Operational classification of seizure types by the International League Against Epilepsy: Position Paper of the ILAE Commission for Classification and Terminology

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.     

Generalized onset seizures with focal evolution (GOFE) — A unique seizure type in the setting of generalized epilepsy

PurposeWe report clinical and electrographic features of generalized onset seizures with focal evolution (GOFE) and present arguments for the inclusion of this seizure type in the seizure classification.MethodsThe adult and pediatric Epilepsy Monitoring Unit databases at Vanderbilt Medical Center and Children's Hospital were screened to identify generalized onset seizures with focal evolution. We reviewed medical records for epilepsy characteristics, epilepsy risk factors, MRI abnormalities, neurologic examination, antiepileptic medications before and after diagnosis, and response to medications. We also reviewed ictal and interictal EEG tracings, as well as video-recorded semiology.ResultsTen patients were identified, 7 males and 3 females. All of the patients developed generalized epilepsy in childhood or adolescence (ages 3–15 years). Generalized onset seizures with focal evolution developed years after onset in 9 patients, with a semiology concerning for focal seizures or nonepileptic events. Ictal discharges had a generalized onset on EEG, described as either generalized spike-and-wave and/or polyspike-and-wave discharges, or generalized fast activity. This electrographic activity then evolved to focal rhythmic activity most commonly localized to one temporal or frontal region; five patients had multiple seizures evolving to focal activity in different regions of both hemispheres. The predominant interictal epileptiform activity included generalized spike-and-wave and/or polyspike-and-wave discharges in all patients. Taking into consideration all clinical and EEG data, six patients were classified with genetic (idiopathic) generalized epilepsy, and four were classified with structural/metabolic (symptomatic) generalized epilepsy. All of the patients had modifications to their medications following discharge, with three becoming seizure-free and five responding with > 50% reduction in seizure frequency.ConclusionGeneralized onset seizures may occasionally have focal evolution with semiology suggestive of focal seizures, leading to a misdiagnosis of focal onset. This unique seizure type may occur with genetic as well as structural/metabolic forms of epilepsy. The identification of this seizure type may help clinicians choose appropriate medications, avoiding narrow spectrum agents known to aggravate generalized onset seizures.     

Operationale Klassifikation der Anfallsformen durch die Internationale Liga gegen Epilepsie: Positionspapier der ILAE-Klassifikations- und Terminologiekommission

The International League Against Epilepsy (ILAE) presents a revised operational classification of seizure types. The purpose of this revision is to recognize that some seizure types can have either a focal or generalized onset, to enable a classification when the onset is unobserved, to include some missing seizure types and to implement a more transparent and understandable nomenclature. Because current knowledge is insufficient to form a scientifically based classification, the 2017 classification is operational (practical) and based on the 1981 classification with the amendments from 2010. The changes include the following: (1) “partial” becomes “focal”; (2) awareness (disturbance of consciousness) is used as a classification criterion 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) epileptic spasms as well as atonic, clonic, myoclonic and tonic seizures can have a focal or generalized onset, (6) focal (seizure with progression) to (a) 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 seizures and (8) seizures of unknown onset may have features that can still be classified. The new classification does not represent a fundamental change but enables greater flexibility and transparency in naming seizure types.     

Carbamazepine-exacerbated epilepsy in children and adolescents

Forty-nine children and adolescents whose seizures reportedly worsened while receiving carbamazepine (CBZ) were studied retrospectively. Twenty-six patients met criteria for excellent documentation of carbamazepine-exacerbated seizures. Four epileptic syndromes were particularly affected: childhood absence epilepsy; focal symptomatic, frontal lobe epilepsy; Lennox-Gastaut syndrome; and severe myoclonic epilepsy of infancy. Eight of the 26 patients developed new-onset absence seizures and three patients with established absence epilepsy experienced absence status. Other seizure types, including atonic, tonic-clonic, and myoclonic, developed in eight patients treated with CBZ, and new generalized spike-and-wave discharges were observed in electroencephalograms of nine patients. CBZ is a widely used, effective antiepileptic drug, particularly for partial or partial complex seizures; however, if uncontrolled, generalized seizures occur after CBZ is prescribed for children or adolescents with absence or mixed seizures, a trial of CBZ discontinuation is warranted. The data reported here do not permit calculation of the incidence of this phenomenon.     

