Factors Influencing Delay in Epilepsy Surgery: A Retrospective Data Review for a Tertiary Referral Center

Abstract

Medically intractable focal epilepsy affects a third of patients with seizures which are potentially surgically remediable. Several factors have been suggested for the reasons of the delays in epilepsy surgery. Nationally, the average time to surgery after onset of seizures is 20 years. We analyzed the characteristics of population of patients in Western New York who underwent surgery for refractory epilepsy, the time duration between onset of epilepsy and surgery, and the factors influencing the time duration, in order to determine whether there is any difference between the data from Western New York and all states in United States of America. Retrospective chart review of 51 patients was performed on the patients diagnosed with refractory epilepsy from 2003-2014 who underwent surgery at our center. Demographic Data such age, gender, ethnicity, insurance information, seizure severity, number of medications, EEG results, MRI lesions, and time to surgery were collected. Linear regression forward model was used for analysis with significance value set at 0.05. Mean waiting time to surgery at our center was shorter (13.5 versus 20 years) compared to the other centers in the United States of America. Eighty-one% (37) of the patients were diagnosed with lesions on MRI, of which 13% (6) were tumors. Mean waiting time of patients with a lesion was 13.4 years versus 15.5 years for patients without a lesion. Mean time for pediatric patients was 4.5 years and while for an adult patient was 21 years. When linear regression forward model was applied, a shorter time to surgery was associated with pediatric patients with B = 11.81 (2.42, 21.2), p-value = 0.016. Our study suggests that pediatric patients underwent surgeries earlier compared to adult population, which may be due to earlier identification by the local pediatric neurologists. Further research with bigger sample size is needed to probe the factors influencing the time duration between onset of epilepsy and candidacy of epilepsy surgery.