Subthalamic Nucleus Stimulation Modulates Cognitive Theory of Mind in Parkinson's Disease.

BACKGROUND: Theory of mind (ToM), the ability to infer others' mental state, is essential for social interaction among human beings. It has been widely reported that both cognitive (inference of knowledge) and affective (inference of emotion) components of ToM are disrupted in Parkinson's disease (PD). Previous studies usually focused on the involvement of the prefrontal cortex. OBJECTIVE: This study investigated the causal role of the subthalamic nucleus (STN), a key hub of the fronto-basal ganglia loops, in ToM. METHODS: Thirty-four patients with idiopathic PD (15 women, aged 62.2 ± 8.3 years) completed a Yoni task with deep brain stimulation (DBS) ON and OFF. The Yoni task was designed to separate the cognitive and affective components of ToM. Volumes of tissue activated (VTA) were computed for three subregions of the STN. RESULTS: DBS showed insignificant effects on ToM inference costs at the group level, which may be due to the large interindividual variability. The associative VTA correlated with the cognitive inference cost change but not the affective inference cost change. Patients with greater associative STN stimulation infer more slowly on cognitive ToM. Stimulating associative STN can adversely affect cognitive ToM in PD patients, especially in patients with a wide range of stimulation (≥0.157) or cognitive decline (Montreal Cognitive Assessment < 26). CONCLUSIONS: The associative STN plays a causal role in cognitive ToM in patients with PD. However, stimulating the associative STN likely impairs cognitive ToM and potentially leads to social interaction deficits in PD. © 2024 International Parkinson and Movement Disorder Society.

Deep learning and radiomics based automatic diagnosis of hippocampal sclerosis.

Accurate and rapid segmentation of the hippocampus can help doctors perform intractable temporal lobe epilepsy (TLE) preoperative evaluations to identify good surgical candidates. This study aims to establish a radiomics system for the automatic diagnosis of hippocampal sclerosis with the help of machine learning. A total of 240 cases were analysed to develop a diagnostic model. First, an automatic hippocampal segmentation process was established that exploits a priori knowledge of the relatively fixed location of the hippocampus in brain partitions, as well as a deep-learning segmentation network based on an Attention U-net. Then, we extracted 527 radiomics features from each side of the segmented hippocampus. The iterative sparse representation based on feature selection and a support vector machine classifier were finally used to establish the diagnostic model of hippocampal sclerosis. The diagnostic model consists of two consecutive steps: distinguish hippocampal sclerosis (HS) from normal control (NC) and detect whether the HS is located on the left or right side. When the automatic diagnosis model identified HS and NC, the sensitivity and specificity reached 0.941 and 0.917 in the 10-fold cross-validation set and 0.920 and 0.909 in the independent testing set. When the diagnostic model detected HS lateralization, the sensitivity and specificity reached 0.923 and 0.920 in cross-validation and 0.909 and 0.929 in independent testing. Our results show that the developed radiomics model can help detect TLE patients with hippocampal sclerosis and has the potential to simplify preoperative evaluations and select surgical candidates.

Reoperation for residual or recurrent hemifacial spasm after microvascular decompression.

PURPOSE: Microvascular decompression (MVD) surgery is the only potential curative method for hemifacial spasm (HFS). Little attention is paid to those recurrent/residual HFS cases. We want to study the potential etiology of those recurrent/residual HFS cases and evaluate the value of reoperation. METHODS: We retrospectively reviewed reoperation hemifacial spasm patients in our hospital. Intraoperative videos or images were carefully reviewed, and the etiology of recurrent/residual HFS is roughly divided into three categories. Intraoperative findings, surgical outcomes, and complications were carefully studied to assess the value of reoperation for recurrent/residual HFS patients. RESULTS: A total of 28 cases were included in our case series. Twenty-three of them are recurrent HFS cases, and 5 of them are residual HFS cases. The mean follow-up duration is 24.96 months. There are seventeen patients with missed culprit vessels or insufficient decompression of root exit zone (REZ), eight patients with Teflon adhesion, and three patients with improper application of decompression materials in our case series. The final reoperation outcome with 17 excellent, seven good, and four fair, respectively. Eight (28.57%) of them experienced long-term complications after reoperation. CONCLUSION: Re-operation for recurrent/residual HFS is an effective therapy and can achieve a higher cure rate. However, the complication rate is higher compared to the first MVD surgery. Accurately identifying REZ and proper decompression strategies to deal with the culprit vessels are very important for surgical success. TRIAL REGISTRATION NUMBER: UIN: researchregistry7603. Date of registration: Jan. 31st, 2022 "retrospectively registered".

