The effectiveness of vagus nerve stimulation seems similar in drug-resistant epilepsy patients with or without Lennox-Gastaut syndrome (LGS), according to a new study published in the journal Brain and Behavior. The study also found that patients with LGS may be more prone to fluctuating control of bilateral tonic–clonic seizures.
“We have performed what is to our knowledge the largest and most in-depth analysis of the effectiveness of [vagus nerve stimulation] in LGS patients paying special attention to the impact of [the treatment] on individual seizure types,” the researchers wrote.
Read more about the treatment of LGS
They analyzed 564 patients with LGS and 128 patients without LGS with drug-resistant epilepsy. They assessed overall seizure frequencies before implantation and at 3-month, 6-month, 12-month, 18-month, and 24-month follow-ups.
The results showed that the median reduction in the frequency of all seizures at 24 months was 64.3% in patients with LGS and 66.7% in patients without LGS.
In terms of seizure types, vagus nerve stimulation was most effective at reducing “other” seizures, focal aware seizures, generalized-onset nonmotor seizures, and drop attacks in both groups of patients. The relative reduction rates for these seizure types at 24 months exceeded 90%.
There was no significant difference in the time-to-first response between patients with LGS and patients without LGS. However, a significantly higher proportion of patients with LGS (22.4% ) regressed from bilateral tonic–clonic seizure response compared to patients without LGS (6.7%) at 24 months.
The authors concluded that vagus nerve stimulation is safe and effective in patients with drug-resistant epilepsy with or without LGS.
LGS is a rare but severe type of childhood epilepsy characterized by compounded variable seizure types and intellectual disability, and that is challenging to treat.
VNS therapy involves sending intermittent electrical signals to the left cervical vagus nerve using an implanted device. It is approved for the treatment of patients with drug-resistant epilepsy.
Dibué M, Greco T, Spoor JKH, et al. Does response to vagus nerve stimulation for drug-resistant epilepsy differ in patients with and without Lennox-Gastaut syndrome? Brain Behav. Published online June 29, 2023. doi:10.1002/brb3.3025