Abstracts

Rationale: Vagus nerve stimulation system (VNS) consists of a neuroestimulation device employed worldwide for the treatment of drug-resistant epilepsy non amenable to resective surgery. Initially approved by FDA in 1997 as a palliative treatment for focal epilepsies in adult populations, its spectrum of use has been extended to generalized epilepsies and includes children and elderly people as good candidates for implantation. As experience increased, more patients have benefited from it and growing experience of particular cases has been shown. Pregnancy constituted a contraindication for the enrollment of women in VNS controlled studies and patients were asked to use birth control methods. There have been no clinical studies later regarding efficacy and adverse events among pregnant patients with VNS. Eight cases of pregnancies receiving VNS therapy for epilepsy were reported (6 from pregnancies during clinical studies and two others during clinical practice with unremarkable and healthy deliveries including one set of twins) and one more in a woman with resistant depression. Five outcomes were positive and three negative (two elective abortive procedures, one based on abnormal fetal development attributed to AEDs, and a possible spontaneous abortion) for the epilepsy group and a positive outcome for the depression case. Thus clinical data is lacking but there is no specific contraindication for the use of VNS during pregnancy.Methods: We describe demographic and clinical data of three female patients with focal refractory epilepsy followed in epilepsy clinics of two tertiary hospitals and reference centers for epilepsy in Spain treated with VNS during pregnancy and delivery (Hospital Clínico Universitario of Santiago de Compostela for patients 1 and 2 and Hospital Clinic in Barcelona for patient 3). The three patients underwent presurgical evaluation and finally a VNS was implanted.Results: For clinical data see table 1 and 2. Two pregnancies were unexpected (patients 1, 3). Patient 2 has planned pregnancy after explanation of risks due to polytherapy and unknown effects of VNS. She had one first pregnancy with results of spontaneous abortion. No complications during pregnancy or delivery were directly attibuted to VNS. Two were cesarean births (patient 1 due to premature rupture membranes; patient 2 due to fetal instability) and one was vaginal. Patient 3 suffered uterine atony treated with oxitocine and massage with good response. One child needed critical care due to a Rh incompatibility with good outcome (patient 2). Patient 1 suffered a CPS during delivery and patient 3 during immediately after delivery. No VNS were turned off during pregnancy or delivery.Conclusions: None of the complications reported can be directly attributed to VNS in otherwise difficult-to treat epileptic patients. In our experience, VNS constitutes a safe therapy for the treatment of refractory epilepsies in pregnant women. More experience is required thus communication of preliminary clinical data is of high interest.