High-Density (HD) Scalp EEG Findings in "Benign" Childhood Epilepsy with Centrotemporal Spikes (BCECTS).

Despite characteristic clinical and scalp EEG findings, BCECTS pathophysiology is unclear regarding involvement of large-scale neuronal networks. Higher number of scalp electrodes with HD-EEG may promote accurate localization of the cortical generators in BCECTS providing additional insight in those with neurocognitive problems. We aimed to determine the value of visual interpretation of topographical maps using 256 channels (when compared to standard 21 channel array) HD-EEG in BCECTS and attempted to source localize interictal discharges (IEDs) using Geosource 2 software. Patient records were reviewed for demographic, seizure, brain magnetic resonance imaging (MRI) details; scalp and HD-EEG findings. HD-EEG software was used to review raw EEG data (21 scalp EEG electrodes were compared to 256 HD-EEG electrodes); select, average, and source localize IEDs.Five BCECTS patients with HD-EEG were identified. Seizure onset age ranged from 5-11 years with 1-18 lifetime seizures; both focal (n = 3) and focal to bilateral tonic-clonic (n = 2). Neurocognitive co-morbidities noted in our cohort included attention deficit hyperactivity disorder, speech/developmental delay and a specific learning disorder. Scalp EEG showed typical findings with IEDs over the centrotemporal regions (bilateral n = 3; unilateral n = 2). Visualization and inspection of expanded coverage topographic maps with HD-EEG showed well-defined islands of maximum negativity and positivity of a dipole compared to conventional channels where boundary delineation was obscured. Further, HD-EEG localized IEDs/"spike-generator" to areas such as the pre-and post-central, middle-frontal and temporal gyrus, and the inferior parietal lobule. In BCECTS, HD-EEG may show affection for a broader neural network and may provide a better insight into the associated neurocognitive morbidities.

Seizures in Patients With Metastatic Brain Tumors: Prevalence, Clinical Characteristics, and Features on EEG.

INTRODUCTION: Metastases to the brain (MB) occur in up to 30% of adults with cancer; of these, 15% to 35% may have seizures. We investigated clinical and pathologic associations with seizure and EEG findings in patients with MB, given the sparse literature in this area. METHODS: We performed a retrospective chart review of adults with pathologically confirmed MB treated at a large tertiary care center between April 8, 2006, and December 14, 2018. Primary outcomes were odds of "chart-documented seizure" (CDS) in the full sample and EEG-captured seizure or any epileptiform discharges among those monitored on EEG. RESULTS: We studied 187 patients with MB, of whom 55 (28.3%) were monitored on EEG. We found an overall CDS prevalence of 29.4% and an EEG-captured seizure of 18.9% among patients monitored on EEG. Of those monitored on EEG, 47.2% had epileptiform discharges. Adenocarcinoma pathology was associated with lower odds of CDS (odds ratio [OR] 0.50, 95% CI 0.26-0.96) and EEG-captured seizure (OR 0.09, 95% CI 0.01-0.87) versus other pathologies. When modeled separately, melanoma pathology was associated with CDS (OR 4.45, 95% CI 1.58-12.57) versus other pathologies. Hemorrhagic MB were associated with any epileptiform discharges (OR 5.50, 95% CI 1.65-18.37), regardless of pathology modeled. Increasing size of the largest dimension of the largest MB was associated with lower odds of CDS (OR 0.68, 95% CI 0.52-0.89 when adenocarcinoma modeled, OR 0.69, 95% CI 0.53-0.91 when melanoma modeled). CONCLUSIONS: Seizures and epileptiform discharges are common in patients with MB. Tumor size and pathology were significantly associated with CDS. Larger studies are needed for further analysis.

Clinical characteristics, EEG findings and implications of status epilepticus in patients with brain metastases.

PURPOSE: To evaluate the clinical implications of status epilepticus in patients with metastases to the brain as well as associated demographic, clinical, EEG and radiographic features. METHODS: Retrospective chart review of 19 patients with metastases to the brain who subsequently developed status epilepticus. RESULTS: Of the patients who developed status epilepticus only 36.8% had a prior history of seizures since diagnosis of brain metastases. Status epilepticus most commonly occurred in the setting of a new structural injury to the brain such as new metastases, increase in size of metastases or hemorrhage. 57.9% of patients had either refractory or super-refractory status epilepticus. Focal non-convulsive status epilepticus was the most common subtype occurring in 42.1% of patients. 31.6% of patients died within 30 days of the onset of status epilepticus. CONCLUSION: Status epilepticus eventually resolved with treatment in all patients with brain metastases; however, it is associated with poor outcomes as nearly one-third was deceased within 30-days of onset. Nevertheless, no patients died during status epilepticus. Thus, status epilepticus may be indicative of an overall poor clinical status among patients with brain metastases.

