When should we test patients with epilepsy for autoimmune antibodies? Results from a French retrospective single center study

BACKGROUND AND PURPOSE

Seizures represent a core symptom of autoimmune encephalitides with specific therapeutic issues. To date, patients with new-onset seizures or established epilepsy are not systematically tested for autoimmune antibodies. We aimed to identify clinical and paraclinical criterion that could help to select patients requiring additional autoimmune antibodies serum and cerebrospinal fluid (CSF) detection.

METHODS

In this retrospective single center study from the French Salpêtrière Hospital, data from 286 adult patients with epilepsy who received an autoantibody assay for the first time were analyzed. All patients were evaluated at our institution between January 2007 and December 2018 for assessment of new-onset epilepsy (n = 90) or established epilepsy (n = 196). We only analyzed patients that were screened for autoimmune antibodies. Demographic, clinical and neuroimaging measures were compared between patients with and without autoimmune encephalitis using Fisher's exact test for categorical variables and Welch's t test for continuous variables. Our primary goal was to identify significant factors that differentiated patients with and without autoimmune encephalitis.

RESULTS

We identified 27 patients with autoimmune epilepsy (9.4% of the patients who had been tested for autoantibodies). The significant factors differentiating patients with and without autoimmune encephalitis were: (i) the existence of a new-onset focal epilepsy + (e.g., newly diagnosed epilepsy < 6 months associated with additional symptoms, mainly cognitive or psychiatric symptoms), (ii) the presence of faciobrachial dystonic seizures very suggestive of anti- Leucine-rich glioma inactivated 1 (LGI1) encephalitis, and (iii) the presence of magnetic resonance imaging (MRI) abnormalities suggestive of encephalitis.

CONCLUSION

New-onset focal seizures combined with cognitive or psychiatric symptoms support the test for autoimmune antibodies. Further clinical already known red flags for an autoimmune origin are the presence of faciobrachial dystonic seizures and MRI signal changes consistent with encephalitis. On the other hand, isolated new-onset seizures and chronic epilepsy, even with associated symptoms, seem rarely linked to autoimmune encephalitis and should not lead to systematic testing.

Molecular diagnostics in drug-resistant focal epilepsy define new disease entities

Structural brain lesions, including the broad range of malformations of cortical development (MCD) and glioneuronal tumors, are among the most common causes of drug-resistant focal epilepsy. Epilepsy surgery can provide a curative treatment option in respective patients. The currently available pre-surgical multi-modal diagnostic armamentarium includes high- and ultra-high resolution magnetic resonance imaging (MRI) and intracerebral EEG to identify a focal structural brain lesion as epilepsy underlying etiology. However, specificity and accuracy in diagnosing the type of lesion have proven to be limited. Moreover, the diagnostic process does not stop with the decision for surgery. The neuropathological diagnosis remains the gold standard for disease classification and patient stratification, but is particularly complex with high inter-observer variability. Here, the identification of lesion-specific mosaic variants together with epigenetic profiling of lesional brain tissue became new tools to more reliably identify disease entities. In this review, we will discuss how the paradigm shifts from histopathology toward an integrated diagnostic approach in cancer and the more recent development of the DNA methylation-based brain tumor classifier have started to influence epilepsy diagnostics. Some examples will be highlighted showing how the diagnosis and our mechanistic understanding of difficult to classify structural brain lesions associated with focal epilepsy has improved with molecular genetic data being considered in decision making.

Interictal spike networks predict surgical outcome in patients with drug-resistant focal epilepsy

OBJECTIVE

To determine if properties of epileptic networks could be delineated using interictal spike propagation seen on stereo-electroencephalography (SEEG) and if these properties could predict surgical outcome in patients with drug-resistant epilepsy.

METHODS

We studied the SEEG of 45 consecutive drug-resistant epilepsy patients who underwent subsequent epilepsy surgery: 18 patients with good post-surgical outcome (Engel I) and 27 with poor outcome (Engel II-IV). Epileptic networks were derived from interictal spike propagation; these networks described the generation and propagation of interictal epileptic activity. We compared the regions in which spikes were frequent and the regions responsible for generating spikes to the area of resection and post-surgical outcome. We developed a measure termed source spike concordance, which integrates information about both spike rate and region of spike generation.

RESULTS

Inclusion in the resection of regions with high spike rate is associated with good post-surgical outcome (sensitivity = 0.82, specificity = 0.73). Inclusion in the resection of the regions responsible for generating interictal epileptic activity independently of rate is also associated with good post-surgical outcome (sensitivity = 0.88, specificity = 0.82). Finally, when integrating the spike rate and the generators, we find that the source spike concordance measure has strong predictability (sensitivity = 0.91, specificity = 0.94).

INTERPRETATIONS

Epileptic networks derived from interictal spikes can determine the generators of epileptic activity. Inclusion of the most active generators in the resection is strongly associated with good post-surgical outcome. These epileptic networks may aid clinicians in determining the area of resection during pre-surgical evaluation.

Increased ciliary neurotrophic factor in blood serum and lacrimal fluid as a potential biomarkers of focal epilepsy

PURPOSE

To evaluate ciliary neurotrophic factor (CNTF) level in blood serum (BS) and lacrimal fluid (LF) of people with epilepsy (PWE).

METHODS

A case-control study of 72 consecutive patients with focal epilepsy (cases, epilepsy group) and 60 age- and gender-matched healthy volunteers (controls) was performed. Based on comorbid depression, two subgroups of PWE were formed. CNTF level was measured by an enzyme-linked immunosorbent assay (ELISA) in the BS and LF. For measurements of low CNTF levels in the BS, the methodology previously improved by the authors was applied.

RESULTS

As compared to controls, CNTF level (pg/mL) in PWE was increased both in the BS (7.0±2.9 vs. 3.7±2.0, P<0.000) and in LF (34.0±8.0 vs. 30.6±4.8, P=0.005). No significant correlation was found between CNTF level in the BS and LF either in PWE or in controls. No impact of comorbid depression or any demographic or clinical parameters studied on CNTF level in the BS or LF of PWE could be detected.

CONCLUSIONS

In patients with focal epilepsy, CNTF level is increased both in the BS and LF, though without correlation between them. No association of CNTF levels with age, gender, or clinical parameters, as well as depression occurrence, was found. High CNTF levels in the BS and LF could be considered as non-invasive biomarkers of focal epilepsy.

A qualitative awake EEG score for the diagnosis of continuous spike and waves during sleep (CSWS) syndrome in self-limited focal epilepsy (SFE): A case-control study

PURPOSE

To determine whether awake EEG criteria can differentiate epileptic encephalopathy with continuous spike and waves during sleep (EE-CSWS) at the time of cognitive regression from typical, self-limited focal epilepsy (SFE).

METHODS

This retrospective case-control study was based on the analysis of awake EEGs and included 15 patients with EE-CSWS and 15 age-matched and sex-matched patients with typical SFE. The EEGs were anonymised and scored by four independent readers. The following qualitative and quantitative EEG indices were analysed: slow-wave index (SLWI), spike-wave index (SWI), spike-wave frequency (SWF), long spike-wave clusters (CLSW) and EEG score (between grades 0 and 4). Sensitivity and specificity were assessed using receiver operating characteristic (ROC) curves and their reproducibility with a kappa test.

RESULTS

Based on a highly sensitive cut-off, EE-CSWS patients were 8.4 times more likely than those with SFE to have an SLWI > 6%, 15 times more likely to have an SWI > 10 % and six times more likely to have a CLSW of ≥ 1 s. There was substantial agreement between readers (with kappa values of 0.64, 0.69 and 0.67). EE-CSWS patients were 13 times more likely to have an SWF of > 11 % and 149 times more likely to have an EEG score of ≥ 3 than typical SFE patients. Agreement about these ratings was almost perfect (kappa 0.91 and 0.86).

CONCLUSION

An EEG score of ≥ 3 on a 20-min awake EEG differentiates typical SFE from EE-CSWS at the time of cognitive regression, with good reliability across readers with different levels of expertise.

Diagnostic yield of seizure recordings and neuroimaging in patients with focal epilepsy without interictal epileptiform discharges

OBJECTIVE

Repeated routine electroencephalography (EEG) or even long-term video-EEG monitoring (VEM) does not always record interictal epileptiform discharges (IEDs) in some patients with epilepsy. The present study investigated whether focal seizures detected by VEM and focal abnormalities on neuroimaging are useful for the diagnosis of patients with focal epilepsy without IEDs.

