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Seminars in Neurology Dec 2020Seizures affect the lives of 10% of the global population and result in epilepsy in 1 to 2% of people around the world. Current knowledge about etiology, diagnosis, and... (Review)
Review
Seizures affect the lives of 10% of the global population and result in epilepsy in 1 to 2% of people around the world. Current knowledge about etiology, diagnosis, and treatments for epilepsy is constantly evolving. As more is learned, appropriate and updated definitions and classification systems for seizures and epilepsy are of the utmost importance. Without proper definitions and classification, many individuals will be improperly diagnosed and incorrectly treated. It is also essential for research purposes to have proper definitions, so that appropriate populations can be identified and studied. Imprecise definitions, failure to use accepted terminology, or inappropriate use of terminology hamper our ability to study and advance the field of epilepsy. This article begins by discussing the pathophysiology and epidemiology of epilepsy, and then covers the accepted contemporary definitions and classifications of seizures and epilepsies.
Topics: Epilepsy; Humans; Seizures
PubMed: 33155183
DOI: 10.1055/s-0040-1718719 -
Epilepsia Apr 2017The International League Against Epilepsy (ILAE) presents a revised operational classification of seizure types. The purpose of such a revision is to recognize that some...
The International League Against Epilepsy (ILAE) presents a revised operational classification of seizure types. The purpose of such a revision is to recognize that some seizure types can have either a focal or generalized onset, to allow classification when the onset is unobserved, to include some missing seizure types, and to adopt more transparent names. Because current knowledge is insufficient to form a scientifically based classification, the 2017 Classification is operational (practical) and based on the 1981 Classification, extended in 2010. Changes include the following: (1) "partial" becomes "focal"; (2) awareness is used as a classifier of focal seizures; (3) the terms dyscognitive, simple partial, complex partial, psychic, and secondarily generalized are eliminated; (4) new focal seizure types include automatisms, behavior arrest, hyperkinetic, autonomic, cognitive, and emotional; (5) atonic, clonic, epileptic spasms, myoclonic, and tonic seizures can be of either focal or generalized onset; (6) focal to bilateral tonic-clonic seizure replaces secondarily generalized seizure; (7) new generalized seizure types are absence with eyelid myoclonia, myoclonic absence, myoclonic-atonic, myoclonic-tonic-clonic; and (8) seizures of unknown onset may have features that can still be classified. The new classification does not represent a fundamental change, but allows greater flexibility and transparency in naming seizure types.
Topics: Epilepsy; Humans; International Agencies; Seizures; Societies, Medical; Terminology as Topic
PubMed: 28276060
DOI: 10.1111/epi.13670 -
Handbook of Clinical Neurology 2019The first weeks of life are a time of heightened risk for seizures due to age-dependent physiologic features of the developing brain that lead to increased neuronal... (Review)
Review
The first weeks of life are a time of heightened risk for seizures due to age-dependent physiologic features of the developing brain that lead to increased neuronal excitation and decreased inhibition. Usually, seizures in neonates are a symptom of an acute brain injury; seizures are only rarely due to neonatal-onset epilepsy syndromes. Neonatal seizures are harmful to the developing brain; early and accurate diagnosis is critical. For suspected seizures, EEG monitoring should be initiated as soon as is feasible, in order to evaluate for events of concern, screen for subclinical seizures, and assess the EEG background. Amplitude-integrated EEG can provide excellent complementary data, particularly with regard to evolution of background patterns, but has limited sensitivity to detect individual neonatal seizures. An urgent and systematic approach to precise etiologic diagnosis is key for optimal management and estimates of prognosis. Evaluation of the seizure etiology must occur in parallel with initiation of appropriate treatment. It is critical that neonatologists and neurologists develop hospital-specific, consensus-based practice pathways for neonatal seizure evaluation and treatment. Such practice pathways can streamline medical decision making, facilitate rapid medication administration, and potentially decrease seizure burden and optimize outcomes. Herein, the pathophysiology, epidemiology, treatment, and long-term management considerations for neonatal seizures are presented.
