Vagus nerve stimulation for refractory status epilepticus: A systematic review

Area of Science:

• Neurology
• Neurosurgery
• Epileptology

Background:

• Refractory status epilepticus (RSE) presents significant morbidity and mortality.
• Limited evidence exists for standardized RSE treatments, and the role of vagus nerve stimulation (VNS) is unclear.

Purpose of the Study:

• To systematically review and synthesize current evidence on VNS therapy for RSE.
• To evaluate the efficacy and functional outcomes of VNS in patients with RSE.

Main Methods:

• Systematic review of VNS outcome studies for acute-to-subacute RSE (≤ 90 days).
• Primary endpoint: RSE cessation. Secondary endpoints: seizure freedom (ILAE Class 1) and functional outcome (modified Rankin Scale [mRS]).
• Included 23 articles with 61 patients, predominantly pediatric (79%) and diagnosed with super-refractory status epilepticus (SRSE) (100%) or new-onset refractory status epilepticus (NORSE) (69%).

Main Results:

• VNS demonstrated a high RSE cessation rate of 90% (55/61) with a median implantation-to-cessation of 12.7 days.
• Among responders with ≥ 12 months follow-up, 38% achieved seizure freedom.
• Significant functional disability was observed, with 61% having unfavorable outcomes (mRS ≥ 4) and 31% mortality.

Conclusions:

• VNS implantation is a potential treatment for acute-to-subacute SRSE unresponsive to medical therapy.
• Substantial functional disability and uncertain long-term seizure freedom necessitate cautious interpretation.
• Further validation in large prospective studies is required due to potential publication bias and exploratory analyses.