METHODS

We retrospectively reviewed 409 consecutive patients with focal epilepsy (207 men, aged 9 to 76 years) who underwent 4- or 5-day VEM, magnetic resonance imaging (MRI), and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) for diagnosis to identify patients without IEDs. The occurrence of focal seizures during VEM and the presence of focal abnormalities on neuroimaging were investigated in those patients. The occurrence rate of seizures during VEM was investigated in patients with daily, weekly, monthly, and yearly seizure frequency based on history-taking.

RESULTS

Ninety-five (23.2%) of 409 patients with focal epilepsy did not have IEDs. Fifty-five (57.9%) of the 95 patients had focal seizures during VEM. Fifty-four patients (56.8%) showed focal abnormalities compatible with seizure semiology on neuroimaging investigations. Neither seizure recordings nor neuroimaging abnormalities were seen in 16 (16.8%) of the 95 patients. The occurrence rate of seizures during VEM depended on the seizure frequency at history-taking. However, 28 (45.9%) of 61 patients with monthly and yearly seizure frequency had focal seizures during 4- or 5-day VEM with seizure induction.

CONCLUSIONS

Video-EEG monitoring can detect focal seizures in patients with focal epilepsy but no IEDs. Comprehensive assessment including VEM and neuroimaging study is important for the diagnosis.

Psychosis rarely occurs in patients with late-onset focal epilepsy

AIMS

We examined psychosis occurrence in patients with late-onset focal epilepsy.

SUBJECTS AND METHODS

Case records of consecutive patients with focal epilepsy without central nervous system (CNS) disease (n = 873) were retrospectively examined, with gender, age at epilepsy onset, duration of epilepsy, epilepsy type (temporal or extratemporal), and age at the initial examination used as clinical and demographic variables. Patients with onset ≤49 years old (control) were compared with those with late-onset.

RESULTS

In the control group (n = 775), 38 had a history of psychosis, while none in the late-onset group (n = 98) reported that (p = 0.016). Psychosis was only interictal in 32 and predominantly postictal in 6, while 2 patients showed both interictal and postictal psychosis. Duration of illness (p = 0.000001) and temporal lobe epilepsy (p = 0.000343) were significant determinants associated with psychosis. Gender (p = 0.210) and age at examination (p = 0.084) were found to be not contributory to psychosis.

DISCUSSION

The prevalence for a history of psychosis in the present cohort (2.5%) agrees well with that noted in previous studies, and duration of illness proved to be the most powerful determining factor leading to that. A keen awareness of unrecognized underlying CNS or metabolic disease is important when psychosis appears in patients with nonlesional late-onset epilepsy, which should lead to an in-depth investigation of possible underlying and still uncovered CNS disease.

Obstructive sleep apnea risk in patients with focal versus generalized epilepsy

OBJECTIVE

Obstructive sleep apnea (OSA) is common in patients with epilepsy (PWE), and treatment may improve seizure control. However, OSA is often undiagnosed in PWE, and understanding of the risk profile for OSA is important. In this study, we sought to determine if OSA risk is similar in patients with generalized versus focal epilepsy.

METHODS

We recruited 115 patients presenting to the Rutgers-Robert Wood Johnson Epilepsy Clinic with focal or generalized epilepsy. Obstructive sleep apnea risk was assessed using the Sleep Apnea Scale of the Sleep Disorders Questionnaire (SA-SDQ). Sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Demographic and clinical information was gathered from the electronic medical record. Unadjusted and adjusted analyses were carried out to assess differences in the SA-SDQ between patients with generalized versus focal epilepsy. Further analyses were done to assess the relationship between seizure frequency, epilepsy type, and the SA-SDQ.

RESULTS

Unadjusted mean SA-SDQ scores, as well as scores high enough to represent likely OSA, were similar in patients with generalized versus focal epilepsy. However, in adjusted analyses, patients with generalized epilepsy had a significantly higher mean SA-SDQ score. Older age, higher body mass index (BMI), and a history of hypertension (HTN) were also associated with higher SA-SDQ scores. Sleep Apnea Scale of the Sleep Disorders Questionnaire scores were not significantly affected by the presence of a seizure within the prior one month or six months. Average ESS scores and the percentage of scores consistent with an abnormal degree of sleepiness were statistically similar in patients with generalized versus focal epilepsy.

SIGNIFICANCE

Our study suggests that patients with generalized epilepsy have a higher risk of OSA. Further studies measuring OSA directly as well as assessing potential benefits of treatment are needed.

Optically pumped magnetoencephalography in epilepsy

We demonstrate the first use of Optically Pumped Magnetoencephalography (OP-MEG) in an epilepsy patient with unrestricted head movement. Current clinical MEG uses a traditional SQUID system, where sensors are cryogenically cooled and housed in a helmet in which the patient's head is fixed. Here, we use a different type of sensor (OPM), which operates at room temperature and can be placed directly on the patient's scalp, permitting free head movement. We performed OP-MEG recording in a patient with refractory focal epilepsy. OP-MEG-identified analogous interictal activity to scalp EEG, and source localized this activity to an appropriate brain region.

The FAST graph: A novel framework for the anatomically-guided visualization and analysis of cortico-cortical evoked potentials

BACKGROUND

Intracerebral electroencephalography (iEEG) using stereoelectroencephalography (SEEG) methodology for epilepsy surgery gives rise to complex data sets. The neurophysiological data obtained during the in-patient period includes categorization of the evoked potentials resulting from direct electrical cortical stimulation such as cortico-cortical evoked potentials (CCEPs). These potentials are recorded by hundreds of contacts, making these waveforms difficult to quickly interpret over such high-density arrays that are organized in three dimensional fashion.

NEW METHOD

The challenge in analyzing CCEPs data arises not just from the density of the array, but also from the stimulation of a number of different intracerebral sites. A systematic methodology for visualization and analysis of these evoked data is lacking. We describe the process of incorporating anatomical information into the visualizations, which are then compared to more traditional plotting techniques to highlight the usefulness of the new framework.

RESULTS

We describe here an innovative framework for sorting, registering, labeling, ordering, and quantifying the functional CCEPs data, using the anatomical labelling of the brain, to provide an informative visualization and summary statistics which we call the "FAST graph" (Functional-Anatomical STacked area graphs). The FAST graph analysis is used to depict the significant CCEPs responses in patient with focal epilepsy.

CONCLUSIONS

The novel plotting approach shown here allows us to visualize high-density stimulation data in a single summary plot for subsequent detailed analyses. Improving the visual presentation of complex data sets aides in enhancing the clinical utility of the data.

EEG Analysis in Structural Focal Epilepsy Using the Methods of Nonlinear Dynamics (Lyapunov Exponents, Lempel-Ziv Complexity, and Multiscale Entropy)

This paper analyzes a case with the patient having focal structural epilepsy by processing electroencephalogram (EEG) fragments containing the "sharp wave" pattern of brain activity. EEG signals were recorded using 21 channels. Based on the fact that EEG signals are time series, an approach has been developed for their analysis using nonlinear dynamics tools: calculating the Lyapunov exponent's spectrum, multiscale entropy, and Lempel-Ziv complexity. The calculation of the first Lyapunov exponent is carried out by three methods: Wolf, Rosenstein, and Sano-Sawada, to obtain reliable results. The seven Lyapunov exponent spectra are calculated by the Sano-Sawada method. For the observed patient, studies showed that with medical treatment, his condition did not improve, and as a result, it was recommended to switch from conservative treatment to surgical. The obtained results of the patient's EEG study using the indicated nonlinear dynamics methods are in good agreement with the medical report and MRI data. The approach developed for the analysis of EEG signals by nonlinear dynamics methods can be applied for early detection of structural changes.

Focal EEG abnormalities and focal ictal semiology in generalized epilepsy

In clinical practice, the diagnosis of focal vs generalized epilepsy dictates the management of the patient. The distinction between generalized and focal epilepsy is at times imperfect and some epilepsies have features that fall in between these two extremes. An example is the occurrence of focal interictal and focal ictal abnormalities in generalized epilepsies. As a part of the special issue on "The epileptogenic zone in pediatric epilepsy surgery", this focused narrative review will discuss different focal abnormalities seen in generalized epilepsy. An overlap of focal and generalized epileptiform abnormalities may support a continuum between focal and generalized epilepsy. When evaluating patients in the "gray zone", other factors such as ictal semiology, neuroimaging, genetic testing and functional deficits may need to be considered to reach an accurate diagnosis. Being aware of possible occurrence of focal clinical and EEG features in generalized epilepsy will help clinicians select more preferred AED (s), avoiding potential iatrogenic side effects and inappropriate consideration for epilepsy surgery.