Surgery for Epilepsy Involving Rolandic and Perirolandic Cortex: A Case Series Assessing Complications and Efficacy.

BACKGROUND: Surgical removal of lesions around the rolandic cortex remains a challenge for neurosurgeons owing to the high risk of neurological deficits. Evaluating the risk factors associated with motor deficits after surgery in this region may help reduce the occurrence of motor deficits. OBJECTIVE: To report our surgical experience in treating epileptic lesions involving the rolandic and perirolandic cortices. METHODS: We performed a single-center retrospective review of patients undergoing epilepsy surgeries with lesions located in the rolandic and perirolandic cortices. Patients with detailed follow-up information were included. The lesion locations, resected regions, and invasive exploration techniques were studied to assess their relationship with postoperative motor deficits. RESULTS: Forty-one patients were included. Twenty-three patients suffered from a transient motor deficit, and 2 had permanent disabilities after surgery. Six patients with lesions at the posterior bank of the precentral sulcus underwent resection, and 5 experienced short-term motor deficits. Two patients with lesions adjacent to the anterior part of the precentral gyrus, in whom the adjacent precentral gyrus was removed, experienced permanent motor deficits. Lesions located at the bottom of the central sulcus and invading the anterior bank of the central sulcus were observed in 3 patients. The patients did not experience permanent motor deficits after surgery. CONCLUSION: The anterior bank of the central sulcus is indispensable for motor function, and destruction of this region would inevitably cause motor deficits. The anterior bank of the precentral gyrus can also be removed without motor impairment if there is a preexisting epileptogenic lesion.

A novel epigenetic marker, Ten-eleven translocation family member 2 (TET2), is identified in the intractable epileptic brain and regulates ATP binding cassette subfamily B member 1 (ABCB1) in the blood-brain barrier.

Drug-resistant epilepsy (DRE) is a chronic condition derived from spontaneous changes and regulatory effects in the epileptic brain. As demethylation factors, ten-eleven translocation (TET) family members have become a focus in recent studies of neurological disorders. Here, we quantified and localized TET1, TET2 and 5-hydroxymethylcytosine (5-hmC) in the temporal lobe cortex of DRE patients (n = 27) and traumatic brain hemorrhage controls (n = 10) by immunochemical staining. TET2 and ATP binding cassette subfamily B member 1 (ABCB1) expression patterns were determined in the isolated brain capillaries of DRE patients. TET2 expression was significantly increased in the temporal cortical tissue of DRE patients with or without hippocampal sclerosis (HS) compared to control patients, while TET1 and 5-hmC showed no differences in expression. We also found that a particularly strong expression of TET2 in the vascular tissue of DRE patients. ABCB1 and TET2 have evidently higher expression in the vascular endothelium from the neocortex of DRE patients. In blood-brain barrier (BBB) model, TET2 depletion can cause attenuated expression and function of ABCB1. Data from a cohort study and experiments in a BBB model suggest that TET2 has a specific regulatory effect on ABCB1, which may serve as a potential mechanism and target in DRE.

Prognostic value of preoperative inflammatory markers among different molecular subtypes of lower-grade glioma.

