Full-Length Original Research
What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?
Article first published online: 3 APR 2013
Wiley Periodicals, Inc. © 2013 International League Against Epilepsy
Volume 54, Issue 6, pages 1056–1064, June 2013
How to Cite
Wirrell, E. C., Wong-Kisiel, L. C.-L., Mandrekar, J. and Nickels, K. C. (2013), What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?. Epilepsia, 54: 1056–1064. doi: 10.1111/epi.12169
- Issue published online: 4 JUN 2013
- Article first published online: 3 APR 2013
- Manuscript Accepted: 4 MAR 2013
- Mayo Foundation
- Rochester Epidemiology Project. Grant Number: R01-AG034676
- National Institute on Aging
In a population-based retrospective cohort of children with newly diagnosed epilepsy, to determine (1) what proportion meet criteria for early medical intractability, and (2) predictors of enduring intractability.
Children with newly diagnosed epilepsy between 1980 and 2009 while resident in Olmsted County, MN, and followed >36 months, were stratified into groups based on both early medical intractability (“apparent” medical intractability in the first 2 years) and enduring intractability (persisting intractability at final follow-up or having undergone surgery for intractable epilepsy), and variables predicting these outcomes were evaluated.
Three hundred eighty-one children were included, representing 81% of our cohort with newly diagnosed epilepsy. Seventy five (19.7%) had early medical intractability, and predictors of this outcome on multivariable analysis were neuroimaging abnormality (risk ratio, 2.70; p = 0.0004), abnormal neurologic examination at diagnosis (risk ratio, 1.87; p = 0.015), and mode of onset (association was significant for focal vs. generalized onset [risk ratio, 0.25; p < 0.0001] but not unknown vs. generalized onset [p = 0.065]). After a median follow-up of 11.7 years, 49% remained intractable, 8% had rare seizures (≤ every 6 months), and the remainder were seizure-free. The only factor predicting enduring intractability on multivariable analysis was neuroimaging abnormality (risk ratio, 7.0; p = 0.0006).
Although a significant minority of children with early medical intractability ultimately achieved seizure control without surgery, those with an abnormal imaging study did poorly. For this subgroup, early surgical intervention is strongly advised to limit comorbidities of ongoing, intractable seizures. Conversely, a cautious approach is suggested for those with normal imaging, as most will remit with time.