Electroencephalography in Epilepsy Evaluation

PURPOSE OF REVIEW

Epilepsy is a heterogeneous disorder that is often associated with abnormal electroencephalogram (EEG) findings. This article provides an overview of common EEG findings in epileptic disorders. The physiologic basis of EEG and intracranial EEG studies is also discussed.

RECENT FINDINGS

EEG is widely used in clinical practice. Because of the paroxysmal nature of seizure disorders, interictal epileptiform discharges, such as spikes and sharp waves, are often used to support the diagnosis of epilepsy when a habitual seizure is not captured by EEG. Interictal and ictal EEG findings also underlie the classification of seizures and epilepsy. Continuous critical care EEG monitoring has become an invaluable study in the diagnosis and treatment of subclinical seizures and nonconvulsive status epilepticus. Intracranial EEG with subdural or intraparenchymal electrodes is warranted when localization of the seizure focus and mapping of eloquent brain areas are required to plan epilepsy surgery.

SUMMARY

The EEG is a key tool in the diagnosis of epilepsy. Interictal and ictal EEG findings are crucial for the confirmation and classification of seizure disorders. Intracranial EEG monitoring is also indispensable for planning surgery for some patients.

[Electroclinical characteristics of epilepsy children with midline epileptiform discharges related epileptic negative myoclonus as the first symptom]

Objective: To investigate the electroclinical findings in epilepsy children with epileptic negative myoclonus (ENM) restricted to the lower limb as the first seizure type. Methods: Each retrieved electroencephalogram record performed between March 2011 and March 2018 at the Department of Pediatrics of Peking University First Hospital was searched with "midline" . There were 302 records of 175 patients with "benign" or "functional" midline spikes. A retrospective review of each patient's hospital record was performed. Thirteen patients had ENM restricted to the lower limb as the first seizure type. The clinical and electroencephalogram characteristics of them were analyzed. Results: Thirteen patients manifested ENM restricted to the lower limb as the first seizure type, diagnosed as benign childhood focal epilepsy with vertex spikes (BEVS). Six patients had ENM as the first and only seizure type during the short-time follow-up. Among them, there were 1 male and 5 females. The age at seizure onset was (2.5±0.7) years. One of them had electrical status epilepticus during sleep (ESES) identified on electroencephalogram at theage of 4 years and 8 months. The last follow-up age was (3.8±1.5) years. The remaining 7 patients developed nocturnal focal motor seizures. Among them, there were 4 males and 3 females. The age at seizure onset was (3.5±0.7) years. Two of them were diagnosed as BEVS evolving into benign childhood epilepsy with centrotemporal spikes (BECTS) and 5 were diagnosed as BEVS concurring with BECTS. The age at focal seizures was (4.1±0.6) years. The interval ranged from 1 month to 1 years. Six of 7 patients had electrical ESES with the age of (5.2±1.0) years. All had developmental regression, further diagnosed as atypical benign partial epilepsy (ABPE). The median age at last follow-up was 5.9 years. Five of 13 patients had repeated electroencephalogram records at our apartment, showing that epileptiform discharges in midline regions were significantly reduced either in frequency or amplitude with the improvement of ENM restricted to the lower limb and that independent epileptiform discharges in Rolandic regions from midline regions were noticed with the onset of nocturnal focal seizures. Conclusions: ENM restricted to the lower limb has a close association with vertex (midline) epileptiform discharges. ENM restricted to the lower limb as the first seizure type is a peculiar phenomenon of BEVS. Some patients could evolve into BECTS or overlap with BECTS, and further into ABPE. The age of seizure onset in BEVS with ENM restricted to the lower limb as the first symptom is a little earlier than in BECTS. Ignorance of the close association between midline spikes and ENM restricted to the lower limb may lead to misdiagnosis of these patients.

Ketogenic parenteral nutrition in three paediatric patients with epilepsy with migrating focal seizures

Epilepsy of infancy with migrating focal seizures (EIMFS) is a rare epilepsy syndrome, characterized by an onset of multifocal seizures before the age of six months and a rather typical ictal EEG pattern. The ketogenic diet (KD) has been shown to be a treatment option in these patients with variable results. The KD is generally given by enteral formula or solid food, however, patients on the KD often have coexisting medical disorders that may impair the gastrointestinal tract and, in these cases, parenteral nutrition support may be needed. We present our experience with three patients who had been on the KD because of EIMFS, who were acutely unable to absorb nutrients through the intestinal tract. For these patients, we were unable to reach ketogenic ratios higher than 1.5:1 because of the limited fat intake via the parenteral route. This ratio, nevertheless, was adequate for maintenance of seizure control while allowing short-term bowel rest. Even though our report is limited as it provides no controlled evidence, ketogenic parenteral nutrition should be considered in children on the KD when enteral nutrition is not feasible. Special care should be taken to maintain ketosis and avoid undesired carbohydrates. Patients may respond well to ketogenic parenteral nutrition in spite of a lower ketogenic ratio.

Self-stimulation in an adult misdiagnosed with focal epilepsy

Self-stimulation is a normal part of development and a common behaviour in children before puberty, but very rare in adults. The stereotyped semiology can sometimes raise the suspicion of epilepsy. We present a 30-year-old patient who came to our epilepsy monitoring unit for differential diagnosis of nocturnal episodes, interpreted elsewhere as hypermotor status epilepticus associated with a known diagnosis of focal epilepsy and septo-optic dysplasia. The recorded events during video-EEG were consistent with psychogenic self-stimulating behaviour, which improved with psychotherapy. Disturbed sexual development with hypopituitarism and poor eyesight, androgen replacement therapy, alongside a protective environment provided by her parents, were the identified predisposing factors for this uncommon entity in an adult. [Published with video sequence].

Misdiagnosis and pitfalls in Panayiotopoulos syndrome

Panayiotopoulos syndrome (PS) is a frequent (6% among children of 1-15 years) and benign epileptic syndrome, characterized by predominantly autonomic symptoms (emesis, pallor, flushing, cyanosis, mydriasis/miosis, cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility) associated with simple motor focal seizures, which can be followed by secondary generalization. Panayiotopoulos syndrome can be extremely insidious, because it can mimic several condition, such as gastroenteritis, gastroesophageal reflux disease, encephalitis, syncope, migraine, sleep disorders, or even metabolic diseases. This peculiar pleiotropism should be kept in mind by child neurologists and pediatricians and general practitioners, because a wrong diagnosis may lead to inappropriate interventions. The consequences are high morbidity, costly mismanagement, and stress for children and their parents. The availability of electroencephalography (EEG) recording in pediatric Emergency Departments might be useful for a prompt and not-cost-consuming diagnosis. On the other hand, it is important to be aware of the possible, multifaceted, clinical presentations of PS and its clinical, radiological, and neurophysiological features in order to improve both recognition and management.

Absence of an Autonomic Sign Assists in the Diagnosis of Extratemporal Lobe Epilepsy Manifesting Generalized Convulsion with Retained Awareness

We herein report two epilepsy patients with the seizure focus in the non-dominant hemisphere manifesting secondarily generalized convulsion (sGC) with retained awareness characterized by a lack of autonomic signs although GC was complicated by respiratory arrest. Given the semiology and electrophysiological findings, the seizure activity was considered to propagate to the supplementary-motor area and the bilateral primary-motor area, with a clinical manifestation of sGC. The absence of autonomic signs during GC can be a key indicator that the seizure remains in the bilateral suprasylvian area and thus does not involve the region necessary for awareness preservation, which may assist in the diagnosis of this atypical epileptic seizure.

Stereoelectroencephalography Versus Subdural Electrodes for Localization of the Epileptogenic Zone: What Is the Evidence?

