Spectrum of Ictal-Interictal Continuum: The Significance of 2HELPS2B Score and Background Suppression

PURPOSE

The aims of this study were to identify (1) the spectrum of ictal-interictal continuum (IIC) using the two dimensions of 2HELPS2B score and background suppression and (2) the response to subsequent anti-seizure drugs depends on the spectrum of IIC.

METHODS

The study prospectively enrolled 62 patients with IIC on EEG. The diagnosis of nonconvulsive status epilepticus was attempted with Salzburg criteria as well as clinical and neuroimaging data. IICs were dichotomized into patients with nonconvulsive status epilepticus and coma-IIC. The 2HELPS2B score was evaluated as the original proposal. The suppression ratio was analyzed with Persyst software.

RESULTS

Forty-seven cases (75.8%) were nonconvulsive status epilepticus-IIC and 15 cases (24.2%) were coma-IIC. Multivariate analysis revealed that the 2HELPS2B score was the only significant variable dichotomizing the spectrum of IIC (odds ratio, 3.0; 95% confidence interval, 1.06-8.6; P = 0.03 for nonconvulsive status epilepticus-IIC). In addition, the suppression ratio was significantly negatively correlated with 2HELPS2B scores (Spearman coefficient = -0.37, P = 0.004 for left hemisphere and Spearman coefficient = -0.3, P = 0.02 for right hemisphere). Furthermore, patients with higher 2HELPS2B score (74% [14/19] in ≥2 points vs. 44% [14/32] in <2 points, P = 0.03 by χ 2 test) and lower suppression ratio (62% [23/37] in ≤2.18 vs. 35% [6/17] in >2.18, P = 0.06 by χ 2 test) seemed to be more responsive to subsequent anti-seizure drug.

CONCLUSIONS

The 2HELPS2B score and background suppression can be used to distinguish the spectrum of IIC and thereby predict the response to subsequent anti-seizure drug.

Alterations in the metabolic networks of temporal lobe epilepsy patients: A graph theoretical analysis using FDG-PET

OBJECTIVE

The aim of this study is to investigate changes in metabolic networks based on fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with drug-resistant temporal lobe epilepsy (TLE) (with and without hippocampal sclerosis [HS]) when compared with healthy controls.

METHODS

We retrospectively enrolled 30 patients with drug-resistant temporal lobe epilepsy (17 patients with HS and 13 patients without HS) and 39 healthy controls. All subjects underwent interictal FDG-PET scans, which were analyzed to obtain metabolic connectivity using graph theoretical analysis. We investigated the differences in metabolic connectivity between patients with drug-resistant TLE (with and without HS) and healthy controls.

RESULTS

When compared with healthy controls, TLE patients with HS showed alterations of global and local metabolic connectivity. When considering global connectivity, TLE patients with HS had a decreased average degree with increased modularity. When considering local connectivity, TLE patients with HS displayed alterations of betweeness centrality in widespread regions. However, there were no alterations of global metabolic connectivity in TLE patients without HS when compared with healthy controls. In addition, when compared to TLE patients without HS, TLE patients with HS had increased modularity.

SIGNIFICANCE

Our study demonstrates more severe alterations in metabolic networks based on FDG-PET in TLE patients with HS than in those without HS and healthy controls. This may represent distinct epileptic networks in TLE patients with HS versus those without HS, although both are drug-resistant focal epilepsy.

Robotic-assisted latissimus dorsi muscle flap for autologous chest reconstruction in poland syndrome

BACKGROUND

As chest reconstructions in Poland syndrome are performed for patients at young ages, patients are generally concerned about conspicuous scars. Meanwhile, a robotic-assisted latissimus dorsi (LD) muscle harvest with inconspicuous scars has been performed for autologous breast reconstruction. As our experience with robotic-assisted LD flap harvest has increased over the years, we have made improvements in surgical techniques to optimize results. The purpose of this study was to introduce and identify the role of the refined robotic-assisted LD muscle flap harvest technique in autologous chest reconstruction in patients with Poland syndrome.

METHODS

Autologous chest reconstruction using a robotic-assisted LD muscle flap harvest was performed for 21 patients with Poland syndrome. Subjective assessments were performed to evaluate improvement in chest deformity, patient satisfaction with overall outcomes, chest symmetry, and scars. Assessments by the operator and two independent evaluating investigators were carried out with patients' photographs. The complication rates and the time for robotic surgery were also evaluated.

RESULTS

At the last visit, the average patient grades for improvement in chest deformity, satisfaction with overall outcomes, chest symmetry, and scars were 4.80, 4.72, 4.18, and 4.87, respectively. Assessments by the operator and two independent evaluating investigators demonstrated that improvement in chest deformity was achieved in all patients. No serious complications such as flap loss were recorded for any patient. The time for robotic surgery markedly decreased as experience accumulated.

CONCLUSIONS

Surgical refinements for robotic-assisted LD flap harvest might be effective and reduce operative times for patients with Poland syndrome.

Characteristics of Perfusion Computed Tomography Imaging in Patients with Seizures Mimicking Acute Stroke

Introduction: Seizures as acute stroke mimics are a diagnostic challenge. Objective: The aim of the study was to characterize the perfusion patterns on perfusion computed tomography (PCT) in patients with seizures masquerading as acute stroke. Methods: We conducted a study on patients with acute seizures as stroke mimics. The inclusion criteria for this study were patients (1) initially presenting with stroke-like symptoms but finally diagnosed to have seizures and (2) with PCT performed within 72 h of seizures. The PCT of seizure patients (n = 27) was compared with that of revascularized stroke patients (n = 20) as the control group. Results: Among the 27 patients with seizures as stroke mimics, 70.4% (n = 19) showed characteristic PCT findings compared with the revascularized stroke patients, which were as follows: (1) multi-territorial cortical hyperperfusion {(73.7% [14/19] vs. 0% [0/20], p = 0.002), sensitivity of 73.7%, negative predictive value (NPV) of 80%}, (2) involvement of the ipsilateral thalamus {(57.9% [11/19] vs. 0% [0/20], p = 0.007), sensitivity of 57.9%, NPV of 71.4%}, and (3) reduced perfusion time {(84.2% [16/19] vs. 0% [0/20], p = 0.001), sensitivity of 84.2%, NPV of 87%}. These 3 findings had 100% specificity and positive predictive value in predicting patients with acute seizures in comparison with reperfused stroke patients. Older age was strongly associated with abnormal perfusion changes (p = 0.038), with a mean age of 66.8 ± 14.5 years versus 49.2 ± 27.4 years (in seizure patients with normal perfusion scan). Conclusions: PCT is a reliable tool to differentiate acute seizures from acute stroke in the emergency setting.