BACKGROUND: The inflammatory response is closely related to cancer progression and prognosis. The aim of this study was to determine the prognostic value of preoperative inflammatory markers among different molecular subtypes of lower-grade glioma (LGG). METHODS: We performed a retrospective analysis of 214 patients with LGG from 2001 to 2013, evaluating the effect of the neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), platelet/lymphocyte ratio (PLR) and derived NLR (dNLR) on prognosis among different molecular subtypes. Isocitrate dehydrogenase (IDH) and telomerase reverse transcriptase (TERT) promotor mutations were detected by gene sequencing, and Chromosome arms 1p and 19q (1p/19q) codeletion was estimated via fluorescence in situ hybridization. RESULTS: Survival analysis showed that a high NLR, low LMR, and high dNLR were associated with poor prognosis, while the PLR had no prognostic significance. The subsequent molecular subtype analysis indicated that a high NLR and dNLR predicted worse survival in the IDH mutation only group, a high NLR and PLR predicted worse survival in the IDH and TERT promoter mutation group, and a high PLR was associated with shorter survival in the triple-positive group. Furthermore, univariate and multivariate Cox regression analysis suggested that the dNLR was an independent prognostic factor for LGG. Finally, the prognostic nomogram was developed by integrating the inflammatory marker dNLR and independent clinical risk factors. CONCLUSION: The results of this study indicated that a high dNLR was an independent risk factor for overall survival rates in patients with LGG, which may increase prognostic accuracy and improve patient outcomes.

Morphologic brain network predicts levodopa responsiveness in Parkinson disease.

Background: The levodopa challenge test (LCT) has been routinely used in Parkinson disease (PD) evaluation and predicts the outcome of deep brain stimulation (DBS). Guidelines recommend that patients with an improvement in Unified Parkinson's Disease Rating Scale (UPDRS)-III score > 33% in the LCT receive DBS treatment. However, LCT results are affected by many factors, and only provide information on the immediate effectiveness of dopamine. The aim of the present study was to investigate the relationship between LCT outcome and brain imaging features of PD patients to determine whether the latter can be used to identify candidates for DBS. Methods: A total of 38 PD patients were enrolled in the study. Based on improvement in UPDRS-III score in the LCT, patients were divided into low improvement (PD-LCT-L) and high improvement (PD-LCT-H) groups. Each patient's neural network was reconstructed based on T1-weighted magnetic resonance imaging data using the Jensen-Shannon divergence similarity estimation method. The network was established with the multiple kernel support vector machine technique. We analyzed differences in individual morphologic brain networks and their global and local metrics to determine whether there were differences in the connectomes of PD-LCT-L and PD-LCT-H groups. Results: The 2 groups were similar in terms of demographic and clinical characteristics. Mean ± SD levodopa responsiveness was 26.52% ± 3.47% in the PD-LCT-L group (N = 13) and 58.66% ± 4.09% in the PD-LCT-H group (N = 25). There were no significant differences between groups in global and local metrics. There were 43 consensus connections that were affected in both groups; in PD-LCT-L patients, most of these connections were decreased whereas those related to the dorsolateral superior frontal gyrus and left cuneus were significantly increased. Conclusion: Morphologic brain network assessment is a valuable method for predicting levodopa responsiveness in PD patients, which can facilitate the selection of candidates for DBS.

Association of xenobiotic receptor polymorphisms with carbamazepine response in epilepsy patients.

PURPOSE: Drug-resistant epilepsy is a problem worldwide. Xenobiotic receptors may play a significant role in the establishment of resistance to antiepileptic agents. Previous studies have confirmed that the metabolism and efficacy of carbamazepine (CBZ) can be influenced by xenobiotic receptors, especially pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AHR). Therefore, this study intends to elucidate the pharmacogenomic associations of polymorphisms of these xenobiotic receptors with the CBZ response in epilepsy patients, and these genetic data may be useful for the treatment of clinical prophylaxis and individualized treatment of intractable epilepsy. METHODS: Adult patients with epilepsy who were on CBZ-based monotherapy and combination therapy (n = 257) were genotyped, and the patients were divided into drug-responsive and drug-resistant groups according to the International League Against Epilepsy criteria. We sought to tag single-nucleotide polymorphisms (SNPs) of PXR, CAR and AHR that principally represent alleles associated with drug resistance risk; in addition, a gene interaction analysis reference panel was constructed for SNP-based imputation. RESULTS: No significant effects of PXR or AHR polymorphisms were observed. However, an interaction between the CAR rs2502815 variant and CBZ response was observed: in CBZ-based monotherapy and combination therapy patients, the GG genotype of the CAR rs2502815 variant (vs. wild-type homozygous) was independently associated with CBZ response after adjusting for variables [odds ratio (OR) = 0.389, 95% confidence interval (CI) 0.203-0.743, p = 0.004]. The results of the haplotype and gene interaction case-control analyses of the CBZ response were negative. Our results provide clinical data regarding the genetic possibilities of drug responses related to CAR variation in epilepsy patients. CONCLUSION: This study is the first to indicate a potentially relevant interaction between the CAR rs2502815 polymorphism and the CBZ response in epilepsy patients.

