Electrographic Features of Lateralized Periodic Discharges Stratify Risk in the Interictal-Ictal Continuum.
OBJECTIVE
To risk-stratify electrographic features of lateralized periodic discharges (LPDs) in acute structural brain lesions for predictors of electrographic seizures.


METHODS
This is a retrospective review of 100 consecutive patients with LPDs. Epileptiform features of LPDs were described based on electrographic features: blunt delta morphology, sharply contoured, overlying fast frequencies, and/or rhythmicity (loss of interdischarge interval lasting ≥1 second). EEG seizures were defined as evolving in frequency, distribution, or morphology at ≥2 Hz for ≥10 seconds.


RESULTS
Overall, electrographic seizures occurred in 55% of patients with LPDs. Lateralized periodic discharges with rhythmicity (odds ratio 13.91) were most significant for predicting status epilepticus and/or seizures. This was followed by LPDs with overlying faster frequencies (odds ratio 5.16) and then sharply contoured morphology (odds ratio 4.09). Blunt delta morphology (0.24) had the lowest risk for seizures.


CONCLUSIONS
Electrographic features of LPDs may help determine seizure risk in patients with acute structural lesions. Sharply contoured morphology, overlying fast frequencies, or rhythmicity, showed progressively higher risk of seizures on continuous electroencephalography, whereas blunt delta morphology had the lowest risk of seizures.
*Department of Neurology, University of Missouri, Columbia, Missouri, U.S.A.; †Cleveland Clinic, Epilepsy Center, Neurological Institute, Cleveland, Ohio, U.S.A.; and ‡Cleveland Clinic, Cerebrovascular Center, Neurological Institute, Cleveland, Ohio, U.S.A.
Christopher R
CR
Newey
Pradeep
P
Sahota
Stephen
S
Hantus
D000368:Aged; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D012189:Retrospective Studies; D013226:Status Epilepticus / Q000175:diagnosis* / Q000503:physiopathology*