Hostname: page-component-7479d7b7d-jwnkl Total loading time: 0 Render date: 2024-07-12T07:43:10.309Z Has data issue: false hasContentIssue false
  • English
  • Français

Cortical Location of Benign Paroxysmal Rhythms in the Electrocorticogram

Published online by Cambridge University Press:  14 September 2018

Richard S. McLachlan  and
Neda Lubus
Richard S. McLachlan*
Affiliation:
Department of Clinical Neurological Sciences, London Health Sciences Centre, London, ON Canada
Neda Lubus
Affiliation:
Department of Clinical Neurological Sciences, London Health Sciences Centre, London, ON Canada
*
Richard S. McLachlan, Shaikh Khalifa Medical Center, P. O. Box 51900, Abu Dhabi, United Arab Emirates
Rights & Permissions [Opens in a new window]

Abstract:

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.
Background:

Six/second spike waves, 14 and 6/second positive spikes and small sharp spikes are apiculate paroxysmal rhythms in the electroencephalogram, thought to be of no diagnostic importance. The cortical origin of these discharges is documented in this report.

Methods:

These waveforms were assessed in recordings from the surface of the cerebral cortex using implanted subdural electrodes in 61 patients monitored for possible epilepsy surgery.

Results:

Eight patients had 6/second spike wave, four had 14 and 6/second positive spikes and 3 had small sharp spikes. The 6/second spike waves were localised to the posterior cingulate gyrus, a more restricted region than would be predicted from scalp recordings and the 14 and 6/second spikes to the posterior mesial temporal cortex. Small sharp spikes were more widely distributed but also predominated in the posterior mesial temporal area. None of the discharges were congruent with the focus of seizure origin and no interaction with other interictal spikes was found.

Conclusions:

These benign paroxysmal rhythms can appear incidentally in the electrocorticograms of patients with focal epilepsy and should not be confused with focal pathological spike activity or considered to be of any value in localizing the seizure focus.

Résumé:

Résumé:Introduction:

Les pointe-ondes à 6 cycles/secondes, les pointes positives à 14 et 6 cycles/seconde et les pointes brèves sont des rythmes paroxystiques apiculés auxquels on n’attribue pas d’importance diagnostique à l’électroencéphalogramme. L’origine corticale de ces décharges est documentée dans cet article.

Méthodes:

Ces ondes ont été évaluées lors d’enregistrements faits à la surface du cortex cérébral au moyen d’électrodes sous-durales implantées chez 61 patients sous observation en vue d’une chirurgie de l’épilepsie.

Résultats:

Huit patients avaient des pointe-ondes à 6 cycles/seconde, 4 avaient des pointes positives à 14 et 6 cycles/seconde et 3 avaient des pointes brèves. Les pointeondes à 6 cycles/seconde ont été localisées à la circonvolution postérieure du corps calleux, une région plus restreinte que celle prédite à partir des enregistrements de surface, et les pointes à 14 et 6 cycles/seconde au cortex temporal mésial postérieur. Aucune des décharges n’était congruente avec le foyer d’origine de la crise et aucune interaction avec d’autres pointes interictales n’a été observée.

Conclusions:

Ces rythmes paroxystiques bénins peuvent apparaître accessoirement à l’électrocorticogramme de patients présentant une épilepsie focale et ne devraient pas être confondus avec une activité de pointes pathologiques focales ou considérés comme un élément de localisation valable d’un foyer épileptique.

