title: What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Epilepsy and Child and Adolescent Neurology, Mayo Clinic, Rochester, Minnesota 55905, USA. wirrell.elaine@mayo.edu
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Wirrell
authors.forename: Lily C-L
authors.initials: LC
authors.lastname: Wong-Kisiel
authors.forename: Jay
authors.initials: J
authors.lastname: Mandrekar
authors.forename: Katherine C
authors.initials: KC
authors.lastname: Nickels
mesh_terms: D000927:Anticonvulsants / Q000627:therapeutic use; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000473:pathology; D004827:Epilepsy / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D004829:Epilepsy, Generalized / Q000175:diagnosis / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D059906:Neuroimaging; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants
references.citation: Ann Neurol. 1990 Nov;28(5):699-705
references.pmid: 2260857
references.citation: Epilepsia. 1996 Jan;37(1):19-23
references.pmid: 8603618
references.citation: Mayo Clin Proc. 1996 Mar;71(3):266-74
references.pmid: 8594285
references.citation: Epilepsia. 2001 Dec;42(12):1553-62
references.pmid: 11879366
references.citation: Epilepsia. 2008 Jan;49(1):65-72
references.pmid: 17645538
references.citation: Epilepsia. 2011 Aug;52(8):1522-6
references.pmid: 21762438
references.citation: Arch Neurol. 1995 Jun;52(6):589-92
references.pmid: 7763207
references.citation: Epilepsia. 2010 Apr;51(4):676-85
references.pmid: 20196795
references.citation: N Engl J Med. 2000 Feb 3;342(5):314-9
references.pmid: 10660394
references.citation: J Child Neurol. 2003 Apr;18(4):272-87
references.pmid: 12760431
references.citation: Epilepsia. 2012 Apr;53(4):741-51
references.pmid: 22417003
references.citation: Clin Neurophysiol. 1999 Jul;110(7):1245-51
references.pmid: 10423189
references.citation: Epilepsia. 1987 Jul-Aug;28(4):324-30
references.pmid: 3622407
references.citation: Am J Epidemiol. 2005 Aug 1;162(3):199-200
references.pmid: 15987728
references.citation: Epilepsia. 1997 Jan;38(1):31-46
references.pmid: 9024182
references.citation: Epilepsia. 2000 Sep;41(9):1230-3
references.pmid: 10999565
references.citation: Epilepsia. 1993 Sep-Oct;34(5):930-6
references.pmid: 8404749
references.citation: Epilepsia. 2005 Sep;46(9):1526-32
references.pmid: 16146449
references.citation: Epilepsia. 1987 Mar-Apr;28(2):97-106
references.pmid: 3816713
references.citation: Epilepsia. 2010 Apr;51(4):671-5
references.pmid: 19732133
references.citation: Neurology. 1998 Nov;51(5):1256-62
references.pmid: 9818842
references.citation: Arch Neurol. 1998 May;55(5):668-73
references.pmid: 9605723
references.citation: Epilepsia. 2011 Apr;52(4):738-45
references.pmid: 21320114
references.citation: Epilepsy Res. 2001 Jan;43(1):75-84
references.pmid: 11137389
references.citation: Neurology. 2001 Jun 12;56(11):1445-52
references.pmid: 11402099
references.citation: N Engl J Med. 1984 Oct 11;311(15):944-7
references.pmid: 6433201
references.citation: Epilepsia. 1999 Jun;40(6):726-34
references.pmid: 10368070
references.citation: Epilepsy Res. 2004 Nov;62(1):75-87
references.pmid: 15519134
references.citation: Lancet Neurol. 2008 Feb;7(2):151-60
references.pmid: 18207113
references.citation: Ann Neurol. 2007 Oct;62(4):382-9
references.pmid: 17880009