Instruction manual for the ILAE 2017 operational classification of seizure types

This companion paper to the introduction of the International League Against Epilepsy (ILAE) 2017 classification of seizure types provides guidance on how to employ the classification. Illustration of the classification is enacted by tables, a glossary of relevant terms, mapping of old to new terms, suggested abbreviations, and examples. Basic and extended versions of the classification are available, depending on the desired degree of detail. Key signs and symptoms of seizures (semiology) are used as a basis for categories of seizures that are focal or generalized from onset or with unknown onset. Any focal seizure can further be optionally characterized by whether awareness is retained or impaired. Impaired awareness during any segment of the seizure renders it a focal impaired awareness seizure. Focal seizures are further optionally characterized by motor onset signs and symptoms: atonic, automatisms, clonic, epileptic spasms, or hyperkinetic, myoclonic, or tonic activity. Nonmotor‐onset seizures can manifest as autonomic, behavior arrest, cognitive, emotional, or sensory dysfunction. The earliest prominent manifestation defines the seizure type, which might then progress to other signs and symptoms. Focal seizures can become bilateral tonic–clonic. Generalized seizures engage bilateral networks from onset. Generalized motor seizure characteristics comprise atonic, clonic, epileptic spasms, myoclonic, myoclonic–atonic, myoclonic–tonic–clonic, tonic, or tonic–clonic. Nonmotor (absence) seizures are typical or atypical, or seizures that present prominent myoclonic activity or eyelid myoclonia. Seizures of unknown onset may have features that can still be classified as motor, nonmotor, tonic–clonic, epileptic spasms, or behavior arrest. This “users’ manual” for the ILAE 2017 seizure classification will assist the adoption of the new system.     

Nonconvulsive Status Epilepticus in Adults: Thirty-Two Consecutive Patients from a General Hospital Population

We studied all adult patients who between 1984 and 1989 were initially diagnosed at our hospital as having nonconvulsive status epilepticus. Thirty-two patients fulfilled the criteria, which included ictal EEG recordings. The annual incidence was 1.5 in 100,000 inhabitants. The median age at onset of status was 51 years. Ten patients had status as their first epileptic manifestation, but most patients had a previous history of epilepsy. Median duration of epilepsy at onset of status was 4 years. Fourteen patients had focal ictal seizure activity on EEG and thus met the criteria for complex partial status. Eighteen patients had generalized seizure activity on EEG, but only 6 of these had a history of absence epilepsy or juvenile myoclonic epilepsy. None had Lennox-Gastaut syndrome. The clinical features of status in the remaining 12 patients were in some respects similar to those of the patients with complex partial status. We hypothesize that the EEG seizure activity in these patients may have been generalized from an initial focus.     

Idiopathic generalized epilepsies misdiagnosed as partial epilepsies

Idiopathic generalized epilepsy (IGE) is often not recognized with serious consequences on the sufferers. We examined factors contributing to the missed diagnosis of IGE in 41 adults attending our epilepsy clinic with diagnosis of partial epilepsy who had semiology or EEG findings suggesting a possible differential diagnosis. After careful re-evaluation, the diagnosis of IGE was established in 25 patients: 22 (88%) with JME, one with juvenile absence, one with perioral myoclonia with absences, one with eyelid myoclonia with typical absences. Myoclonic jerks, the hallmark of the JME and other IGE, were not usually reported by patients or misdiagnosed as focal motor seizures. Brief and infrequent absence seizures and focal EEG abnormalities were other factors contributing to not recognizing JME. All 25 patients did not achieve seizure control before re-evaluation of diagnosis. After appropriate diagnosis of IGE and change of AED to valproate or valproic acid, 19 (76%) became seizure free and six (24%) had a significant improvement on seizure control. Association with lamotrigine provided further improvement in three of these patients. An appropriate questioning to identify myoclonic and absence seizures and a proper interpretation in the context of whole clinical constellation are essential for a correct seizure classification and diagnosis of IGE in adults.     

