January 30, 2023

Vagal Nerve Stimulation May Benefit Patients With Medically Intractable Epilepsy 

Article published by AJMC

A new review suggests that vagal nerve stimulation (VNS) can offer palliative benefit for patients with epilepsy that is refractory to medical management and not amenable to resective surgery.

This review of randomized controlled trials (RCTs) and prospective nonrandomized studies was published in Journal of Central Nervous System Disease. The final review included 6 total trials.

The authors identified 3 adult trials and 1 pediatric trial in their comprehensive literature search. Across these 4 RCTs, high-frequency VNS stimulation—defined as frequency greater than 20 Hz—consistently achieved a greater seizure frequency reduction, ranging between 23.4% and 33.1%, compared with low-frequency VNS—defined as 1 Hz—which ranged between 0.6% and 15.2%.

The authors also identified 2 RCTs that looked at whether the parameters of VNS influenced seizure control. According to the results from these 2 trials, VNS achieved seizure control comparable to that reported by the first 4 RCTs, with a reduction in seizure frequency ranging between 22% and 43%, irrespective of the parameters utilized for VNS.

“While the reduction in seizure frequency did not reach significance in every RCT, the studies that reported insignificant differences were also those with fewer patients, suggesting that inadequate sample size contributed to the variation in the reported outcome,” the authors said.

Additionally, VNS-associated morbidities were found to be consistently higher in adults who underwent high-frequency VNS, while these differences were not observed in the pediatric population.