Quantitative analysis of cerebellar lobule morphology and clinical cognitive correlates in refractory temporal lobe epilepsy patients.

PURPOSE: This study was conducted to explore the cerebellar substructure volumetric alterations in refractory unilateral temporal lobe epilepsy (TLE) patients and the relationship with clinical factors and cognitive scores. METHODS: A total of 48 unilateral refractory TLE patients and 48 age- and gender-matched normal controls (NCs) were retrospectively studied. All subjects underwent high-resolution magnetic resonance imaging (MRI) and automatically segmented volumetric brain information was obtained using volBrain and Data Processing Assistant for Resting-State fMRI (DPARSF) separately. Clinical seizure features and cognitive scores were acquired by a structured review of medical records. RESULTS: The total volumes (TVs) of bilateral crus I, crus II, and IX were significantly smaller in the refractory unilateral TLE epilepsy patients. The gray matter volumes (GMVs) of cerebellar lobules showed lateralized reduction in ipsilateral III, IX, and contralateral crus II. Contralateral crus II GMV showed significant negative correlation with the duration of epilepsy (r = -0.31, p = 0.035) and positive association with the cognitive scores including long-term memory (LTM) (r = 0.39, p = 0.017), short-term memory (STM) (r = 0.51, p = 0.001) verbal comprehension index (VCI) (r = 0.37, p = 0.024), and perceptual organization index (POI) (r = 0.36, p = 0.030). The voxel-based morphometry (VBM) analysis proved similar results. The contralateral crus I GMV was significantly smaller in the generalized onset group (t = 2.536, p = 0.015). CONCLUSIONS: The lobules of the cerebellar in refractory TLE patients manifest different volumetric change characteristics. Crus II contralateral GMV is negatively correlated with the duration of epilepsy and positively associated with the cognitive scores.

Diagnosis and surgical treatment of non-lesional temporal lobe epilepsy with unilateral amygdala enlargement.

OBJECTIVE: Exploring the role of amygdala enlargement (AE) in temporal lobe epilepsy (TLE) without ipsilateral mesial temporal sclerosis (MTS) using comprehensive presurgical workup tools including traditional tools, automatically volumetric analysis, high-density EEG (HD-EEG) source imaging (HD-ESI), and stereoelectroencephalography (SEEG). METHODS: Nine patients diagnosed with TLE-AE who underwent resective surgeries encompassing the amygdala were retrospectively studied. HD-ESI was obtained using 256-channel HD-EEG on the individualized head model. For automatic volumetric analysis, 48 matched controls were enrolled. Diagnosis and surgical strategies were based on a comprehensive workup following the anatomo-electro-clinical principle. RESULTS: At post-operative follow-up (average 30.9 months), eight patients had achieved Engel class I and one Engel class II recovery. HD-ESI yielded unifocal source estimates in anterior mesial temporal region in 85.7% of cases. Automatic volumetric analysis showed the AE sides were consistent with the values determined through other preoperative workup tools. Furthermore, the amygdala volume of the affected sides in AE was significantly greater than that of the larger sides in controls (p < 0.001). Meanwhile, the amygdala volume lateral index (LI) of AE was significantly higher than in controls (p < 0.001). SEEG analysis showed that ictal onsets arose from the enlarged amygdala (and hippocampus) in all cases. CONCLUSION: In addition to traditional workup tools, automatic volumetric analysis, HD-ESI on individualized head model, and invasive SEEG can provide evidence of epileptogenicity in TLE-AE. Resective surgical strategies encompassing the amygdala result in better prognosis. In suspected TLE cases, more attention should be focused on detecting enlargement of amygdala which sometimes is "hidden" in "MR-negative" non-MTS cases.

