The vagus nerve stimulator (VNS) is a surgical treatment option for patients that have drug resistant epilepsy and who are not a candidate for resective surgery. The purpose of a VNS is to decrease seizure frequency, severity, duration and to increase the quality of life for these patients.
The VNS is a medical device that is implanted under the skin, in the upper left side of the chest with electrodes that wrap around the vagus nerve. VNS Therapy is delivered through a device that sends mild pulses to the vagus nerve at regular intervals throughout the day in an effort to prevent seizures. An additional dose of therapy may stop or shorten your seizure, decrease its intensity and improve your recovery.
Here are the 3 modes of VNS Therapy
- Standard Mode: this is a prevention mode where therapy (an electrical pulse) is delivered at regular intervals, all day, and every day in an effort to prevent seizure activity.
- Detect & Respond Mode: this is a responsive delivery where an automatic delivery of an extra dose of therapy is activated when a rapid increase in heart rate is detected, which may be associated with seizures. This may stop or shorten a seizure once it starts.
- Magnet Mode: this is on-demand delivery which provides the patient or the caregiver the ability to manually deliver an additional dose of therapy in order to stop or shorten a seizure once it starts.
VNS surgery is not brain surgery. It is a surgery completed in the Operating Room by our neurosurgeon, where a small incision is placed in the upper chest to implant the device and a small incision in the neck where they attach the lead to the vagus nerve. Recovery is generally a day or two in the hospital and then the patient is discharged home.
After the implantation of the VNS, initial clinic visits are required around every two weeks for programming the device. Programming the VNS Therapy settings are completed by the Epilepsy Team here at Children’s Hospital, LHSC. There is a systematic process in place to increase the VNS settings. This is to ensure optimization of the device in an effort to control seizure activity. After reaching optimal settings, visits are then spaced out as needed.
Please refer to the VNS link for more information.