Topics: Adult; Electroencephalography; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Pregnancy; Seizures
PubMed: 31324320
DOI: 10.1016/B978-0-444-64029-1.00017-5 -
Continuum (Minneapolis, Minn.) Apr 2019The classification of seizures, epilepsies, and epilepsy syndromes creates a framework for clinicians, researchers, and patients and their families. This classification... (Review)
Review
PURPOSE OF REVIEW
The classification of seizures, epilepsies, and epilepsy syndromes creates a framework for clinicians, researchers, and patients and their families. This classification has evolved over the years, and in 2017 the International League Against Epilepsy (ILAE) published an operational classification of seizures and epilepsies. Understanding this classification is important in the diagnosis, treatment, and understanding of seizures and epilepsies, including epilepsy incidence.
RECENT FINDINGS
The 2017 ILAE classification system builds on newly formulated definitions of seizures and epilepsy. Seizure classification begins by determining whether the initial manifestations of the seizure are focal or generalized. If the onset of the seizure is missed or unclear, the seizure is of unknown onset. Focal seizures are classified according to the individual's level of awareness, the most prominent motor or nonmotor features of the seizure, and whether the focal seizure evolves to a bilateral tonic-clonic seizure. Similarly, generalized seizures are classified according to motor or nonmotor manifestations. Motor seizures are either tonic-clonic or other motor seizures. Nonmotor generalized seizures primarily refer to absence seizures. Similar to seizure classification, the epilepsies can be classified as focal or generalized. In addition, the new classification system recognizes two new categories: combined generalized and focal epilepsy and unknown epilepsy. The concept of an epilepsy syndrome has been introduced under the new classification system and refers to a cluster of features incorporating seizure types, EEG, imaging, and other features including genetics. The new classification system emphasizes the etiology of seizures and epilepsies.
SUMMARY
The recent ILAE seizure and epilepsy classification system aims to create a framework to better classify seizures and the epilepsies. Universal adoption and implementation of this system will enable patients, their families, clinicians, and researchers to better define and treat the epilepsies. Incidence studies have not generally classified seizures and the epilepsies, and use of this classification system, which emphasizes etiology, will lead to a better understanding of epilepsy incidence.
Topics: Epilepsy; Epileptic Syndromes; Humans; Seizures
PubMed: 30921011
DOI: 10.1212/CON.0000000000000707 -
Seminars in Neurology Apr 2020Neonates are exquisitely susceptible to seizures due to several physiologic factors and combination of risks that are uniquely associated with gestation, delivery, and... (Review)
Review
Neonates are exquisitely susceptible to seizures due to several physiologic factors and combination of risks that are uniquely associated with gestation, delivery, and the immediate postnatal period. Neonatal seizures can be challenging to identify; therefore, it is imperative that clinicians have a high degree of suspicion for seizures based on the clinical history or the presence of encephalopathy with or without paroxysmal abnormal movements. Acute symptomatic neonatal seizures are due to an acute brain injury, whereas neonatal-onset epilepsy may be related to underlying structural, metabolic, or genetic disorders. Though initial, acute treatment is similar, long-term treatment and prognosis varies greatly based on underlying seizure etiology. Early identification and treatment are likely important for long-term outcomes in acute symptomatic seizures, though additional studies are needed to understand optimal seizure control metrics and the ideal duration of treatment. Advances in genetic medicine are increasingly expanding our understanding of neonatal-onset epilepsies and will continue to open doors for personalized medicine to optimize outcomes in this fragile population.
Topics: Humans; Infant, Newborn; Infant, Newborn, Diseases; Seizures
PubMed: 32143234
DOI: 10.1055/s-0040-1702943 -
Current Neurology and Neuroscience... Sep 2022To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential... (Review)
Review
PURPOSE OF REVIEW
To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential strategies to treat seizures.