Clinical associations of occipital intermittent rhythmic delta activity

Association of occipital intermittent rhythmic delta activity with absence seizures has been well documented in the published literature. Two recent studies have also described an association with focal seizures. After obtaining approval from our Institutional Review Board, all electroencephalograms with occipital intermittent rhythmic delta activity at our institution between July 1, 2006 and December 31, 2009 were identified. Charts of these patients were reviewed to collect clinical data. A matched comparison group was assembled. Thirty-one of the patients who met criteria had evaluable clinical data. Fifteen had generalized seizures (9 absence; 2 tonic-clonic; 3 absence and tonic-clonic; 1 absence, tonic-clonic, myoclonic, and atonic). Eleven had focal seizures. One had both generalized tonic-clonic and focal seizures. Events in 1 were nonepileptic in nature. Documentation was inadequate for seizure classification in 3. There was a statistically significant difference between the study and comparison groups for absence seizures, but not for focal seizures.     

De novo late‐onset absence status epilepticus or late‐onset idiopathic generalized epilepsy? A case report and systematic review of the literature

Aim. Idiopathic (genetic) generalized epilepsies (IGEs) are age‐related epileptic syndromes with typical age onset in childhood or adolescence. We report a patient with de novo late‐onset absence status epilepticus (ASE) occurring at the age of 64 years, with clinical and EEG features suggestive of late‐onset IGE. We also discuss the relationship between de novo late‐onset ASE and late‐onset IGE, and provide a comprehensive and critical review of the available literature on late‐onset (i.e. onset ≥60 years) IGE. Methods. MEDLINE (1966–2016 [23^th April]) was systematically searched in order to identify reports of patients with late‐onset IGE. Grey literature was also comprehensively searched. Results. We identified nine patients with electroclinical features suggestive of late‐onset IGE. Median age at seizure onset was 71 years (range: 60–80), with a female prevalence (67%). A family history of epilepsy was reported in 67% of cases. All patients had generalized tonic‐clonic seizures, and 44% also had myoclonic seizures. Treatment and outcome were reported for six patients; all of whom reached seizure freedom under monotherapy with valproic acid (83%) or lamotrigine (17%) (range of follow‐up: 3 to 24 months). Conclusion. Late‐onset IGE are entities with unknown prevalence and incidence, and should be differentiated on the basis of late‐onset reactivation of previous IGE. Late‐onset IGEs are probably unrecognized or misdiagnosed, based on a common misconception that all elderly individuals with first‐ever seizures have focal symptomatic epilepsy. Late‐onset IGE should be actively investigated by accurate history taking aimed at identifying seizures, which may have been unnoticed, and familial antecedents of epilepsy. In elderly patients presenting with de novo late‐onset ASE, a diagnosis of late‐onset IGE should be considered in the differential diagnosis, particularly in atypical cases (e.g. absence of triggering factors, coexistence of generalized tonic‐clonic or myoclonic seizures, and interictal generalized epileptiform discharges).     

Electroclinical features of epilepsy in patients with juvenile type dentatorubral-pallidoluysian atrophy

Purpose: To clarify the electroclinical characteristics of epileptic seizures in patients with juvenile type dentatorubral‐pallidoluysian atrophy (DRPLA). Methods: Seventeen patients with juvenile type DRPLA confirmed by genetic analysis were studied retrospectively. The clinical records of all 17  patients and the ictal video electroencephalography (EEG) recordings from 12 of the 17 patients were reviewed. Results: Electroclinical studies in 12 patients identified 11 habitual seizures in 6 patients as partial seizures on ictal video EEG recordings. Clinical manifestations composed mainly of versions of the head and loss of consciousness. These partial seizures were persistently recorded throughout the clinical course. Brief generalized seizures (atypical absence and myoclonic seizure) were observed in 6 of 12 patients at the early stage. In contrast, generalized tonic–clonic seizures (GTCS) were recorded in four advanced stage patients who were almost bedridden. Semiological studies in 17 patients showed that the prevalence of partial seizures was significantly higher in patients with younger epilepsy onset (below 10 years of age; χ² test, p < 0.05) and that the age of epilepsy onset was significantly lower in patients with partial seizures than in those without partial seizures (Mann‐Whitney U test, p = 0.02). However, the number of CAG repeats and age at clinical onset were not significantly different between two groups. Discussion: Partial seizure is one of the common epileptic features in juvenile type DRPLA, especially in patients with younger epilepsy onset. Seizure types may be affected in an age‐dependent manner and change evolutionally during progression of the clinical stage.     