Ictal stereo-electroencephalography onset patterns of mesial temporal lobe epilepsy and their clinical implications.

OBJECTIVE: The differences in mesial temporal epilepsy (MTE) stereo-electroencephalography (SEEG) seizure-onset patterns and their clinical implications remains unclear. METHODS: We analyzed consecutive patients with MTE undergoing non-invasive workup, SEEG evaluation and resective surgery. Cases were classified into either mesial temporal sclerosis (MTS) group or non-MTS group based on magnetic resonance imaging (MRI). Seizure-onset patterns of SEEG were classified to analyze their correlation with surgical outcome and clinical subtypes. RESULTS: Twenty-eight patients were studied. Twenty (71.4%) patients had Engel I outcome. Thirteen patients had one seizure-onset pattern, 15 had two or more patterns. Five patterns of seizure-onset were identified and seizure-onset zones differed significantly across the 5 patterns. No difference was observed in surgical outcome between patients with single or multiple seizure-onset patterns. Periodic spike-onset pattern was associated with MTS (P = 0.003) while burst-onset was associated with non-MTS lesions (P = 0.003). Patients with seizure-onsets outside the resected temporal lobe (multiple onsets) had poorer prognosis (P = 0.0046). CONCLUSION: We identified 5 distinct onset patterns of MTE and correlated two of them with MRI findings. Multiple seizure-onset patterns in MTE may not necessarily suggest poor outcome. Patients with multi-focal seizure-onsets including seizures originating outside the resected temporal lobe have poorer outcome. SIGNIFICANCE: This study identifies distinct onset patterns of MTE and their clinical implications.

Implantation of glial cell line-derived neurotrophic factor-expressing adipose tissue-derived stromal cells in a rat Parkinson's disease model.

In previous studies, the effects of glial cell line-derived neurotrophic factor (GDNF) expressing adipose tissue-derived stromal cells (ADSCs) on Parkinson's disease (PD) models have been studied but have not been elucidated. The present study aims to investigate this phenomenon and trace their differentiation in vivo. In our study, ADSCs were harvested from adult Sprague-Dawley rats, then genetically modified into GDNF-expressing system by lentivirus. The secretion of GDNF from the transduced cells was titrated by enzyme-linked immunosorbent assay (ELISA). Cellular differentiation in vitro was observed after induction. To examine survival and differentiation in vivo, they were injected into the striatum of 6-hydroxydopamine-lesioned rats, whose apomorphine-induced rotations were examined 2, 7, 14 and 21d after grafting. It's found that GDNF-expressing ADSCs can differentiate into neuron-like cells in vitro. Moreover, engrafted GDNF-expressing ADSCs survived at least 90 days post-grafting and differentiated into dopaminergic neuron-like cells. Most importantly, these cells drastically improved the clinical symptoms of PD rats. In conclusion, ADSCs can be efficiently engineered by lentivirus system and deliver a therapeutic level of the transgene to target tissues. GDNF-ADSCs can improve behavior phenotype in the rat PD model. Moreover, ADSCs is a more readily available source of dopaminergic neurons, though a more effective procedure needs to be developed to enrich the number of differentiation.

Urinary incontinence following deep brain stimulation of the globus pallidus internus: case report.

Deep brain stimulation (DBS) is a well-established therapy for patients with advanced Parkinson's disease (PD), dystonia, and other movement disorders. In contrast to the strong positive effects that have been documented for motor symptoms, the effects of DBS on nonmotor symptoms have not been fully elucidated. Some reports suggest that stimulation of the subthalamic nucleus may improve lower urinary tract symptoms in patients with PD; however, reports of the effects of globus pallidus internus (GPi) DBS on urinary symptoms are limited. The authors present the case of a 49-year-old woman with PD who developed severe urinary incontinence after 27 months of GPi DBS. The urinary incontinence disappeared when stimulation was turned off, and reemerged after it was turned on again. After activation of a more dorsal contact in the left electrode, the patient's urinary dynamics returned to normal.

