Neurological Sciences

, Volume 35, Issue 5, pp 707–713 | Cite as

Positive sharp waves in the EEG of children and adults

  • A. Bruce Janati
  • Muhammad Umair
  • Naif Saad AlghasabEmail author
  • Kareemah Salem Al-Shurtan
Original Article


Interictal epileptiform discharges (IEDs) with negative polarity have been extensively studied in the EEG literature. However, little attention has been drawn to IED with positive polarity [positive sharp waves (PSWs)]. In this paper, we discuss pathophysiological, neuroimaging, and clinical correlates of this pattern in a heterogeneous group of children and adults who demonstrated PSW in their scalp EEG. We prospectively reviewed the EEGs of 1,250 patients from a heterogeneous population over a period of 1 year. Thirty-one patients had PSW in their EEG. We documented EEG parameters as well as demographic, clinical, and neuroimaging data. Statistical analysis was performed to correlate the aforementioned data. The analysis showed that PSW is an epileptogenic pattern with localizing significance, occurring primarily in the younger age groups. Furthermore, there was a strong association of PSW with chronic and/or static CNS pathology, in particular, congenital CNS anomalies, often accompanied by psychomotor retardation. Patients with “multifocal’’ PSW invariably exhibited severe intellectual and motor deficits associated consistently with a variety of congenital CNS insults. PSW is a rare and under-reported EEG abnormality which, similar to negative IED, signifies focal epileptogenecity. The presence of PSW should prompt neuroimaging studies to investigate an associated chronic/static CNS pathology, in particular, congenital CNS anomalies. This association is particularly strong when PSW is multifocal in which case patients present with severe intellectual and motor deficits.


Positive sharp waves (PSWs) Epilepsy EEG Epileptogenecity 



Acknowledgment for the assistance of Jeffrey F. Ricablanca, Mary Grace Lorente, Abdulmohsen S. Alghassab.


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Copyright information

© Springer-Verlag Italia 2013

Authors and Affiliations

  • A. Bruce Janati
    • 1
  • Muhammad Umair
    • 2
  • Naif Saad Alghasab
    • 3
    Email author
  • Kareemah Salem Al-Shurtan
    • 3
  1. 1.Center for Neurology in FairfaxFairfaxUSA
  2. 2.Dow Medical College, KKHHailKingdom of Saudi Arabia
  3. 3.Hail University, Hail, King Faisal Specialist HospitalRiyadhKingdom of Saudi Arabia

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