Electrocerebral recovery during the intracarotid amobarbital procedure: influence of interval between injections.
OBJECTIVE
During the intracarotid amobarbital procedure (IAP) at the University of Michigan, continuous scalp EEG monitoring guides the timing for presentation of memory items and postinjection testing. Most of our patients have undergone bilateral injections. The interval between injections varied from 22 to 60 min, depending on the test and recovery time, as well as the time to catheterize the second side. After noting a trend toward prolonged electrographic recovery following the second injection, we tested our clinical impression that recovery of the second hemisphere may be influenced by (a) the time between injections and (b) which hemisphere is injected first (epileptogenic or nonepileptogenic). To study these questions, we analyzed EEG recovery data from 48 consecutive IAPs. Approximately half the patients had the epileptogenic side injected first.


RESULTS
We found that (a) electrographic recovery after the second injection is prolonged if the interval between bilateral injections is less than 40 minutes and (b) electrographic recovery is more rapid after injection of the epileptogenic hemisphere.


CONCLUSIONS
We now recommend waiting at least 45 min between injections. The pathophysiology of more prolonged amobarbital effect on the nonepileptogenic hemisphere than on the epileptogenic hemisphere remains unclear.
Selwa
L M
LM
Department of Neurology, University of Michigan, Ann Arbor 48109, USA.
Buchtel
H A
HA
Henry
T R
TR
D000654:Amobarbital / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology / Q000601:surgery; D002339:Carotid Arteries; D003700:Delta Rhythm / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D013702:Temporal Lobe / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery; D013997:Time Factors
D000654:Amobarbital