Thalamic nuclei volumes and network in juvenile myoclonic epilepsy

OBJECTIVE

The aim of this study was to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with juvenile myoclonic epilepsy (JME) compared to healthy controls.

METHODS

We enrolled 50 patients with JME and 42 healthy controls. We obtained structural volumes of the individual thalamic nuclei based on T1-weighted imaging and performed intrinsic thalamic network analysis using graph theoretical analysis. We analyzed the differences of thalamic nuclei volumes and intrinsic thalamic networks between the patients with JME and healthy controls.

RESULTS

In the patients with JME, there were significant alterations of thalamic nuclei volumes compared to healthy controls. Right laterodorsal and left suprageniculate nuclei volumes were significantly increased (0.0019% vs 0.0014%, P < .0001; 0.0011% vs 0.0008%, P = .0006, respectively), whereas left ventral posterolateral, left ventromedial, and left pulvinar inferior nuclei volumes (0.0572% vs 0.0664%, P = .0001; 0.0013% vs 0.0015%, P = .0002; 0.0120% vs 0.0140%, P < .0001, respectively) were decreased in the patients with JME. Furthermore, the intrinsic thalamic network of the patients with JME was significantly different from that of the healthy controls. The modularity in the patients with JME was significantly increased over that in healthy controls (0.0785 vs 0.0212, P = .039).

CONCLUSION

We found that there were significant alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with JME compared to healthy controls. These findings might contribute to the underlying pathogenesis of in JME.

A Case of a ‘Rude’ but Not to be Missed Manifestation of Epilepsy: Ictal Swearing

Swearing is described in various neurological conditions such as Tourette syndrome, Lesch–Nyhan syndrome and post stroke or encephalitis. However, swearing as an ictal manifestation or automatism has rarely been reported. We herein describe a case with swearing as a predominant manifestation in focal epilepsy.

Cognitive Intervention with Musical Stimuli Using Digital Devices on Mild Cognitive Impairment: A Pilot Study

The effect of music therapy on cognitive function has been widely reported; however, its clinical implications remain controversial. Performing therapeutic musical activities in groups using individualized instruments can help overcome the issues of engagement and compliance. We aimed to evaluate the effect of a cognitive intervention with musical stimuli using digital devices on mild cognitive impairment (MCI). In this prospective study, 24 patients with MCI (intervention group, 12; and control group, 12) were enrolled. We developed an electronic device with musical instruments and the Song-based Cognitive Stimulation Therapy protocol (SongCST). Patients in the intervention group underwent a 10-week cognitive intervention involving musical stimuli generated by our device. Effect of the intervention on cognitive function was evaluated by the Mini-Mental State Examination-Dementia Screening (MMSE-DS), Montreal Cognitive Assessment-Korean (MOCA-K), and Clinical Dementia Rating Scale Sum of Boxes (CDR-SOB). In the intervention group, MMSE-DS and MOCA-K scores improved significantly after the 10-week intervention. The changes in MOCA-K and CDR-SB scores were significantly different between the intervention and control groups. Our study showed that music therapy with digital devices has a positive effect on the executive function and overall disease severity in patients with MCI. Our study can facilitate individualization of music therapy using digital devices in groups.

A rare but treatable cause of recurrent chest pain - Ictal chest pain

Background

Chest pain as the primary manifestation of epilepsy is extremely rare and has only been reported once to date.

Case presentation

We herein describe a 47-year-old woman with recurrent chest pain for 3 years. The cause of her chest pain remained elusive despite extensive investigations including comprehensive cardiac work-up. She was referred to the neurology clinic for one episode of confusion. Video-electroencephalographic monitoring detected unequivocal ictal changes during her habitual chest pain events. She has remained chest pain (seizure) free with a single antiseizure drug.

Conclusions

This case underlines the importance of epilepsy as a rare yet treatable cause of recurrent chest pain. Further studies are required to determine the pathophysiology of ictal chest pain.

A Nomogram for Predicting Amyloid PET Positivity in Amnestic Mild Cognitive Impairment

BACKGROUND

Most clinical trials focus on amyloid-β positive (Aβ+) amnestic mild cognitive impairment (aMCI), but screening failures are high because only a half of patients with aMCI are positive on Aβ PET. Therefore, it becomes necessary for clinicians to predict which patients will have Aβ biomarker.

OBJECTIVE

We aimed to compare clinical factors, neuropsychological (NP) profiles, and apolipoprotein E (APOE) genotype between Aβ+ aMCI and Aβ-aMCI and to develop a clinically useful prediction model of Aβ positivity on PET (PET-Aβ+) in aMCI using a nomogram.

METHODS

We recruited 523 aMCI patients who underwent Aβ PET imaging in a nation-wide multicenter cohort. The results of NP measures were divided into following subgroups: 1) Stage (Early and Late-stage), 2) Modality (Visual, Verbal, and Both), 3) Recognition failure, and 4) Multiplicity (Single and Multiple). A nomogram for PET-Aβ+ in aMCI patients was constructed using a logistic regression model.

