Latency to first spike in the EEG of epilepsy patients

Abstract

The study suggests the need to consider a change in EEG strategy to assess interictal epileptiform activity. The greatest probability of capturing an interictal abnormality within 20min was in individuals with generalized epilepsy. In individuals with suspected epilepsy in whom electrographic interictal spike confirmation is deemed necessary, after a first nonspecific or normal routine EEG, a 24h EEG should be the next step in the electrographic assessment. This study suggests that there may not be much benefit in monitoring for durations longer than 24h, unless capturing a seizure is the intent.

Is it time for individualized testing in the electroencephalogram (EEG) laboratory?

“…A trend was found towards earlier recording of IEDs in inpatients with generalized versus localization‐related epilepsy. This finding was previously reported by several investigators and was attributed to higher IED frequency in generalized epilepsy.…”

“…Several factors that may be related to this discrepancy, especially limited resources and economic considerations, incited different studies that investigated the effect of recording time reduction on the detection of EEG abnormalities [4][5][6][7][8][9][10]. Several of these studies examined both epileptiform and non-epileptiform abnormalities [4,5,8], admission status was unclear or included both inpatients and outpatients [4][5][6][7][8], age was not specified or different age groups, both children and adults, were included [4,[7][8][9][10], and several EEG procedures, i.e. standard, sleep and/or variable duration of long-term continuous EEG, were included in others [4,[6][7][8][9][10].…”

Effects of Antiepileptics on Behavioral and Electroencephalographic Seizure Induced by Pentetrazol in Mice

“…In this study, it was also found that spiking activity and spike-wave discharge were observed in correlation with MCL and CL, respectively, after PTZ administration. It was reported that there is a close relationship between convulsive behavior and EEG seizures in epileptic patients (12). In addition, it is well known that EEG spike indicates the action potential of stimulated nerve cells, and excitation of the brain was observed in the area showing the EEG spike.…”

“…It is well known that the changes of electroencephalogram (EEG) are observed in patients with generalized and partial seizures (10,11), and EEG data are useful information in the diagnosis of epilepsy (12). In human absence epilepsy, a bilaterally synchronous 3-Hz spike and wave complex is mainly observed on the EEG (13).…”

What has changed in the utility of pediatric EEG over the last decade?

“…The ACNS guidelines recommend at least 20 min of artifact-free recording as necessary for routine EEG, and the International League Against Epilepsy (ILAE) recommends at least 30 min recording should be performed for baseline EEGs (4,7). Some studies have evaluated the effect of longer recording on the detection of EEG abnormalities, and they have found that most epileptiform abnormalities (37%-89%) are seen in the first 20 min of recording (5,8). On the other hand, some studies have evaluated short EEG recordings, and claim that reducing the recording time of standard EEGs to 15 min may fail to register some abnormalities (9).…”