Montages for Noninvasive EEG Recording.

Identifying the localization, distribution, and polarity of waveforms are the prime goals of clinical scalp EEG analysis. Appropriate choices of bipolar and referential montages are keys to emphasizing the diagnostic features of interest, and demand some understanding of the spatiotemporal physical behavior of the underlying neuronal generators. Several examples drawn from canonical epilepsy syndromes are used to illustrate this general message.

Seizures in patents with primary central nervous system lymphoma: Prevalence and associated features.

OBJECTIVE: Primary central nervous system (CNS) lymphoma (PCNSL) is a rare, aggressive, yet highly chemosensitive form of non-Hodgkin lymphoma which is associated with significant morbidity. Very little is known about the long-term risk for and features of seizures associated with this condition. METHODS: We performed a retrospective and longitudinal analysis of 36 patients with pathologically and radiographically confirmed primary CNS lymphoma to evaluate the incidence, prevalence and features associated with seizures. Demographic, radiographic, histological and electroencephalographic (EEG) data were included as part of the study. RESULTS: One-third of patients with primary CNS lymphoma had clinical seizures of which two-thirds occurred at time of initial presentation, while the remainder developed during a mean follow-up time of 1.49 years. The incidence rate of first seizure in PCNSL was 224.4 per 1000 persons, per year. There was a trend towards association with seizures in patients with cortical lesions relative to patients with subcortical lesions. EEG revealed epileptiform discharges in 44.4% of patients with both PCNSL and clinical seizures which suggests that it is a useful diagnostically in a substantial proportion of patients. CONCLUSIONS: A significant percentage of patients with primary CNS lymphoma develop comorbid seizures during their disease course. Increased awareness and collaboration between neuro-oncologists and epileptologists may enhance and improve care for these patients.

Interictal Epileptiform Discharge Detection in EEG in Different Practice Settings.

OBJECTIVE: The goal of the study was to measure the performance of academic and private practice (PP) neurologists in detecting interictal epileptiform discharges in routine scalp EEG recordings. METHODS: Thirty-five EEG scorers (EEGers) participated (19 academic and 16 PP) and marked the location of ETs in 200 30-second EEG segments using a web-based EEG annotation system. All participants provided board certification status, years of Epilepsy Fellowship Training (EFT), and years in practice. The Persyst P13 automated IED detection algorithm was also run on the EEG segments for comparison. RESULTS: Academic EEGers had an average of 1.66 years of EFT versus 0.50 years of EFT for PP EEGers (P < 0.0001) and had higher rates of board certification. Inter-rater agreement for the 35 EEGers was fair. There was higher performance for EEGers in academics, with at least 1.5 years of EFT, and with American Board of Clinical Neurophysiology and American Board of Psychiatry and Neurology-E specialty board certification. The Persyst P13 algorithm at its default setting (perception value = 0.4) did not perform as well at the EEGers, but at substantially higher perception value settings, the algorithm performed almost as well human experts. CONCLUSIONS: Inter-rater agreement among EEGers in both academic and PP settings varies considerably. Practice location, years of EFT, and board certification are associated with significantly higher performance for IED detection in routine scalp EEG. Continued medical education of PP neurologists and neurologists without EFT is needed to improve routine scalp EEG interpretation skills. The performance of automated detection algorithms is approaching that of human experts.

Characteristics of EEG Interpreters Associated With Higher Interrater Agreement.