RESULTS

PET-Aβ+ had significant associations with NP profiles for several items, including high Clinical Dementia Rating Scale Sum of Boxes score (OR 1.47, p = 0.013) and impaired memory modality (impaired both visual and verbal memories compared with visual only, OR 3.25, p = 0.001). Also, presence of APOEɛ4 (OR 4.14, p < 0.001) was associated with PET-Aβ+. These predictors were applied to develop the nomogram, which showed good prediction performance (C-statistics = 0.79). Its prediction performances were 0.77/0.74 in internal/external validation.

CONCLUSIONS

The nomogram consisting of NP profiles, especially memory domain, and APOEɛ4 genotype may provide a useful predictive model of PET-Aβ+ in patients with aMCI.

Sex-specific relationship of cardiometabolic syndrome with lower cortical thickness

OBJECTIVE

To investigate whether cardiometabolic factors were associated with age-related differences in cortical thickness in relation to sex.

METHODS

In this cross-sectional study, we enrolled 1,322 cognitively normal elderly (≥65 years old) individuals (774 [58.5%] men, 548 [41.5%] women). We measured cortical thickness using a surface-based analysis. We analyzed the associations of cardiometabolic risk factors with cortical thickness using multivariate linear regression models after adjusting for possible confounders and interactions with age.

RESULT

Among women, hypertension (β = -1.119 to -0.024, p < 0.05) and diabetes mellitus (β = -0.920, p = 0.03) were independently associated with lower mean cortical thickness. In addition, there was an interaction effect between obesity (body mass index [BMI] ≥27.5 kg/m²) and age on cortical thickness in women (β = -0.324 to -0.010, p < 0.05), suggesting that age-related differences in cortical thickness were more prominent in obese women compared to women with normal weight. Moreover, low education level (<6 years) was correlated with lower mean cortical thickness (β = -0.053 to -0.046, p < 0.05). Conversely, among men, only being underweight (BMI ≤18.5 kg/m², β = -2.656 to -0.073, p < 0.05) was associated with lower cortical thickness.

CONCLUSIONS

Our findings suggest that cortical thickness is more vulnerable to cardiometabolic risk factors in women than in men. Therefore, sex-specific prevention strategies may be needed to protect against accelerated brain aging.

Clinical opinion: Earlier employment of polytherapy in sequential pharmacotherapy of epilepsy

Modern pharmacotherapy for epilepsy consists of orderly, sequential drug trials, in which antiepileptic drugs (AEDs) are chosen under the concept of individual patient-oriented (or - tailored) pharmacotherapy. Although monotherapy has been established as the preferred mode of AEDs therapy in both newly diagnosed and drug resistant epilepsies, there are still lack of evidence to favor either monotherapy or polytherapy in epilepsy, which has generated continuing controversies on the preferred mode of pharmacotherapy. However, each mode of pharmacotherapy may have both advantages and disadvantages, which are different and variable related to individual case scenario. We conducted a brief comparative overview between monotherapy and polytherapy to provide clues for earlier employment of polytherapy in each steps of sequential drug trials. Previous claims about the advantages of monotherapy over polytherapy are not supported but gradually losing its ground by the introduction of a large number of drugs carrying pharmacological advantages for combination therapy. Current evidence stresses the importance of combining drugs having synergistic interactions for better outcome of polytherapy, which has not been considered in previous clinical investigations comparing monotherapy and polytherapy. It is likely that a significant improvement in the outcome of current AEDs therapy is feasible by earlier employment of polytherapy as well as identification of combination drug regimens carrying synergistic interactions. At present, lamotrigine(LTG) and valproate(VPA) combination regimen is the only well documented synergistic regimen, but there are a long-list of candidate regimens requiring future trials in appropriate designs.

Antiepileptic Drug Therapy in Patients with Drug-Resistant Epilepsy

Antiepileptic drug (AED) therapy starts with an accurate diagnosis of epilepsy and is followed by sequential drug trials. Seizure freedom is largely achieved by the first two drug trials; thus, epilepsy that cannot be controlled after appropriately conducted trials of the first two drugs is defined as drug-resistant epilepsy (DRE). It is still unclear which mode of pharmacotherapy, among monotherapy and polytherapy, shows better outcomes in cases of DRE. However, in a recent large hospital cohort study over past two decades, combination therapy was associated with a progressive increase in seizure-free rate than monotherapy in DRE. The benefits of polytherapy in the management of DRE might be related to the recent introduction of many new AEDs with different and novel mechanisms of action and better pharmacokinetic and tolerability profiles. These new AEDs were introduced to the market after they have proven their superiority over placebos in randomized controlled trials (RCTs) on add-on therapy in patients with DRE. Therefore, polytherapy including these new AEDs in the regimen is the approved mode of treatment for cases of DRE; this has prompted physicians to try various combinations of polytherapy to optimize the clinical outcomes. In addition, the significant discrepancies in AED responder rates between RCTs and real-world practice may support the importance of judicious use of new drugs in polytherapy by experienced epileptologists. Most experts now agree to the concept of “rational polytherapy” consisting of mechanistic combinations of AEDs exerting synergistic interactions and to the importance of continuing trials of different rational polytherapy regimens to improve the outcome of the core population of epilepsy patients in the long term.

Effect of 12-week home-based cognitive training on cognitive function and brain metabolism in patients with amnestic mild cognitive impairment

Purpose

We assessed the effect of home-based cognitive intervention (HCI) on cognitive function along with brain metabolism by 18F-FDG PET in patients with amnestic MCI (aMCI).

Patients and methods

Fifty-seven patients with aMCI from three hospitals were randomized (30 HCI, 27 control). For 12 weeks, subjects received HCI. Thirty-two subjects (15 HCI, 17 control) underwent brain 18-F-FDG-PET imaging at baseline and at 12 and 24 weeks.

Results

The HCI group showed significant improvement in the scores of the Controlled Oral Word Association Test (COWAT) 12 and at 24 weeks. Significant brain metabolic changes by 18F-FDG PET were not observed.

Conclusion

The current study suggests that HCI was effective in improving general cognition along with frontal executive function in patients with aMCI.

