Efficiency and Safety of Vagus Nerve Stimulation in Intractable Epilepsy: An Updated Systematic Review and Meta-analysis
Hadeer Elsaeed AboElfarh1, Mariam Abdelhady2, Mohamed Shehata3, Ibraheem Alkhawaldeh4, Maickel Kamal 5, Mohamed Hany Ezz6
1Neurology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt, 2Faculty of Medicine, October 6 University, Giza, Egypt, 3Neurology Department, Nasr City Insurance Hospital, Cairo, Egypt, 4Faculty of Medicine, Mutah University, Al-Karak, Jordan, 5Faculty of Medicine, Cairo University, Cairo, Egypt, 6Faculty of Medicine, Tanta University, Tanta, Egypt
Objective:
To evaluate the current evidence regarding the Efficiency and safety of Vagus Nerve Stimulation (VNS) in the management of intractable epilepsy.
Background:
Epilepsy and seizures affect around 1% of the population. They are treated primarily with antiepileptic drugs (AEDs). Yet, around one-third of patients with seizures are unresponsive to medical treatment which indicates a need for effective alternatives such as Vagus Nerve Stimulation (VNS).
Design/Methods:
We conducted a comprehensive search of electronic databases including PubMed, Ovid Medline, SCOPUS, Web of Science, and the Cochrane Controlled Register of Trials (CENTRAL) for studies published from inception to August 2023. Only randomized controlled trials (RCTs) of class 1 evidence were included. Data on seizure frequency, treatment response, and adverse events were extracted. We performed meta-analyses using fixed-effect models to estimate the pooled outcomes.
Results:
Our search yielded a total of 8 studies, encompassing 724 patients. Meta-analysis demonstrated that high-frequency VNS significantly reduced seizure frequency (mean difference = -13.23, 95% CI = -20.15, -6.30, p = .0002) and improved treatment response (risk ratio = 1.95, 95% CI = 1.40, 2.73, p <.0001) compared to low-frequency VNS. This significance persisted for the subgroup analyses of the VNS modality of both outcomes and after removing studies contributing to significant heterogeneity. Adverse events were reported in 8 studies, with no increase in major side effects or mortality in the high-frequency VNS group compared to low-frequency VNS group. The most common complications were hoarseness, throat pain, and coughing, but these were generally transient and tolerable.
Conclusions:
This updated meta-analysis reaffirms that VNS, particularly high-frequency VNS, is an effective and safe treatment modality for intractable epilepsy, contributing to significant reductions in seizure frequency and enhanced treatment responses advocating for its broader consideration in the management of drug-resistant epilepsy. Further research is warranted to explore mechanisms optimizing VNS parameters for individual patients