Main Article Content


Background: Paroxysmal fast activity (PFA) is defined by fast paroxysmal events in the electroencephalogram (EEG), usually associated with Lennox-Gastaut syndrome (LGS). Our aims were to verify the frequency of LGS and non-LGS in EEGs with PFA; and to correlate the EEG features (spatial distribution, frequency, amplitude and duration) between the two clinical groups.

Methods: We analyzed 38 EEG tracings with PFA from 38 patients. We evaluated the spatial distribution, frequency, amplitude and duration of fast paroxysms. The two clinical groups (LGS and non-LGS) were statistically compared relative to the EEG data.

Results: With regard to epileptic syndromes, 23 patients (60%) were classified as LGS and 15 patients (40%) as non-LGS. Concerning spatial distribution, our results showed that 86.8% of the examinations showed symmetrical PFA and 13.2% showed asymmetrical PFA. The statistical analysis did not show any difference between the two groups regarding the EEG spatial distribution or other EEG data.

Conclusions: PFA can occur in other epileptic syndromes apart from LGS. The EEG features did not offer any distinction between the two clinical groups. The PFA is not a specific EEG marker of LGS.



Lennox-Gastaut syndrome EEG paroxysmal fast activity

Article Details

Author Biography

Marilisa M Guerreiro, State University of Campinas (Unicamp)

Head, Department of Neurology

Chair, Child Neurology Unit

How to Cite
Bento, C. M., Coan, A. C., & Guerreiro, M. M. (2019). Paroxysmal fast activity: Does this EEG pattern occur only in Lennox-Gastaut syndrome?. Journal of the International Child Neurology Association, 1(1).


  1. Bourgeois BFD, Douglass LM, Sankar R: Lennox-Gastaut syndrome: A consensus approach to differential diagnosis. Epilepsia. 2014, 55: 4-9.
  2. Mohammadi M, Okanishi T, Okanari K, Baba S, Sumiyoshi H, Sakuma S, Ochi A, Widjaja E, Go CY, Snead OC 3rd, Otusbo H: Asymmetrical generalized paroxysmal fast activities in children with intractable localization-related epilepsy. Brain & Development. 2015, 37: 59–65.
  3. Wu JY, Koh S, Sankar R, Mathern GW. Paroxysmal fast activity: An interictal scalp EEG marker of epileptogenesis in children. Epilepsy Research. 2008, 82: 99-106.
  4. Crespel A, Gélisse P, Nikanorova M, Ferlazzo E, Genton P: Lennox-Gastaut syndrome. In Epileptic Syndromes in Infancy, Childhood and Adolescence. 5th edition. Edited by Bureau M, Genton P, Dravet C, Delgado-Escueta AV, Tassinari CA, Thomas P, Wolf P. John Libbey Eurotext; Paris, 2012: 189-216.
  5. Arzimanoglou A, French J, Blume WT, Cross JH, Ernst JP, Feucht M, Genton P, Guerrini R, Kluger G, Pellock JM, Perucca E, Wheless JW: Lennox-Gastaut syndrome: a consensus approach on diagnosis, assessment, management, and trial methodology. Lancet Neurol. 2009, 8: 82-93.
  6. Halasz P, Janszky J, Barcs G. Generalised paroxysmal fast activity (GPFA) is not always a sign of malignant epileptic encephalopathy. Seizure. 2004, 13: 270-276.
  7. Fisher RS, Cross JH, French JA, Higurashi N, Hirsch E, Jansen FE, Lagae L, Moshé SL, Peltrola J, Perez ER, Scheffer IE, Zuberi SM: Operational classification of seizure types by the International League Against Epilepsy: Position Paper of the ILAE Commission for Classification and Terminology. Epilepsia. 2017,58:522-530.
  8. Pillay N, Archer JS, Badawy RAB, Flanagan DF, Berkovic SF, Jackson G: Networks underlying paroxysmal fast activity and slow spike and wave in Lennox-Gastaut syndrome. Neurology. 2013, 81: 665-673.
  9. Piña-Garza JE, Chung S, Montouris GD, Radtke RA, Resnick T, Wechsler RT: Challenges in identifying Lennox-Gastaut syndrome in adults: A case series illustrating its changing nature. Elsevier. 2016, 5: 38-43.
  10. Berg AT, Berkovic SF, Brodie MJ, Buchhalter J, Cross JH, van Emde Boas W, Engel J, French J, Glauser TA, Mathern GW, Moshé SL, Nordli D, Plouin P, Scheffer IE: Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology. Epilepsia. 2009, 51:676–685.
  11. Berg AT and Scheffer I: New concepts in classification of the epilepsies: Entering the 21st century. Epilepsia. 2011, 52:1058-1062.
  12. Engel JJ: A Proposed Diagnostic Scheme for People with Epileptic Seizures and with Epilepsy: Report of the ILAE Task Force on Classification and Terminology. Epilepsia. 2001, 42:796-803.
  13. Engel JJ: Report of the ILAE Classification Core Group. Epilepsia. 2006, 47: 1558-1568.
  14. Conover WJ: Practical Nonparametric Statistics. 3ª ed. John Wiley & Sons Inc; New York, 1999.
  15. Fleiss JL: Statistical Methods for Rates and Proportions. 2nd ed. John Wiley & Sons Inc; New York, 1981.
  16. Ferlazzo E, Nikaronova M, Italiano D, Bureau M, Dravet C, Calarese T, Viallat D, Kolmel M, Bramanti P, De Santi L, Genton P: Lennox-Gastaut syndrome in adulthood: Clinical and EEG features. Epilepsy Research. 2010, 89: 271-277.
  17. Sueda K, Takeuchi F, Shiraishi H, Nakane S, Sakurai K, Yagyu K, Asahina N, Kohsaka S, Saitoh S: Magnetoencephalographic analysis of paroxysmal fast activity in patients with epileptic spasms. Epilepsy Res. 2013, 104: 68–77.
  18. Archer JS, Warren AEL, Stagnitti MR, Masterton RA, Abbott DF, Jackson GD: Lennox-Gastaut syndrome and phenotype: Secondary network epilepsies. Epilepsia. 2014, 55: 1245-1254.