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

BACKGROUND

We aimed to evaluate the brain morphology of patients with genetic generalized epilepsy (GGE) compared to healthy subjects. In addition, we investigated whether there are differences in brain morphology among different GGE syndromes.

METHODS

We enrolled 100 patients with a clinical diagnosis of GGE. The patients were classified into different syndrome groups according to their predominant seizure type, age of seizure onset, and electroencephalography characteristics (12 childhood absence epilepsy [AE], 13 juvenile AE, 56 juvenile myoclonic epilepsy, and 19 epilepsy with generalized tonic-clonic alone). We used surface-based morphometry of brain magnetic resonance imaging to evaluate brain morphology.

RESULTS

We found significantly widespread alterations of brain morphology, including cortical thickness and volumes in several regions in the patients with GGE compared to healthy controls. In addition, we observed significant differences in alterations of cortical thickness and volumes among the different GGE syndromes. However, there were no differences in cortical surface areas between the patients with GGE and healthy controls. There was a significantly negative correlation between the duration of epilepsy and most of the each measures of abnormal brain morphology.

CONCLUSIONS

The main finding of this study is that brain morphology in patients with GGE is significantly different from that in healthy controls. In addition, we found that the different GGE syndromes show distinct structural brain morphology, especially cortical thickness, which can help us understand the pathogenesis of GGE syndromes.

Pivotal Role of Subcortical Structures as a Network Hub in Focal Epilepsy: Evidence from Graph Theoretical Analysis Based on Diffusion-Tensor Imaging

Background and Purpose

There is accumulating evidence that epilepsy is caused by network dysfunction. We evaluated the hub reorganization of subcortical structures in patients with focal epilepsy using graph theoretical analysis based on diffusion-tensor imaging (DTI). In addition, we investigated differences in the values of diffusion tensors and scalars, fractional anisotropy (FA), and mean diffusivity (MD) of subcortical structures between patients with focal epilepsy and healthy subjects.

Methods

One hundred patients with focal epilepsy and normal magnetic resonance imaging (MRI) findings and 80 age- and sex-matched healthy subjects were recruited prospectively. All subjects underwent DTI to obtain data suitable for graph theoretical analysis. We investigated the differences in the node strength, cluster coefficient, eigenvector centrality, page-rank centrality measures, FA, and MD of subcortical structures between patients with epilepsy and healthy subjects.

Results

After performing multiple corrections, the cluster coefficient and the eigenvector centrality of the globus pallidus were higher in patients with epilepsy than in healthy subjects (p=0.006 and p=0.008, respectively). In addition, the strength and the page-rank centrality of the globus pallidus tended to be higher in patients with epilepsy than in healthy subjects (p=0.092 and p=0.032, respectively). The cluster coefficient of the putamen was lower in patients with epilepsy than in healthy subjects (p=0.004). The FA values of the caudate nucleus and thalamus were significantly lower in patients with epilepsy than in healthy subjects (p=0.009 and p=0.007, respectively), whereas the MD value of the thalamus was higher than that in healthy subjects (p=0.005).

Conclusions

We discovered the presence of hub reorganization of subcortical structures in focal epilepsy patients with normal MRI findings, suggesting that subcortical structures play a pivotal role as a hub in the epilepsy network. These findings further reinforce the idea that epilepsy is a network disease.

Vascular factors and neuropathy in lower limb of diabetic patients

Asymmetric clinical presentation in some patients with diabetic polyneuropathy may result from the different vascular environments in both lower limbs. The aim of the study is to determine the association of neuropathy with vascular factors in each lower limb of diabetic patients. A total of 102 patients (204 lower limbs) given a diagnosis of diabetic polyneuropathy were enrolled. The primary end points are sensory nerve action potential (SNAP) amplitude and conduction velocity (CV) of the sural nerve and independent variables are vascular and nonvascular factors. Vascular factors include mean arterial pressure and pulse pressure at the ankle, ankle-brachial index, and arterial stiffness assessed by pulse wave velocity. Nonvascular factors include age, gender, height, body weight, body mass index, total cholesterol, and hemoglobin A₁C. Age, hemoglobin A₁C, and ankle pulse pressure were inversely correlated with SNAP amplitude of the sural nerve, while no factors were correlated with CV of the sural nerve. Increased arterial stiffness was significant in the limbs group with abnormal SNAP amplitude of the sural nerve, while increased height was significant in the limbs group with abnormal CV of the sural nerve. Vascular factors were more significantly associated with decreased SNAP amplitude rather than decreased CV of the sural nerve in the nerve conduction study of diabetic patients.

Reduction of ipsilateral thalamic volume in temporal lobe epilepsy with hippocampal sclerosis

The thalamus plays an important role in the modulation of both focal and generalized seizures, but the mechanisms related to seizures may be different among epilepsy syndromes. The aim of this study is to investigate the thalamic atrophy in different epilepsy syndromes. We enrolled a total of 72 patients with epilepsy (22 patients with temporal lobe epilepsy with hippocampal sclerosis, 21 patients with extra-temporal lobe epilepsy, and 29 patients with juvenile myoclonic epilepsy). We analyzed structural volumes of the brain with FreeSurfer 5.1 software, and compared them among subgroups of epilepsy and normal control subjects. Moreover, we quantified correlations between the duration of epilepsy and the structural volumes with age and sex as covariates. The volumes of the ipsilateral hippocampus in temporal lobe epilepsy with hippocampal sclerosis were significantly smaller than those in extra-temporal lobe epilepsy and normal control subjects [analysis of variance (ANOVA), p < 0.001]. Although the volumes of the ipsilateral thalamus were not different from those of normal control subjects, the volumes of the ipsilateral thalamus were negatively correlated with duration of epilepsy in temporal lobe epilepsy with hippocampal sclerosis (r = -0.5, p = 0.02). However, the volumes of interest in extra-temporal lobe epilepsy and juvenile myoclonic epilepsy were not different from those in normal control subjects, and none of these structures were correlated with duration of epilepsy. These findings suggest that the role of the thalamus may be different in thalamo-limbic circuits among epilepsy syndromes.

