MRI-identified pathology in adults with new-onset seizures

Approach to Patients with Seizures and Epilepsy: A Guide for Primary Care Physicians

Seizures and epilepsy are common neurologic conditions that are frequently encountered in the outpatient primary care setting. An accurate diagnosis relies on a thorough clinical history and evaluation. Understanding seizure semiology and classification is crucial in conducting the initial assessment. Knowledge of common seizure triggers and provoking factors can further guide diagnostic testing and initial management. The pharmacodynamic characteristics and side effect profiles of anti-seizure medications are important considerations when deciding treatment and counseling patients, particularly those with comorbidities and in special populations such as patient of childbearing potential.

The latest advances in the pharmacological management of focal epilepsies in children: a narrative review

INTRODUCTION

Focal epilepsy constitutes the most common epilepsy in children, and medical treatment represents the first-line therapy in this condition. The main goal of medical treatment for children and adolescents with epilepsy is the achievement of seizure freedom or, in drug-resistant epilepsies, a significant seizure reduction, both minimizing antiseizure medications (ASM)-related adverse events, thus improving the patient's quality of life. However, up to 20-40% of pediatric epilepsies are refractory to drug treatments. New ASMs came to light in the pediatric landscape, improving the drug profile compared to that of the preexisting ones. Clinicians should consider several factors during the drug choice process, including patient and medication-specific characteristics.

AREAS COVERED

This narrative review aims to summarize the latest evidence on the effectiveness and tolerability of the newest ASMs administered as monotherapy or adjunctive therapy in pediatric epilepsies with focal onset seizures, providing a practical appraisal based on the existing evidence.

EXPERT OPINION

The latest ASMs have the potential to be effective in the pharmacological management of focal onset seizures in children, and treatment choice should consider several drug- and epilepsy-related factors. Future treatments should be increasingly personalized and targeted on patient-specific pathways. Future research should focus on discovering new chemical compounds and repurposing medications used for other indications.

Clinical Impact and Risk Factors of Seizure After Liver Transplantation: A Nested Case-Control Study

Seizures are a frequent neurological consequence following liver transplantation (LT), however, research on their clinical impact and risk factors is lacking. Using a nested case-control design, patients diagnosed with seizures (seizure group) within 1-year post-transplantation were matched to controls who had not experienced seizures until the corresponding time points at a 1:5 ratio to perform survival and risk factor analyses. Seizures developed in 61 of 1,243 patients (4.9%) at median of 11 days after LT. Five-year graft survival was significantly lower in the seizure group than in the controls (50.6% vs. 78.2%, respectively, p < 0.001) and seizure was a significant risk factor for graft loss after adjusting for variables (HR 2.04, 95% CI 1.24-3.33). In multivariable logistic regression, body mass index <23 kg/m2, donor age ≥45 years, intraoperative continuous renal replacement therapy and delta sodium level ≥4 mmol/L emerged as independent risk factors for post-LT seizure. Delta sodium level ≥4 mmol/L was associated with seizures, regardless of the severity of preoperative hyponatremia. Identifying and controlling those risk factors are required to prevent post-LT seizures which could result in worse graft outcome.

Targeted nanotheranostics for the treatment of epilepsy through in vivo hijacking of locally activated macrophages

Epilepsy refers to a disabling neurological disorder featured by the long-term and unpredictable occurrence of seizures owing to abnormal excessive neuronal electrical activity and is closely linked to unresolved inflammation, oxidative stress, and hypoxia. The difficulty of accurate localization and targeted drug delivery to the lesion hinders the effective treatment of this disease. The locally activated inflammatory cells in the epileptogenic region offer a new opportunity for drug delivery to the lesion. In this work, CD163-positive macrophages in the epileptogenic region were first harnessed as Trojan horses after being hijacked by targeted albumin manganese dioxide nanoparticles, which effectively penetrated the brain endothelial barrier and delivered multifunctional nanomedicines to the epileptic foci. Hence, accumulative nanoparticles empowered the visualization of the epileptogenic lesion through microenvironment-responsive MR T1-weight imaging of manganese dioxide. Besides, these manganese-based nanomaterials played a pivotal role in shielding neurons from cell apoptosis mediated by oxidative stress and hypoxia. Taken together, the present study provides an up-to-date approach for integrated diagnosis and treatment of epilepsy and other hypoxia-associated inflammatory diseases. STATEMENT OF SIGNIFICANCE: The therapeutic effects of antiepileptic drugs (AEDs) are hindered by insufficient drug accumulation in the epileptic site. Herein, we report an efficient strategy to use locally activated macrophages as carriers to deliver multifunctional nanoparticles to the brain lesion. As MR-responsive T1 contrast agents, multifunctional BMC nanoparticles can be harnessed to accurately localize the epileptogenic region with high sensitivity and specificity. Meanwhile, catalytic nanoparticles BMC can synergistically scavenge ROS, generate O2 and regulate neuroinflammation for the protection of neurons in the brain.

Long-term physical and psychiatric morbidities and mortality of untreated, deferred, and immediately treated epilepsy

OBJECTIVE

In Australia, 30% of newly diagnosed epilepsy patients were not immediately treated at diagnosis. We explored health outcomes between patients receiving immediate, deferred, or no treatment, and compared them to the general population.

METHODS

Adults with newly diagnosed epilepsy in Western Australia between 1999 and 2016 were linked with statewide health care data collections. Health care utilization, comorbidity, and mortality at up to 10 years postdiagnosis were compared between patients receiving immediate, deferred, and no treatment, as well as with age- and sex-matched population controls.

RESULTS

Of 603 epilepsy patients (61% male, median age = 40 years) were included, 422 (70%) were treated immediately at diagnosis, 110 (18%) received deferred treatment, and 71 (12%) were untreated at the end of follow-up (median = 6.8 years). Immediately treated patients had a higher 10-year rate of all-cause admissions or emergency department presentations than the untreated (incidence rate ratio [IRR] = 2.0, 95% confidence interval [CI] = 1.4-2.9) and deferred treatment groups (IRR = 1.7, 95% CI = 1.0-2.8). They had similar 10-year risks of mortality and developing new physical and psychiatric comorbidities compared with the deferred and untreated groups. Compared to population controls, epilepsy patients had higher 10-year mortality (hazard ratio = 2.6, 95% CI = 2.1-3.3), hospital admissions (IRR = 2.3, 95% CI = 1.6-3.3), and psychiatric outpatient visits (IRR = 3.2, 95% CI = 1.6-6.3). Patients with epilepsy were also 2.5 (95% CI = 2.1-3.1) and 3.9 (95% CI = 2.6-5.8) times more likely to develop a new physical and psychiatric comorbidity, respectively.

SIGNIFICANCE

Newly diagnosed epilepsy patients with deferred or no treatment did not have worse outcomes than those immediately treated. Instead, immediately treated patients had greater health care utilization, likely reflecting more severe underlying epilepsy etiology. Our findings emphasize the importance of individualizing epilepsy treatment and recognition and management of the significant comorbidities, particularly psychiatric, that ensue following a diagnosis of epilepsy.

Magnetic resonance imaging findings in Kenyans and South Africans with active convulsive epilepsy: An observational study

OBJECTIVE

Focal epilepsy is common in low- and middle-income countries. The frequency and nature of possible underlying structural brain abnormalities have, however, not been fully assessed.

METHODS

We evaluated the possible structural causes of epilepsy in 331 people with epilepsy (240 from Kenya and 91 from South Africa) identified from community surveys of active convulsive epilepsy. Magnetic resonance imaging (MRI) scans were acquired on 1.5-Tesla scanners to determine the frequency and nature of any underlying lesions. We estimated the prevalence of these abnormalities using Bayesian priors (from an earlier pilot study) and observed data (from this study). We used a mixed-effect modified Poisson regression approach with the site as a random effect to determine the clinical features associated with neuropathology.

