Polyspike and Waves Do Not Predict Generalized Tonic-Clonic Seizures in Childhood Absence Epilepsy

Vierck, Esther; Cauley, Ryan; Kugler, Steven L.; Mandelbaum, David E.; Pal, Deb K.; Durner, Martina

doi:10.1177/0883073809341665

Cited by 20 publications

(11 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other studies have reported EEG focalities in 30–55% of JME patients . The reported frequency of focal or lateralized EEG abnormalities in patients with absence seizures ranges from 16% to 37% . Temporal intermittent rhythmic delta activity was reported among 13% of patients with juvenile absence epilepsy (JAE) compared to none in JME from a single study based on video‐EEG .…”

Section: Resultsmentioning

confidence: 99%

Focal abnormalities in idiopathic generalized epilepsy: A critical review of the literature

2014

View full text Add to dashboard Cite

SUMMARYConventionally, epilepsy is dichotomized into distinct "focal" and "generalized" categories. However, many studies have reported so-called focal features among patients with idiopathic generalized epilepsy (IGE) in the domains of semiology, electroencephalography, neuropsychology, neuropathology, and neuroimaging. We sought to review such features and clinical implications. A Web of Science database search was conducted to identify relevant publications. Our search yielded 145 papers describing focal features involving different domains in IGE, with 117 papers analyzed after excluding abstracts and case reports. Focal semiologic features are commonly seen in IGE. There are conflicting data from studies in the domains of electroencephalography, neuroimaging, and neuropathology. Studies on neuropsychology are suggestive of frontal lobe functional deficits in juvenile myoclonic epilepsy. Most advanced neuroimaging studies demonstrate the involvement of both the thalamus and the cortex during generalized spike-wave discharges (GSWDs). A few electroencephalographic and neuroimaging studies indicate that the cortex precedes the thalamus at the onset of GSWD. Focal features may contribute to misdiagnosis of IGE as focal epilepsy. However there are methodologic limitations in the studies that affect the results. KEY WORDS: Electroencephalographic, Epilepsy semiology, Generalized seizures, Partial seizures, Neuroimaging, Neuropsychology.Idiopathic generalized epilepsy (IGE; genetic generalized epilepsy) constitutes a rubric of several electroclinical syndromes based on specific clinical features and electroencephalography (EEG) abnormalities.1,2 The traditional approach of classifying epilepsies into "focal" and "generalized" implies there can be no "focal" features in "generalized" epilepsies. However, there has been a gradual paradigm shift in the conceptualization of seizure generation and spread based on epileptic networks. This change is reflected in a recent publication by the International League Against Epilepsy (ILAE) on revised terminology of seizures and epilepsies.2 This paper conceptualizes focal seizures as those arising from networks confined to a single cerebral hemisphere, whereas generalized seizures "originate at some point within, and rapidly engage bilaterally distributed networks" including cortical and subcortical structures, leaving open the possibility of a focal origin within the network.Amid the ongoing debate and discussion about the pathogenesis and classification of IGE, a body of literature highlighting various focal features of IGE has gradually accumulated over the years. In this paper, we review the literature on focal characteristics of IGE in the domains of semiology, EEG, neuropsychology, neuropathology, and neuroimaging.

show abstract

Section: Resultsmentioning

confidence: 99%

Focal abnormalities in idiopathic generalized epilepsy: A critical review of the literature

2014

View full text Add to dashboard Cite

show abstract

“…3); Sadleir et al. (2006) found occipital onset in 19 of 339 absences (5.6%); and Vierck et al. (2010) noticed posterior FSWDs in 8% of their 115 children.…”