Cortical morphology in patients with transient global amnesia

OBJECTIVE

This study evaluated alterations in cortical morphology in patients with transient global amnesia (TGA).

MATERIALS AND METHODS

Diagnoses of TGA occurred at our hospital. Evaluation involved a structured interview to obtain clinical information and a brain magnetic resonance imaging scan. We analyzed whole-brain T1-weighted MRI data using FreeSurfer 5.1. Measures of cortical morphology, such as thickness, surface area, volume, and curvature were compared between patients with TGA and healthy controls. We also quantified the correlations between clinical variables and each measure of abnormal cortical morphology.

RESULTS

Seventy patients met the inclusion criteria. Compared to healthy controls, patients with TGA had significant alterations in cortical thickness in several regions of bilateral hemisphere. Moreover, several regions of cortical volumes in left hemisphere were significantly different between patients with TGA and healthy controls. In addition, there were significant correlations between the durations of episodes and cortical thickness, especially in the parietal cortex. However, there were no differences between groups in other measures of cortical morphology, including surface area and curvatures.

CONCLUSIONS

We observed significant alterations in cortical morphology in patients with TGA; these alterations are implicated in the pathogenesis of TGA.

Trafficking patterns of NMDA and GABAA receptors in a Mg2+-free cultured hippocampal neuron model of status epilepticus

An altered pattern of receptor trafficking is one of the pathophysiologic mechanisms of status epilepticus (SE). The gradual internalization of GABA_A receptors (GABARs) occurs in both in vitro and in vivo models of SE and is thought to be a cause of decreased GABAergic inhibition. Unlike GABARs, little is known about alterations in NMDA receptor (NMDAR) trafficking during SE, even though increased activity of NMDARs is indispensable for the induction and maintenance of SE. Therefore, we aimed to simultaneously investigate the changes in the trafficking patterns of GABARs and NMDARs in an in vitro cultured hippocampal neuron model of SE. For induction of epileptiform discharges, hippocampal neurons were exposed to external medium without Mg²⁺. Biotinylation assay and immunofluorescence staining for GABAR β2,3 and NMDAR NR1 subunits were performed to quantify and visualize surface GABARs and NMDARs, respectively. The frequency of spontaneous action potentials increased more than 4-fold after Mg²⁺-free induction. The level of surface GABARs decreased over time after Mg²⁺-free induction, dropping to approximately 50% of control levels an hour after Mg²⁺-free induction. By contrast, the trafficking of NMDARs to the surface was enhanced after a slight time lag, increasing by 30% of control levels an hour after Mg²⁺-free induction. Our data showed the changes of both NMDAR and GABAR trafficking during prolonged SE induced by a Mg²⁺-free extracellular environment and confirmed that this in vitro SE model is suitable for examining alterations in the receptor trafficking pattern by prolonged seizure activity. These results suggest that targeting of surface NMDAR could be a promising method in controlling benzodiazepine-resistant SE.

Can we predict drug response by volumes of the corpus callosum in newly diagnosed focal epilepsy?

OBJECTIVE

The aim of this study was to investigate whether volumes of the corpus callosum could predict a response to antiepileptic drugs in patients with newly diagnosed focal epilepsy.

METHODS

Fifty-three patients with newly diagnosed focal epilepsy of unknown etiology and healthy subjects were enrolled in this study. First, we analyzed the differences in the volumes of the corpus callosum between patients with epilepsy and healthy subjects. Second, we divided patients with epilepsy into antiepileptic drug responders and drug nonresponders groups, according to their seizure controls, and evaluated the differences in the volumes of the corpus callosum between the groups. Third, we conducted correlation analyses between the volumes of the corpus callosum and mean diffusion measures in healthy subjects.

RESULTS

The volumes of the corpus callosum in patients with epilepsy were significantly lower than those in normal controls (p = .0001). Among epilepsy patients, the volumes of the corpus callosum were significantly lower in antiepileptic drug responders compared with nonresponders (p = .0481), which was the only independent variable for predicting antiepileptic drug response (OR = 10.07, p = .0434). In addition, we found that the volumes of the corpus callosum were significantly correlated with the mean diffusion measures (fractional anisotropy, r = .408, p = .0027; mean diffusivity, r = -0.403, p = .0028) in normal controls.

CONCLUSIONS

We demonstrated that the volumes of the corpus callosum were different according to antiepileptic drug responses in patients with newly diagnosed focal epilepsy, which might suggest that the volumes of the corpus callosum could be a new biomarker for predicting responses to antiepileptic drugs.

Atrophy of the pedunculopontine nucleus region in patients with sleep-predominant seizures: A voxel-based morphometry study

Non-rapid eye movement (NREM) sleep increases interictal epileptiform discharges and frequency of seizures, whereas REM sleep suppresses them. The pedunculopontine nucleus (PPN), one of the REM sleep-modulating structures, is postulated to have a potent antiepileptogenic role. We asked if patients with sleep-predominant seizures (SPS) show volume changes in the region of the PPN compared to those with seizures occurring during awake state only (nSPS). The volume of the PPN region was assessed in patients with SPS, those with nSPS, and healthy volunteers, through voxel-based morphometry and automated, nonbiased region of interest (ROI) analysis of T1 magnetic resonance (MR) images. The volume of PPN region was statistically smaller in patients with SPS (n = 33) than in those with nSPS (n = 40) and healthy controls (n = 30) after controlling for covariates. These results suggest that a structural change in the PPN may be associated with sleep-predominant timing of seizure occurrence. Our findings might help understand the intervening pathomechanism that lies between the human sleep-wake cycle and epilepsy.

Clinical Significance of Fluid-Attenuated Inversion Recovery Vascular Hyperintensities in Borderzone Infarcts

BACKGROUND AND PURPOSE

Fluid-attenuated inversion recovery vascular hyperintensities (FVHs) are seen in some cases with cerebral hemodynamic impairment and collateral flow. Because the worst outcomes of patients with borderzone infarcts were mainly correlated with impaired hemodynamics, the presence of FVH might provide another clue for predicting the prognosis of patients with borderzone infarcts.