RESULTS

MRI abnormalities were found in 140 of 240 (modeled prevalence = 59%, 95% confidence interval [CI]: 53%-64%) of people with epilepsy in Kenya, and in 62 of 91 (modeled prevalence = 65%, 95% CI: 57%-73%) in South Africa, with a pooled modeled prevalence of 61% (95% CI: 56%-66%). Abnormalities were common in those with a history of adverse perinatal events (15/23 [65%, 95% CI: 43%-84%]), exposure to parasitic infections (83/120 [69%, 95% CI: 60%-77%]) and focal electroencephalographic features (97/142 [68%, 95% CI: 60%-76%]), but less frequent in individuals with generalized electroencephalographic features (44/99 [44%, 95% CI: 34%-55%]). Most abnormalities were potentially epileptogenic (167/202, 82%), of which mesial temporal sclerosis (43%) and gliosis (34%) were the most frequent. Abnormalities were associated with co-occurrence of generalized non-convulsive seizures (relative risk [RR] = 1.12, 95% CI: 1.04-1.25), lack of family history of seizures (RR = 0.91, 0.86-0.96), convulsive status epilepticus (RR = 1.14, 1.08-1.21), frequent seizures (RR = 1.12, 1.04-1.20), and reported use of anti-seizure medication (RR = 1.22, 1.18-1.26).

SIGNIFICANCE

MRI identified pathologies are common in people with epilepsy in Kenya and South Africa. Mesial temporal sclerosis, the most common abnormality, may be amenable to surgical correction. MRI may have a diagnostic value in rural Africa, but future longitudinal studies should examine the prognostic role.

Assessing 72 h vs. 24 h of long-term video-EEG monitoring to confirm the diagnosis of epilepsy: a retrospective observational study

Introduction

Paroxysmal seizure-like events can be a diagnostic challenge. Inpatient video-electroencephalography (EEG) monitoring (VEM) can be a valuable diagnostic tool, but recommendations for the minimal duration of VEM to confirm or rule out epilepsy are inconsistent. In this study, we aim to determine whether VEM of 48 or 72 h was superior to 24 h.

Methods

In this monocentric, retrospective study, we included 111 patients with paroxysmal, seizure-like events who underwent at least 72 h of VEM. Inclusion criteria were as follows: (1) Preliminary workup was inconclusive; (2) VEM admission occurred to confirm a diagnosis; (3) At discharge, the diagnosis of epilepsy was conclusively established. We analyzed the VEM recordings to determine the exact time point of the first occurrence of epileptic abnormalities (EAs; defined as interictal epileptiform discharges or electrographic seizures). Subgroup analyses were performed for epilepsy types and treatment status.

Results

In our study population, 69.4% (77/111) of patients displayed EAs during VEM. In this group, the first occurrence of EAs was observed within 24 h in 92.2% (71/77) of patients and within 24-72 h in 7.8% (6/77). There was no statistically significant difference in the incidence of EA between medicated and non-medicated patients or between focal, generalized epilepsies and epilepsies of unknown type. Of the 19 recorded spontaneous electroclinical seizures, 6 (31.6%) occurred after 24 h.

Discussion

A VEM of 24 h may be sufficient in the diagnostic workup of paroxysmal seizure-like events under most circumstances. Considering the few cases of first EA in the timeframe between 24 and 72 h, a prolonged VEM may be useful in cases with a high probability of epilepsy or where other strategies like sleep-EEG or ambulatory EEG show inconclusive results. Prolonged VEM increases the chance of recording spontaneous seizures. Our study also highlights a high share of subjects with epilepsy that do not exhibit EAs during 72 h of VEM.

Later onset focal epilepsy with roots in childhood: Evidence from early learning difficulty and brain volumes in the Human Epilepsy Project

OBJECTIVE

Visual assessment of magnetic resonance imaging (MRI) from the Human Epilepsy Project 1 (HEP1) found 18% of participants had atrophic brain changes relative to age without known etiology. Here, we identify the underlying factors related to brain volume differences in people with focal epilepsy enrolled in HEP1.

METHODS

Enrollment data for participants with complete records and brain MRIs were analyzed, including 391 participants aged 12-60 years. HEP1 excluded developmental or cognitive delay with intelligence quotient <70, and participants reported any formal learning disability diagnoses, repeated grades, and remediation. Prediagnostic seizures were quantified by semiology, frequency, and duration. T1-weighted brain MRIs were analyzed using Sequence Adaptive Multimodal Segmentation (FreeSurfer v7.2), from which a brain tissue volume to intracranial volume ratio was derived and compared to clinically relevant participant characteristics.

RESULTS

Brain tissue volume changes observable on visual analyses were quantified, and a brain tissue volume to intracranial volume ratio was derived to compare with clinically relevant variables. Learning difficulties were associated with decreased brain tissue volume to intracranial volume, with a ratio reduction of .005 for each learning difficulty reported (95% confidence interval [CI] = -.007 to -.002, p = .0003). Each 10-year increase in age at MRI was associated with a ratio reduction of .006 (95% CI = -.007 to -.005, p < .0001). For male participants, the ratio was .011 less than for female participants (95% CI = -.014 to -.007, p < .0001). There were no effects from seizures, employment, education, seizure semiology, or temporal lobe electroencephalographic abnormalities.

SIGNIFICANCE

This study shows lower brain tissue volume to intracranial volume in people with newly treated focal epilepsy and learning difficulties, suggesting developmental factors are an important marker of brain pathology related to neuroanatomical changes in focal epilepsy. Like the general population, there were also independent associations between brain volume, age, and sex in the study population.

Automated detection of hippocampal sclerosis using real-world clinical MRI images

Background

Hippocampal sclerosis (HS) is the most common pathological type of temporal lobe epilepsy (TLE) and one of the important surgical markers. Currently, HS is mainly diagnosed manually by radiologists based on visual inspection of MRI, which greatly relies on MRI quality and physician experience. In clinical practice, non-thin MRI scans are often used due to the time and efficiency needed for the acquisition. However, these scans can be difficult for junior physicians to interpret accurately. Thus, the rapid and accurate diagnosis of HS using real-world MRI images in clinical settings is a challenging task.

Objective

Our aim was to explore the feasibility of using computer vision methods to diagnose HS on real-world clinical MRI images and to provide a reference for future clinical applications of artificial intelligence methods to aid in detecting HS.

Methods

We proposed a deep learning algorithm called "HS-Net" to discriminate HS using real-world clinical MRI images. First, we delineated and segmented a region of interest (ROI) around the hippocampus. Then, we utilized the fractional differential (FD) method to enhance the textures of the ROIs. Finally, we used a small-sample image classification method based on transfer learning to fine-tune the feature extraction part of a pretrained model and added two fully connected layers and an output layer. In the study, 96 TLE patients with HS confirmed by postoperative pathology and 89 healthy controls were retrospectively enrolled. All subjects were cross-validated, and models were evaluated for performance, robustness, and clinical utility.

Results

The HS-Net model achieved an area under the curve (AUC) of 0.894, an accuracy of 82.88%, an F1-score of 84.08% in the test cohort based on real, routine, clinical T2-weighted fluid attenuated inversion recovery (FLAIR) sequence MRI images. Additionally, the AUC, accuracy and F1 scores of our model all increased by around 3 percentage points when the inputs were augmented with the ROIs of the textures enhanced using the FD method.

Conclusions

Our computational model has the potential to be used for the diagnosis of HS in real clinical MRI images, which could assist physicians, particularly junior physicians, in improving the accuracy of discrimination.

Neuroimaging in Adults and Children With Epilepsy

OBJECTIVE

This article discusses the fundamental importance of optimal epilepsy imaging using the International League Against Epilepsy-endorsed Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS) protocol and the use of multimodality imaging in the evaluation of patients with drug-resistant epilepsy. It outlines a methodical approach to evaluating these images, particularly in the context of clinical information.

LATEST DEVELOPMENTS

Epilepsy imaging is rapidly evolving, and a high-resolution epilepsy protocol MRI is essential in evaluating newly diagnosed, chronic, and drug-resistant epilepsy. The article reviews the spectrum of relevant MRI findings in epilepsy and their clinical significance. Integrating multimodality imaging is a powerful tool in the presurgical evaluation of epilepsy, particularly in "MRI-negative" cases. For example, correlation of clinical phenomenology, video-EEG with positron emission tomography (PET), ictal subtraction single-photon emission computerized tomography (SPECT), magnetoencephalography (MEG), functional MRI, and advanced neuroimaging such as MRI texture analysis and voxel-based morphometry enhances the identification of subtle cortical lesions such as focal cortical dysplasias to optimize epilepsy localization and selection of optimal surgical candidates.

