Abstracts

Rationale: Deep Brain Stimulation(DBS) is an alternative treatment to treat patients with severe pharmacoresistant epilepsy. However, there is no randomized control study assessing the effect of ANT-DBS in patients who have failed medical treatment and vagus nerve stimulation (VNS). We aimed to compare the efficacy of ANT-DBS in pharmacoresistant epileptic patients who have failed VNS, to the efficacy of best medical therapy.

Methods: We conducted a randomized controlled trial in 12 French expert centers for epilepsy. We recruited patients who failed medical and VNS treatment and who experienced at least 4 severe seizures (according to the Chalfont Scale) per month for 3 months during the screening period.

Enrolled patients were randomized in either a neurostimulation group (DBS group) or a best medical therapy group (BMT group). VNS therapy was maintained ON in patients in whom it was not stopped at the inclusion. Patients assigned into the DBS group were stimulated bilaterally using different type of stimulation during 12 months.

The primary endpoint was the difference in the mean number of severe seizures that occurred during 3 months before the randomization and that occurred during the last 3 months at 1-year follow up, as assessed by a Khi-deux test. We also assessed the side effects occurring in all patients, focusing on mood disorders possibly induced by DBS. The trial is registered with clinicalTrials.gov NCT02076698.

Results: We enrolled 67 patients and 61 were randomized, 30 in the neurostimulation group (DBS group) and 31 in the best medical therapy group (BMT group). For the DBS group, 29 received bilateral implantation of the ANT using the 3389 lead from Medtronic. 59 patients completed the final assessment at 12 months.

In the DBS group, 37,93% of patients achieved 50% of reduction of all seizures versus 16.67% in the BMT group (p= 0.066), and 51.72% of patients achieved 40% of severe seizure reduction, compared to 30% in the BMT group (p= 0.08). The Beck depression inventory scored was improved in 88.46% of the patients in the DBS group, versus 55.56% in the BMT group (p=0.014). 2 patients died due to SUDEP, one in each group, before having received DBS.

Conclusions: The result of this randomized study shows that ANT-DBS tend to have an effect on the number of severe seizures and on the total number of seizures in a population of patients suffering from severe epilepsy and who failed medications and VNS, compared to a control group who received the best medical treatment including VNS. DBS was also safe and there was a significant higher number of patients who improved their mood on the Beck depression inventory scale on the DBS group. However, caution must be taken when interpreting those data due to the possible lack of power of the study, with a unexpected high rate of responders in the BMT group.

Funding: Please list any funding that was received in support of this abstract.: This work was supported by the Direction Générale de l Offre de Soins , ministère de la santé, France.