What are the definitions of treatment-resistant epilepsy used in the literature?
• Treatment resistance is infrequently defined in the literature. Less than one third of the surveyed publications reported any definition of this term. • When treatment resistance was defined, definitions typically included the number of AEDs a patient tried before being considered treatment-resistant. Some definitions also included seizure frequency, duration of illness, and whether AEDs were administered at maximum tolerable doses. • Drug trials tended to require fewer failures of AED treatment compared to surgical trials. This is because a very thorough assessment of drug regimens is usually attempted before surgery is considered. Assessments are usually less thorough when giving a patient another AED. • Despite the fact that reports of clinical trials and review articles regularly use terms such as “intractable,” “refractory,” or “treatment-resistant” to describe patients for whom one or more treatments have failed, no consensus exists as to precisely what these terms mean.