PURPOSE: The goal of the project is to determine characteristics of academic neurophysiologist EEG interpreters (EEGers), which predict good interrater agreement (IRA) and to determine the number of EEGers needed to develop an ideal standardized testing and training data set for epileptiform transient (ET) detection algorithms. METHODS: A three-phase scoring method was used. In phase 1, 19 EEGers marked the location of ETs in two hundred 30-second segments of EEG from 200 different patients. In phase 2, EEG events marked by at least 2 EEGers were annotated by 18 EEGers on a 5-point scale to indicate whether they were ETs. In phase 3, a third opinion was obtained from EEGers on any inconsistencies between phase 1 and phase 2 scoring. RESULTS: The IRA for the 18 EEGers was only fair. A select group of the EEGers had good IRA and the other EEGers had low IRA. Board certification by the American Board of Clinical Neurophysiology was associated with better IRA performance but other board certifications, years of fellowship training, and years of practice were not. As the number of EEGers used for scoring is increased, the amount of change in the consensus opinion decreases steadily and is quite low as the group size approaches 10. CONCLUSIONS: The IRA among EEGers varies considerably. The EEGers must be tested before use as scorers for ET annotation research projects. The American Board of Clinical Neurophysiology certification is associated with improved performance. The optimal size for a group of experts scoring ETs in EEG is probably in the 6 to 10 range.

Comparison of a Novel Dry Electrode Headset to Standard Routine EEG in Veterans.

OBJECTIVE: This purpose of this study was to evaluate the usefulness of a prototype battery-powered dry electrode system (DES) EEG recording headset in Veteran patients by comparing it with standard EEG. METHODS: Twenty-one Veterans had both a standard electrode system recording and DES recording in nine different patient states at the same encounter. Setup time, patient comfort, and subject preference were measured. Three experts performed technical quality rating of each EEG recording in a blinded fashion using the web-based EEGnet system. Power spectra were compared between DES and standard electrode system recordings. RESULTS: The average time for DES setup was 5.7 minutes versus 21.1 minutes for standard electrode system. Subjects reported that the DES was more comfortable during setup. Most subjects (15 of 21) preferred the DES. On a five-point scale (1-best quality to 5-worst quality), the technical quality of the standard electrode system recordings was significantly better than for the DES recordings, at 1.25 versus 2.41 (P < 0.0001). But experts found that 87% of the DES EEG segments were of sufficient technical quality to be interpretable. CONCLUSIONS: This DES offers quick and easy setup and is well tolerated by subjects. Although the technical quality of DES recordings was less than standard EEG, most of the DES recordings were rated as interpretable by experts. SIGNIFICANCE: This DES, if improved, could be useful for a telemedicine approach to outpatient routine EEG recording within the Veterans Administration or other health system.

Standardized database development for EEG epileptiform transient detection: EEGnet scoring system and machine learning analysis.

The routine scalp electroencephalogram (rsEEG) is the most common clinical neurophysiology procedure. The most important role of rsEEG is to detect evidence of epilepsy, in the form of epileptiform transients (ETs), also known as spike or sharp wave discharges. Due to the wide variety of morphologies of ETs and their similarity to artifacts and waves that are part of the normal background activity, the task of ET detection is difficult and mistakes are frequently made. The development of reliable computerized detection of ETs in the EEG could assist physicians in interpreting rsEEGs. We report progress in developing a standardized database for testing and training ET detection algorithms. We describe a new version of our EEGnet software system for collecting expert opinion on EEG datasets, a completely web-browser based system. We report results of EEG scoring from a group of 11 board-certified academic clinical neurophysiologists who annotated 30-s excepts from rsEEG recordings from 100 different patients. The scorers had moderate inter-scorer reliability and low to moderate intra-scorer reliability. In order to measure the optimal size of this standardized rsEEG database, we used machine learning models to classify paroxysmal EEG activity in our database into ET and non-ET classes. Based on our results, it appears that our database will need to be larger than its current size. Also, our non-parametric classifier, an artificial neural network, performed better than our parametric Bayesian classifier. Of our feature sets, the wavelet feature set proved most useful for classification.

Reliability and validity of the Turkish version of the pediatric sleep questionnaire: a tool for prediction of sleep related breathing disorder.