Accurate and safe localization of epileptic foci is the crux of surgical therapy for focal epilepsy. As an initial evaluation, patients with drug-resistant epilepsy often undergo evaluation by noninvasive methods to identify the epileptic focus (i.e., the epileptogenic zone (EZ)). When there is incongruence of noninvasive neuroimaging, electroencephalographic, and clinical data, direct intracranial recordings of the brain are often necessary to delineate the EZ and determine the best course of treatment. Stereoelectroencephalography (SEEG) and subdural electrodes (SDEs) are the 2 most common methods for recording directly from the cortex to delineate the EZ. For the past several decades, SEEG and SDEs have been used almost exclusively in specific geographic regions (i.e., France and Italy for stereo-EEG and elsewhere for SDEs) for virtually the same indications. In the last decade, however, stereo-EEG has started to spread from select centers in Europe to many locations worldwide. Nevertheless, it is still not the preferred method for invasive localization of the EZ at many centers that continue to employ SDEs exclusively. Despite the increased dissemination of the SEEG method throughout the globe, important questions remain unanswered. Which method (SEEG or SDEs) is superior for identification of the EZ and does it depend on the etiology of epilepsy? Which technique is safer and does this hold for all patient populations? Should these 2 methods have equivalent indications or be used selectively for different focal epilepsies? In this review, we seek to address these questions using current invasive monitoring literature. Available meta-analyses of observational data suggest that SEEG is safer than SDEs, but it is less clear from available data which method is more accurate at delineating the EZ.

Inappropriate Laughter and Behaviours: How, What, and Why? Case of an Adult with Undiagnosed Gelastic Seizure with Hypothalamic Hamartoma

Gelastic seizures (GS) are a rare form of epilepsy characterized by inappropriate, uncontrolled laughter. They are highly associated with abnormal cognitive development and behavioral problems in patients. Research has shown that GS can originate from hypothalamic hamartomas (HH), non- neoplastic masses consisting of gray matter with large and small neurons interspersed with glial nuclei. GS have also been observed in patients with frontal and temporal lobe lesions. The patient in this case report is a 40-year-old man with a past medical history significant for brain tumor, diabetes mellitus, and schizophrenia who presented with a long standing history of sudden, involuntary laughter occurring 2-3 times a week since 8 years old. Since the onset of these laughing spells the patient has displayed gradual cognitive impairment and increasing behavioral problems. Subsequent EEG (21-channel electroencephalogram) showed focal epileptiform activity in the right frontotemporal region and MRI studies revealed a mass arising from the hypothalamus suggestive of a HH. Other conditions should be considered in the differential diagnosis for laughing spells and distinguishing different causes can be challenging. As demonstrated by this case report, in patients with behavioral issues, especially those with inappropriate uncontrolled laughter, gelastic seizures need to be included in the differential diagnosis. Thus, a thorough workup should include neuroimaging with attention to the suprasellar region and EEG. Accurate, early diagnosis and patient education are critical in avoiding excessive and unnecessary treatments. This condition may be pharmacoresistant and is often associated with progressive cognitive and behavioral issues. Studies have shown a surgical treatment approach may be effective.

[A case series of 4 epilepsy patients with promnesia]

Promnesia is a feeling of familiarity and foreknowledge and is a manifestation of simple partial seizures (focal aware seizures). It is similar to déjà vu and has been reported to be a rare symptom in patients with temporal lobe epilepsy. Here, we investigated the clinical characteristics in 4 patients with partial epilepsy presenting promnesia. Three out of 4 patients showed abnormal electroencephalography (EEG) and/or MRI findings in the temporal lobe. Furthermore, in 2 patients, promnesia was the only aura. It is important to actively obtain medical history of patients about promnesia because this is useful for identifying the epileptic focus. Further cases need to be analyzed to evaluate the sensitivity and specificity of promnesia for diagnosis and therapy of partial epilepsy.

[Frequency, semiology and prognosis of benign infantile epilepsy]

INTRODUCTION

Benign infantile epilepsy is an epileptic syndrome of infancy. Until now, only a small number of case-series have been published.

AIM

To study the frequency, semiology and prognosis of benign infantile epilepsy.

PATIENTS AND METHODS

The 827 patients with one or more epileptic seizures seen at our hospital between 1 June 1994 and 1 March 2011 were included and prospectively followed. A diagnosis of benign infantile epilepsy was made in patients that fulfilled the following criteria at six month of evolution: one or more focal and/or generalised seizures, onset before 24 months, no neurological deficit and normal neuroimaging and interictal EEG.

RESULTS

77 cases (9%) met the diagnostic criteria. Semiology of the seizures was similar to that of other focal seizures in children under 24 months. 25% of the patients remained as isolated seizures. Among those with two or more seizures, the probability of achieving a 3 year initial remission without antiepileptic treatment was 86%. In the subgroup of patients with focal seizures without family history the probability was 74% and in five cases a global developmental delay/intellectual disability was detected thereafter.

CONCLUSIONS

Benign infantile epilepsy is a frequent epileptic syndrome. Semiology of seizures is not useful to characterize the syndrome. A diagnosis of benign infantile epilepsy at six month of evolution implies a reasonably good prognosis, but possibly not as good as for other self-limited epilepsies of infancy.

Occipital epilepsy versus progressive myoclonic epilepsy in a patient with continuous occipital spikes and photosensitivity in electroencephalogram: A case report

INTRODUCTION

Progressive myoclonic epilepsy (PME) is rare epilepsy syndrome. Although EEG is a useful neurophysiological technique in the evaluation of epilepsy, few EEG abnormalities have been described in PME. So, how to use EEG hints to establish the suspected diagnosis of PME as soon as possible should be addressed.

CASE PRESENT

We presented a case with refractory myoclonic seizures, and progressive neurological deterioration, diagnosed as PME and neuronal ceroid lipofuscinosis disease by gene testing. The patient manifested with a significant regression in her speech ability and motor balance. The mini-mental state examination showed poor scores of 15/30. The magnetic resonance imaging showed diffused atrophy. Her EEG showed slow background with continuous occipital small spikes and photosensitivity. The following genetic testing with mutation in CLN6 confirmed the diagnosis and excluded the occipital epilepsy.

CONCLUSION

Our case showed rare manifestations and special EEG features of PME, which may be confused with occipital epilepsy or photosensitive epilepsy. Thus, if the continuous occipital spikes and photosensitivity were presented in a patient with refractory seizures and developmental regression, PME should be considered.

Seizure Outcomes in Occipital Lobe and Posterior Quadrant Epilepsy Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Occipital lobe epilepsy (OLE) is an uncommon but debilitating focal epilepsy syndrome with seizures often refractory to medical management. While surgical resection has proven a viable treatment, previous studies examining postoperative seizure freedom rates are limited by small sample size and patient heterogeneity, thus exhibiting significant variability in their results.

OBJECTIVE

To review the medical literature on OLE so as to investigate rates and predictors of both seizure freedom and visual outcomes following surgery.

METHODS

We reviewed manuscripts exploring surgical resection for drug-resistant OLE published between January 1990 and June 2015 on PubMed. Seizure freedom rates were analyzed and potential predictors were evaluated with separate meta-analyses. Postoperative visual outcomes were also examined.

RESULTS

We identified 27 case series comprising 584 patients with greater than 1 yr of follow-up. Postoperative seizure freedom (Engel class I outcome) was observed in 65% of patients, and was significantly predicted by age less than 18 yr (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.13-2.18), focal lesion on pathological analysis (OR 2.08, 95% CI 1.58-2.89), and abnormal preoperative magnetic resonance imaging (OR 3.24, 95% 2.03-6.55). Of these patients, 175 also had visual outcomes reported with 57% demonstrating some degree of visual decline following surgery. We did not find any relationship between postoperative visual and seizure outcomes.

CONCLUSION

Surgical resection for OLE is associated with favorable outcomes with nearly two-thirds of patients achieving postoperative seizure freedom. However, patients must be counseled regarding the risk of visual decline following surgery.

Cowden Syndrome with a Novel PTEN Mutation Presenting with Partial Epilepsy Related to Focal Cortical Dysplasia

Cowden syndrome is a rare autosomal dominant disorder characterized by multiple hamartomas of the ectoderm and brain. A 36-year-old Japanese man presented with right facial seizure during sleep and was admitted to our hospital. He showed cobblestoning over the tongue and palmar pitting but no neurological abnormalities while he was not having a seizure. Brain magnetic resonance imaging showed focal cortical dysplasia in the left frontal lobe. Electroencephalography showed sharp waves over the left frontal lesion. A genetic analysis revealed a novel mutation of PTEN. The administration of carbamazepine ended the seizures. This is the first Japanese case of Cowden syndrome with a novel PTEN gene mutation and cortical dysplasia.

Personalization of NonEEG-based seizure detection systems

Seizures affect each patient differently, so personalization is a vital part of developing a reliable nonEEG based seizure detection system. This personalization must be done while the patient is undergoing video EEG monitoring in an epilepsy monitoring unit (EMU) because seizure detection by EEG is considered to be the ground truth. We propose the use of confidence interval analysis for determining how many seizures must be captured from a patient before we can reliably personalize such a seizure detection system for him/her. Our analysis indicates that 6 to 8 seizures are required. In addition, we create seizure likelihood tables for future use by said system by comparing the number of times a prespecified biosignal activity level is induced by seizure to the total number of occurrences of that level of activity. We focus on complex partial seizures in this paper because they are more difficult to detect than are generalized seizures.