First-ever, door-to-door cross-sectional representative study in Prey Veng province (Cambodia)

Purpose: To estimate the lifetime prevalence of epilepsy in Prey Veng province (Cambodia). Methods: Door‐to‐door screening was performed using a random cluster survey whereby all people >1 year of age were screened for epilepsy by using a validated and standardized questionnaire for epilepsy in tropical countries. Suspected epilepsy patients identified by the questionnaire were revisited and examined by epileptologists. The confirmation of epilepsy was based on an in‐depth clinical examination. Electroencephalograms were recorded at the community dispensary. Key Findings: Five hundred three potential epilepsy cases were identified from 16,510 screened subjects, and 96 were diagnosed to have epilepsy. An overall prevalence of 5.8 per 1,000 [95% confidence interval (CI) 4.6–7.0 per 1,000] was obtained. Generalized epilepsy (76%) was more common than partial epilepsy (12.5%). Three cases were of generalized myoclonic epilepsy (3.1%) and one case each (1.0%) were of absence and olfactory partial epilepsy. Six cases (5.2%) had more than one seizure type [one case with absence + generalized tonic–clonic (GTC), one case each with GTC + partial seizures with secondary generalization and absence + generalized myoclonic seizures and absence + simple partial seizures, and two cases with GTC + complex partial seizures]. Electroencephalography (EEG) studies revealed spike and wave discharges in 43.8%, focal spikes in 21.0%, generalized slow waves in 19.2%, and generalized slowing of background in 15.7%. Significance: This is the first population‐based study in Cambodia that had epilepsy as a primary objective, and compared to Western and neighboring countries it shows a lower prevalence.     

Ictal single photon emission computed tomography in absence seizures: apparent implication of different neuronal mechanisms

Absence seizures represent a complex group of epilepsy, characterized by lapse of consciousness with staring. Bilateral, synchronous, and symmetric bursts of 3-Hz spike-and-wave discharges are observed on the electroencephalogram, whereas interictal background activity is normal. This kind of epilepsy has to be differentiated from other generalized epilepsies such as juvenile absence epilepsy and juvenile myoclonic epilepsy. Moreover, absence seizures, together with generalized spike-and-wave discharges, may coexist with other types of epilepsy such as frontal lobe epilepsy, temporal lobe epilepsy, benign epilepsy with centrotemporal spikes, and childhood epilepsy with occipital paroxysms. We have carried out ictal single photon emission computed tomography (SPECT) in 10 patients with clinical evidence of absence seizures with the aim to better understand and to distinguish this kind of seizure as primarily or secondarily generalized to a specific area and to obtain more information on the neuronal mechanisms involved in the different types of seizures, usually not identifiable at the first appearance. During the long follow-up period (9 months to 14 years), 7 of the 10 examined patients underwent interictal SPECT when they became seizure free. Our data permitted, in two patients, the diagnosis of childhood absence seizures; in three patients, they suggested the possibility of later appearance of other seizure types, on the basis of focal hyperperfusion indicating a possible focal firing. In three of the examined patients, the diagnosis of idiopathic localization-related epilepsies mimicking childhood absence seizures could be performed. In the last two patients, the hypothesis of a coexistence of absences with partial and generalized seizures was considered. From our results, it can be presumed that ictal SPECT findings may contribute to the physiopathologic classification of the different types of epilepsies. Moreover, anticonvulsant treatment more appropriate to the different forms of seizures can be used.     