ESSENTIAL POINTS

The neurologist has a unique role in understanding the clinical history and seizure phenomenology, which are the cornerstones of neuroanatomic localization. When integrated with advanced neuroimaging, the clinical context has a profound impact on identifying subtle MRI lesions or finding the "epileptogenic" lesion when multiple lesions are present. Patients with an identified lesion on MRI have a 2.5-fold improved chance of achieving seizure freedom with epilepsy surgery compared with those without a lesion. This clinical-radiographic integration is essential to accurate classification, localization, determination of long-term prognosis for seizure control, and identification of candidates for epilepsy surgery to reduce seizure burden or attain seizure freedom.

Comorbidities in newly diagnosed epilepsy: Pre-existing health conditions are common and complex across age groups

OBJECTIVES

People with epilepsy have a higher prevalence of medical and psychiatric comorbidities compared to the general population. Comorbidities are associated with poor epilepsy outcomes, and there have been recommendations for screening and early identification to improve clinical management. Data from 'First Seizure Clinics' (FSCs) with expert epileptological review can inform about disorders already present at the point of diagnosis of epilepsy or unprovoked seizures. Here, we aimed to describe pre-existing conditions with a focus on psychiatric, substance use, cardiac, neurological, and cancer health domains.

METHODS

We included 1383 adults who received a new diagnosis of epilepsy or unprovoked seizures at Austin Hospital (AH) or Royal Melbourne Hospital (RMH) (Australia) FSCs from 2000 to 2010. Data were audited from FSC records, primarily detailed interviews undertaken by epileptologists. Logistic regression examined age distribution and other risk factors.

RESULTS

The median age at FSC presentation was 37 years (IQR 26-53, range 18-94). Pre-existing conditions were reported by 40 %; from 32 % in the youngest group (18-30 years) to 53 % in the oldest (65+ years). Psychiatric (18 %) and substance use (16 %) disorders were most common, with higher prevalence among patients 18 to 65 years of age compared to those older than 65 years (p < 0.001). Cardiac, neurological, or cancer conditions were reported by 3-6 %, most often amongst those older than 65 years (p < 0.01). Eight percent (n = 112) reported disorders in >1 health domain. The commonest combination was a psychiatric condition with substance use disorder. Of the sixty-two patients reporting this combination, 61 were ≤65 years of age.

CONCLUSIONS

Pre-existing health conditions are present in a substantial proportion of patients diagnosed with epilepsy or unprovoked seizures. Disorders are highest amongst elders, but one-third of younger adults also reported positive histories. These are predominantly psychiatric and/or substance use disorders, conditions strongly associated with poor outcomes in the general population. These findings inform post-diagnosis planning and management, as well as research examining post-diagnostic outcomes and associations between comorbidities and epilepsy.

Brain magnetic resonance imaging findings among children with epilepsy in two urban hospital settings, Kampala-Uganda: a descriptive study

Background

Epilepsy is one of the most common neurological conditions in children worldwide. Its presentation is heterogeneous, with diverse underlying aetiology, clinical presentation, and prognosis. Structural brain abnormalities are among the recognized causes of epilepsy. Brain Magnetic Resonance Imaging (MRI) is the imaging modality of choice for epilepsy workup.

We aimed to determine the prevalence and describe the structural abnormalities identified in the brain MRI studies performed on children with epilepsy from two urban hospitals in Kampala, Uganda.

Methods

This was a cross-sectional descriptive study performed at two urban hospital MRI centres. The study population was 147 children aged 1 day to 17 years with confirmed epilepsy. Brain MRI was performed for each child and a questionnaire was used to collect clinical data.

Results

The prevalence of structural abnormalities among children with epilepsy was 74.15% (109 out of 147). Of these, 68.81% were male, and the rest were female. Among these, the majority, 40.14% (59 of 144) were aged 1 month to 4 years. Acquired structural brain abnormalities were the commonest at 69.22% with hippocampal sclerosis (HS) leading while disorders of cortical development were the most common congenital causes.

An abnormal electroencephalogram (EEG) was significant for brain MRI abnormalities among children with epilepsy with 95% of participants with an abnormal EEG study having epileptogenic structural abnormalities detected in their brain MRI studies.

Conclusion and recommendation

Two-thirds of children with epilepsy had structural brain abnormalities. Abnormal activity in the EEG study was found to positively correlate with abnormal brain MRI findings. As such, EEG study should be considered where possible before MRI studies as a determinant for children with epilepsy who will be having imaging studies done in the Ugandan setting.

Development and Validation of a Deep Learning Model for Predicting Treatment Response in Patients With Newly Diagnosed Epilepsy

Importance

Selection of antiseizure medications (ASMs) for epilepsy remains largely a trial-and-error approach. Under this approach, many patients have to endure sequential trials of ineffective treatments until the "right drugs" are prescribed.

Objective

To develop and validate a deep learning model using readily available clinical information to predict treatment success with the first ASM for individual patients.

Design, Setting, and Participants

This cohort study developed and validated a prognostic model. Patients were treated between 1982 and 2020. All patients were followed up for a minimum of 1 year or until failure of the first ASM. A total of 2404 adults with epilepsy newly treated at specialist clinics in Scotland, Malaysia, Australia, and China between 1982 and 2020 were considered for inclusion, of whom 606 (25.2%) were excluded from the final cohort because of missing information in 1 or more variables.

Exposures

One of 7 antiseizure medications.

Main Outcomes and Measures

With the use of the transformer model architecture on 16 clinical factors and ASM information, this cohort study first pooled all cohorts for model training and testing. The model was trained again using the largest cohort and externally validated on the other 4 cohorts. The area under the receiver operating characteristic curve (AUROC), weighted balanced accuracy, sensitivity, and specificity of the model were all assessed for predicting treatment success based on the optimal probability cutoff. Treatment success was defined as complete seizure freedom for the first year of treatment while taking the first ASM. Performance of the transformer model was compared with other machine learning models.

Results

The final pooled cohort included 1798 adults (54.5% female; median age, 34 years [IQR, 24-50 years]). The transformer model that was trained using the pooled cohort had an AUROC of 0.65 (95% CI, 0.63-0.67) and a weighted balanced accuracy of 0.62 (95% CI, 0.60-0.64) on the test set. The model that was trained using the largest cohort only had AUROCs ranging from 0.52 to 0.60 and a weighted balanced accuracy ranging from 0.51 to 0.62 in the external validation cohorts. Number of pretreatment seizures, presence of psychiatric disorders, electroencephalography, and brain imaging findings were the most important clinical variables for predicted outcomes in both models. The transformer model that was developed using the pooled cohort outperformed 2 of the 5 other models tested in terms of AUROC.

Conclusions and Relevance

In this cohort study, a deep learning model showed the feasibility of personalized prediction of response to ASMs based on clinical information. With improvement of performance, such as by incorporating genetic and imaging data, this model may potentially assist clinicians in selecting the right drug at the first trial.

Risk factors and consequences of self-discontinuation of treatment by patients with newly diagnosed epilepsy

OBJECTIVE

Patients with epilepsy not uncommonly self-discontinue treatment with antiseizure medications (ASM). The rate, reasons for this, and consequences have not been well studied.

METHODS

We analyzed self-discontinuation of ASM treatment in patients with recently diagnosed epilepsy via review of clinic letters and hospital correspondence in a prospective cohort of first seizure patients.

RESULTS

We studied 489 patients with newly diagnosed and treated epilepsy (median age 41, range 14-88, 62% male), followed up for a median duration of 3.0 years (interquartile range [IQR]: 1.2-6.0). Seventy eight (16.0%) self-discontinued ASM therapy after a median treatment duration of 1.4 years (IQR: 0.4-2.9), and after a median duration of seizure freedom of 11.8 months (IQR: 4.6-31.8). Patients commonly self-discontinued treatment due to adverse effects (41%), perception that treatment was no longer required (35%), and planned or current pregnancy (12%). Patients who self-discontinued were less likely to have epileptogenic lesions on neuroimaging (hazard ratio [HR] = 0.44, 95% confidence interval [CI]: 0.23-0.83), presentation with seizure clusters (HR = 0.32, 95% CI: 0.14-0.69) and presentation with tonic-clonic seizures (HR = 0.36, 95% CI: 0.19-0.70). Patients with shorter interval since the last seizure (HR = 0.76, 95% CI: 0.66-0.86) were more likely to self-discontinue treatment. Sleep deprivation prior to seizures before diagnosis (HR = 1.80, 95% CI: 1.05-3.09) and significant alcohol or illicit drug use (HR = 2.35, 95% CI: 1.20-4.59) were also associated with higher rates of discontinuation. After discontinuation, 51 patients (65%) experienced seizure recurrence, and 43 (84%) restarted treatment. Twenty two patients (28%) experienced a seizure-related injury after treatment discontinuation.