RECENT FINDINGS
Recent studies have highlighted the role of functional network systems underlying epileptiform activation in sleep in several epilepsy syndromes, including absence epilepsy, benign focal childhood epilepsy, and epileptic encephalopathy with spike-wave activation in sleep. Sleep disorders are common in epilepsy, and early recognition and treatment can improve seizure frequency and potentially reduce SUDEP risk. Additionally, epilepsy is associated with cyclical patterns, which has led to new treatment approaches including chronotherapy, seizure monitoring devices, and seizure forecasting. Adenosine kinase and orexin receptor antagonists are also promising new potential drug targets that could be used to treat seizures. Sleep and epilepsy have a bidirectional relationship that intersects with many aspects of clinical management. In this article, we identify new areas of research involving future therapeutic opportunities in the field of epilepsy.
Topics: Child; Electroencephalography; Epilepsies, Partial; Epilepsy; Humans; Seizures; Sleep; Sleep Wake Disorders
PubMed: 35802300
DOI: 10.1007/s11910-022-01219-1 -
International Journal of Environmental... Oct 2018Febrile seizures (FS), events associated with a fever in the absence of an intracranial infection, hypoglycaemia, or an acute electrolyte imbalance, occur in children... (Review)
Review
Febrile seizures (FS), events associated with a fever in the absence of an intracranial infection, hypoglycaemia, or an acute electrolyte imbalance, occur in children between six months and six years of age. FS are the most common type of convulsions in children. FS can be extremely frightening for parents, even if they are generally harmless for children, making it important to address parental anxiety in the most sensitive manner. The aim of this review was to focus on the management of FS in the pediatric age. An analysis of the literature showed that most children with FS have an excellent prognosis, and few develop long-term health problems. The diagnosis of FS is clinical, and it is important to exclude intracranial infections, in particular after a complex FS. Management consists of symptom control and treating the cause of the fever. Parents and caregivers are often distressed and frightened after a FS occurs and need to be appropriately informed and guided on the management of their child's fever by healthcare professionals. Due to the inappropriate use of diagnostic tests and treatments, it is extremely important to improve the knowledge of pediatricians and neurologists on FS management and to standardize the diagnostic and therapeutic work-up.
Topics: Child; Child, Preschool; Diagnosis, Differential; Humans; Infant; Prognosis; Seizures, Febrile
PubMed: 30321985
DOI: 10.3390/ijerph15102232 -
Clinical and experimental insight into pathophysiology, comorbidity and therapy of absence seizures.Brain : a Journal of Neurology Aug 2020Absence seizures in children and teenagers are generally considered relatively benign because of their non-convulsive nature and the large incidence of remittance in... (Review)
Review
Absence seizures in children and teenagers are generally considered relatively benign because of their non-convulsive nature and the large incidence of remittance in early adulthood. Recent studies, however, show that 30% of children with absence seizures are pharmaco-resistant and 60% are affected by severe neuropsychiatric comorbid conditions, including impairments in attention, cognition, memory and mood. In particular, attention deficits can be detected before the epilepsy diagnosis, may persist even when seizures are pharmacologically controlled and are aggravated by valproic acid monotherapy. New functional MRI-magnetoencephalography and functional MRI-EEG studies provide conclusive evidence that changes in blood oxygenation level-dependent signal amplitude and frequency in children with absence seizures can be detected in specific cortical networks at least 1 min before the start of a seizure, spike-wave discharges are not generalized at seizure onset and abnormal cortical network states remain during interictal periods. From a neurobiological perspective, recent electrical recordings and imaging of large neuronal ensembles with single-cell resolution in non-anaesthetized models show that, in contrast to the predominant opinion, cortical mechanisms, rather than an exclusively thalamic rhythmogenesis, are key in driving seizure ictogenesis and determining spike-wave frequency. Though synchronous ictal firing characterizes cortical and thalamic activity at the population level, individual cortico-thalamic and thalamocortical neurons are sparsely recruited to successive seizures and consecutive paroxysmal cycles within a seizure. New evidence strengthens previous findings on the essential role for basal ganglia networks in absence seizures, in particular the ictal increase in firing of substantia nigra GABAergic neurons. Thus, a key feature of thalamic ictogenesis is the powerful increase in the inhibition of thalamocortical neurons that originates at least from two sources, substantia nigra and thalamic reticular nucleus. This undoubtedly provides a major contribution to the ictal decrease in total firing and the ictal increase of T-type calcium channel-mediated burst firing of thalamocortical neurons, though the latter is not essential for seizure expression. Moreover, in some children and animal models with absence seizures, the ictal increase in thalamic inhibition is enhanced by the loss-of-function of the astrocytic GABA transporter GAT-1 that does not necessarily derive from a mutation in its gene. Together, these novel clinical and experimental findings bring about paradigm-shifting views of our understanding of absence seizures and demand careful choice of initial monotherapy and continuous neuropsychiatric evaluation of affected children. These issues are discussed here to focus future clinical and experimental research and help to identify novel therapeutic targets for treating both absence seizures and their comorbidities.
