The first choice in the treatment of epilepsy is usually anti-seizure medication. In some patients, however, seizures continue despite the use of appropriate drugs.
Drug-Resistant Epilepsy
The International League Against Epilepsy (ILAE) defines “drug-resistant epilepsy” as failure to achieve seizure control despite two appropriately chosen anti-seizure drug regimens used at adequate dose and for an adequate period.
At this point what matters is that the patient should be assessed at an epilepsy surgery center, rather than continuing to try different drugs for years. Current ILAE expert opinion recommends that patients be referred for surgical assessment once drug resistance has been established. Being assessed for surgery does not mean that an operation will necessarily follow.
Who May Benefit from Surgery?
The aim is to determine as precisely as possible the region of the brain from which the seizures arise. The following investigations are assessed together:
- the seizure history;
- video-EEG recordings;
- detailed MRI of the brain;
- where required, PET, neuropsychological testing or further investigations.
Surgery may be a strong option in patients whose seizures are considered to arise from a defined region of the brain that can be treated safely. In other patients, methods such as neuromodulation may be considered instead of resective surgery.
What Is the Success Rate?
Success varies with the type of epilepsy and with the region from which the seizures arise. The results are particularly strong in appropriately selected temporal lobe epilepsy.
In a classic randomized controlled trial, 58% of patients who underwent surgery were entirely free of seizures impairing consciousness at one year, compared with 8% in the group that continued on medication alone.
Broader reviews report that rates of seizure freedom in patients operated upon for drug-resistant focal epilepsy range from approximately 34% to 74% according to the study and the type of epilepsy, with a median of around 62%.
The Most Important Message
If seizures continue despite two appropriate drug treatments, the reason to attend an experienced epilepsy center is not that “surgery is essential”, but to establish whether surgery or other advanced treatments are possible.
The decision to operate must be individualized for each patient through multidisciplinary assessment.
For detailed information on the procedures used in epilepsy surgery and on the process itself, see the Epilepsy Surgery page.
References
- International League Against Epilepsy (ILAE)
- Jehi et al., Epilepsia, 2022
- Wiebe et al., New England Journal of Medicine, 2001
- Jobst & Cascino, JAMA, 2015