SIGNIFICANCE

Self-initiated discontinuation of ASM treatment was not uncommon in patients with newly treated epilepsy. Reasons for discontinuation highlight areas for improved discussion with patients, including the chronicity of epilepsy and management strategies for current or potential adverse effects.

A myriad spectrum of seizures on magnetic resonance imaging – A pictorial essay

Patients with seizures represent a challenging clinical population both in pediatrics and adults. Accurate diagnosis of the cause of a seizure is important in choosing an effective treatment modality, surgical planning, predicting a prognosis, and follow-up. Magnetic resonance (MR) imaging using a dedicated epilepsy protocol plays a key role in the workup of these patients. Additional MR techniques such as T2 relaxometry and MR spectroscopy show a promising role to arrive at a final diagnosis. The spectrum of epileptogenic causes is broad. Radiologists and physicians need to be updated and require a patterned approach in light of clinical history and electroencephalogram findings to arrive at a reasonable differential diagnosis. This pictorial essay aims to review a few of the common and uncommon causes of seizures and their imaging features.

The language of seizure identification: A qualitative investigation

OBJECTIVE

Clinical history taking is often the most important factor in seizure recognition and the diagnosis of epilepsy. Apart from subspecialist evaluation, patients frequently present for initial evaluation of seizures in emergency departments, urgent care clinics, and primary care clinics. We utilized qualitative methods to assess the current approaches and language used by both subspecialist and non-specialist physicians when interviewing adult patients with suspected seizures to create a clinical tool to aid in seizure diagnosis.

METHODS

We carried out semi- structured interviews with 10 physicians spanning a range of specialties, practice locations, and clinical experience. This included epilepsy specialists and non-specialists in fields where evaluation of new-onset seizures is common: emergency medicine, internal medicine, and family medicine. Thematic analysis was used to develop a "Seizure Identifier" questionnaire, which was subsequently reviewed by five independent experts for content and face validity.

RESULTS

Our analysis revealed that across specialties and practice settings, physicians have a structured approach in evaluating patients who present with suspected seizures. Five key characteristics important for identifying seizures emerged across interviews: sudden-onset unprovoked symptoms, short-lasting symptoms, strange or difficult-to-describe symptoms, highly stereotyped symptoms, and postictal symptoms. After independent review, these were translated into an eight-question "Seizure Identifier" tool.

SIGNIFICANCE

This study highlights important concepts for clinical practice regarding seizure identification. Using themes from our analysis, we were able to create a tool that may aid non-specialists in the approach to history taking for adult patients who present with suspected seizures and may help improve time to subspecialist evaluation. Importantly, this tool can be tested in future research for improving seizure recognition and improving timely epilepsy diagnosis.

Relationship of white matter hyperintensities with clinical features of seizures in patients with epilepsy

BACKGROUND

Although epilepsy is primarily known as a cortical disorder, there is growing body of research demonstrating white matter alterations in patients with epilepsy.

OBJECTIVE

To investigate the prevalence of white matter hyperintensities (WMH) and its association with seizure characteristics in patients with epilepsy.

METHODS

The prevalence of WMH in 94 patients with epilepsy and 41 healthy controls were compared. Within the patient sample, the relationship between the presence of WMH and type of epilepsy, frequency of seizures, duration of disease and the number of antiepileptic medications were investigated.

RESULTS

The mean age and sex were not different between patients and healthy controls (p>0.2). WMH was present in 27.7% of patients and in 14.6% of healthy controls. Diagnosis of epilepsy was independently associated with the presence of WMH (ß=3.09, 95%CI 1.06-9.0, p=0.039). Patients with focal epilepsy had higher prevalence of WMH (35.5%) than patients with generalized epilepsy (14.7%). The presence of WMH was associated with older age but not with seizure characteristics.

CONCLUSIONS

WMH is more common in patients with focal epilepsy than healthy controls. The presence of WMH is associated with older age, but not with seizure characteristics.

Cutting edge approaches to detecting brain mosaicism associated with common focal epilepsies: implications for diagnosis and potential therapies

INTRODUCTION

Mosaic variants arising in brain tissue are increasingly being recognized as a hidden cause of focal epilepsy. This knowledge gain has been driven by new, highly sensitive genetic technologies and genome-wide analysis of brain tissue from surgical resection or autopsy in a small proportion of patients with focal epilepsy. Recently reported novel strategies to detect mosaic variants limited to brain have exploited trace brain DNA obtained from cerebrospinal fluid liquid biopsies or stereo-electroencephalography electrodes.

AREAS COVERED

The authors review the data on these innovative approaches published in PubMed before 12 June 2021, discuss the challenges associated with their application, and describe how they are likely to improve detection of mosaic variants to provide new molecular diagnoses and therapeutic targets for focal epilepsy, with potential utility in other nonmalignant neurological disorders.

EXPERT OPINION

These cutting-edge approaches may reveal the hidden genetic etiology of focal epilepsies and provide guidance for precision medicine.

Causes and classification of first unprovoked seizures and newly-diagnosed epilepsy in a defined geographical area- an all-comers analysis

PURPOSE

The ILAE recently updated the operational definition of epilepsy and the classifications of seizures and epilepsy incorporating aetiology into the classification framework. To date, these classifications have not been applied in any whole population incidence study.

METHODS

Multiple overlapping methods of case identification were applied to a defined geographical area (population 542,868 adults and children) to identify all first unprovoked seizures and new diagnosis of epilepsy presenting during the calendar year 2017. The 2017 ILAE classification frameworks were applied. Incidence was age-standardised to the 2013 Standard European Population.

RESULTS

The annual incidence per 100,000 population was 44 for focal epilepsy, 6.8 for generalized epilepsy and 10.9 for unclassified epilepsy (age standardized 56, 6.9 and 11.4, respectively). Focal epilepsy was diagnosed in all age groups, though incidence increased in those ≥55 years of age. Primary generalised epilepsy accounted for 10% (n = 32) of newly diagnosed epilepsy. The most frequently diagnosed aetiology was structural (54%, n = 182). In 30% (n = 102) of newly diagnosed epilepsy, aetiology was not established.

CONCLUSION

We report on the causes of incident first unprovoked seizures and epilepsy in accordance with recently updated ILAE definitions and classification systems employing standard diagnostic investigations. We report a higher proportion of structural aetiology than previous studies, which may reflect incorporation of imaging in aetiology classification. Despite improved access to diagnostic testing, aetiology of a large fraction of first seizures and newly diagnosed epilepsy remains unknown.

Sudden unexpected death in epilepsy: Experience of neurologists in Saudi Arabia

IMPORTANCE

Sudden unexpected death in epilepsy (SUDEP) may account for up to 17% of all deaths in epilepsy. However, it is unknown if neurologists discuss this risk with patients.

OBJECTIVE

This study aimed to examine the understanding and practices of SUDEP by neurologists in Saudi Arabia.

METHODS

An electronic web-based survey was sent to 125 neurologists using the mailing list of the Saudi Neurology Society. The survey questions included respondents' demographics, frequency of SUDEP discussion, reasons for discussing/not discussing SUDEP, and perceived patient reactions. Respondents' knowledge of the SUDEP risk factors was examined using 12 items from the currently available literature. Logistic regression analyses were applied to examine the factors that influence the frequency of SUDEP discussions and perceived patient reactions.

PARTICIPANTS

The participants were neurologists who had completed postgraduate training, devoted >5% of their time to clinical care, and had at least one patient with epilepsy in their independent neurology clinic.

RESULTS

A total of 60 respondents met the eligibility criteria and completed the surveys. Of them, 25% discussed SUDEP most of the time, 65% sometimes or rarely, and 10% never discussed it. Of those who discussed SUDEP with their patients, 63.3% did it if the patient was at high risk. Poor compliance with antiepileptic drugs (AEDs) was the most common patient factor highlighted (81.7%). The perceived patients' reactions were variable, with positive reactions (motivation to comply and appreciation) being the most frequent. The majority of respondents (78.3%) had incomplete understanding of the published SUDEP risk factors, with SUDEP knowledge scores ≤2.5 (≤50% of the possible total score). The most identified risk factors were frequent generalized tonic-clonic seizures (83.3%), long duration of epilepsy (53.3%), lack of use or sub-therapeutic levels of AEDs (50%), and AED polytherapy (50%). No association was found between how often SUDEP was discussed and other factors, including training in epilepsy, ≥10 years in practice, seeing ≥100 patients, and having SUDEP cases in the past two years. It was found that patients positively reacted to discussion on SUDEP if neurologists had a good understanding of the SUDEP risk factors (χ² = 5.773, p = 0.016).