Heart rate variability as a biomarker for epilepsy seizure prediction

OBJECTIVE

Epilepsy is a neurological disorder that causes seizures of many different types. Recent research has shown that epileptic seizures can be predicted by using the electrocardiogrami instead of the electroencephalogram. In this study, we used the heart rate variability that is generated by the fluctuating balance of sympathetic and parasympathetic nervous systems to predict epileptic seizures.

METHODS

We studied 11 epilepsy patients to predict the seizure interval. With regar tos the fact that HRV signals are nonstationary, our analysis focused on linear features in the time and frequency domain of HRV signal such as RR Interval (RRI), mean heart rate (HR), high-frequency (HF) (0.15-0.40 Hz) and low-frequency (LF) (0.04-0.15 Hz), as well as LF/HF. Also, quantitative analyses of Poincaré plot features (SD1, SD2, and SD1/SD2 ratio) were performed. HRV signal was divided into intervals of 5 minutes. In each segment linear and nonlinear features were extracted and then the amount of each segment compared to the previous segment using a threshold. Finally, we evaluated the performance of our method using specificity and sensitivity.

RESULTS

During seizures, mean HR, LF/HF, and SD2/SD1 ratio significantly increased while RRI significantly decreased. Significant differences between two groups were identified for several HRV features. Therefore, these parameters can be used as a useful feature to discriminate a seizure from a non-seizure The seizure prediction algorithm proposed based on HRV achieved 88.3% sensitivity and 86.2 % specificity.

CONCLUSION

These results indicate that the HRV signal contains valuable information and can be a predictor for epilepsy seizure. Although our results in comparison with EEG ares a little bit weaker, the recording of ECG is much easier and faster than EEG. Also, our finding showed the results of this study are considerably better than recent research based on ECG (Tab. 1, Fig. 10, Ref. 17).

A 15-year epileptogenic period after perinatal brain injury

Seizures are a frequent acute neurological event in the neonatal period. Up to 12 to 18% of all seizures in newborns are due to perinatal stroke and up to 39% of affected children can then develop epilepsy in childhood. We report the case of a young patient who presented stroke-related seizures in the neonatal period and then developed focal symptomatic epilepsy at 15 years of age, and in whom the epileptic focus was found to co-localize with the site of his ischemic brain lesion. Such a prolonged silent period before onset of remote symptomatic epilepsy has not previously been reported. This case suggests that newborns with seizures due to a neonatal stroke are at higher risk of epilepsy and that the epileptogenic process in these subjects can last longer than a decade.

Comparing Generic and Condition-Specific Preference-Based Measures in Epilepsy: EQ-5D-3L and NEWQOL-6D

BACKGROUND

There is debate about the psychometric characteristics of the three-level EuroQol five-dimensional questionnaire (EQ-5D-3L) for use in epilepsy. In response to the concerns, an epilepsy-specific preference-based measure (NEWQOL-6D) was developed. The psychometric characteristics of the NEWQOL-6D, however, have not been assessed.

OBJECTIVES

To investigate the validity and responsiveness of the EQ-5D-3L and the Quality of Life in Newly Diagnosed Epilepsy Instrument-six dimensions (NEWQOL-6D) for use in the assessment of treatments for newly diagnosed focal epilepsy.

METHODS

The analysis used data from the Standard And New Antiepileptic Drugs trial including patients with focal epilepsy. We assessed convergent validity using correlations, and known-group validity across different epilepsy and general health severity indicators using analysis of variance and effect sizes. The responsiveness of the measures to change over time was assessed using standardized response means. We also assessed agreement between the measures.

RESULTS

There was some level of convergence and agreement between the measures in terms of utility score but divergence in the concepts measured by the descriptive systems. Both instruments displayed known-group validity, with significant differences between severity groups, and generally slightly larger effect sizes for the NEWQOL-6D across the epilepsy-specific indicators. Evidence for responsiveness was less clear, with small to moderate standardized response means demonstrating different levels of change across different indicators.

CONCLUSIONS

There was an overall tendency for the NEWQOL-6D to better reflect differences across groups, but this does not translate into large absolute utility differences. Both the EQ-5D-3L and the NEWQOL-6D show some evidence of validity for providing utility values for economic evaluations in newly diagnosed focal epilepsy.

The value of resting-state functional magnetic resonance imaging for detecting epileptogenic zones in patients with focal epilepsy

Objective

To determine the value of resting-state functional magnetic resonance imaging (RS-fMRI) based on the local analysis methods regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional ALFF (fALFF), for detecting epileptogenic zones (EZs).

Methods

A total of 42 consecutive patients with focal epilepsy were enrolled. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of visually assessed RS-fMRI, MRI, magnetic resonance spectroscopy (MRS), video electroencephalography (VEEG), and positron-emission tomography computed tomography (PET-CT) in EZ localization were evaluated to assess their diagnostic abilities. ReHo, ALFF, and fALFF were also compared for their diagnostic values.

Results

RS-fMRI showed comparable sensitivity to PET (83.3%) and specificity to VEEG (66.7%), respectively, for EZ localization in patients with focal epilepsy. There were no significant differences between RS-fMRI and the other localization techniques in terms of sensitivity, specificity, PPV, and NPV. The sensitivities of ReHo, ALFF, and fALFF were 69.4%, 52.8%, and 38.9%, respectively, and for specificities of 66.7%, 83.3%, and 66.7%, respectively. There were no significant differences among ReHo, ALFF, and fALFF, except that ReHo was more sensitive than fALFF.

Conclusions

RS-fMRI may be an efficient tool for detecting EZs in focal epilepsy patients.

Neurorehabilitation with FORAMENRehab for attention impairment in children with epilepsy

Epilepsy is a frequent neurological disorder in children and often accompanied with attention impairment. Still, few systematically controlled rehabilitation techniques for children exist. The aim of this study was to design and measure the impact of the FORAMENRehab computer-based intervention method for attention impairment rehabilitation in children with epilepsy. We chose the FORAMENRehab program because it allows separate training for different attention components based on individual needs. Forty-eight children participated in the study. At baseline, all patients underwent neuropsychological examination of attention with the NEPSY test battery. The study group consisted of 17 8- to 12-year-old children with partial epilepsy and attention impairment who received neurorehabilitation over 5weeks (10 sessions) with FORAMENRehab Attention module accompanied by a therapist. Two control groups were included: the first control group of 12 children with partial epilepsy and attention impairment (waiting-list) participated in assessments with baseline tasks before and after the five-week period and received no active training. Additionally, all patients participated in the follow-up assessment 1.31years later. The second control group consisted of 19 typically developing children who only participated in the first assessment. After the intervention, study group patients showed significant improvement in complex attention and tracking (P<0.025). To achieve the effect of intervention in children with partial epilepsy, 10 sessions tailored to individual levels of ability were the minimum. Three attention components - sustained, complex, and tracking - need selective and longer training for more effective remediation. Follow-up assessment revealed a long-term positive effect of intervention. After 1.31years, the study group had significantly improved in three out of the four attention components (P<0.025), whereas the waiting-list group showed improvement in only two aspects of one complex attention component. In conclusion, attention impairment rehabilitation with FORAMENRehab is effective for children with epilepsy. Rehabilitation should focus on training specific components of attention and follow an individual-based rehabilitation process.

Adult Focal Epilepsies

PURPOSE OF REVIEW

Focal epilepsy is the most common type of epilepsy in adulthood. This article discusses the seizure symptomatology, EEG findings, and imaging findings of the various forms of focal epilepsy. The majority of the article focuses on temporal and frontal lobe epilepsy as these represent the majority of focal epilepsies.

RECENT FINDINGS

While significant overlap exists in the clinical symptomatology of the focal epilepsies, detailed seizure descriptions can often provide useful clinical evidence to help establish an accurate diagnosis. EEG and MRI continue to serve as the main diagnostic tools for the diagnosis of focal epilepsy.

SUMMARY

The various forms of focal epilepsy generate seizure presentations that are dependent on the anatomic structures that are involved in the seizure. By understanding the symptoms typically generated in each region of the brain, a better understanding of the possible seizure localizations can be made. Most forms of epilepsy have clear changes on EEG that permit accurate localization, but several pitfalls exist, which are discussed in this article. Imaging has revolutionized our ability to accurately identify lesions associated with epilepsy and increased our ability to localize seizures in the brain.