METHODS

We reviewed 1377 consecutive patients with ischemic stroke. Cortical borderzone (CBZ) and internal borderzone infarcts were selected based on diffusion-weighted imaging. FVHs were defined as tubular- or serpentine-shaped hyperintensities in the subarachnoid space. We investigated the clinical significance of FVHs in borderzone-infarcted patients.

RESULTS

Among 87 patients with borderzone infarcts, the presence of FVH was observed in 30 (34.5%). We identified 62 patients with CBZ infarcts and 25 patients with internal borderzone infarcts. In the cases with CBZ infarcts, the initial National Institutes of Health Stroke Scale scores and the portions of nonfavorable outcome at 3 months in the FVH(+) group were significantly higher than in the FVH(-) group (P<0.05 and P<0.001, respectively). Unlike the cases with CBZ infarcts, there were no significant differences of these clinical features between the FVH(+) group and the FVH(-) group in the patients with internal borderzone infarcts.

CONCLUSIONS

The findings of FVH are associated with relatively severe clinical presentation and nonfavorable prognosis in patients with CBZ infarcts, but not in patients with internal borderzone infarcts. The presence of FVH may help to identify CBZ-infarcted patients who require close observation and hemodynamic control.

The Pivotal Role of the Parieto-Occipital Lobe in Card Game-Induced Reflex Epilepsy: A Voxel-Based Morphometry Study

<b><i>Background:</i></b> The pathogenesis of card game-induced reflex epilepsy has not been determined so far. The aim of this study was to evaluate structural abnormalities using voxel-based morphometry (VBM) analysis, which may give some clue about the pathogenesis in card game-induced reflex epilepsy. <b><i>Methods:</i></b> The 3 subjects were diagnosed with card game-induced reflex epilepsy. Evaluation involved a structured interview to obtain clinical information and brain MRI. In VBM analysis, Statistical Parametric Mapping 8 running on the MATLAB platform was employed to analyze the structural differences between patients with card game-induced reflex epilepsy and age- and sex-matched control subjects. <b><i>Results:</i></b> The results of VBM analysis revealed that patients with card game-induced reflex epilepsy had significantly increased gray matter volume in the right occipital and parietal lobe. However, there were no structures with decreased gray matter volume in patients with card game-induced reflex epilepsy compared with control subjects. In addition, we found that the patients with card game-induced reflex epilepsy had onset of seizures in adulthood rather than in adolescence, and all of the patients were men. <b><i>Conclusions:</i></b> The parieto-occipital lobes might be partially involved in the neuronal network responsible for card game-induced reflex epilepsy.

GWAS identifies two susceptibility loci for lamotrigine-induced skin rash in patients with epilepsy

PURPOSE

Lamotrigine (LTG)-induced maculopapular eruption (MPE) often causes treatment discontinuation and rising burdens on current healthcare systems. We conducted a genome-wide association study to identify novel susceptibility loci associated with LTG-induced MPE in patients with epilepsy.

MATERIALS AND METHODS

We enrolled patients with LTG-induced MPE (n=34) and utilized the Korea Association Resource project cohort as a control group (n=1214). We explored associations between LTG-induced MPE and single nucleotide polymorphisms (SNPs) through imputation and replicated these associations in samples from 59 LTG-induced MPE cases and 98 LTG tolerant-controls.

RESULTS

We found two novel SNPs associated with LTG-induced MPE: rs12668095 near CRAMP1L/TMEM204/IFT140/HN1L (P=4.89×10(-7)) and rs79007183 near TNS3 (P=3.15×10(-10)), both of which were replicated in an independent cohort.

CONCLUSION

These two validated SNPs may be good candidate markers for predicting LTG-induced MPE in epilepsy patients, although further experimental validation is needed.

ILAE official report: a practical clinical definition of epilepsy

Epilepsy was defined conceptually in 2005 as a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures. This definition is usually practically applied as having two unprovoked seizures >24 h apart. The International League Against Epilepsy (ILAE) accepted recommendations of a task force altering the practical definition for special circumstances that do not meet the two unprovoked seizures criteria. The task force proposed that epilepsy be considered to be a disease of the brain defined by any of the following conditions: (1) At least two unprovoked (or reflex) seizures occurring >24 h apart; (2) one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; (3) diagnosis of an epilepsy syndrome. Epilepsy is considered to be resolved for individuals who either had an age-dependent epilepsy syndrome but are now past the applicable age or who have remained seizure-free for the last 10 years and off antiseizure medicines for at least the last 5 years. "Resolved" is not necessarily identical to the conventional view of "remission or "cure." Different practical definitions may be formed and used for various specific purposes. This revised definition of epilepsy brings the term in concordance with common use. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

A newly discovered LGI1 mutation in Korean family with autosomal dominant lateral temporal lobe epilepsy

PURPOSE

A new leucine-rich glioma-inactivated 1 gene (LGI1) mutation inducing an amino acid sequence substitution was found in a Korean family with autosomal dominant lateral temporal lobe epilepsy (ADLTE). We report the clinical features and characteristics of this newly identified LGI1 mutation.

METHODS

Clinical data were collected from a large ADLTE family. All exons and flanking regions of the LGI1 gene were directly sequenced. 243 healthy controls were screened for the putative mutation. The 'Sorting Tolerant From Intolerant' algorithm was employed for the prediction of mutated LGI1 protein stability. LGI1 protein secretion was confirmed in vitro by immunoblotting assay.

RESULTS

The main clinical characteristics included a young age at onset (mean, 12.4 years), diverse phenotypic manifestations, the occurrence of generalized tonic-clonic seizures, and a favorable prognosis. The genetic analysis detected a nonsynonymous single nucleotide polymorphism of c.137G>T coding for p.C46F in the five affected family members. This variant was not found in the normal control population and one unaffected family member. All the amino acids substituted for cysteine at position 46 of the LGI1 protein were predicted to damage protein stability in in silico analysis. Mutated C46F protein was retained within the cell at the immunoblotting assay.

