Abstracts

Immediate ([lt]24 hours) postoperative seizures occur in approximately 10% of the patients submitted to epilepsy surgery. These seizures are more often distinct from the patient[acute]s habitual seizure[acute]s type and bear no correlation to the long-term seizure[acute]s outcome. This paper reports on a specific subpopulation of patients that are highly prone to present immediate postoperative seizures. Eleven consecutive adult patients who were receiving lamotrigine (minimal dose=150mg/day ; mean=200mg / day) and who had been submitted to cortical resections were studied. Seven patients have been submitted to cortico-amygdalo-hippocampectomy (CAH) and 4 to extra-temporal resections. Concomitant medication included carbamazepine (n=8; mean dose=1400mg/day), oxcarbazepine (n=3; mean dose=2400mg/day), valproate (n=4; mean dose=2000mg/day), fenobarbital (n=10; mean dose=100mg/day) and clobazam (n=7; mean dose=20mg/day). All were submitted to standard CAH under the same anesthetic procedure as the other patients in the temporal lobe surgery series, which basically consisted of propofol and forane (with or without precedex). All patients received IV phenytoin preoperatively (15mg/kg bolus). All patients left the operating room awake and without deficits. Nine patients presented tonic-clonic generalized seizures during the first postoperative hours. In all, administration of lamotrigine through a nasogastric tube abolished the seizure[acute]s cluster. A high prevalence of early postoperative seizures was noted in patients using lamotrigine preoperatively (81% versus 10% in the general series). Lamotrigine should be administered very early intraoperatively or early postoperative in patients submitted to epilepsy surgery. Especial caution is advised in patients receiving lamotrigine and valproate concomitantly. (Supported by Sao Paulo[apos]s Secretary of Health)