Another researcher recruited more than 300 patients with seemingly uncontrolled epilepsy into an observational study. Approximately 10% of the cohort fulfilled the ILAE definition of drug resistance. Among patients who were not drug-resistant and not seizure-free, the most common reason for their outcome was an inadequate dose of AED (ie, less than 50% of the defined daily dose). For some of the patients, treating neurologists increased the AED dose or changed or added an AED. During a three-year period, 17% of patients whose treatment was modified became seizure-free. In contrast, none of the patients in the drug-resistant group became seizure-free. The proportion of seizure-free patients was similar for patients who received an increased dose of the same AED and patients who received a different AED.
“The patient seizure-free rate was significantly lower in patients who had failed at least one AED at an adequate dose,” said Dr. Kwan. “This reinforces the concept that … failure of an adequate dose of at least one AED has a very strong prediction of subsequent outcome,” Dr. Kwan concluded.
—Erik Greb