Clinical applications and the effect of mexiletine on refractory epilepsies

Twenty-four patients with refractory epilepsy were treated with mexiletine as an additional antiepileptic drug. As the initial responses, seizures were decreased by 50% or more in 7 (46.7%) of 15 patients with symptomatic partial epilepsy (SPE), in none of 7 with symptomatic generalized epilepsy (SGE), and in 1 of 2 with undetermined epilepsy. Seizures increased in 3 patients (20.0%) with SPE, and in 3 (42.9%) with SGE. Concerning seizure types, mexiletine had significant effects on 1 of 2 patients with simple partial seizures, on 7 of 13 with complex partial seizures, on 1 of 5 with secondarily generalized seizures, and on 1 of 8 with tonic seizures. No patients with a myoclonic seizure or atypical absence improved. Exacerbation of the seizures was observed in 2 of 13 patients with complex partial seizures, in 1 of 5 with secondarily generalized seizures, in 3 of 8 with tonic seizures, and in 2 of 3 with myoclonic seizures. Partial seizures were controlled well, whereas generalized seizures sometimes worsened. EEG improved in 3 patients with SPE; decrease of focal spikes in 2 patients and disappearance of secondary generalization in 1. Follow-up for more than 3 months showed seizures to be lessened in 2 patients. Mexiletine is useful for the treatment of refractory epilepsies, especially SPE.     

Clinical and electroencephalographic findings prior to the onset of juvenile myoclonic epilepsy: A case series

The purpose of this study was to investigate the timing of generalized electroencephalographic abnormalities in patients with juvenile myoclonic epilepsy who were followed up long term before the onset of juvenile myoclonic epilepsy. We enrolled juvenile myoclonic epilepsy patients whose course of epilepsy had been observed for >5 years before the onset of juvenile myoclonic epilepsy, those who had undergone electroencephalogram recording more than twice before the onset of juvenile myoclonic epilepsy, and those who had terminated antiseizure medications for at least 2 years before the onset of juvenile myoclonic epilepsy. Patients who had transitioned from childhood absence epilepsy to juvenile myoclonic epilepsy were excluded. We retrospectively reviewed the medical records and neurophysiological data of the patients. Four patients met the inclusion criteria. One patient was diagnosed with febrile seizures during childhood, and the remaining three had transitioned to juvenile myoclonic epilepsy from other epileptic disorders, such as self-limited epilepsy with autonomic seizures, genetic epilepsy with febrile seizure plus, or nonspecific genetic generalized epilepsy. All patients exhibited generalized spike–wave discharges or photoparoxysmal responses for >2 years before the onset of juvenile myoclonic epilepsy. The four patients had transitioned to juvenile myoclonic epilepsy from other epileptological preconditions. Patients with juvenile myoclonic epilepsy may show generalized electroencephalographic abnormality many years prior to the onset of symptoms. Generalized spike–waves on the electroencephalogram during the course of any type of epilepsy or febrile seizure may be a risk factor for developing juvenile myoclonic epilepsy.     

Anleitung („instruction manual“) zur Anwendung der operationalen Klassifikation von Anfallsformen der ILAE 2017

This companion paper to the introduction of the International League Against Epilepsy (ILAE) 2017 classification of seizure types provides guidance on how to employ the classification. The classification is illustrated by tables, a glossary of relevant terms, a table mapping old to new terms, recommended abbreviations and examples. Basic and extended versions of the classification are available depending on the desired degree of detail. Key signs and symptoms of seizures (semiology) are used as a basis for categorization of seizures that are focal or generalized from onset or with unknown onset. Any focal seizure can be further optionally characterized with respect to whether awareness is retained or impaired. Impaired awareness during any segment of the seizure renders it classified as a focal impaired awareness seizure. Focal seizures can be further optionally characterized by the first motor signs and symptoms as atonic, automatisms, clonic, epileptic spasms, hyperkinetic, myoclonic or tonic activity. Nonmotor onset seizures can be manifested as autonomic, behavior arrest, cognitive, emotional, or sensory dysfunction. The earliest prominent manifestation defines the seizure type, which can then further progress to other signs and symptoms. Focal seizures can become bilateral tonic–clonic seizures. Generalized seizures include an early involvement of bilateral networks from the onset. Generalized motor seizure characteristics comprise atonic, clonic, epileptic spasms, myoclonic, myoclonic–atonic, myoclonic–tonic–clonic, tonic or tonic–clonic manifestatíons. Nonmotor (absence) seizures are typical or atypical or seizures that present prominent myoclonic activity or eyelid myoclonia. Seizures of unknown origin may have features that can still be classified as motor, nonmotor, tonic–clonic, epileptic spasms or behavior arrest. This users’ manual for the ILAE 2017 seizure classification can assist the acceptance of the new system.     