Predictors to quality of life improvements after subthalamic stimulation in Parkinson's disease.

INTRODUCTION: Subthalamic deep brain stimulation (STN DBS) has been reported to improve the quality of life (QoL) related to Parkinson's disease (PD). However, not all subjects are satisfied with the postsurgical QoL outcome. We aimed to detect the related factors and possible predictors to QoL improvement for those PD patients one year after STN DBS. MATERIALS AND METHODS: A total of 45 PD patients with bilateral STN DBS surgery were included and followed up for 1 year. The Reliable Change Index (RCI) was adapted to determine the individual postsurgical QoL outcome. The changes of QoL were correlated with baseline parameters and the changes of progression parameters using Pearson's correlation. The exploratory stepwise regressions were adopted to detect the extents of baseline variables and progression parameters. The predictors to QoL outcome were detected using the logistic regression analysis. RESULTS: A total of 51.1% of the patients reported a better QoL, 40.0% of patients reported an unchanged QoL, while 8.9% of patients reported a worsening of QoL. The subdomains of mobility, activity of daily living, cognition, and bodily discomfort improved significantly after the surgery. The presurgical factors including QoL, dopaminergic medication burden, disease stages, depression scores, and postsurgical reductions in depression and nonmotor scores were found to correlate with QoL changes. Furthermore, the greater presurgical QoL burden, lesser dopaminergic medication exposure, and earlier disease stages were predictors to QoL improvements. CONCLUSION: The clinicians should carefully evaluate the nonmotor symptoms and life quality in those patients at relatively earlier stages and with lower medicine dosage to get more successful DBS outcomes.

Accurate source imaging based on high resolution scalp electroencephalography and individualized finite difference head models in epilepsy pre-surgical workup.

PURPOSE: High-density electroencephalographic source imaging (HD-ESI) has emerged as a useful tool for pre-surgical epilepsy workup. However, it is not routinely used in clinical evaluations due to several factors, one of which is the challenge associated with creating anatomically accurate head models. Reasonable solutions now exist and the present study aims to evaluate the use of these highly resolved individual head models in pre-surgical epilepsy evaluation. METHODS: Nine patients with intractable epilepsy who were candidates for resective epilepsy surgeries participated in the study. For each patient, 256-channel electroencephalography data were acquired along with individual structural MRI data that was used to construct individual finite difference models (iFDM). Accuracy of HD-ESI based on iFDM (HD-ESI-iFDM) was evaluated using multiple criteria, including concordance with intracranial electroencephalography (icEEG) and location of surgical resection. Performance of HD-ESI-iFDM was also compared against MRI and positron emission tomography (PET) results. RESULTS: In all but one patient resective surgeries resulted in seizure-free outcome. Source locations derived from HD-ESI-iFDM demonstrated concordance with surgical resection and with icEEG data, when available. The HD-ESI-iFDM also contributed to the planning of intracranial electrodes implantation. Compared to MRI or PET, HD-ESI-iFDM provided more accurate localization of the epileptogenic zone. CONCLUSION: When acquired with high-density sensor arrays and source imaging is performed with anatomically accurate head models, electroencephalography can contribute meaningfully to epilepsy pre-surgical workup for localization of the epileptogenic zone. Now that both high-density electroencephalography and individualized FDM models can be routinely obtained, it can be incorporated as part of clinical practice.

Comprehensive preoperative work-up and surgical treatment of low grade tumor/benign lesion related temporal lobe epilepsy.

