Vagus nerve stimulation and Lennox-Gastaut syndrome: a review of the literature and data from the VNS patient registry
Karceski S.
CNS Spectr. 2001 Sep;6(9):766-70.
https://doi.org/10.1017/s1092852900001516.
Continuing on the theme of vagus nerve stimulation (#VNS) and Lennox-Gastaut syndrome (#LGS), this work by Karceski (Sep. 2001) examined the efficiency of VNS in patients with LGS by reviewing the literature and data from the VNS Patient Registry.
The VNS Patient Registry is a database established by the VNS device company Livanova (Cyberonics). The database includes medical histories, VNS parameter settings, and #seizure frequency changes.
552 LGS patients were enrolled. The majority, 483 patients, did not undergo epilepsy surgery before VNS implantation. 61 patients had corpus callosotomy before VNS implantation.
For the group without prior surgery, the responder rates at 3, 6, 12 and 18 months follow-up were 50% (n=149), 57% (n=91), 65% (n=94), and 55% (n=74), respectively. For the group with prior callosotomy, the responder rates at 3 and 12 months were 57% (n=25 and 13, respectively). 7% of the patients without prior surgery became seizure-free at 12 months, while the corresponding value was 4% for the group with prior callosotomy.
Noteworthy, the effectiveness of VNS was similar to the results from callosotomy. 5%-10% of patients became seizure-free after callosotomy[1], while 4%-7% became seizure-free after VNS implantation. The responder rate for callosotomy is 60%-80%. For the VNS, 37%-83% of the patients without prior surgery were responders.
The results suggest that VNS is an effective and safe alternative to callosotomy. Furthermore, considering the similar effectiveness of VNS for patients with or without prior callosotomy, VNS can be a safe and effective option for patients who do not gain any significant improvement from callosotomy.
Ref.
[1] Roberts, D. Corpus callosotomy. In: Engel J, Pedley TA, eds. Epilepsy: A Comprehensive Textbook. Philadelphia, Pa: Lippincott-Raven Publishers; 1997:1851-1858
“Responders” were defined as the patients who achieved a > 50% seizure frequency reduction following VNS treatment.
