Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Apr;120(4):665-72.
doi: 10.1016/j.clinph.2009.01.010. Epub 2009 Mar 4.

Transitional Sharp Waves at Ictal Onset--A Neocortical Ictal Pattern


Transitional Sharp Waves at Ictal Onset--A Neocortical Ictal Pattern

Nabil J Azar et al. Clin Neurophysiol. .


Objective: Some seizures are characterized by a transitional sharp wave (TShW) at ictal onset. We evaluated the clinical significance and localizing value of TShW in partial-onset seizures.

Methods: We identified and analyzed all scalp ictal recordings with a TShW at ictal onset in the Vanderbilt Epilepsy Monitoring Unit over a period of 12 months.

Results: A total of 52 ictal discharges in 13 patients started with a TShW. The center of TShW field was concordant with the final localization/lateralization, while that of the subsequent ictal discharge was concordant in only 6 patients. The subsequent rhythmic ictal discharge was non-localizing in 4 patients and misleading in the remaining 3 patients. The final localization was neocortical temporal or frontal in 11 patients, occipito-parietal in one, and undetermined in 1 patient. None of 61 ictal discharges in 15 patients with mesial temporal lobe epilepsy studied in the same time period started with a TShW.

Conclusion: In this patient series, the TShW was a marker of neocortical seizure onset. The TShW field provided more accurate localization or lateralization of the ictal focus than the following rhythmic ictal discharge.

Significance: TShW at seizure onset should suggest a neocortical rather than hippocampal seizure onset.

Similar articles

See all similar articles

Cited by 4 articles

  • Seizure localization using three-dimensional surface projections of intracranial EEG power.
    Lee HW, Youngblood MW, Farooque P, Han X, Jhun S, Chen WC, Goncharova I, Vives K, Spencer DD, Zaveri H, Hirsch LJ, Blumenfeld H. Lee HW, et al. Neuroimage. 2013 Dec;83:616-26. doi: 10.1016/j.neuroimage.2013.07.010. Epub 2013 Jul 11. Neuroimage. 2013. PMID: 23850575 Free PMC article.
  • Temporal lobe epilepsy in children.
    Nickels KC, Wong-Kisiel LC, Moseley BD, Wirrell EC. Nickels KC, et al. Epilepsy Res Treat. 2012;2012:849540. doi: 10.1155/2012/849540. Epub 2011 Oct 20. Epilepsy Res Treat. 2012. PMID: 22957247 Free PMC article.
  • Neocortical temporal lobe epilepsy.
    Bercovici E, Kumar BS, Mirsattari SM. Bercovici E, et al. Epilepsy Res Treat. 2012;2012:103160. doi: 10.1155/2012/103160. Epub 2012 Jul 16. Epilepsy Res Treat. 2012. PMID: 22953057 Free PMC article.
  • Differentiating parasomnias from nocturnal seizures.
    Boursoulian LJ, Schenck CH, Mahowald MW, Lagrange AH. Boursoulian LJ, et al. J Clin Sleep Med. 2012 Feb 15;8(1):108-12. doi: 10.5664/jcsm.1676. J Clin Sleep Med. 2012. PMID: 22334817 Free PMC article. No abstract available.

LinkOut - more resources