OBJECTIVE: Generally low-grade tumor/benign lesion related temporal lobe epilepsy (LGT/BL-TLE) is considered easier to treat and has better prognosis when compared to non-lesional TLE. However, multiple disputes exist in surgical management of this epilepsy entity. This study aims to discuss comprehensive preoperative work-up, surgical strategies and outcome of it. METHODS: A retrospective review of sixty LGT/BL-TLE cases which underwent comprehensive preoperative work-up and then resective surgeries was conducted. Surgical strategies were categorized into limited and expanded resections. Surgical efficacy was evaluated using Engel grading after telephone or clinic follow-up and compared statistically. RESULTS: Preoperative work-up includes magnetic resonance imaging (MRI), conventional electroencephalography, semiology evaluation, positron emission tomography (PET) and 256-channel dense-array electroencephalography source imaging (256-ch dESI). In aspect of concordance with epileptic lesions demonstrated on MRI, 256-ch dESI was more accurate than PET (72.7% vs. 39.4%) (p<0.05). Limited resections were performed in 28 cases while expanded resections in 32 cases. Altogether the surgical efficacy was: Engel grade I 86.7%, I+II 95.0%. Comparison of surgical outcome showed neither the outcome between limited and expanded resection nor the outcome between mesial and neocortical TLE (mTLE & nTLE) undergoing limited resections was significantly different (p>0.05). CONCLUSIONS: For LGT/BL-TLE, most surgical strategies can be made preoperatively after comprehensive work-up rather than intraoperatively. Limited and expanded strategies yield similar surgical outcome in either nTLE or mTLE as long as comprehensive work-up supports the strategy and the epileptic lesion is totally removed. 256-ch dESI which can visualize both structural and electrophysiological lesions may be contributable to surgical planning of this entity.

Application of 256-channel dense array electroencephalographic source imaging in presurgical workup of temporal lobe epilepsy.

OBJECTIVE: This study evaluated the localization precision of 256-channel dense array electroencephalographic source imaging (dESI) in comparison to conventional noninvasive tools. In addition, the study was designed to analyze the relationship between the 256-channel dESI source patterns and surgical outcome. METHODS: Forty-three patients with temporal lobe epilepsy (TLE) who underwent one-stage resective surgeries were recruited in this study. We compared dESI with other noninvasive evaluation methods by comparing results with resections that eliminate or significantly reduced seizures according to sub-lobule and lobule criteria. Sensitivity and specificity of multiple evaluation methods were calculated. Kaplan-Meier analysis was performed to evaluate the relationship between source patterns and surgical outcome. RESULTS: dESI showed the best sensitivity (sub-lobule, 91.4%; lobule, 97.1%) and specificity (75%) for both sub-lobule and lobule criteria. The Kaplan-Meier survival analysis showed that cases with "single source" had better prognosis than with "multiple sources" (p<0.05); cases of "sources within resection" showed better surgical prognosis than cases of "sources outside resection" (p<0.05). CONCLUSION: In this study, 256-channel dESI provided a higher clinical yield than the other most broadly used noninvasive presurgical workup tools. dESI results with "single source" correlated strongly to good prognosis, while cases with "multiple sources" may cautiously be considered as candidates for one-stage resective surgeries. The resection of the irritative zone identified by interictal epileptiform discharges (IEDs) was related to good surgical prognosis in TLE. SIGNIFICANCE: In the presurgical workup of TLE, the clinical yield of 256-channel dESI is high. Patterns of dESI results are related to surgical prognosis, and they can be instructive for presurgical planning. The resection of the irritative zone can be related to good surgical prognosis in TLE.

Application of intraoperative motor evoked potential monitoring during giant internal carotid artery aneurysm surgery using prolonged temporary occlusion.