Generalized spike-and-wave patterns in children: clinical correlates

All electroencephalograms performed in our institution between 1980 and 1990 were reviewed. The clinical characteristics of children with epilepsy and generalized spike-and-wave (SW) patterns were analyzed. The SW patterns were classified according to their frequency. Electroencephalograms of 154 children with epilepsy revealed SW patterns. Absence seizures were the most common first seizure, but partial seizures were frequent. More than 40% had several types of seizures. Sixty percent of the epileptic syndromes were generalized, but almost 25% were partial. The typical SW pattern was associated with absence seizures, a normal examination and computed tomographic scan, idiopathic generalized epilepsies, monotherapy, freedom from seizures, and lack of recurrence. The slow SW pattern was associated with West syndrome; a younger age at seizure onset; atonic, myoclonic, tonic, and partial simple seizures; an abnormal examination and computed tomographic scan; cryptogenic or symptomatic generalized epilepsy or symptomatic partial epilepsy; polytherapy; and poor seizure control. The fast SW pattern was associated with secondary generalized, partial, tonic-clonic, and complex partial seizures; a normal computed tomographic scan; cryptogenic partial epilepsy; isolated seizures; and seizure recurrence. Epilepsy with a typical SW pattern should be considered benign, epilepsy with a slow SW pattern malignant, and epilepsy with a fast SW pattern treacherous.     

Refractory grand mal seizures with onset during infancy including severe myoclonic epilepsy in infancy.

In 1978, Dravet proposed a clinical entity called severe myoclonic epilepsy in infancy (SMEI). In the same year, a patient group, which was later called high voltage slow wave-grand mal syndrome (HVSW-GM), is reported in Japan. Both syndromes are very similar, except for seizure manifestation: generalized tonic-clonic convulsions (GTC) with myoclonic and other polymorphic seizures in SMEI vs. GTC only in HVSW-GM. To study the pathophysiology of these refractory epilepsies, the author formulated new clinical diagnostic criteria common to both syndromes as follows: GTC with onset before the age of 1 year as the principal seizure type; an epilepsy entity unclassifiable either as partial or generalized by all the clinical data including EEG findings; mental and motor dysfunction absent prior to seizure onset but appearing later; absence of epileptiform activities on EEG in the initial stage; stubborn refractoriness to conventional antiepileptic medication. Twenty-two patients meeting all of five clinical criteria above mentioned were recruited in the study. Detailed analysis of clinico-electrical features and long-term follow-up of these patients led the author to the conclusion that GTC in combination with seizures of other types will contribute to an unfavorable pathophysiological or prognostic conditions, and, especially when GTC exists in combination with myoclonic seizures, the severity of epilepsy will increase. The author claimed that the three clinical entities, SMEI, HVSW-GM, and their variant form, share certain characteristics in common and may constitute a unique epilepsy syndrome for which a new name of infantile refractory grand mal syndrome (IRGMS) was offered. This is a more basic concept with broader spectrum than SMEI, encompassing not only SMEI but also related borderlands like HVSW-GM. More recently, the author observed that early zonisamide medication within 1 year after seizure onset may improve seizure prognosis in IRGMS, by preventing the development of myoclonic seizures.     

