Efficacy and tolerability of vagus nerve stimulation therapy (VNS) in Slovenian epilepsy patients: younger age and shorter duration of epilepsy might result in better outcome

Kavčič A, Kajdič N, Rener-Primec Z, Krajnc N, Žgur T.
Acta Clin Croat. 2019 Jun; 58(2): 255–264.
https://doi.org/10.20471/acc.201.958.02.08

Continuing on the theme of vagus nerve stimulation (#VNS) and early implantation, this retrospective study by Kavčič et al. 2019 aimed to evaluate the efficacy of VNS Therapy on seizure burden and quality of life (#QoL) in Slovenian patients with drug resistant epilepsy (#DRE). Special emphasis was put on the impact of epilepsy duration and age at implantation on VNS outcomes.Continuing on the theme of vagus nerve stimulation (#VNS) and early implantation, this retrospective study by Kavčič et al. 2019 aimed to evaluate the efficacy of VNS Therapy on seizure burden and quality of life (#QoL) in Slovenian patients with drug resistant epilepsy (#DRE). Special emphasis was put on the impact of epilepsy duration and age at implantation on VNS outcomes.

Highlights

● Patients ≤6 years of age showed a remarkably increased responder rate (71.4% compared to 33.3% in the overall presentation).

●  More favorable effects on quality of life (#QoL) parameters and seizure burden was reported in younger patients.

● A shorter epilepsy duration (<8 years) was significantly associated with improvements in concentration, energy, mood and progress in schoolwork.

The analysis included data from 39 patients undergoing VNS implantation between 2001-2015. Analysis was performed in 2016 and the mean duration of VNS Therapy at this time-point was 7.2 years (range: 1.6-15 years).

After a follow-up duration of 12 months, 46.2% of the overall population experienced a seizure frequency reduction, while 33.3% of the patients were responders (defined as a ≥50% #seizure frequency reduction).

Noteworthy, patients ≤6 years of age showed a remarkably increased responder rate (71.4%). Similarly, the effects of VNS Therapy on seizure duration, seizure severity and post-ictal recovery time was more prominent in younger patients.

Interestingly, improvements in most QoL parameters (alertness, concentration, energy, memory, mood and progress in schoolwork) were reported in 33% of the patients. Noteworthy, a shorter epilepsy duration (<8 years) was a significantly associated with improvements in concentration, energy, mood and progress in schoolwork.

According to the current results, a young age at VNS implantation as well as a shorter epilepsy duration appears to be associated with more favorable VNS outcomes. However, as young patients tend to have a shorter epilepsy duration, it is difficult to distinguish which factor (or both) that is influencing VNS efficacy. Nevertheless, these observations highlights the importance of considering VNS Therapy as early possible in the treatment pathway.

● Patients ≤6 years of age showed a remarkably increased responder rate (71.4% compared to 33.3% in the overall presentation).

● More favorable effects on quality of life (#QoL) parameters and seizure burden was reported in younger patients.

● A shorter epilepsy duration (<8 years) was significantly associated with improvements in concentration, energy, mood and progress in schoolwork.

The analysis included data from 39 patients undergoing VNS implantation between 2001-2015. Analysis was performed in 2016 and the mean duration of VNS Therapy at this time-point was 7.2 years (range: 1.6-15 years).

After a follow-up duration of 12 months, 46.2% of the overall population experienced a seizure frequency reduction, while 33.3% of the patients were responders (defined as a ≥50% #seizure frequency reduction).

Noteworthy, patients ≤6 years of age showed a remarkably increased responder rate (71.4%). Similarly, the effects of VNS Therapy on seizure duration, seizure severity and post-ictal recovery time was more prominent in younger patients.

Interestingly, improvements in most QoL parameters (alertness, concentration, energy, memory, mood and progress in schoolwork) were reported in 33% of the patients. Noteworthy, a shorter epilepsy duration (<8 years) was a significantly associated with improvements in concentration, energy, mood and progress in schoolwork.

According to the current results, a young age at VNS implantation as well as a shorter epilepsy duration appears to be associated with more favorable VNS outcomes. However, as young patients tend to have a shorter epilepsy duration, it is difficult to distinguish which factor (or both) that is influencing VNS efficacy. Nevertheless, these observations highlights the importance of considering VNS Therapy as early possible in the treatment pathway.