CONCLUSIONS

Neurologists in Saudi Arabia do not often discuss SUDEP with patients that have epilepsy. Moreover, when they do, they stress a more individualized approach despite having only a limited understanding of the SUDEP risk factors. Our findings suggest that more guidance should be provided to practitioners on how best to counsel their patients about SUDEP.

Epilepsy: A Clinical Overview

The diagnosis and treatment of seizures and epilepsy is a common task of the physician. Approximately 1 in 10 people will have a seizure during their lifetime. Epilepsy is the tendency to have unprovoked seizures. Epilepsy is the fourth most common neurological disorder and affects 1 in 26 people in the United States and 65 million people worldwide. Evaluation of a patient presenting with a seizure involves excluding an underlying neurologic or medical condition, classifying the seizure type and determining if the patient has epilepsy. Proper treatment requires accurate diagnosis of the epilepsy type and syndrome and use of a medication that is effective and without adverse effects. Most patients can achieve complete seizure control with medication, but if medication is unsuccessful, surgical treatment can be an option. Special situations in the care of people with epilepsy include status epilepticus, women with epilepsy, the older adult, and safety issues.

Narrative review of epilepsy: getting the most out of your neuroimaging

Neuroimaging represents an important step in the evaluation of pediatric epilepsy. The crucial role of brain imaging in the diagnosis, follow-up and presurgical assessment of patients with epilepsy is noted and has to be familiar to all neuroradiologists and trainees approaching pediatric brain imaging. Morphological qualitative imaging shows the majority of cerebral lesions/alterations underlying focal epilepsy and can highlight some features which are useful in the differential diagnosis of the different types of epilepsy. Recent advances in MRI acquisitions including diffusion-weighted imaging (DWI), post-acquisition image processing techniques, and quantification of imaging data are increasing the accuracy of lesion detection during the last decades. Functional MRI (fMRI) can be really useful and helps to identify cortical eloquent areas that are essential for language, motor function, and memory, and diffusion tensor imaging (DTI) can reveal white matter tracts that are vital for these functions, thus reducing the risk of epilepsy surgery causing new morbidities. Also positron emission tomography (PET), single photon emission computed tomography (SPECT), simultaneous electroencephalogram (EEG) and fMRI, and electrical and magnetic source imaging can be used to assess the exact localization of epileptic foci and help in the design of intracranial EEG recording strategies. The main role of these "hybrid" techniques is to obtain quantitative and qualitative informations, a necessary step to evaluate and demonstrate the complex relationship between abnormal structural and functional data and to manage a "patient-tailored" surgical approach in epileptic patients.

Short- and long-term outcomes of immediate and delayed treatment in epilepsy diagnosed after one or multiple seizures

OBJECTIVES

To compare the outcomes between immediate and deferred treatments in patients diagnosed after one or multiple (two or more) seizures.

METHODS

Our observational study investigated seizure recurrence and 12-month seizure remission in patients with newly diagnosed epilepsy, comparing immediate to deferred treatment in patients diagnosed after one seizure or after two or more seizures.

RESULTS

Of 598 patients (62% male, median age 39 years), 347 (58%) were treated at diagnosis and 251 (42%) received deferred or no treatment. Seizure recurrence was higher with deferred treatment both in patients diagnosed after two or more seizures (n = 363; adjusted hazard ratio [aHR] = 2.38, 95% confidence interval [CI]: 1.79-3.14, p < 0.001) and after one seizure (n = 235; aHR = 1.41, 95% CI: 0.995-1.99, p = 0.05). Cumulative seizure recurrence rates at two years in patients diagnosed after two or more seizures were 73% with deferred treatment and 49% with immediate treatment (risk-factor-corrected number-needed-to-treat [NNT] = 4), and in those diagnosed after one seizure the rates were 60% and 51% (NNT = 8). Of 380 patients with eligible follow-up (median 4.3 years), 287 (76%) had been in seizure remission for at least one year and 211 (56%) remained in remission at last follow-up. Long-term remission rates were similar between immediate and deferred treatments, and between patients diagnosed after one seizure and those with two or more seizures.

SIGNIFICANCE

Immediate rather than deferred treatment was less likely to influence seizure recurrence in patients diagnosed with epilepsy after a single seizure than in those diagnosed after two or more seizures, and showed no differences in long-term seizure freedom.

Newly diagnosed seizures assessed at two established first seizure clinics: Clinic characteristics, investigations, and findings over 11 years

Objective

'First seizure' clinics (FSCs) aim to achieve early expert assessment for individuals with possible new-onset epilepsy. These clinics also have substantial potential for research into epilepsy evolution, outcomes, and costs. However, a paucity of FSCs details has implications for interpretation and utilization of this research.

Methods

We reviewed investigation findings over 11 years (2000-2010) from two established independent FSCs at Austin Health (AH) and Royal Melbourne Hospital (RMH), Australia. These adult clinics are in major public hospitals and operate with similar levels of expertise. Organizational differences include screening and dedicated administration at AH. Included were N = 1555 patients diagnosed with new-onset unprovoked seizures/epilepsy (AH n = 901, RMH n = 654). Protocol-driven interviews and investigations had been recorded prospectively and were extracted from medical records for study.

Results

Median patient age was 37 (IQR 26-52, range 18-94) years (AH 34 vs RMH 42 years; P < .001). Eighty-six percent of patients attended FSC within three weeks postindex seizure (median AH 12 vs RMH 25 days; P < .01). By their first appointment, 42% had experienced ≥2 seizures. An EEG was obtained within three weeks postindex seizure in 73% of patients, demonstrating epileptiform discharges in 25% (AH 33% vs RMH 15%). Seventy-six percent of patients had an MRI within 6 weeks. Of those with imaging (n = 1500), 19% had potentially epileptogenic abnormalities (RMH 28% vs AH 12%; P < .01). At both sites, changes due to previous stroke/hemorrhage were the commonest lesions, followed by traumatic brain injury. ≥WHO level 1 brain tumors diagnosed at presentation comprised a very small proportion (<1%) at each clinic. At both sites, epilepsy type could be determined in 60% of patients; RMH had more focal and AH more generalized epilepsy diagnoses.

Significance

Differences between the clinics' administrative and screening practices may contribute to differences in investigation findings. Insight into these differences will facilitate interpretation and utilization, and planning of future research.

Predictive value of functional MRI and EEG in epilepsy diagnosis after a first seizure

It is often difficult to predict seizure recurrence in subjects who have suffered a first-ever epileptic seizure. In this study, the predictive value of physiological signals measured using Electroencephalography (EEG) and functional MRI (fMRI) is assessed. In particular those patients developing epilepsy (i.e. a second unprovoked seizure) that were initially evaluated as having a low risk of seizure recurrence are of interest. In total, 26 epilepsy patients, of which 8 were initially evaluated as having a low risk of seizure recurrence (i.e. converters), and 17 subjects with only a single seizure were included. All subjects underwent routine EEG as well as fMRI measurements. For diagnostic classification, features related to the temporal dynamics were determined for both the processed EEG and fMRI data. Subsequently, a logistic regression classifier was trained on epilepsy and first-seizure subjects. The trained model was tested using the clinically relevant converters group. The sensitivity, specificity, and AUC (mean ± SD) of the regression model including metrics from both modalities were 74 ± 19%, 82 ± 18%, and 0.75 ± 0.12, respectively. Positive and negative predictive values (mean ± SD) of the regression model with both EEG and fMRI features are 84 ± 14% and 78 ± 12%. Moreover, this EEG/fMRI model showed significant improvements compared to the clinical diagnosis, whereas the models using metrics from either EEG or fMRI do not reach significance (p > 0.05). Temporal metrics computationally derived from EEG and fMRI time signals may clinically aid and synergistically improve the predictive value in a first-seizure sample.

