-rising time. In addition, a physician involved in the presurgical evaluation of the patients, evaluated the automated ESI results (up to four clusters per patient) in clinical context and selected the dominant cluster and the analysis time-point (semi-automated approach). The reference standard was location of the resected area and outcome one year after operation. ResultsAccuracy was 61% (95% CI: 45–76%) for the fully automated approach and 78% (95% CI: 62–89%) for the semi-automated approach. ConclusionAutomated ESI has an accuracy similar to previously reported neuroimaging methods. SignificanceAutomated ESI will contribute to increased utilization of source imaging in the presurgical evaluation of patients with epilepsy.

Urodynamics are necessary for patients with asymptomatic pelvic organ prolapse.

To evaluate the role of pre-operative urodynamics in women with pelvic organ prolapse, who are asymptomatic for urinary symptoms. Correlate urodynamics findings with King's Health Questionnaire (KHQ) responses. Retrospective review of prospectively collected data on routine pre-operative urodynamics investigations in women with urogenital prolapse requiring surgery. Patients who were reported to be asymptomatic of urinary symptoms at the urogynaecological clinical consultation, were included for analysis. KHQ and urodynamics data were reviewed. A 800 records of women having routine pre-operative urodynamics were collected over a 10-year period, were reviewed. 98/800 (12%) were aymptomatic of urinary symptoms and underwent urodynamics. 82/98 (84%) completed the KHQ. 48/98 (49%) had normal urodynamics. 30/98 (31%) had detrusor overactivity (DO). 17/98 (17%) showed occult urodynamic stress incontinence (USI). 3/98 (3%) both DO and USI. 28/98 (29%) had peak flow rate less than 15 mL/s. Forty-five percent of women reporting nocturia had DO. Nine percent had over 100 mL residuals after the free flow study. Routine pre-operative urodynamics changed management in 25/98 (25%) of asymptomatic prolapse patients. TVT was performed in 12 patients. One patient who declined TVT for moderate occult USI, developed new-onset stress urinary incontinence post-operatively. This data show, that an accurate pre-surgical evaluation of patients with prolapse is incomplete without a structured validated questionnaire and urodynamics, due to the high proportion of abnormal KHQ and UDS findings in presumably "asymptomatic" patients.

The role of magnetoencephalography in the presurgical evaluation of patients with MRI-negative operculo-insular epilepsy

PurposeMagnetoencephalography (MEG) is considered to be a useful clinical tool to provide additional information for localising the epileptogenic zone or planning intracranial electrode implantation. This study aimed to evaluate the value of MEG in the presurgical localisation of the operculo-insular epileptogenic zone in patients with negative magnetic resonance imaging (MRI). MethodsThirteen patients with operculo-insular epilepsy and negative MRI who were identified by presurgical evaluation and underwent resective surgery from January 2011 to June 2015 were included and analysed in the study. ResultsIn presurgical evaluation, the ictal symptoms looked reliable enough to characterise operculo-insular seizures in four patients. MEG spike sources were shown in the operculo-insular region in 11 of 13 (84.6%) patients, including cluster spike sources in 7 patients and scatter spike sources in 4 patients. After MEG examination, the original plan of intracranial electrode implantation was changed in five patients. In these patients, electrodes exploring the operculo-insular cortex were not part of the original plan. The pathological examination showed focal cortical dysplasia (FCD) in 12 patients and FCD with heterotopia in 1 patient. Nine (69.2%)patients were seizure-free in 2–6 years’ follow-up. ConclusionsMEG played an additional and valuable role in the localisation of operculo-insular epilepsy for patients with a negative MRI finding.

Changes in resting-state connectivity in pediatric temporal lobe epilepsy.

OBJECTIVE Functional connectivity magnetic resonance imaging (fcMRI) is a form of fMRI that allows for analysis of blood oxygen level-dependent signal changes within a task-free, resting paradigm. This technique has been shown to have efficacy in evaluating network connectivity changes with epilepsy. Presurgical data from patients with unilateral temporal lobe epilepsy were evaluated using the fcMRI technique to define connectivity changes within and between the diseased and healthy temporal lobes using a within-subjects design. METHODS Using presurgical fcMRI data from pediatric patients with unilateral temporal lobe epilepsy, the authors performed seed-based analyses within the diseased and healthy temporal lobes. Connectivity within and between temporal lobe seeds was measured and compared. RESULTS In the cohort studied, local ipsilateral temporal lobe connectivity was significantly increased on the diseased side compared to the healthy temporal lobe. Connectivity of the diseased side to the healthy side, on the other hand, was significantly reduced when compared to connectivity of the healthy side to the diseased temporal lobe. A statistically significant regression was observed when comparing the changes in local ipsilateral temporal lobe connectivity to the changes in inter-temporal lobe connectivity. A statistically significant difference was also noted in ipsilateral connectivity changes between patients with and those without mesial temporal sclerosis. CONCLUSIONS Using fcMRI, significant changes in ipsilateral temporal lobe and inter-temporal lobe connectivity can be appreciated in unilateral temporal lobe epilepsy. Furthermore, fcMRI may have a role in the presurgical evaluation of patients with intractable temporal lobe epilepsy.

18F-FDG PET and high-resolution MRI co-registration for pre-surgical evaluation of patients with conventional MRI-negative refractory extra-temporal lobe epilepsy.

Epilepsy that originates outside of the temporal lobe can present some of the most challenging problems for surgical therapy, especially for patients with conventional magnetic resonance imaging (MRI)-negative refractory extra-temporal lobe epilepsy (ETLE). This study aimed to evaluate the clinical value of pre-surgical 18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG PET) and high-resolution MRI (HR-MRI) co-registration in patients with conventional MRI-negative refractory ETLE, and compare their surgical outcomes. Sixty-seven patients with conventional MRI-negative refractory ETLE were prospectively included for pre-surgical 18F-FDG PET and HR-MRI examinations. Under the guidance of 18F-FDG PET and HR-MRI co-registration, HR-MRI images were re-read. Based on the image result changes from first reading to re-reading, patients were divided into three groups: Change-1 (lesions of subtle abnormality could be identified in re-read), Change-2 (non-specific abnormalities reported in the first reading were considered as lesions on HR-MRI re-read) and No-change. Post-surgical follow-ups were conducted for up to 59months. Visual analysis of 18F-FDG PET showed focal or regional abnormality in 46 patients (68.6%), while the abnormal rate increased to 94.0% (P < 0.05) by co-registration. Of the 67 patients, 46.3% of them were identified as Change-1, and 11.9% as Change-2 after co-registration and HR-MRI re-read. Patients with Change-1 and -2 were more likely to be recommended to receive surgical resection (P< 0.001). In the 17 post-surgical patients, 88% had good outcomes, whereas 11.7% had poor outcomes during our study period. Pre-surgical evaluation by co-registration of 18F-FDG PET and HR-MRI could improve the identification of the epileptogenic onset zone (EOZ), and may further guide the surgical decision-making and improve the outcome of the refractory ETLE with normal conventional MRI; therefore, it should be recommended as a standard procedure for pre-surgical evaluation of these patients.