CONCLUSION

We identified a new LGI1 mutation in a large Korean ADLTE family which appeared to be involved in the development of epilepsy through suppressing LGI1 protein secretion.

Reflex epilepsy induced by playing Go-stop or Baduk games

PURPOSE

Seizures can be triggered by complex mental activities. The aim of this study was to investigate the clinical characteristics of reflex epilepsy induced by playing Go-stop or Baduk games.

METHODS

The study comprised 11 patients with this type of reflex epilepsy identified from our patient database. We collected data on clinical features, EEG, and brain MRI as well as seizure outcomes.

RESULTS

The patients had a late age of onset (range, 43-65 years, except for one patient with an age of onset of 11 years). An MRI abnormality and interictal EEG abnormalities were found in one patient respectively. The seizures exhibited diverse semiological features suggesting a focal or generalized onset. No myoclonic seizures were observed. Individualized strategies such as avoiding the precipitating game or reducing exposure to the stimulus were most effective in preventing the seizures.

CONCLUSION

The pathophysiological mechanisms underlying Go-stop- or Baduk-induced seizures may be different from other cognition-associated reflex epileptic phenomena. This type of reflex epilepsy may be a heterogeneous syndrome manifesting in a range of diverse semiological features.

The localizing and lateralizing value of auras in lesional partial epilepsy patients

PURPOSE

We investigated the localizing and lateralizing values of auras in patients with lesional partial epilepsy on an outpatient basis.

MATERIALS AND METHODS

A total of 276 subjects were retrospectively selected for this study if they had a unilateral single lobar lesion based on magnetic resonance image (MRI) results, and their scalp electroencephalography (EEG) findings were not discordant with the MRI-defined lobar localization and lateralization. According to the lesion locations, subjects were considered as having mesial temporal (MTLE), lateral temporal (LTLE), frontal (FLE), parietal (PLE), or occipital (OLE) lobe epilepsies. Auras were classified into 13 categories.

RESULTS

A hundred and seventy-six subjects (63.8%) had experienced at least one aura. FLE subjects had the fewest number of auras. Epigastric and psychic auras were frequent among MTLE subjects, while visual auras were common in those with PLE and OLE. Somatosensory auras and whole body sensations were more frequent in the subjects with PLE than those without. Autonomic auras were more common in MTLE subjects than in LTLE subjects. Dysphasic auras were more frequently found in left-sided epilepsies. Five pairs of aura categories showed concurrent tendencies, which were the epigastric and autonomic auras, autonomic and emotional auras, visual and vestibular auras, auditory and vestibular auras, and whole-body sensation and auditory auras. Autonomic and emotional auras had a concurrent tendency in left-sided epilepsies, but not in right-sided epilepsies.

CONCLUSION

Our results support the previously known localizing value of auras, and suggest that dysphasic auras and the association of emotional and autonomic auras may have a lateralizing value.

Short-term efficacy and safety of zonisamide as adjunctive treatment for refractory partial seizures: a multicenter open-label single-arm trial in Korean patients

OBJECTIVE

To evaluate the efficacy and safety of adjunctive zonisamide (ZNS) therapy in Korean adults with uncontrolled partial epilepsy.

METHODS

Study patients had an average of at least one seizure per 4-week (averaged over a 12-week historical baseline) despite the use of one to three antiepileptic drugs. The starting dose of ZNS was 100mg/day, and was increased to 200mg/day after 2weeks. During the 12-week maintenance period, the dose of ZNS was adjusted to 200-400mg/day based on the physicians' discretion. The global evaluation scale (GES) and quality of life (QOLIE-31) were also evaluated.

RESULTS

A total of 121 patients were enrolled, of which 88 patients completed the study. The median percent reduction in weekly seizure frequency over the treatment period was 59.0%. The ≥50% and ≥75% responder rates were 57.3% and 38.5%, respectively. Seizure freedom over the treatment period was observed in 25 patients, but seizure freedom throughout the 16-week treatment period was attained in only 16 patients. On investigator's GES, 84 patients were considered improved, with 33 patients showing marked improvement. In QOLIE-31 scale, seizure worry improved significantly but emotional well-being deteriorated. Treatment-emergent adverse events (AEs) were reported in 80 patients. The most common AEs were dizziness (28.1%), somnolence (24.0%), anorexia (18.2%), headache (14.0%), nausea (13.2%), and weight loss (10.7%). Twenty-two patients discontinued the trial due to drug-related AEs.

CONCLUSIONS

Our results suggest that adjunctive ZNS therapy for the treatment of refractory partial epilepsy, though efficacious, is associated with significant tolerability problems.

Simple Partial Status of Forced Thinking Originated in the Mesial Temporal Region: Intracranial Foramen Ovale Electrode Recording and Ictal PET

Forced thinking (FT) is a rare epileptic phenomenon which is usually seen in patients with frontal lobe epilepsy. We report a rare case of mesial temporal lobe epilepsy presenting FT as simple partial status epilepticus. A 50-year-old woman with left hippocampal sclerosis developed a prolonged episode of continuous FT for five days after she experienced a clustering of complex partial seizures during the period of preoperative video-electroencephalography (EEG) monitoring. The EEG demonstrated continuous focal ictal discharges in the left foramen ovale electrodes. Positron emission tomography showed focal glucose hypermetabolism in the left mesial temporal region. This case indicates that the anatomical substrate for the development of FT is located in the mesial temporal region as well as the frontal lobe, and prolonged FT can occur as a seizure manifestation.

