Dear Editor,rnEpilepsy is a common neurological disease.About 30％ of epileptic patients develop resistance to antiepileptic drugs (AEDs), and are considered to have refractory or drugresistant epilepsy [1].Based on the time course over which drug-resistance develops, refractory epilepsy can be further divided into an early-onset type (drug-resistance more likely innate and correlated with gene mutations) and a delayed-onset type (drug-resistance emerges after a period of medication) [2].The latter usually displays a more complex constellation of pathological findings, often associated with mesial temporal sclerosis [3].Longitudinal neuroimaging studies have shown that the degree of brain atrophy is more extensive in patients with the delayedonset type than in those with an early onset [4].After repeated trials with unsuccessful drug treatments, uncontrolled seizures, along with other complications including impaired memory, often put patients\' health at risk.At that time, even epilepsy surgery adds limited value to thetreatment of these patients.Thus, an alternative therapeutic strategy is urgently needed for patients with delayed-onset refractory epilepsy.