BACKGROUND: Clipping and bypass surgery are common therapeutic options for the management of giant internal carotid artery (ICA) aneurysms. However, potential ischemic risks may be exaggerated by prolonged temporary occlusion (PTO) during the surgery. Monitoring motor-evoked potentials (MEPs) is a sensitive technique for detecting potential ischemia intraoperatively. This preliminary study was designed to evaluate the effectiveness of applying MEP monitoring during giant ICA aneurysm surgery using PTO. METHODS: From July 2009 to July 2012, 11 patients with giant ICA aneurysms who could not pass the preoperative hemodynamic evaluations were enrolled in this study. MEP monitoring was utilized intraoperatively in all cases. Clipping was performed if there were no significant MEP changes under PTO. A variant extracranial-to-intracranial (EC-IC) bypass was performed if there was reproducible loss of MEP signals after PTO or unclippable anatomic features. RESULTS: Five patients underwent clipping alone and six underwent bypass. There were no significant differences in baseline clinical data between the two groups. The overall percentage of patients with good outcomes (Glasgow Outcome Score ≥4) improved from 72.7 % (8/11) postoperatively to 90.9 % (10/11) after 26.0 ± 9.5 months of follow-up. There were no significant differences between the clipping and bypass groups regarding short- and long-term outcomes (p = 0.545 and p = 1.000). CONCLUSIONS: MEP monitoring is useful for evaluating the safety of PTO, surgical strategy, and outcomes of giant ICA aneurysm surgery. Direct clipping during safe PTO under intraoperative MEP monitoring is applicable for giant ICA aneurysms. Its use achieved favorable outcomes by indicating the need for bypass surgery.

Surgical treatment of MRI-negative temporal lobe epilepsy based on PET: a retrospective cohort study.

INTRODUCTION: Using retrospective and comparative methods, we aim to discuss the surgical treatment of magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) presented with positive positron emission tomography (PET) results. METHODS: From the viewpoint of semiology, demography, surgical treatment and prognosis evaluation, we compared 19 MRI-negative, PET-positive TLE patients to 41 TLE with hippocampal sclerosis patients, and then statistically analyzed the differences between these 2 cohorts. RESULTS: Under intraoperative electrocorticography monitoring, all patients underwent successful standard anterior temporal lobectomy. It appears that there is no significant difference between the surgical outcome of MRI-negative/PET-positive TLE (Engle class I: 68.4%, Engle class I + II: 84.2%) and TLE with hippocampal sclerosis (Engle class I: 68.3%, Engle class I + II: 80.5%). The analysis also shows that to some extent MRI-negative, PET-positive TLE might be distinct from TLE with hippocampal sclerosis as a clinical entity, i.e. the former is not a subtype of the latter. History of febrile convulsion and occurrence of secondary generalized tonic-clonic seizure may possibly differentiate them from each other. CONCLUSION: Successful resective surgery of MRI-negative TLE based on PET can yield similar favorable results to TLE with hippocampal sclerosis. This study demonstrates that with reasonable presurgical workup, such TLE subtypes can be surgically treated without invasive intracranial electrode implantation.

Motor evoked potential monitoring during surgery of middle cerebral artery aneurysms: a cohort study.

BACKGROUND: Motor evoked potential (MEP) monitoring has been widely used in brain or spine surgery to recognize potential damage of the pyramidal motor system. However, its ability to detect ischemic injury during middle cerebral artery (MCA) aneurysm surgery remains unclear. A prospective cohort study was designed to evaluate MEP changes during MCA aneurysm surgery. METHODS: From January 2009 to August 2011, 89 patients underwent MCA aneurysm surgery and were prospectively divided into 2 groups: MEP monitoring group and control group. Based on an amplitude decrement of >50% or loss, a 2-stage warning criterion of MEP changes was established. Concomitant somatosensory evoked potential changes were also recorded. MEP changes occurred in 15 patients, and various methods were used to avoid continued brain ischemia. Indocyanine green angiography and Doppler ultrasonography were performed if needed. A head computed tomography scan was performed immediately and the day after the operation. RESULTS: At discharge, neither motor status nor Glasgow Coma Scale score was significantly different between the 2 groups. However, at the latest follow-up (mean, 31.9 months), motor status of the patients in the monitoring group was better (P = 0.037). MEP monitoring was identified as an independent prognostic factor for motor outcome in long-term results by multivariate analysis (P = 0.042). Both wave loss and >50% amplitude decrement of MEP monitoring showed good predictive value when used as part of a 2-stage warning criterion. CONCLUSIONS: MEP monitoring is reliable for evaluation of the ischemic status of the pyramidal motor system during MCA aneurysm surgery and can improve surgical outcomes when used appropriately.