Abdominal epilepsy as an unusual cause of abdominal pain: a case report

INTRODUCTION

Abdominal pain, in etiology sometimes difficult to be defined, is a frequent complaint in childhood. Abdominal epilepsy is a rare cause of abdominal pain.

OBJECTIVES

In this article, we report on 5 year old girl patient with abdominal epilepsy.

METHODS

Some investigations (stool investigation, routine blood tests, ultrasonography (USG), electrocardiogram (ECHO) and electrocardiograpy (ECG), holter for 24hr.) were done to understand the origin of these complaints; but no abnormalities were found. Finally an EEG was done during an episode of abdominal pain and it was shown that there were generalized spikes especially precipitated by hyperventilation. The patient did well on valproic acid therapy and EEG was normal 1 month after beginning of the treatment.

DISCUSSION

The cause of chronic recurrent paroxymal abdominal pain is difficult for the clinicians to diagnose in childhood. A lot of disease may lead to paroxysmal gastrointestinal symptoms like familial mediterranean fever and porfiria. Abdominal epilepsy is one of the rare but easily treatable cause of abdominal pain.

CONCLUSION

In conclusion, abdominal epilepsy should be suspected in children with recurrent abdominal pain.

Time Distribution of Seizures during Long Term Video-EEG Monitoring

The purpose of this study was to investigate the duration of monitoring, number of seizures recorded, and date and time of occurrence of seizures in different patient groups during video-EEG monitoring (VEEGM). Patients with partial or psychogenic seizures who were admitted to our VEEGM unit between September 1996 and March 2002 were retrospectively evaluated. Duration of monitoring, date and time of occurrence of seizures were identified in each patient. For practical reasons, a day was divided into 3 equal time periods (period I: 08–16; period II: 16–24 and period III: 24–08 hrs), and the period in which the seizure occurred was noted. Patients were classified in 5 groups: 1 -temporal; 2-frontal; 3-parieto-occipital; 4-psychogenic and 5-unclassified. Duration of monitoring, the number of seizures recorded and time distribution of seizures were identified in each group and compared statistically.

We evaluated 746 seizures in 209 patients. Seizures were more likely to occur in periods I and III in groups 1 (p=0.004) and 5 (p<0.001). In group 4 they were more likely to occur in periods I and II (p<0.001). Duration of monitoring was not statistically different between the groups. However, the number of seizures recorded varied significantly (p=0.006). Patients in group 5 had the greatest number of seizures and were followed by groups 2, 4, 3 and 1, respectively. Groups also differed according to date of seizure occurrence (p<0.001). We conclude that the number of seizures recorded and time distribution of seizures during VEEGM are influenced by the lobe of onset of seizures.

Focal Seizures and EEG: Prognostic Considerations

The goal of this study was to determine whether the EEG could predict if patients with focal seizures would eventually be uncontrolled (U), more than two seizures per month, or be controlled (C), fewer than two seizures per year. Using these latter criteria, U and C patients were randomly selected from our files, 150 in each of these two groups; 804 EEGs were found in the U and 674 in the C group. Excluded were patients with generalized epilepsy and also the benign epilepsies of childhood. Age was an important factor since patients 5–18 yrs old were more often under good control (C group), and those 21–48 yrs of age were more often under poor control (U group). With rare exceptions, focal spikes and focal slow waves in every area were much more often seen in U patients than C patients. No spikes or rare spikes appeared especially in the controlled patients, and many or very many spikes in the uncontrolled patients, mainly on the first or second EEG. No slow waves or a mild degree of slowing was seen especially in the C patients, while greater degrees of slow wave abnormalities were noted much more often in the U patients.

For conditions to identify the C group, the best predictors were no spikes or rare spikes, especially on the first or second EEG, properly identifying two-thirds of the C patients and misidentifying only one-fourth of the U group. To identify the U patients on any EEG, many or very many spikes at any location or frontal spikes correctly designated a U patient in 84%, but incorrectly predicted a C patient as uncontrolled in 29%. For the first or second EEG, these values were 61% and 21%. Thus, the EEG, especially by its first or second record, can predict well the probable future of the uncontrolled patient, so that extraordinary means may be instituted early to avoid a deteriorating condition. When complete EEGs are done with sleep records and the results are quantified, reasonable prediction of eventual outcome can usually occur that is much more timely than waiting over 9 yrs, using only clinical data.

Optimising EEG-fMRI for Localisation of Focal Epilepsy in Children

BACKGROUND

Early surgical intervention in children with drug resistant epilepsy has benefits but requires using tolerable and minimally invasive tests. EEG-fMRI studies have demonstrated good sensitivity for the localization of epileptic focus but a poor yield although the reasons for this have not been systematically addressed. While adults EEG-fMRI studies are performed in the "resting state"; children are commonly sedated however, this has associated risks and potential confounds. In this study, we assessed the impact of the following factors on the tolerability and results of EEG-fMRI in children: viewing a movie inside the scanner; movement; occurrence of interictal epileptiform discharges (IED); scan duration and design efficiency. This work's motivation is to optimize EEG-fMRI parameters to make this test widely available to paediatric population.

METHODS

Forty-six children with focal epilepsy and 20 controls (6-18) underwent EEG-fMRI. For two 10 minutes sessions subjects were told to lie still with eyes closed, as it is classically performed in adult studies ("rest sessions"), for another two sessions, subjects watched a child friendly stimulation i.e. movie ("movie sessions"). IED were mapped with EEG-fMRI for each session and across sessions. The resulting maps were classified as concordant/discordant with the presumed epileptogenic focus for each subject.

FINDINGS

Movement increased with scan duration, but the movie reduced movement by ~40% when played within the first 20 minutes. There was no effect of movie on the occurrence of IED, nor in the concordance of the test. Ability of EEG-fMRI to map the epileptogenic region was similar for the 20 and 40 minute scan durations. Design efficiency was predictive of concordance.

CONCLUSIONS

A child friendly natural stimulus improves the tolerability of EEG-fMRI and reduces in-scanner movement without having an effect on IED occurrence and quality of EEG-fMRI maps. This allowed us to scan children as young as 6 and obtain localising information without sedation. Our data suggest that ~20 minutes is the optimal length of scanning for EEG-fMRI studies in children with frequent IED. The efficiency of the fMRI design derived from spontaneous IED generation is an important factor for producing concordant results.

[THE PROPAGATION AND SEMIOLOGY OF FOCAL EPILEPTIC SEIZURES. CASES CONNECTED TO THE INSULA. THEORETICAL CONSIDERATIONS]

STUDY OBJECTIVES

The developing of diagnostical examinations in epileptology provides new challenges in seizure semiology. On the analysis of seizures it is important to examine the mechanisms of their propagation. The brain connectivity (based on the neuroimaging), the shadowing of the movement of excessive neuronal activity (based on computerized EEG and MEG methods), the cognition of the physiological and pathological brain networks are the footstone of the epileptic seizure propagation. The investigators prove, by means of case demonstrations of the role of the network nodes and the role of the epileptic hubs in the seizure symptomatology.

METHODS

The preoperative, intra and postoperative data are analised of three insular and one parietal epileptic patients in point of view of their seizure symptomes. Complex neuroimaging, noninvasive and invasive electrophysiology, intensive long-term video-EEG monitoring, computerized EEG analysis, fuctional mapping, intraoperative corticography were used. The etiology were confirmed with hystology.

RESULTS

It is observed that on seizure semiology our patients plays the insula a double role. In some cases, it is the focus of insular seizures with their symptoms difficult to identify. However, in the majority of cases and as a consequence of its rich neural connections, the insula has a peculiar property in the evolution of the symptomatogenic features of seizures. This observations are developing new relationships between the mechanism of seizure propagation and its semiological consequences.

CONCLUSIONS

On epileptological point of view there are brain structures which has peculiar role in the "designe" of propagation of the epileptic excitement. The numerous new methods in neuroimaging and neurophysiology allowed the connectomical examination of the epileptic networks. The role of the epileptic diathesis is approachable with the metholdology of the brain connectivity. Theoretically the node of the epileptic network consist of the potential pathes where the localised excessive excitement can propagete. The route where the actual seizure can go adhead is determined by the actual edpileptic propensity of the above mentioned potential pathes.