Microsatellite analysis as a tool for discriminating an interfamily hybrid between olive flounder and starry flounder

An interspecific artificial hybrid was produced between two economically important aquaculture flatfish: olive flounder (Paralichthys olivaceus) and starry flounder (P. stellatus). This hybrid displays the rapid growth characteristic of the former and tolerance to low temperatures and low salinity of the latter, but the genetics of inheritance in this hybrid have not been elucidated. Polymorphic microsatellite markers developed for P. olivaceus and P. stellatus were tested to determine if these markers can be used for analysis of parentage and genetic inheritance. Multiplex PCR using two primer sets that were specific to each species produced PCR products of different sizes; these could be used for the identification of interspecific hybrids. Among the 192 primers derived from olive flounder, 25.5% of the primer sets successfully amplified genomic DNA from starry flounder, and 23% of the 56 primer sets originating from starry flounder amplified DNA from olive flounder. Analysis of genetic inheritance in the hybrid using seven of the 62 microsatellite markers common to both species demonstrated classic Mendelian inheritance of these markers in the hybrid progeny, with the exception of one locus identified as a null allele in the hybrid. These results demonstrate that cross-specific microsatellite markers can be used tools for parentage analysis of hybrid flatfish, for mapping quantitative trait loci, for marker-assisted selective breeding, and for studies of the evolution of fish.

Comparison of temporal lobectomies of children and adults with intractable temporal lobe epilepsy

INTRODUCTION

The aim of the study was to assess the difference in clinical characteristics and postsurgical outcomes between children and adults who have undergone temporal lobectomy (TL).

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 52 patients who had undergone TL between 2006 and 2008. Nineteen patients were classified as children (<or=18 years old), and 33 patients were classified as adults (>18 years old) according to the age when TL had been performed.

RESULTS

Twelve of 19 (63.2%) children and 24 of 33 (72.7%) adults became seizure free. Rapid secondary generalization such as generalized tonic or tonic-clonic seizures showed a tendency to be more prominent in children (four of 19, 21.1%) than in adults (three of 33, 9.1%). Patients in childhood had significantly more multifocal discharges on interictal electroencephalography (EEG) (42.1%) compared to adults (15.2%, p = 0.014). The mean extent of surgical excision was 5.0 cm in children and 4.1 cm in adults (p = 0.001). The incidence of hippocampal sclerosis, the most common pathologic finding in the two groups, was 57.9% (11 of 19) in children and 78.8% (26 of 33) in adults. Malformations of cortical development were significantly more frequent in children (nine of 19, 47.4%) than in adults (seven of 33, 21.2%). Dual pathology was found in 31.6% of children and in 12.1% of adults. The intelligence quotient and memory quotient values in children with temporal lobe resection remained nearly steady during follow-up period without significant decline.

CONCLUSION

Patients undergoing TL during childhood compared to during adulthood had distinctively different interictal EEG, resectional extents, and pathologic findings.

Inhibition of apoptosis signal-regulating kinase 1 reduces endoplasmic reticulum stress and nuclear huntingtin fragments in a mouse model of Huntington disease

Huntington's disease (HD) is characterized clinically by chorea, psychiatric disturbances, and dementia, while it is characterized pathologically by neuronal inclusions as well as striatal and cortical neurodegeneration. The neurodegeneration arises from the loss of long projection neurons in the cortex and striatum. In this study, we investigated the role of apoptosis signal-regulating kinase 1 (Ask1) in the pathogenesis of HD. We analyzed the expression of Ask1 and huntingtin (htt) within the striatum and cortex and also examined the interaction of Ask1 with htt fragments in HD (R6/2) mice. Additionally, we inhibited Ask1 and analyzed the resulting changes in brain-derived neurotrophic factor (BDNF) expression, motor function, and striatal atrophy. Ask1 activity was blocked using an Ask1 antibody raised against the C-terminus of the Ask1 protein. The anti-Ask1 antibody was infused into the striatum of the HD mice for four weeks using a micro-osmotic pump. The levels of Ask1 protein and endoplasmic reticulum (ER) stress were increased in HD mice. Binding of inactivated Ask1 to htt fragments was more prevalent in the cytosol than the nucleus of cortical neurons. Binding of inactivated Ask1 to htt fragments prevented translocation of the htt fragments into the nucleus, resulting in an improvement in motor dysfunction and atrophy. In the normal state, active Ask1 may help htt fragments enter the nucleus, while inactivated Ask1 hinders this translocation by binding to but not releasing fragmented htt into the nucleus. We propose that Ask1 may interact with htt fragments and subsequently induce ER stress. BDNF depletion may be prevented by targeting Ask1; this would decrease ER stress and possibly ameliorate behavioral or anatomical abnormalities that accompany HD. Therefore, regulating the amounts and activity of the Ask1 protein is a novel strategy for treatment of HD.

Chronic cerebral hypoperfusion protects against acute focal ischemia, improves motor function, and results in vascular remodeling

Atherosclerosis may cause severe stenosis of the arteries supplying the brain, which induces chronic cerebral hypoperfusion. Although an infarction often occurs in this area, it is uncertain how brain vessels respond to the chronic hypoperfusion or how the vascular responses are related to stroke severity when the area has been subjected to severe ischemia. To address these uncertainties, we induced chronic cerebral hypoperfusion in Sprague-Dawley rats with a bilateral common carotid artery ligation (BCAL). A middle cerebral artery occlusion/reperfusion (MCAO/R) was introduced with a nylon suture four weeks after either BCAL (BCAL-MCAO) or a sham operation (Sham-MCAO). Motor disability scores and infarct sizes, based on 2,3,5-triphenyltetrazolium chloride staining, were significantly reduced with BCAL-MCAO treatment compared with sham-MCAO treatment (P<0.01). The diameters of the posterior cerebral, posterior communicating, and basilar arteries on the brain surface were larger and more tortuous in BCAL-treated rats (P<0.01). The density of large capillary- and arteriole-sized vessels in the brain parenchyma also increased in BCAL-treated rats (P<0.05). Strokes were less severe when the vicinity subjected to infarction was preconditioned with chronic cerebral hypoperfusion. Increasing the vascular reserve with adaptive vascular remodeling may have contributed to this response.