Seizure characterization and electroencephalographic features in Glut-1 deficiency syndrome

PURPOSE: To characterize seizure types and electroencephalographic features of glucose transporter type 1 deficiency syndrome (Glut-1 DS). METHODS: Twenty children with clinical and laboratory features of Glut-1 DS were evaluated. Age at seizure diagnosis, seizure classification, and response to treatment were determined by chart review. Thirty-two continuous 24-h EEG monitoring sessions and reports of 42 routine EEG studies were assessed. RESULTS: Age at seizure diagnosis was between 4 weeks and 18 months (mean, 5 months). Seizure types were generalized tonic or clonic (14), absence (10), partial (nine), myoclonic (six), or astatic (four). During 24-h EEGs, background activity showed generalized 2.5- to 4-Hz spike-wave discharges (41%), generalized slowing or attenuation (34%), no abnormalities (34%), focal epileptiform discharges (13%), or focal slowing or attenuation (9%). No seizures were captured during 69% of the studies; the remainder had absence (19%), myoclonic (9%), or partial seizures (3%). On evaluation of routine and 24-h EEG studies, focal epileptiform discharges (24%) and slowing (11%) were more frequent in ages 0-24 months. In older children (2-8 years), generalized epileptiform discharges (37.5%) and slowing (21%) were more common. CONCLUSIONS: In all ages, a normal interictal EEG was the most common EEG finding. When abnormalities occurred, focal slowing or epileptiform discharges were more prevalent in the infant. In older children (2 years or older), a generalized 2.5- to 4-Hz spike-wave pattern emerged. Seizure types observed included, absence, myoclonic, partial, and astatic.     

Focal semiologic and electroencephalographic features in patients with juvenile myoclonic epilepsy

PURPOSE: A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring. METHODS: Twenty-six patients (nine males and 17 females) who had seizures recorded during video-EEG monitoring were included. Age at seizure onset was 0 to 22 years (mean, 12.3 years), and age at monitoring was 12 to 44 years (mean, 26.5 years). In one patient with left parietooccipital epilepsy, primary generalized tonic-clonic seizures developed after resection of the parietal tumor. Two patients had both temporal lobe epilepsy and JME. Videotaped seizures in each patient were analyzed. Interictal and ictal EEG also were analyzed for any focal features. RESULTS: Focal semiologic features were observed in 12 (46%) of 26 patients. Six patients had focal myoclonic seizures, and two had Figure 4 sign: one with version to the left, and another had left version followed by Figure 4 sign, and left arm clonic seizure. Their ictal EEGs were generalized at onset but with a lateralized evolution over the right hemisphere. The patient who had both JME and left parietooccipital epilepsy, right arm clonic seizure, and Figure 4 sign was seen during a generalized EEG seizure. Interictally, one patient had temporal sharp waves, and another had run of spikes in the right frontal region. CONCLUSIONS: Fourteen (54%) of 26 patients with JME exhibited focal semiologic or electroencephalographic features or both. Video-EEG was essential in reaching a correct diagnosis and choosing an appropriate antiepileptic drug regimen.     

Managing Lafora body disease with vagal nerve stimulation

A 17‐year‐old female, of consanguineous parents, presented with a history of seizures and cognitive decline since the age of 12 years. She had absence, focal dyscognitive, generalized myoclonic, and generalized tonic‐clonic seizures, all of which were drug resistant. The diagnosis of Lafora body disease was made based on a compatible clinical, EEG, seizure semiology picture and a disease‐causing homozygous mutation in the EPM2A gene. A vagus nerve stimulator (VNS) was inserted and well tolerated with a steady decrease and then stabilization in seizure frequency during the six months following insertion (months 1–6). At follow‐up, at 12 months after VNS insertion, there was a persistent improvement. Seizure frequency during months 7–12, compared to pre‐VNS, was documented as follows: the absence seizures observed by the family had decreased from four episodes per month to 0 per month, the focal dyscognitive seizures from 300 episodes per month to 90 per month, the generalized myoclonic seizures from 90 clusters per month to eight per month, and the generalized tonic‐clonic seizures from 30 episodes per month to 1.5 per month on average. To our knowledge, this is the second case reported in the literature showing efficacy of VNS in the management of seizures in Lafora body disease.