Skip to Main Content


Seizures and drug resistance

Yale Medicine Magazine, 2003 - Summer


Researchers have shown for the first time how long it takes to establish resistance to drugs that control partial epilepsy. A multicenter study directed by Susan S. Spencer, M.D., FW ’78, professor of neurology, and published in the journal Neurology in February examined 333 patients to analyze outcomes of surgical treatment of partial epilepsy and to identify factors that predict when seizures become intractable. About 80 percent of those with partial epilepsy cannot control seizures with medications.

Researchers found that an average of about nine years passed before at least two drugs failed to control recurrent seizures. During that interval, a quarter of those in the study had remissions lasting up to a year and slightly fewer than 9 percent had remissions of five years or more. A younger age at the onset of seizures predicted longer seizure-free intervals. “This kind of information,” Spencer said, “leads us to explore the mechanisms by which treatment resistance develops over so many years, and prompts consideration and investigation of preventive strategies for the future.”