Topics: Adolescent; Animals; Child; Comorbidity; Humans; Seizures
PubMed: 32437558
DOI: 10.1093/brain/awaa072 -
Seizure May 2019To summarize the clinical features, suggested work-up, treatment and prognosis of new-onset refractory status epilepticus (NORSE), a condition recently defined as the... (Review)
Review
PURPOSE
To summarize the clinical features, suggested work-up, treatment and prognosis of new-onset refractory status epilepticus (NORSE), a condition recently defined as the occurrence of refractory status epilepticus (RSE) in a patient without active epilepsy, and without a clear acute or active structural, toxic or metabolic cause; and of the related syndrome of febrile infection-related epilepsy syndrome (FIRES), also recently defined as a subgroup of NORSE preceded by a febrile illness between 2 weeks and 24 h prior to the onset of RSE.
METHOD
Narrative review of the medical literature about NORSE and FIRES.
RESULTS
NORSE and FIRES mainly affect school-age children and young adults. A prodromal phase with flu-like symptoms precedes the SE onset in two third of NORSE cases, and by definition in all FIRES. Status epilepticus usually starts with repeated focal seizures with secondary bilateralization. Most cases evolve to super RSE (SRSE) and have unfavorable outcome, with short-term mortality of 12-27%, long-term disability and epilepsy. No specific imaging or laboratory abnormalities have been identified so far that allows an early diagnosis and half of adult cases remain of unknown etiology. A standardized diagnostic algorithm is provided and. Autoimmune encephalitis is the most frequent identified cause. In the absence of specific diagnosis, immunotherapy could be tried in addition to antiepileptic treatment.
CONCLUSIONS
This review presents the rare but devastating syndrome of NORSE, including the subcategory of FIRES. Early recognition with complete work-up is primordial to identify the underlying cause and promptly start appropriate treatment.
Topics: Humans; Status Epilepticus
PubMed: 30482654
DOI: 10.1016/j.seizure.2018.09.018 -
Acta Neurologica Scandinavica Dec 2022Most seizures in critical ill patients are non-convulsive, and some patients may develop non-convulsive status epilepticus (NCSE), a state of continuous or repetitive... (Review)
Review
Most seizures in critical ill patients are non-convulsive, and some patients may develop non-convulsive status epilepticus (NCSE), a state of continuous or repetitive seizures without convulsions. With the growing use of continuous electroencephalogram (EEG) monitoring in neuro-intensive care units, non-convulsive seizure (NCS) and NCSE are increasingly diagnosed in patients with impaired consciousness, and progress has been made in identifying various EEG characteristics of NCS/NCSE. Epidemiological studies have contributed to a better understanding of etiologies and risk factors for NCS and NCSE. However, sufficient clinical trials about the treatment of NCS and NCSE are still lacking. The appropriate level of aggressiveness in the treatment of NCSE is still debated, particularly with regard to the use of anesthetics in patients with refractory NCSE. In this review, we summarize the EEG, clinical, epidemiological, diagnostic and therapeutic knowledge of NCS and NCSE in the neuro-intensive care setting in detail.
Topics: Humans; Status Epilepticus; Seizures; Electroencephalography; Intensive Care Units; Critical Care
PubMed: 36285875
DOI: 10.1111/ane.13718