The sensitivity and significance of lateralized interictal slow activity on magnetoencephalography in focal epilepsy

OBJECTIVE

Asymmetric large-amplitude slow activity is sometimes observed on interictal electroencephalography (EEG) in epilepsy. However, few studies have examined slowing during magnetoencephalography (MEG) recordings, which are performed primarily to localize interictal spikes. Also, no prior investigations have compared the sensitivity of MEG to scalp EEG in detecting slow rhythms.

METHODS

We performed a retrospective cohort study of focal epilepsy patients who received MEG followed by surgical resection at our institution. We examined MEG, simultaneous EEG, and long-term EEG recordings for prominent asymmetric slow activity (delta-range, 1-4 Hz), and evaluated post-operative seizure outcomes.

RESULTS

We studied 132 patients with ≥ 1 year post-operative follow-up (mean, 3.6 years). Mean age was 27 (range, 3-68) years, and 55% of patients were male. Asymmetric large-amplitude slow wave activity was observed on interictal MEG in 21 of 132 (16%) patients. Interictal slowing lateralized to the hemisphere of resection in all but one (95%) patient. Among the 21 patients with interictal MEG slowing, 11 (52%) individuals had similarly lateralized EEG slowing, 7 patients had no EEG slowing, and 3 had bilateral symmetric EEG slowing. Meanwhile, none of the 111 patients without lateralized MEG slowing had asymmetric EEG slowing, suggesting significantly higher sensitivity of MEG versus EEG in detecting asymmetric slowing (χ(2)=63.4, p<0.001). MEG slowing was associated with shorter epilepsy duration with an odds ratio of 5.4 (1.7-17.0, 95% confidence interval). At last follow-up, 92 (70%) patients were seizure free (Engel I outcome), with no difference in seizure freedom rates between patients with (71%) or without (69%) asymmetric MEG slowing (χ(2)=0.4, p=0.99).

SIGNIFICANCE

MEG has higher sensitivity than scalp EEG in detecting asymmetric slow activity in focal epilepsy, which reliably lateralizes to the epileptogenic hemisphere. Other uses of MEG beyond spike localization may further improve presurgical evaluations in epilepsy.

The effect of recurrent seizures on cognitive, behavioral, and quality-of-life outcomes after 12 months of monotherapy in adults with newly diagnosed or previously untreated partial epilepsy

PURPOSE

The purpose of this study was to determine whether seizure recurrence has a negative impact on cognition, psychological function, and health-related quality of life (HRQoL) over a 12-month period of monotherapy in adults with newly diagnosed or previously untreated partial epilepsy.

METHODS

Seizure freedom (SF) was defined as no seizure recurrence during the 40-week maintenance period of medication. Neuropsychological tests, the Symptom Checklist-90 (SCL-90), and the Quality of Life in Epilepsy-31 (QOLIE-31) were administered at baseline and after 48 weeks of carbamazepine or lamotrigine monotherapy. Seventy-three patients successfully continued treatment until the 48-week follow-up time point. Fifty patients (68.5%) had SF, and the remaining 23 were not seizure-free (NSF). A seizure outcome group-by-time interaction was analyzed using a linear mixed model.

RESULTS

A group-by-time interaction was identified for the total QOLIE-31 score (p<0.05) and score on two QOLIE-31 subscales (social function: p<0.001 and seizure worry: p<0.001), with a significant improvement over time only present in the SF group (all p<0.001). There was no significant group-by-time interaction for most cognitive function tests, with the exception of the serial clustering score (p<0.01) and number of recognition hits on the California Verbal Learning Test (p<0.05). Serial clustering did not differ between the SF and NSF groups at baseline, but was significantly more used in the NSF group than in the SF group at 48 weeks (p<0.01). There was no significant group-by-time interaction for any dimension of the SCL-90.

CONCLUSION

Recurrent seizures had a significant effect on HRQoL, a subtle effect on cognitive performance, and no effect on psychological symptoms over one year in newly diagnosed or previously untreated adults with partial epilepsy.

Partial epilepsy: A pictorial review of 3 TESLA magnetic resonance imaging features

Epilepsy is a disease with serious consequences for patients and society. In many cases seizures are sufficiently disabling to justify surgical evaluation. In this context, Magnetic Resonance Imaging (MRI) is one of the most valuable tools for the preoperative localization of epileptogenic foci. Because these lesions show a large variety of presentations (including subtle imaging characteristics), their analysis requires careful and systematic interpretation of MRI data. Several studies have shown that 3 Tesla (T) MRI provides a better image quality than 1.5 T MRI regarding the detection and characterization of structural lesions, indicating that high-field-strength imaging should be considered for patients with intractable epilepsy who might benefit from surgery. Likewise, advanced MRI postprocessing and quantitative analysis techniques such as thickness and volume measurements of cortical gray matter have emerged and in the near future, these techniques will routinely enable more precise evaluations of such patients. Finally, the familiarity with radiologic findings of the potential epileptogenic substrates in association with combined use of higher field strengths (3 T, 7 T, and greater) and new quantitative analytical post-processing techniques will lead to improvements regarding the clinical imaging of these patients. We present a pictorial review of the major pathologies related to partial epilepsy, highlighting the key findings of 3 T MRI.

Childhood Epilepsy with Occipital Paroxysm: Classification, Atypical Evolution and Long-Term Prognosis in 35 Patients

We studied childhood epilepsy with occipital paroxysms (CEOP) with regard to typical and/or atypical ictal symptoms, EEG findings, as well as atypical evolution and outcome. This report focuses on the main clinical and EEG features of CEOP underlying its atypical symptoms and its management. Thirty-five patients with CEOP were subdivided into Panayiotopoulos syndrome (n=15), Gastaut syndrome (n=11), and mixed type (n=9). Nine patients (25%) with CEOP (mixed type) had shown atypical ictal manifestations and presented combinations of vomiting (100%) along with visual symptoms (66%), and/or eye deviation (66%), and headaches (44%). Five patients with CEOP had atypical evolution. However, the dictate for strict delineation into either the early-onset or late-onset forms of CEOP should be discarded because many children will present mixed clinical findings at varying ages. We think a detailed evaluation should be carried out as to why certain patients who apply have atypical findings, and whether each patient has age related evolution or not.

Automatic ictal HFO detection for determination of initial seizure spread

High-frequency oscillations (HFOs) are a reliable indicator for the epileptic seizure onset zone (SOZ) in ECoG recordings. We propose a novel method for the automatic detection of ictal HFOs in the ripple band (80-250 Hz) based on CFAR matched sub-space filtering. This allows to track the early propagation of ictal HFOs, revealing initial and follow-up epileptic activity on the electrodes. We apply this methodology to two seizures from one patient suffering from focal epilepsy. The electrodes identified are in very good accordance with the visual HFO analysis by clinicians. Furthermore the electrodes with initial HFO activity are correlated well with the SOZ (conventional v-activity).

Duration of focal complex, secondarily generalized tonic-clonic, and primarily generalized tonic-clonic seizures--A video-EEG analysis

INTRODUCTION

Identifying seizures with prolonged duration during video-electroencephalographic (EEG) monitoring is of importance to inform clinicians when to start emergency treatment of seizures to prevent status epilepticus. The aims of this study were to assess the clinical and EEG seizure duration (SD) in consecutive patients with epilepsy who underwent prolonged video-EEG monitoring and to identify a seizure type-dependent time point to start emergency treatment based on the likelihood that seizures will not stop spontaneously. Furthermore, we sought to determine predictors of SD and explored the relationship between antiepileptic drug (AED) serum levels and SD.

MATERIAL AND METHODS

We retrospectively analyzed 1796 seizures in 200 patients undergoing video-EEG monitoring between January 2006 and March 2008.

RESULTS

Focal simple seizures lasted significantly shorter (clinical SD: 28s, EEG SD: 42 s) compared with focal complex seizures (clinical SD: 64 s, EEG SD: 62 s), and both seizure types lasted significantly shorter compared with secondarily generalized tonic-clonic seizures (GTCSs; clinical SD: 90 s, EEG SD: 96 s). There was no difference between the duration of the convulsive phase of primary GTCSs (defined as nonfocal) and that of secondarily GTCSs (each 65 s). Cumulative clinical SD (99%) was 7 min in focal complex seizures and 11 min in focal simple seizures. Mixed linear regression model demonstrated that history of status epilepticus (P = 0.034), temporal lobe seizure onset (P = 0.040), and MRI lesions (P = 0.013) were significantly associated with logarithmic EEG SD in focal epilepsies recorded with scalp electrodes. We found significant negative correlations between the AED serum level and the EEG SD in patients treated with monotherapy: carbamazepine (P < 0.001), levetiracetam (P = 0.001), oxcarbazepine (P = 0.001), and valproic acid (P = 0.038) but not with lamotrigine monotherapy and EEG SD.