Pediatric Epilepsy Surgery in Focal and Generalized Epilepsy: Current Trends and Recent Advancements

For a subset of children with medically intractable epilepsy, surgery may provide the best chances of seizure freedom. Whereas the indications for epilepsy surgery are commonly thought to be limited to patients with focal epileptogenic foci, modern imaging and surgical interventions frequently permit successful surgical treatment of generalized epilepsy. Resection continues to be the only potentially curative intervention; however, the advent of various neuromodulation interventions provides an effective palliative strategy for generalized or persistent seizures. Although the risks and benefits vary greatly by type and extent of intervention, the seizure outcomes appear to be uniformly favorable. Advances in both resective and nonresective surgical interventions provide promise for improved seizure freedom, function, and quality of life. This review summarizes the current trends and recent advancements in pediatric epilepsy surgery from diagnostic workup and indications through surgical interventions and postoperative outcomes.

Evaluation of pediatric patients in new-onset seizure clinic (NOSc)

AIM

We evaluated the clinical and demographic features of children presenting with unprovoked seizures at a regional new-onset seizure clinic (NOSc).

METHODS

We retrospectively reviewed charts of 492 consecutive patients evaluated in the NOSc at the Childrne's Healthcare of Atlanta RESULTS: Nonepileptic events (NEE) were diagnosed in 102 (24%) and epileptic seizures in the remaining 326 (76%). Patients with NEE were younger than patients with epileptic seizure (5.0 vs. 7.4 years). Except for headache which occurred more frequently in NEE (14% vs. 6%), frequencies of comorbidities were similar in groups with NEE and epileptic seizure. Electroencephalogram (EEG) was performed in 98%, and finding was abnormal in 51%. Brain magnetic resonance imaging (MRI) was performed in 55%, and finding was abnormal in 15%. An electroclinical epilepsy syndrome was diagnosed in 42%. Antiseizure medication was started in 25% with first seizure and in 77% with recurrent seizures.

INTERPRETATION

For children with newly-presenting seizures, a regional NOSc provided efficient, timely diagnosis and appropriate evaluations and treatment. Timely recognition of NEE resulted in fewer unnecessary evaluations and treatment for a quarter of referred patients whereas identification of the specific types of seizures and epilepsy allowed appropriate use, including deferral, of neuroimaging and guided treatment selection.

Associations between seizures and MRI in patients with anti-NMDAR encephalitis

OBJECTIVES

Seizures are a prominent feature of anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. Nearly half of brain magnetic resonance image (MRI) results are abnormal. The aim of our study was to evaluate the associations between seizures and brain MRI results in patients with anti-NMDAR encephalitis.

METHODS

Patients with anti-NMDAR encephalitis were enrolled between January 2015 and December 2018. The patients included were divided into normal and abnormal MRI groups. Seizure outcomes and modified Rankin Scale scores at the 1-year follow-up were assessed. Seizure characteristics and outcomes were compared between groups.

RESULTS

Of 35 patients with anti-NMDAR encephalitis, 28 patients (80%) had reported seizures in the acute phase. Patients with abnormal MRI findings more frequently had focal seizures than patients with normal MRI findings (72.7% vs 17.6%, P < .01). The incidence of patients treated with 2 or more antiepileptic drugs was higher in the normal MRI group than in the abnormal MRI group (100% vs 45.4%, P < .01). The onset-immunotherapy time was shorter in the abnormal MRI group than in the normal MRI group (P < .05). There were no statistically significant differences in seizure outcomes between the normal and abnormal MRI groups (P > .05).

CONCLUSIONS

Focal seizures were most common in patients with abnormal MRI lesions. In the acute stage of the disease, the abnormal MRI group was more likely than the normal MRI group to achieve seizure control. Abnormal MRI findings did not affect the overall good prognosis of patients with anti-NMDAR encephalitis with seizures.

MRI-negative PET-negative epilepsy long-term surgical outcomes: A single-institution retrospective review

PURPOSE

Surgical planning for people with drug resistant non-lesional focal epilepsy can be challenging. Prior studies focus on cases that are only MRI-negative or MRI-negative with PET-positive imaging, but little is known about outcomes in patients with non-lesional findings on both MRI and PET imaging. In this study, we investigate 5-year surgical outcomes in patients who underwent epilepsy surgery for drug resistant MRI/PET-negative focal epilepsy.

METHODS

We collected clinical and testing data on 131 consecutive patients with drug resistant non-lesional epilepsy who were presented at a multidisciplinary epilepsy surgery conference at the New York University Comprehensive Epilepsy Center between 2010 and 2014, and identified those who underwent epilepsy surgery in order to review 5-year surgical outcomes.

RESULTS

There were 103 with non-lesional MRI studies, and of these, 22 had corresponding non-lesional PET imaging. 14 MRI/PET-negative patients pursued a surgical treatment option and 9 underwent resections after intracranial EEG. At 5 years, 77.8 % of patients had favorable (ILAE class 1 and 2) outcomes. Most (77.8 %) had focal cortical dysplasia type Ia (FCDIa) on pathology.

CONCLUSION

These findings suggest that with careful planning and patient selection, surgery for patients with drug resistant MRI/PET-negative focal epilepsy can be successful.

Neuroimaging of first seizure in the adult emergency patients

The aim is to establish the role of head computed tomography (CT) and magnetic resonance imaging (MRI) in adults presenting to the emergency department (ED) with first-time seizure (FS) and to analyze the potential predictor variables for the adverse imaging outcome. We retrospectively reviewed the medical records of all adults who underwent cranial CT or MRI between January 1, 2011, and December 1, 2016, to an academic ED for FS. Patients were excluded if were under 18 years of age, had known recent intracranial pathology, known brain tumor or having a history of trauma. Important predictive variables to indicate pathology in either CT or MR scan in patients with FS were evaluated with logistic regression analysis. A total of 546 FS (293 men and 253 women; range, 18-81 years; mean, 47 years) were identified in patients receiving either cranial CT or MR scan. Of them, abnormal findings were observed in 22/451 (4.8%) patients on CT and 18/95 (18.9%) patients on MRI. Predictor variables of age greater than 50 years, focal neurologic deficit, hypoglycemia, and history of malignancy were identified on CT, whereas a history of malignancy, age greater than 50 years and focal neurological deficit were determined on MRI. Limiting neuroimaging to this population would potentially reduce head CT scans by 67% and would potentially reduce head MRI scans by 47%. Clinical suspicion should be heightened and the neuroimaging should be considered for advanced age, history of malignancy, hypoglycemia or focal neurological deficits in patients with FS.

Diagnosis of epilepsy after first seizure. Introducing the SWISS FIRST study

Diagnosis of epilepsy after a first unprovoked seizure is possible according to the guidelines by the International League Against Epilepsy, if the risk recurrence of a second unprovoked seizure is exceeding 60%. However, this cutoff constitutes only a proxy depending on the patients’ history, magnetic resonance imaging (MRI), and electroencephalography (EEG) findings but nevertheless also from the treating neurologists’ individual experience. In a Switzerland-wide observational study, we aim to recruit patients that were admitted to the emergency department with the referral diagnosis of a first and unprovoked seizure. We make use of optimized MRI protocols to identify potential structural epileptogenic lesions, introduce new imaging-based markers of epileptogenecity, and use most recent postprocessing methods as automatic morphometry, spike map analysis, and functional connectivity. With these diagnostic tools, we aim to segregate patients that present with epileptic seizures versus mimicks and non-epileptic seizures and stratify for every finding in MRI and EEG its predictive value for a second unprovoked seizure. These findings shall support neurologists to calculate and not only estimate the seizure recurrence rate in future.

Prevalence of MRI abnormalities in people with epilepsy in rural China

OBJECTIVE

To assess the prevalence of brain MRI abnormalities in people with epilepsy in rural China and to compare it with that of individuals in the United Kingdom.

METHODS

Brain MRI scans were obtained in people with epilepsy who participated in a rural community-based program in China between July 2010 and December 2012. Individual epileptogenic lesion types were reviewed and their associations with seizure control examined. The MRI findings were compared with 2 previous similar studies in the United Kingdom.

RESULTS

Among the 597 individuals (58% male, median age 38 years) with MRI scans analyzed, 488 (82%) had active epilepsy. The MRI was abnormal in 389 individuals (65%), with potentially epileptogenic lesion in 224 (38%) and nonspecific abnormalities in 165 (28%), and 108 (18%) were potentially resectable. The potentially epileptogenic lesions were less frequently detected in children (<18 years old, 12 of 68, 18%) than in adults (212 of 529, 40%; p < 0.001). In people with potentially epileptogenic lesions, 67% (150 of 224) had failed ≥2 antiseizure medications. They had higher risk of uncontrolled epilepsy than those with normal MRI (risk ratio [RR] 1.25; p < 0.001) and those with nonspecific abnormality (RR 1.15; p = 0.002) after adjustment for age and sex. The diagnostic yield of MRI was similar to that reported in community- and hospital-based studies in the United Kingdom.