Use of a questionnaire that predicts the diagnosis and influence of sleep related breathing disorder (SRBD) may be a cost-effective method to aid in both diagnostic algorithm and therapy. Therefore, the aim of this study was to adapt Pediatric Sleep Questionnaire (PSQ) into Turkish and to test the validity and reliability of the Turkish questionnaire. Total of 111 children (59 male, 52 female) aged 2 to 17 years who had symptoms suggestive of SRBD were enrolled consecutively. Demographic characteristics such as age and gender of all children enrolled in the study were recorded. All parents were questioned about symptom severity, frequency and duration. Lastly, PSQ was administered to all parents. Mean age of the children enrolled in the study was 8.1 ± 3.4 years. Total PSQ score ranged between 0 and 0.95 and mean score was 0.35 ± 0.22. Comparison of total PSQ scores between children reporting different symptom frequencies demonstrated that PSQ score increased as the symptom frequency increased (p< 0.001). There was a significant difference of all PSQ scores among the groups (p< 0.05 for all). Total PSQ score for children that did not report snoring was 0.2 ± 0.5 wile that for the ones who snore throughout sleep was 3.8 ± 0.5 (p< 0.001). Cronbach's alpha values for all domains of PSQ were satisfactory. All items were significantly correlated with their corresponding scale. Turkish version of PSQ is a valid and reliable tool that may be used in the initial evaluation of Turkish children with symptoms suggestive of SRBD.

Nonepileptic paroxysmal events in a pediatric population.

Nonepileptic paroxysmal events in children are common, and may be more diverse in etiology than those seen in adults. We determined the types of nonepileptic events that are most prominent in the pediatric population, and stratified those events by age group. Ninety-four of 416 pediatric patients monitored during a 3-year period (23%) were found to have had nonepileptic events. Thirty-eight percent of these children were diagnosed with psychogenic nonepileptic seizures, and 72% of those were adolescents. In children younger than 5 years of age, behavioral events and parasomnias were the most common mimickers of epilepsy. Other events, including stereotyped movements and myoclonus, were also diagnosed. We suggest that children with refractory paroxysmal events should be considered for early inpatient monitoring.

Nonconvulsive status epilepticus manifesting as pure alexia (alexia without agraphia).

Pure alexia is a rare disorder usually caused by an ischemic or hemorrhagic stroke. We describe a case of pure alexia due to nonconvulsive status epilepticus (NCSE). This 57-year-old man presented in a hyperosmolar, nonketotic state with fluctuations in mental status and an inability to read. His EEG was diagnostic of NCSE originating from the left temporo-occipital region. MRI of the brain revealed increased FLAIR signal over the left occipitotemporal region. Following initiation of antiepileptic treatment, his neurological examination normalized concomitantly with resolution of the NCSE. A follow-up MRI scan of the brain obtained 1 month later was normal. NCSE can have unusual clinical manifestations, and a high index of suspicion is necessary to correctly diagnose these patients.

Diagnostic and localizing value of ictal SPECT in patients with nonconvulsive status epilepticus.

In this study, we evaluate the diagnostic and localizing value of SPECT in three patients with nonconvulsive status epilepticus (NCSE). Our results indicate that ictal/subtraction ictal SPECT is a useful complementary noninvasive diagnostic test in patients with focal NCSE. This is especially the case when the EEG findings are inconclusive and for patients in whom surgical treatment is being considered.

Full neurologic recovery after fulminant thrombotic thrombocytopenic purpura with status epilepticus.

Thrombotic thrombocytopenic purpura (TTP) is an ischemic vasculopathy frequently associated with neurological dysfunction including seizures. However, status epilepticus (SE) has rarely been reported in this condition. We report on a 70-year-old woman with fulminant TTP who developed convulsive SE despite high therapeutic serum levels of phenytoin and phenobarbital. Her electroencephalogram (EEG) was characterized by bilateral independent periodic lateralizing epileptiform discharges (BIPLEDs) propagating into clinical and electrographic seizures. She recovered completely after intensive plasmapheresis and treatment with pentobarbital induced coma for 5 days. This case illustrates that aggressive treatment with pentobarbital and plasmapheresis may prevent permanent neurologic deficits when TTP is complicated by SE and that periodic lateralizing epileptiform discharges (PLEDs) in this syndrome can be the manifestation of a reversible ischemic insult.

Sporadic Creutzfeldt-Jakob disease presenting with nonconvulsive status epilepticus.

Creutzfeldt-Jakob disease (CJD) is a rare prion disease characterized by a spongiform encephalopathy in humans. Although the characteristic triad of myoclonus, dementia, and periodic EEG activity is easy to recognize, unusual manifestations of the disease may be challenging and create a diagnostic dilemma. We report a case of CJD that occurred in a 26-year-old patient who presented with a receptive (Wernicke's) aphasia secondary to nonconvulsive status epilepticus.