DISCUSSION

Based on the results of this study, we propose 2 min of convulsive seizure activity (irrespective of focal or generalized onset) as a prolonged seizure, which could serve as a time point to consider treatment to prevent status epilepticus. In focal complex seizures, we suggest an upper limit of 7 min, and in focal simple seizures 11 min, as definition of prolonged seizures. History of status epilepticus, temporal seizure onset, and lesional MRI findings are factors associated with significantly longer SD. Negative correlations of carbamazepine, levetiracetam, oxcarbazepine, and valproic acid serum levels and SD suggest a prolonging effect on seizures during withdrawal of these AEDs during video-EEG monitoring sessions. This article is part of a Special Issue entitled "Status Epilepticus".

[Formula: see text]Differences in memory functioning between children with attention-deficit/hyperactivity disorder and/or focal epilepsy

Prior research has shown that attention-deficit/hyperactivity disorder (ADHD) and epilepsy are frequently comorbid and that both disorders are associated with various attention and memory problems. Nonetheless, limited research has been conducted comparing the two disorders in one sample to determine unique versus shared deficits. Hence, we investigated differences in working memory (WM) and short-term and delayed recall between children with ADHD, focal epilepsy of mixed foci, comorbid ADHD/epilepsy and controls. Participants were compared on the Core subtests and the Picture Locations subtest of the Children's Memory Scale (CMS). Results indicated that children with ADHD displayed intact verbal WM and long-term memory (LTM), as well as intact performance on most aspects of short-term memory (STM). They performed worse than controls on Numbers Forward and Picture Locations, suggesting problems with focused attention and simple span for visual-spatial material. Conversely, children with epilepsy displayed poor focused attention and STM regardless of the modality assessed, which affected encoding into LTM. The only loss over time was found for passages (Stories). WM was intact. Children with comorbid ADHD/epilepsy displayed focused attention and STM/LTM problems consistent with both disorders, having the lowest scores across the four groups. Hence, focused attention and visual-spatial span appear to be affected in both disorders, whereas additional STM/encoding problems are specific to epilepsy. Children with comorbid ADHD/epilepsy have deficits consistent with both disorders, with slight additive effects. This study suggests that attention and memory testing should be a regular part of the evaluation of children with epilepsy and ADHD.

Temporal lobe epilepsy is a predisposing factor for sleep apnea: A questionnaire study in video-EEG monitoring unit

OBJECTIVE

The interaction between epilepsy and sleep is known. It has been shown that patients with epilepsy have more sleep problems than the general population. However, there is no recent study that compares the frequency of sleep disorders in groups with medically refractory temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE). The main purpose of this study was to investigate the occurrence of sleep disorders in two subtypes of epilepsy by using sleep questionnaire forms.

METHODS

One hundred and eighty-nine patients, out of 215 who were monitored for refractory epilepsy and were followed by the video-EEG monitoring unit, were divided into a group with TLE and a group with ETLE. The medical outcome study-sleep scale (MOS-SS), Epworth sleepiness scale (ESS), and sleep apnea scale of the sleep disorders questionnaire (SD-SDQ) were completed after admission to the video-EEG monitoring unit. The total scores in the group with TLE and group with ETLE were compared.

RESULTS

Of the patients, TLE was diagnosed in 101 (53.4%) (45 females), and ETLE was diagnosed in 88 (46.6%) (44 females). Comparison of MOS-SS and Epworth sleepiness scale scores in the two subgroups did not reveal significant differences. In the group with TLE, SD-SDQ scores were significantly higher compared to that in the group with ETLE.

CONCLUSION

Patients with temporal lobe epilepsy have higher risk of obstructive sleep apnea (OSA) according to their reported symptoms. Detection of OSA in patients with epilepsy by using questionnaire forms may decrease the risk of ictal or postictal respiratory-related 'Sudden Unexpected Death in Epilepsy'.

Using functional MRI alone for localization in focal epilepsy

In the present study, we developed a method for the purpose of localizing epilepsy related hemodynamic foci for patients suffering intractable focal epilepsy using resting state fMRI alone. We studied two groups of subjects: five patients with intractable focal epilepsy, and ten healthy volunteers performing motor tasks. Spatial independent component analysis (ICA) was performed on the fMRI alone data and a set of independent component (IC) selection criteria was developed to identify epilepsy related ICs. The method was then evaluated in the healthy group with motor tasks. In all five surgery patients, there was at least one identified IC concordant with surgical resection. In the motor task study of healthy subjects, our method revealed components with concordant spatial and temporal features as expected from the unilateral motor tasks. These results suggest the lateralization and localization value of fMRI alone in presurgical evaluation for patients with intractable unilateral focal epilepsy. The proposed method is noninvasive in nature and easy to implement. It has the potential to be incorporated in current presurgical workup for the diagnosis of intractable focal epilepsy patients.

Validating the effect of muscle artifact suppression in localizing focal epilepsy

Source localization of an epileptic seizure is becoming an important diagnostic tool in pre-surgical evaluation of epileptic patients. However, for localizing the epileptogenic zone precisely, the epileptic activity needs to be isolated from other activities that are not related to the epileptic source. In this study, we aim at an investigation of the effect of muscle artifact suppression by using a low-pass filter (LPF), independent component analysis (ICA), and a combination of ICA-LPF prior to source localization in focal epilepsy. These techniques were applied on the EEG data obtained from a left-temporal lobe epileptic patient by artificially contaminating the isolated spike interval, present in the four left-temporal electrodes, with a muscle artifact. The results show that the muscle artifact was fully suppressed. Applying the dipole and current-density reconstruction (CDR) source-analysis algorithms on the filtered data, we were able to identify the location of the epileptogenic zone similar to that of the original undistorted data.

In vivo imaging of epileptic foci in rats using a miniature probe integrating diffuse optical tomography and electroencephalographic source localization

OBJECTIVE

The goal of this work is to establish a new dual-modal brain-mapping technique based on diffuse optical tomography (DOT) and electroencephalographic source localization (ESL) that can chronically/intracranially record optical/electroencephalography (EEG) data to precisely map seizures and localize the seizure-onset zone and associated epileptic brain network.

METHODS

The dual-modal imaging system was employed to image seizures in an experimental acute bicuculline methiodide rat model of focal epilepsy. Depth information derived from DOT was used as constraint in ESL to enhance the image reconstruction. Groups of animals were compared based on localization of seizure foci, either at different positions or at different depths.

RESULTS

This novel imaging technique successfully localized the seizure-onset zone in rat induced by bicuculline methiodide injected at a depth of 1, 2, and 3 mm, respectively. The results demonstrated that the incorporation of the depth information from DOT into the ESL image reconstruction resulted in more accurate and reliable ESL images. Although the ESL images showed a horizontal shift of the source localization, the DOT identified the seizure focus accurately. In one case, when the bicuculline methiodide (BMI) was injected at a site outside the field of view (FOV) of the DOT/ESL interface, ESL gave false-positive detection of the focus, while DOT showed negative detection.

SIGNIFICANCE

This study represents the first to identify seizure-onset zone using implantable DOT. In addition, the combination of DOT/ESL has never been documented in neuroscience and epilepsy imaging. This technology will enable us to precisely measure the neural activity and hemodynamic response at exactly the same tissue site and at both cortical and subcortical levels.

Multimodal imaging in nonlesional medically intractable focal epilepsy

Identification and localization of epileptogenic zone (EZ) is vital in patients with medically-intractable focal epilepsy, who may be candidates for potentially curative resective epilepsy surgery. Presence of a lesion on magnetic resonance imaging (MRI) influences both diagnostic classification and selection for surgery. However, the implications for MRI-negative cases are not well-defined for such patients. Most of these patients undergo invasive long-term Electroencephalography recordings before a final decision regarding resection is possible. Recent developments in structural and functional neuroimaging which include quali-quantitative MRI, Positron Emission Tomography, Single Photon Emission Computed Tomography, and functional MRI have significantly changed presurgical epilepsy evaluation. Source analysis based on electrophysiological information, using either EEG or magnetoencephalography are also promising in order to noninvasively localize the EZ and to guide surgery in medically-intractable focal epilepsy patients that exhibit nonlesional MRI. This chapter aims to review the value of the combined use of structural and functional imaging techniques, and how this multimodal approach improves both selection of surgical candidates and post-operative outcomes in medically-intractable nonlesional focal epilepsy.