Abstracts

rTMS is a noninvasive method for cortical stimulation that is emerging as a new therapeutic tool in epilepsy. The technique is based on the principle of electromagnetic induction where small intracranial electrical currents are induced by a strong rapidly-changing extracranial magnetic field. Limited human trials and animal experiments in our laboratory show acute suppression and reduction in frequency of partial seizures with EEG-guided single pulse and 0.5 Hz rTMS. However, the capacity of rTMS to suppress generalized (absence) seizures has not been thoroughly examined. Accordingly, we sought to determine whether whether 0.5 Hz rTMS can suppress frequent PTZ-induced generalized seizures in a rat absence epilepsy model., Generalized (absence) seizures were triggered in adult male Long Evans rats (n=10) with PTZ (50 mg/kg, i.p.). Immediately after PTZ injection, and thereafter at 30-minute intervals, one group (n=4) was treated with 0.5 Hz repetitive TMS for 10 minutes (300 stimuli). A second group (n=6) remained as untreated controls. Continuous EEG was recorded with subdermal wires electrodes for 120 minutes after PTZ injection, and then analyzed for seizure frequency during periods between TMS sessions., (1) Frequent brief absence seizures accompanied by generalized spike-wave discharges on surface EEG were triggered by PTZ injection in all rats. (2) 3/6 untreated rats died within the monitoring period [ndash] 0/4 rats died in the 0.5 Hz rTMS group. (3) Average cumulative seizure frequency was lower in the treated group after 60 min (t=2.65; p[lt]0.033), 90 min (t=2.98; p[lt]0.021) and 120 min (t=2.85; p[lt]0.030) of monitoring., 0.5 Hz rTMS is effective in suppression of generalized seizures in the PTZ absence epilepsy rat model. Or finding may be a step toward eventual treatment of generalized epilepsy with low frequency rTMS., (Supported by Citizens United for Research in Epilepsy (CURE).)