Responsiveness to Vagal Nerve Stimulation in adult epilepsy

Full text

Dr.Ehtesham Khalid
SR Neurology, MRCP (UK)
National Neurosciences Institute
King Fahad Medical City, Riyadh

Vagal nerve stimulator (VNS) is a well recognized
treatment for intractable epilepsy with upto
50% improvement in seizures.

Introduction—
We report results of VNS in our institute for its
significance based on types of seizures and
responsiveness.

Method—
We retrospectively reviewed our cohort of 10
patients who underwent VNS implantation
(Cyberonics, Model 102 and 103) for intractable
seizures who had failed evaluation for epilepsy
surgery.
We studied demographics, types of seizures,
duration of epilepsy, seizure frequency pre and
post VNS insertion

n=10 Sex Age (Yrs) Duration of
epilepsy (Yrs) Type of Epilepsy
1 M 33 28 Focal+SGE
2M 22 20 Focal+SGE
3 M 24 20 IGE, JME
4M 17 10 IGE
5 M 14 12 IGE, MAE
6 F 27 17 Focal+SGE
7 F 16 11 Focal+SGE
8 F 14 13 Focal+SGE
9 F 19 11 Focal+SGE
10 M19 14 IGE
IGE: Idiopathic Generalized Epilepsy; SGE: Secondary Generalized Epilepsy ; MAE: Myoclonic Astatic
Epilepsy

Duration of Follow
Up in Months Seizure Frequency
Pre-surgery (Per
Month)
Seizure
Frequency Post-
surgery (Per
month)
Percentage of
seizure
improvement
31 4 0.36 91%
20 3 3 0%
27 10 190%
2 3 0 100%
20 180 10 94%
28 7 1 86%
810 370%
360 30 50%
27 15 193%
6 3 1 67%

Results—
10 patients (6-males, 4-females) who
underwent VNS surgery over a period of 4
years.
Average age 20.5(±6.4) years.
Duration of seizures 15.6(±6) years.
Generalized seizures (6 with focal with
secondary generalization and 4 with primary
generalized epilepsy).

Average duration of follow up 17.2(+11.3)
months.
Mean seizure frequency was 29.5(range: 3-180)
per month.
Seizure frequency post surgery was 5.0 (range:
36-30) per month.
All but 1 had >50% improvement in seizure
frequency. 7 patients improved by >70% with 1
patient being seizure free.
There was no statistically significant correlation
to the type of seizure and response.

VNS is beneficial in majority of adult patients
with intractable epilepsy and should be
considered in carefully selected patients who
are not good candidates for epilepsy surgery

VNS works by giving intermittent stimulation
to left Vagus nerve in neck to improve seizure
frequency and severity. This device does not
cause any changes in baseline EEG patterns.
Seizure control is better with passage of time.
Usually there is no complete improvement in
seizures. It is usually recommended in patients
with partial epilepsy who are unable to tolerate
the side effects of anti-epileptic drugs and to
improve quality of life.

Contributors:
Khurram A.Siddiqui
Shobhit Sinha
Abdulrahman J. Sabbagh
Fawziah Ba.Moggadam
Majed Al.Hameed

THANK YOU