Optimizing parameters for terminating cortical afterdischarges with pulse stimulation.
OBJECTIVE
We previously reported that brief pulses of electrical stimulation (BPSs) can terminate afterdischarges (ADs) during cortical stimulation. We investigated conditions under which BPS is more likely to suppress ADs.


METHODS
We analyzed parameters altering BPS effectiveness on 200 ADs in seven patients with implanted subdural electrodes.


RESULTS
The odds of BPSs stopping ADs was 8.6 times greater at primary sites (directly stimulated electrodes) than at secondary sites (adjacent electrodes) (p = 0.016). BPS applied within 4.5 s after onset of AD had 2 times greater odds of stopping ADs (p = 0.014). BPS applied when AD voltage was negative was 1.9 times more likely to stop ADs (p = 0.012). ADs with rhythmic pattern responded best (p < 0.0001). BPS stopped 100% of ADs not starting immediately after localization stimulus (LS) versus 29% of those starting immediately (p < 0.0001).


CONCLUSIONS
BPS is more likely to terminate ADs at primary electrodes, if given early, if applied to the negative peak of the AD waveform, if AD has a rhythmic pattern, and if AD did not start immediately after LS.
Department of Neurology, The Johns Hopkins University, Baltimore, Maryland, U.S.A.
Gholam K
GK
Motamedi
Ronald P
RP
Lesser
Diana L
DL
Miglioretti
Yuko
Y
Mizuno-Matsumoto
Barry
B
Gordon
William R S
WR
Webber
Darryl C
DC
Jackson
Jehuda P
JP
Sepkuty
Nathan E
NE
Crone
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004599:Electric Stimulation Therapy / Q000379:methods; D004828:Epilepsies, Partial / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011930:Reaction Time; D016896:Treatment Outcome
D000927:Anticonvulsants