Section: Discussionmentioning

confidence: 98%

Focal and generalized EEG paroxysms in childhood absence epilepsy: Topographic associations and distinctive behaviors during the first cycle of non‐REM sleep

et al. 2012

View full text Add to dashboard Cite

SUMMARYPurpose: To better understand the nature of the focal spike-wave discharges (FSWDs) and focally led generalized spike-wave discharges (GSWDs) in typical childhood absence epilepsy (CAE) and by implication their nosologic and taxonomic significance. Methods: Twenty-four abnormal video-electroencephalography (EEG) studies from 13 consecutive children with CAE and good response to appropriate antiepileptic drugs (AEDs) were analyzed. We studied the association between the topography of absence onset and the ictal automatisms, and the topographic correlation between FSWDs and GSWDs and their respective behavior during hyperventilation and the different states of phasic and nonphasic non-rapid eye movement (NREM) sleep. GSWDs were considered as of ''focal'' onset if a lead-in could be visibly recognized at a paper speed of 60 mm/s, and were classified by their topography. Key Findings: (1) Multifocal absences occurred in 10 children; anterior onset was noted in 81 absences (73.6%) from 12 children and posterior in 18 (16.4%) from 7 children; there was no association between topography of absence onset and ictal automatisms; (2) FSWDs occurred in 85% of children and were multifocal in 73% of them; 85% of FSWDs were anterior and 14% posterior; (3) there was good topographic association between FSWDs and the leading spike of GSWDs of ''focal'' onset in all children with FSWDs; (4) both FSWDs and GSWDs increased during hyperventilation; (5) FSWDs occurred mainly during noncyclical NREM sleep and during periods of reduced vigilance of cyclical NREM sleep, whereas GSWDs occurred during the periods of enhanced vigilance of NREM sleep; GSWDs occurred significantly more frequently than FSWDs at the transition from reduced to enhanced vigilance of NREM sleep. Significance: Our findings suggest that in CAE focal EEG paroxysms reflect a system of multifocal nonlocalizing electrically unstable cortical areas that under the facilitatory influence of exogenous or endogenous factors like sleep instability can foster a corticothalamic response of sufficient strength to generate 3-Hz GSWDs that are conditionally sustainable and potentially ictal. FSWDs can be viewed as incomplete forms of the GSWDs; together they define the EEG identity of idiopathic ''generalized'' epileptogenesis.

show abstract

“…In the same study, interictal polyspikes were witnessed in 40%, which were confined to drowsiness and sleep. Another study found polyspike‐wave discharges in 26% (Vierck et al., 2010).…”

Section: Interictal Eeg In Childhood Absence Epilepsy (Cae)mentioning

confidence: 99%

“…Other studies have reported EEG focalities in 30–55% of patients with JME (Panayiotopoulos et al., 1994). The reported frequency of focal or lateralized EEG abnormalities in patients with absence seizures ranges from 16–35% (Matur et al., 2009; Vierck et al., 2010). Based on the results of these studies, it appears that focal interictal EEG abnormalities are found among one third of patients with IGE.…”

Section: Focal Eeg Features In Igementioning

confidence: 99%

The electroencephalogram of idiopathic generalized epilepsy

2011

View full text Add to dashboard Cite

SUMMARYIdiopathic generalized epilepsy (IGE) is classified into several subsyndromes based on clinical and electroencephalography (EEG) features. The EEG signature of IGE is bisynchronous, symmetric, and generalized spikewave complex; although focal, irregular, and so called ''fragments'' of discharges are not uncommon. Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. Both human and animal data suggest involvement of the thalamus and the cortex in the generation of spike-wave discharges in IGE. Circadian variations of generalized epileptiform discharges are well described, and these can be useful in diagnostic confirmation. Those discharges tend to occur more often after awakening and during cyclic alternating pattern phase-A of nonrapid eye movement sleep. Activation procedures such as hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are useful techniques to increase the yield of both interictal and ictal EEG abnormalities. Although not in routine use, specific triggers such as pattern stimulation and cognitive tasks may also be of value in eliciting rare reflex seizure-related EEG abnormalities. Variations of EEG abnormalities are evident between different electroclinical syndromes. EEG is also affected by certain external as well as internal factors, which should be borne in mind when interpreting EEG studies in IGE.

show abstract

Polyspike and Waves Do Not Predict Generalized Tonic-Clonic Seizures in Childhood Absence Epilepsy

Cited by 20 publications

References 37 publications

Focal abnormalities in idiopathic generalized epilepsy: A critical review of the literature

Focal abnormalities in idiopathic generalized epilepsy: A critical review of the literature

Focal and generalized EEG paroxysms in childhood absence epilepsy: Topographic associations and distinctive behaviors during the first cycle of non‐REM sleep

The electroencephalogram of idiopathic generalized epilepsy

Contact Info

Product

Resources

About