Risk factors associated with drug resistant focal epilepsy in adults: A case control study.

•Diagnosis of focal epilepsy in the second decade of life is a risk factor for pharmacoresistance.•More than one CPS per month is a risk factor to drug resistance.•Mesial temporal sclerosis and bitemporal epilepsy are risk factors for refractoriness.•Encephalomalacia might be a protective factor against drug resistant epilepsy.•Good response to the first used drug may protect against pharmacoresistance.