CONCLUSIONS

More than one-third of people with chronic epilepsy in rural China have potentially epileptogenic lesions identifiable on brain MRI, with two-thirds fulfilling the definition of pharmacoresistance. These findings highlight the magnitude of the unmet needs for epilepsy surgery in China.

Recent developments in imaging of epilepsy

Purpose of review

Imaging constitutes one of the key pillars in the diagnostic workup after a first seizure as well as for the presurgical workup in epilepsy. The role of imaging in emergency situations, mainly to support the adequate diagnosis, as well as its role in planning of noninvasive image-guided therapies is less well established. Here, we provide an overview on peri-ictal imaging findings to support differential diagnosis in emergency situations and describe recent attempts toward minimal invasive therapy in the treatment of epilepsy and its comorbidities based on a combination of imaging techniques with ultrasound.

Recent findings

Peri-ictal perfusion changes can differentiate ictal stroke mimics from acute ischemic stroke if focal areas of increased perfusion are depicted by computed tomography or MRI. Postictal perfusion patterns in patients with persisting neurological symptoms are frequently normal and do not reach enough diagnostic sensitivity to differentiate between stroke and its mimics. Noninvasive magnetic resonance-techniques as arterial spin labeling may provide a higher sensitivity, especially in combination with diffusion-weighted and susceptibility-weighted MRI. Imaging guided focused ultrasound (FUS) bears the potential to ablate epileptogenic tissue and allows suppression of epileptic activity. Imaging guided blood–brain-barrier opening with FUS offers new options for local drug administration.

Summary

MRI should be considered the method of choice in the differential diagnosis of peri-ictal imaging findings and their differential diagnosis. A combination of various MRI techniques with FUS opens new avenues for treatment of epilepsy.

In Vivo Imaging of Neuroinflammatory Targets in Treatment-Resistant Epilepsy

PURPOSE OF REVIEW

Recent evidence indicates that chronic, low-level neuroinflammation underlies epileptogenesis. Targeted imaging of key neuroinflammatory cells, receptors, and tissues may enable localizing epileptogenic onset zone, especially in those patients who are treatment-resistant and considered MRI-negative. Finding a specific, sensitive neuroimaging-based biomarker could aid surgical planning and improve overall prognosis in eligible patients. This article reviews recent research on in vivo imaging of neuroinflammatory targets in patients with treatment-resistant, non-lesional epilepsy.

RECENT FINDINGS

A number of advanced approaches based on imaging neuroinflammation are being implemented in order to assist localization of epileptogenic onset zone. The most exciting tools are based on radioligand-based nuclear imaging or revisiting of existing technology in novel ways. The greatest limitations stem from gaps in knowledge about the exact function of neuroinflammatory targets (e.g., neurotoxic or neuroprotective). Further, lingering questions about each approach's specificity, reliability, and sensitivity must be addressed, and clinical utility must be validated before any novel method is incorporated into mainstream clinical practice. Current applications of imaging neuroinflammation in humans are limited and underutilized, but offer hope for finding sensitive and specific neuroimaging-based biomarker(s). Future work necessitates appreciation of investigations to date, significant findings, and neuroinflammatory targets worth exploring further.

Recommendations of the Russian League Against Epilepsy (RLAE) on the use of magnetic resonance imaging in the diagnosis of epilepsy

Introduction. The MRI method has revolutionized the diagnosis of epilepsy. However, the widespread adoption of MRI in clinical practice is slowed by an insufficient number of high-field MRI scanners, a shortage of trained specialists, and the lack of standard examination protocols. The aim of this article is to present the Recommendations of the Russian League Against Epilepsy (RLAE) on the use of magnetic resonance imaging in the diagnosis of epilepsy.

Materials and methods. As a structural element of the International League Against Epilepsy (ILAE), the RLAE considers it important to adapt the Protocol developed by ILAE for specialists in Russia and EAEU countries. The working group analyzed and generalized the clinical practice existing in the Russian Federation, the Republic of Kazakhstan, the Republic of Belarus and the Republic of Uzbekistan. These recommendations are intended for doctors in specialized centers of epilepsy surgery, and for doctors in general medical centers. The recommendations are applicable primarily to adult patients, but the general principles are relevant to children as well.

Results. In all patients with convulsive seizures shortly after the first seizure, or patients diagnosed with epilepsy who have an unexplained increase in the frequency of seizures, rapid decrease in cognitive functions or the appearance / worsening of neuropsychiatric symptoms, the RLAE recommends using a unified MR protocol for the neuroimaging of structural sequences in epilepsy with three-dimensional pulse sequences T1 and T2 FLAIR with isotropic voxel 1 × 1 × 1 mm3 and two-dimensional T2- weighted pulse sequences with a pixel size of 1 × 1 mm2 or less. The MRI examination should be combined with EEG or EEG-video monitoring. Using this protocol allows one to set a unified standard for examining patients with epilepsy in order to detect (with high sensitivity) brain lesions playing a key role in the occurrence of seizures. Here, all 13 recommendations are presented.

Conclusion. Implementation of these recommendations in clinical practice will improve the access to high-tech medical care and optimize health care costs. 

Clinical Significance of Asymmetric Minimum Intensity Projection Images of Brain Magnetic Resonance Imaging in Children

Background and Purpose

The susceptibility-weighted imaging form of brain MRI using minimum intensity projection (mIP) is useful for assessing traumatic brain injuries because it readily reveals deoxyhemoglobin or paramagnetic compounds. We investigated the efficacy of using this methodology in nontraumatic patients.

Methods

We retrospectively analyzed the asymmetric mIP findings in nontraumatic patients. Asymmetric mIP images were first verified visually and then using ImageJ software. We enrolled patients with a difference of >5% between hemispheres in ImageJ analysis. All patients underwent detailed history-taking and EEG, and asymmetric mIP findings were compared.

Results

The visual analysis identified 54 pediatric patients (37 males and 17 females) with asymmetric mIP findings. Ten patients were excluded because they did not meet the ImageJ verification criteria. The 44 patients with asymmetry comprised 36 with epilepsy, 6 with headache, and 2 with cerebral infarction. Thirty-one of the 36 epileptic patients showed definite partial seizure activities in semiology, while the remaining patients did not demonstrate a history of partial seizure manifestations. The MRI findings were normal in all patients except for five with periventricular leukomalacia unrelated to seizure symptoms. There was agreement between mIP images and semiology in 29 (93.5%) of the 31 epileptic patients with focal signs, while the other 2 demonstrated discordance. Twenty (64.5%) of the 31 patients showed consistent EEG abnormalities.

Conclusions

Our data suggest that asymmetric mIP findings are an excellent lateralizing indicator in pediatric patients with partial epilepsy.

Paediatric new-onset seizure clinic in Australia: Experience and lessons learnt

AIM

A new-onset seizure clinic (NOSC) was established at our hospital in 2011, with the aim to provide accurate diagnosis and appropriate management to children with new-onset seizures or seizure mimics.

METHODS

We report on the data analysis of the first 200 children seen in NOSC. A paediatric neurologist or paediatric/neurology trainee under supervision of a neurologist reviewed all the children. A detailed history and clinical examination were undertaken. Electroencephalogram (EEGs) were undertaken prior to clinic review in most emergency departments. Children were classified as 'epilepsy positive' (EP+) or 'epilepsy negative' (EP-) after the first consultation.

RESULTS

Of 200 patients, 109 were classified as EP+: generalised epilepsy in 57 of 109, focal in 36, childhood seizure susceptibility syndrome in 26 and epileptic encephalopathy in 5. EEG was available in 192: in 117, it was abnormal - 23 with background abnormalities and 109 with epileptiform activity. Of the 109 patients, 80 were commenced on anti-epileptic drugs (AEDs): 12 were able to come off medication after seizure-free period, 61 were controlled on AEDs and 7 were refractory. Children were followed up for 12-48 months. None of the children had diagnosis revised on follow-up.

