Epilepsy

Epilepsy is a neurological condition causing recurrent, unprovoked seizures, episodes of abnormal electrical activity in the brain that can affect movement, awareness, sensation or behavior, depending on where in the brain they arise. Most patients with epilepsy achieve good seizure control with anti-seizure medication. A meaningful minority, however, continue to have seizures despite appropriate trials of these medications; a situation generally described as drug-resistant (or medically refractory) epilepsy.

Drug-resistant epilepsy generally refers to seizures that have continued despite adequate trials of at least two appropriately chosen and dosed anti-seizure medications. This is the point at which specialist evaluation for surgical or device-based options becomes worth considering, rather than continuing to add or switch medications indefinitely.

Evaluation is generally considered once drug resistance is established and typically starts with detailed assessment to determine whether the seizures arise from a single, identifiable area of the brain (potentially suitable for resective surgery, which removes or disconnects that area) or from a more widespread or multifocal pattern not suitable for resection. For patients who are not candidates for resective surgery, or for whom resective surgery has not fully controlled seizures, two neuromodulation options may be considered:

• Vagus nerve stimulation (VNS): the more established and widely used option, stimulating the vagus nerve in the neck via an implanted device
• Deep brain stimulation (DBS): stimulating a deep brain target, most often within the thalamus, considered for a smaller number of patients following multidisciplinary epilepsy team review

Both are added treatments rather than a cure, aim to reduce seizure frequency and severity rather than guarantee seizure freedom, and are chosen between, alongside continued medical management and, where appropriate, resective surgery, based on individual seizure characterization and patient preference.

• Detailed seizure history, including seizure types, frequency and triggers
• Review of anti-seizure medications tried, at what doses, and for how long
• Video-EEG monitoring, to characterize seizures and identify, where possible, where in the brain they begin
• Brain MRI, using an epilepsy-specific imaging protocol
• Neuropsychological assessment
• Multidisciplinary epilepsy team review to determine whether resective surgery, neuromodulation, or continued medical management is the most appropriate path

Treatment goals vary between patients. For some, particularly where a single seizure focus can be safely removed, the goal may be complete or near-complete seizure freedom. For others, including most patients considered for vagus nerve stimulation, the realistic goal is a meaningful reduction in seizure frequency or severity, and often shorter recovery time after a seizure, rather than complete elimination of seizures.

Risks and limitations depend on the specific treatment being considered and are described on that treatment’s own page. Not every patient with drug-resistant epilepsy is a candidate for every option, and the right path depends on detailed, individual evaluation by a multidisciplinary epilepsy team.