Send to

Choose Destination
  • This is a preview / test site. Please update your PubMed URL to
See comment in PubMed Commons below
Seizure. 2008 Jan;17(1):34-41. Epub 2007 Jul 26.

Latency to first spike in the EEG of epilepsy patients.

Author information

  • 1Comprehensive Epilepsy Center, Weill-Cornell Medical Center & New York Hospital Queens, United States.



Routine EEGs in individuals with epilepsy have interictal spikes in 56% of cases. The availability of prolonged EEG has changed the use of EEG in the assessment of epilepsy.


To determine the time to first epileptiform activity on EEG in patients with epilepsy. This data will help optimize the duration of electrographic assessment for interictal activity in epileptic individuals.


46 consecutive patients aged 10 years or older with epilepsy were evaluated. Individuals with seizures in the prior 24h or with acute symptomatic seizures were excluded. Continuous EEG (for 1-7 days) was analyzed to find the first definite epileptiform activity and the latency assessed.


37% of the patients had epileptiform activity in the first 20min of the continuous recording (duration of a routine EEG). 89% had epileptiform activity within 24h. The yield drops beyond 24h. 8% of the individuals had no epileptiform activity even after 72h.


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.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center