title: Preoperative estimation of seizure control after resective surgery for the treatment of epilepsy.
abstract: OBJECTIVE
  Predicting seizure control after epilepsy surgery is difficult. The objectives of this work are: (a) to estimate the value of surgical procedure, presence of neuroimaging abnormalities, need for intracranial recordings, resection lobe, pathology, durations of epilepsy and follow-up period to predict postsurgical seizure control after epilepsy surgery and (b) to provide empirical estimates of successful outcome after different combinations of the above factors in order to aid clinicians in advising patients presurgically about the likelihood of success under their patients' individual circumstances.
  
  
  METHODS
  We report postsurgical seizure control from all 243 patients who underwent resective surgery for epilepsy at King's College Hospital between 1999 and 2011. Among the 243 patients, 233 had lobar or sub-lobar resections, 8 had multilobar resections and 2 had excision of a hypothalamic hamartoma. We examined the relation between postsurgical seizure control and type of surgical procedure, presence of neuroimaging abnormalities, pathology, resection lobe and the need of intra-cranial electrodes to identify seizure onset.
  
  
  RESULTS
  Among the 243 patients, 126 (52%) enjoyed outcome grade I, 40 (16%) had grade II, 51 (21%) had grade III and 26 (11%) had grade IV (mean follow-up 41.1 months). Normal neuroimaging or need for intracranial recordings was not associated with poorer outcome. Patients undergoing temporal resections showed better outcome than those with frontal resections, due to the poor outcome seen in frontal patients with normal neuroimaging. Among temporal resections, there was no difference in outcome between patients with and without neuroimaging abnormalities. Among patients with lesions on imaging, temporal and frontal resections showed similar outcomes. Likelihood of favourable outcome under the patient's individual circumstances was estimated by the tables provided. There was an 8-9% decrease in the percentage of grade I between follow-up at 12 and >36 months.
  
  
  CONCLUSIONS
  Overall, nearly 70% of patients undergoing resective surgery enjoy favourable post-surgical seizure control. Normal neuroimaging should not discourage surgery in temporal patients but is a negative prognostic sign in normal MRI frontal patients. There were no statistical differences in outcome between patients with neuroimaging lesions in frontal or temporal lobes.
authors.affiliation: Department of Neurosurgery, King's College Hospital, London, UK.
authors.forename: Atul
authors.initials: A
authors.lastname: Kumar
authors.forename: Antonio
authors.initials: A
authors.lastname: Valentín
authors.forename: Danish
authors.initials: D
authors.lastname: Humayon
authors.forename: Alix L
authors.initials: AL
authors.lastname: Longbottom
authors.forename: Diego
authors.initials: D
authors.lastname: Jimenez-Jimenez
authors.forename: Nandini
authors.initials: N
authors.lastname: Mullatti
authors.forename: Robert C D
authors.initials: RC
authors.lastname: Elwes
authors.forename: Istvan
authors.initials: I
authors.lastname: Bodi
authors.forename: Mrinalini
authors.initials: M
authors.lastname: Honavar
authors.forename: Jozef
authors.initials: J
authors.lastname: Jarosz
authors.forename: Richard P
authors.initials: RP
authors.lastname: Selway
authors.forename: Charles E
authors.initials: CE
authors.lastname: Polkey
authors.forename: Irfan
authors.initials: I
authors.lastname: Malik
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alarcón
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D019635:Neurosurgical Procedures / Q000379:methods*; D057234:Preoperative Period; D011379:Prognosis; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Epilepsy surgery; Intracranial recordings; Predictive factors; Presurgical assessment; Prognostic factors