Effect of hyperventilation on seizure activation: potentiation by antiepileptic drug tapering.
OBJECTIVE
To determine prospectively the efficacy of hyperventilation (HV) to activate epileptic seizures and the contribution of antiepileptic drug tapering.


METHODS
Eighty patients with proven epilepsy and referred for long-term video-EEG monitoring were consecutively enrolled from November 2007 to December 2008. A seizure was considered as 'activated' if it occurred during HV or within 5 min after completion. The rate of activated seizures (number of seizures/h) was compared with the rate of spontaneous seizure. The authors finally compared the effect of HV before and during antiepileptic drug (AED) tapering.


RESULTS
The authors analysed 247 days of monitoring. Among 52 recorded seizures, 18 were activated by HV. The rate of activated seizure was nine times higher than the rate of control seizures (p=0.001). In the subgroup of patients with no AED tapering, there was no significant activating effect of HV on seizures. In the subgroup undergoing AED tapering, the effect of HV was not significant before (p=0.257) but very significant during AED tapering (p<0.004).


CONCLUSIONS
The findings confirm that hyperventilation is efficient to activate epileptic seizures in epileptic patients referred for long-term video-EEG monitoring and that this activating effect is mainly related to the potentiating effect of AED tapering. Repeated HVs combined with AED tapering increase the rate of recorded seizures and the diagnostic yield of daytime video-EEG monitoring.
Jonas
Jacques
J
Service de Neurologie, Centre Hospitalier Universitaire de Nancy, 29 avenue du Maréchal de Lattre de Tassigny, Nancy 54035, France.
Vignal
Jean-Pierre
JP
Baumann
Cédric
C
Anxionnat
Jean-François
JF
Muresan
Mirela
M
Vespignani
Hervé
H
Maillard
Louis
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004827:Epilepsy / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012640:Seizures / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology*; D013997:Time Factors; D014741:Video Recording; D055815:Young Adult
D000927:Anticonvulsants