Type
Original Article
Information
Canadian Journal of Neurological Sciences , Volume 29 , Issue 2 , May 2002 , pp. 154 - 158
Copyright
Copyright © Canadian Neurological Sciences Federation 2002

References

1. Reiher, J, Klass, DW. Two common EEG patterns of doubtful clinical significance. Med Clin North America 1968; 52: 933-940.CrossRefGoogle Scholar
2. Thomas, JE, Klass, DW. Six-per-second spike-and-wake pattern in the electroencephalogram: a reappraisal of its clinical significance. Neurology 1968; 18: 587-593.CrossRefGoogle Scholar
3. Dubeau, F, McLachlan, RS. Invasive electrographic recording techniques in temporal lobe epilepsy. Can J Neurol Sci 2000; 27: S29-S34.CrossRefGoogle Scholar
4. Hughes, JR. Two forms of the 6/sec spike and wave complex. Electroencephalogr Clin Neurophysiol 1980; 48: 535-550.CrossRefGoogle Scholar
5. Westmoreland, BF, Reiher, J, Klass, DW. Recording small sharp spikes with depth electroencephalography. Epilepsia 1979; 20: 599-606.CrossRefGoogle Scholar
6. Radhakrishnan, K, Santoshkumar, B, Venugopal, A. Prevalence of benign epileptiform variants observed in an EEG laboratory from South India. Clin Neurophysiol 1999; 110: 280-285.CrossRefGoogle Scholar
7. Drury, I. 14-and-6 Hz positive bursts in childhood encephalopathies. Electroencephalogr Clin Neurophysiol 1989; 72: 479-485.CrossRefGoogle Scholar
8. Silverman, D. Phantom spike-waves and the fourteen and six per second positive spike pattern: a consideration of their relationship. Electroencephalogr Clin Neurophysiol 1967; 23: 207-213.CrossRefGoogle Scholar
9. Buzsaki, G, Leung, LS, Vanderwolf, CH. Cellular bases of hippocampal EEG in the behaving rat. Brain Res Rev 1983; 6: 139-171.CrossRefGoogle Scholar
10. Bragin, A, Jando, G, Nadasdy, Z, van Landeghem, M, Buzsaki, G. Dentate EEG spikes and associated interneuronal population bursts in the hippocampal hilar region of the rat. J Neurophysiol 1995; 73: 1691-1705.CrossRefGoogle Scholar
11. Leung, L-WS, Borst, JGG. Electrical activity in the cingulate cortex of the rat. 1. Generating mechanisms and relations to behavior. Brain Res 1987; 407: 68–80.CrossRefGoogle Scholar
12. Hughes, JR, Gruener, G. Small sharp spikes revisited: further data on this controversial pattern. Clin Electroencephalogr 1984; 15: 208-213.CrossRefGoogle Scholar
13. Saito, F, Fukushima, Y, Kubota, S. Small sharp spikes: possible relationship to epilepsy. Clin Electroencephalogr 1987; 18:114-119.Google Scholar
14. Hughes, JR. A review of the usefulness of the standard of EEG in psychiatry. Clin Electroencephalogr 1996; 27: 35-39.CrossRefGoogle Scholar
15. Boutros, N, Fristad, M, Abdollohian, A. The fourteen and six positive spikes and attention-deficit hyperactivity disorder. Biol Psychiatry 1998; 44: 298-301.CrossRefGoogle Scholar
16. Inui, K, Motomura, E, Okushima, R, et al. Electroencephalographic findings in patients with DSM-IV mood disorder, schizophrenia, and other psychotic disorders. Biol Psychiatry 1998; 43: 69-75.CrossRefGoogle Scholar
17. White, JC, Langston, JW, Pedley, TA. Benign epileptiform transients of sleep. Clarification of the small sharp controversy. Neurology 1977; 27: 1061-1068.CrossRefGoogle Scholar
18. Reiher, J, Carmant, L. Clinical correlates and electroencephalographic characteristics of two additional patterns related to 14 and 6 per second positive spikes. Can J Neurol Sci 1991; 18: 488-491.CrossRefGoogle Scholar
19. Beun, AM, van Emde Boas, W, Dekker, E. Sharp transients in the sleep EEG of healthy adults: a possible pitfall in the diagnostic assessment of seizure disorders. Electroencephalogr Clin Neurophysiol 1998; 106: 44-51.CrossRefGoogle Scholar
20. Jabbari, B, Russo, MB, Russo, ML. Electroencephalogram of asymptomatic adult subjects. Clin Neurophysiol 2000; 111: 102-105.CrossRefGoogle Scholar