CONCLUSIONS

This is the first Australian study to report on a large cohort of children from a NOSC. An EEG and a paediatric neurologist assessment is a good combination to enable diagnostic accuracy: In the first 200 patients seen, there were no revisions of the initial diagnosis on follow-up.

Recommendations for the use of structural magnetic resonance imaging in the care of patients with epilepsy: A consensus report from the International League Against Epilepsy Neuroimaging Task Force

Structural magnetic resonance imaging (MRI) is of fundamental importance to the diagnosis and treatment of epilepsy, particularly when surgery is being considered. Despite previous recommendations and guidelines, practices for the use of MRI are variable worldwide and may not harness the full potential of recent technological advances for the benefit of people with epilepsy. The International League Against Epilepsy Diagnostic Methods Commission has thus charged the 2013-2017 Neuroimaging Task Force to develop a set of recommendations addressing the following questions: (1) Who should have an MRI? (2) What are the minimum requirements for an MRI epilepsy protocol? (3) How should magnetic resonance (MR) images be evaluated? (4) How to optimize lesion detection? These recommendations target clinicians in established epilepsy centers and neurologists in general/district hospitals. They endorse routine structural imaging in new onset generalized and focal epilepsy alike and describe the range of situations when detailed assessment is indicated. The Neuroimaging Task Force identified a set of sequences, with three-dimensional acquisitions at its core, the harmonized neuroimaging of epilepsy structural sequences-HARNESS-MRI protocol. As these sequences are available on most MR scanners, the HARNESS-MRI protocol is generalizable, regardless of the clinical setting and country. The Neuroimaging Task Force also endorses the use of computer-aided image postprocessing methods to provide an objective account of an individual's brain anatomy and pathology. By discussing the breadth and depth of scope of MRI, this report emphasizes the unique role of this noninvasive investigation in the care of people with epilepsy.

Epilepsy in adults

Epilepsy is one of the most common serious brain conditions, affecting over 70 million people worldwide. Its incidence has a bimodal distribution with the highest risk in infants and older age groups. Progress in genomic technology is exposing the complex genetic architecture of the common types of epilepsy, and is driving a paradigm shift. Epilepsy is a symptom complex with multiple risk factors and a strong genetic predisposition rather than a condition with a single expression and cause. These advances have resulted in the new classification of epileptic seizures and epilepsies. A detailed clinical history and a reliable eyewitness account of a seizure are the cornerstones of the diagnosis. Ancillary investigations can help to determine cause and prognosis. Advances in brain imaging are helping to identify the structural and functional causes and consequences of the epilepsies. Comorbidities are increasingly recognised as important aetiological and prognostic markers. Antiseizure medication might suppress seizures in up to two-thirds of all individuals but do not alter long-term prognosis. Epilepsy surgery is the most effective way to achieve long-term seizure freedom in selected individuals with drug-resistant focal epilepsy, but it is probably not used enough. With improved understanding of the gradual development of epilepsy, epigenetic determinants, and pharmacogenomics comes the hope for better, disease-modifying, or even curative, pharmacological and non-pharmacological treatment strategies. Other developments are clinical implementation of seizure detection devices and new neuromodulation techniques, including responsive neural stimulation.

Frequency and Stratification of Epileptogenic Lesions in Elderly With New Onset Seizures

Objective: To evaluate prospectively the frequency of epileptogenic lesions in a consecutive cohort of elderly patients presenting with new onset unprovoked seizures, and who underwent a complete evaluation including dedicated epilepsy protocol MRI.

Methods and materials: We included all consecutive patients 60 years or older who participated in a prospective study on new onset epilepsy. The work-up included the acquisition of a dedicated epilepsy protocol MRI and a 3 h video/EEG recording. We evaluated the frequency and types of epileptogenic lesions in the whole cohort and stratified those variables by age, gender, types and number of seizures at presentation. We also correlated the EEG findings with the clinical characteristics and neuroimaging results.

Results: Of the 101 patients enrolled in the study and who underwent an epilepsy protocol MRI, an epileptogenic lesion was identified in 67% of cases. The most common etiologies were vascular events, followed by tumoral causes and traumatic brain injuries. Epileptogenic lesions were more likely to be identified in patients who presented with only focal aware and impaired awareness seizures. In addition, patients with tumoral epilepsy were significantly more likely to only experience those seizure types compared to patients with other pathological substrates. Interictal/ictal discharges were detected in the EEG of 21% of patients. Epileptiform discharges were significantly more frequent in patients with an epileptogenic lesion on brain MRI, especially in those with a brain tumor.

Conclusions: Our results stress the importance of obtaining a dedicated epilepsy protocol MRI in elderly patients with new onset seizures. An epileptogenic lesion will be identified in approximately two thirds of patients with important implications regarding initiation of treatment. In addition, the data underscore the value of distinguishing the types of seizures experienced at presentation as this will apprise the treating physician on the likelihood of identifying an epileptogenic lesion and on the probable etiologies.

Utility of Magnetic Resonance Imaging Brain Epilepsy Protocol in New-Onset Seizures: How is it Different in Developing Countries?

Introduction

Magnetic resonance imaging (MRI) is the current imaging tool of choice in the investigation of patients with seizures. The advent of high-resolution MRI with a dedicated seizure protocol has significantly increased the chances of identifying a cause, resulting in a positive clinical impact on the management of these patients.

Aims

The aims of this study were to evaluate the diagnostic efficacy of standard MRI, identify whether there is an increase in the diagnostic yield with the addition of dedicated seizure protocol, and compare the diagnostic yields of MRI and electroencephalogram (EEG) individually and in combination.

Subjects and Methods

This is a prospective study of 129 consecutive patients who presented with new-onset seizures over an 18-month period. The MRI scans performed on 1.5T were reviewed for their diagnostic yield and their association with abnormal electrical activity on EEG. Chi-square test of significance (P < 0.05) was used to test for the difference in proportion. The correlation between MRI brain and EEG was studied using McNemer test.

Results

MRI detected potentially epileptogenic lesions in 59 patients (47%). The frequency of epileptogenic lesions was highest in patients who had focal-onset seizures (81%). The most common lesion type was infection and inflammation (28%), with neurocysticercosis being the most common, followed by mesial temporal sclerosis, ischemia, and tumor. About 37% of epileptogenic lesions were missed by standard protocol, which were detected on a dedicated seizure protocol MRI. The diagnostic yield of EEG was 31%. Abnormal MRI and EEG were concordant in 18% of patients, with EEG being normal in 37% of patients with epileptogenic lesions.

Conclusions

MRI detects epileptogenic lesions in almost one half who presented with new-onset seizures and of these, more than third of them were detected using a "dedicated seizure protocol." While almost 50% with seizures will have a cause identified on MRI, the sensitivity can be substantially improved by utilizing a dedicated seizure protocol.

Presentation and management of community-onset vs hospital-onset first seizures

BACKGROUND

New-onset seizures are frequently encountered in community and hospital settings. It is likely that seizures presenting in these distinct settings have different etiologies and prognoses, requiring different investigation and treatment approaches. We directly compare the presentation and management of patients with community- and hospital-onset first seizures attending the same hospital.

METHODS

We reviewed the medical records of patients aged 18 years or older with discharge International Classification of Diseases, Australian Classification (ICD-10-AM) codes of G40 (epilepsy), G41 (status epilepticus), and R56.8 (unspecified convulsions), who attended a general hospital in Melbourne, Australia, from January 1, 2008, through November 30, 2016. Patients with new-onset seizures were included for analysis.

RESULTS

A total of 367 patients were discharged with a relevant ICD-10-AM code. Among them, 151 patients met the inclusion criteria: 97 presented to the emergency department with community-onset seizure (median age 70 years), and 54 experienced seizures during hospitalization for other indications (median age 80.5 years). Provoked seizures were more common in the latter group (26.8% vs 63.0%, p < 0.001), with exposure to proconvulsant drugs a major risk factor. Despite not fulfilling the International League Against Epilepsy (ILAE) diagnostic criteria, 72.5% (58/80) who survived to discharge were prescribed antiepileptic drug (AED) therapy, whereas 19.0% (12/63) of those who met the ILAE criteria were not.

CONCLUSIONS

Hospitalized elderly patients are at an increased risk of provoked seizures, and caution should be exercised when prescribing potential proconvulsant medications and procedures. A more standardized approach to AED prescribing is needed. Further studies should consider morbidity, mortality, and health economic effects of first seizures and assess optimal management to improve outcomes in this cohort.