At what point are epilepsy patients considered to be refractory
Pharmacoresistant (i.e., drug resistant, intractable, refractory) epilepsy is defined by the International League against Epilepsy as the failure of at least two tolerated, appropriately chosen Antiepileptics (AED) trials in achieving seizure freedom.
The definition has evolved over the years based on seminal trials showing that after two to three appropriate AED trials have failed to render a patient seizure free, the chances of that patient ever becoming seizure free on any AED is only about 5% to 10%.
In general, approximately 47% of patients will become seizure free after the first AED and an additional 13% after the second AED.
Further trials of AEDs result in seizure freedom in only 1% to 3%, which argues for the consideration of epilepsy surgery over further, likely futile, AED trials.
Epilepsy surgery in appropriately chosen surgical candidates can still result in seizure freedom between 50% and 80% in pharmacoresistant epilepsy patients.
