Beyond response rates: Residual seizure burden and willingness to undergo vagus nerve stimulation again in drug-resistant epilepsy.

Objective

To assess whether postoperative residual seizure burden may provide patient-centered information beyond relative seizure improvement by examining willingness to undergo vagus nerve stimulation (VNS) again in drug-resistant epilepsy (DRE).

Methods

This single-center cross-sectional study included patients with DRE after VNS implantation. Baseline data were retrieved from an institutional database, and follow-up data were collected using a structured questionnaire. The primary outcome was willingness to undergo VNS again, treated as an exploratory decision-centered patient-reported measure and analyzed as yes versus no/uncertain. Subjective seizure improvement, quality-of-life (QoL) improvement, overall satisfaction, willingness to recommend VNS, and adverse effects were also assessed. Seizure burden before and after VNS was graded using broad frequency-based categories. Category improvement reflected relative improvement, whereas postoperative residual burden reflected the absolute burden remaining after treatment.

Results

Of 58 screened patients, 54 were included. Overall, 32/54 (59.3%) would undergo VNS again, 22/54 (40.7%) were satisfied, and 25/54 (46.3%) would recommend VNS. Subjective seizure improvement and QoL improvement were reported by 35/54 (64.8%) and 33/54 (61.1%) patients, respectively. Seizure burden category improved in 35/54 (64.8%), but 11/54 (20.4%) continued to have daily seizures after VNS. Patients willing to undergo VNS again were more likely than those unwilling or uncertain to report subjective seizure improvement (87.5% vs 31.8%, P < 0.001), QoL improvement (90.6% vs 18.2%, P < 0.001), and seizure burden category improvement (81.2% vs 40.9%, P = 0.004). They also had lower postoperative residual seizure burden (median category 1.0 [IQR 0.0-2.3] vs 3.0 [IQR 2.0-4.0], P < 0.001).

Conclusions

Willingness to undergo VNS again was associated with relative improvement and lower postoperative residual seizure burden. These findings suggest that residual seizure burden may provide complementary patient-centered information when interpreted alongside conventional response measures and established patient-reported outcomes.