Abstracts

Rationale: Epilepsy is a neurological disease characterized by multiple spontaneous seizures. The epileptogenic process can be triggered after the first spontaneous seizure, with observable structural and physiological changes that enable the brain to deflagrate more spontaneous seizure. It is believed that the occurrence of frequent seizures can accelerate this process. Amongst therapeutic options for patients with diagnosed epilepsy, anterior nucleus of thalamus (ANT) deep-brain stimulation (DBS) presents itself as one of the most promising alternatives; however, whether DBS can mitigate or slow down the epileptogenic process in patients who have had seizures but are not yet diagnosed with epilepsy is still unknown. The purpose of our study is to analyse the effects of the ANT DBS therapy in rats with induced epilepsy through the penthylenetetrazole (PTZ) kindling protocol.

Methods: Fifty-three adult rats, divided into three groups: Control (n = 17), SHAM (n = 18) and DBS (n = 18) received, in total, 18 PTZ applications (30 mg/kg, ip) given every other day. Animals in the DBS group underwent electrode placement surgery one week before PTZ injections and were stimulated 2-2.5 h/day, 5 days a week, during 6 weeks. ANT-DBS started 2h previously to PTZ injections and were continued during the observation time. Sham animals underwent electrode placement surgery, but were not stimulated. Seizures were observed for 30 minutes after PTZ injection and categorized through the Racine scale (stages 0-5). A single PTZ injection challenge was used one week after the end of 18 PTZ injections to evaluate possible long-term effects of ANT-DBS. Age-matched naïve rats (n=8) received saline injections. Seizure scores (SS) are expressed as mean + SE, significance level was set as P< 0.05.