Evaluation and programming in vagus nerve stimulation (VNS)

Scenario

A 33-year-old female with drug-resistant focal epilepsy presents for consideration of a vagus nerve stimulator to aid in seizure control. Seizures with change in awareness began at age 20, although upon questioning, she likely had focal aware seizures starting in early teen years. She has tried multiple antiseizure drugs, with some improvement. She continues to have focal impaired aware seizures 2 to 4 times a month and focal impaired awareness every 2–3 months. She had to change careers because of cognitive impairment from seizures and medication side effects. Her inability to drive has limited employment options. She is married and would like to have children. She is interested in exploring all options to improve seizure control prior to pregnancy. Several discussions ensue regarding a plan for further trying to eliminate her seizures.

Resective epilepsy surgery typically offers the best outcome for seizure control, if seizure onset can be localized to one focus in an area that could be safely removed. Video electroencephalography (EEG) monitoring that was done about 5 years ago at a different epilepsy center could not be obtained in this case unfortunately, except for several reports of the interpretations. The patient is not clear if both seizure types were recorded or if medications were withdrawn during monitoring. We recommended repeating the video-EEG in-house monitoring for more definitive information on her seizure onsets.

• Variation : The patient does not want to pursue further testing -- While repeat testing to consider all treatment options is the preferred choice, patients may be reluctant to consider invasive surgery because of work insecurity and desire to have a child, or other reasons. Even if results suggested a cortical resection, patients may prefer to pursue a less invasive approach first. Vagus nerve stimulation (VNS) could be offered in this setting at this juncture of the workup if that were the case.