Abstracts

There is a need for separate classification to measure VNS(vagus nerve stimulation) outcome.Engle[apos]s criterias to study seizure outcome were originally designed to assess seizure outcome in patients who had epilepsy surgery.Epilepsy surgery is a definitive or curative treatment while VNS is not.The response to VNS has a very wide spectrum,i.e reduction in seizure frequency,duration,shortening of postictal state,rapid recovery from postictal state,aborting the actual seizure with use of magnet etc.Because of this wide range of clinical response to VNS we think Engle[apos]s classification for epilepsy surgery outcome cant be effectively used to measure post VNS outcome.
We used a separate classification to study the post VNS outcome in our patient population which is as follow:
Class-I:80-100% reduction in seizure frequency
Class-II: 50-79% reduction in seizure frequency
Class-III:less than 50% reduction in seizure frequency.
Class-IV:no improvement or worsening of seizures.
Class-V: magnet benefit.
Based upon the above proposed classification we are presenting following datas pertaining to our patients:
There were 31 patient included in this study,of these 18 were males and 13 were females.Patient[rsquo]s age ranged between 10 to 64 years with mean age of 27.8 years.
The following was the response of the patients:
Class-I: 10 patients,32.2%
Class-II:9 patients,29.3%.
Class-III:1 patients,2.3%.
Class-IV:8 patients,25.8%
Class-V:3 patients,9.7%
The study revealed that 19(61.2%) of 31 patients with VNS device achieved seizure frequency reduction between 50-100%.10 patients(32.2.3%) had seizure frequency reduction between 80-100% i.e Class-1,while 9 patients(29.8%) had seizure frequency reduced between 50-79% falling in Class-II.One patient(3.2%) had seizure frequency reduction less than 50%,hence catogorised into Class III, while the remaining 8 patients(25.8%) didn[rsquo]t benifit from VNS at all i.e Class-IV.3 patients (9.7%)benifited from use of magnet during seizure activity.This either aborted the seizure ictus or significantly reduced its duration.
Based upon wide range of post-VNS clinical response there is a need to have a different clasification system to study VNS outcome.Engle[apos]s Classification,which was originally/essentially constructed to study postsurgical seizure outcome in intractable epilepsy is inappropriate with patients with VNS to measure seizure outcome