Rates and predictors of long-term seizure freedom after frontal lobe epilepsy surgery: a systematic review and meta-analysis

Clinical article

Restricted access

Object

Frontal lobe epilepsy (FLE) is the second-most common focal epilepsy syndrome, and seizures are medically refractory in many patients. Although various studies have examined rates and predictors of seizure freedom after resection for FLE, there is significant variability in their results due to patient diversity, and inadequate follow-up may lead to an overestimation of long-term seizure freedom.

Methods

In this paper the authors report a systematic review and meta-analysis of long-term seizure outcomes and predictors of response after resection for intractable FLE. Only studies of at least 10 patients examining seizure freedom after FLE surgery with postoperative follow-up duration of at least 48 months were included.

Results

Across 1199 patients in 21 studies, the overall rate of postoperative seizure freedom (Engel Class I outcome) was 45.1%. No trend in seizure outcomes across all studies was observed over time. Significant predictors of long-term seizure freedom included lesional epilepsy origin (relative risk [RR] 1.67, 95% CI 1.36–28.6), abnormal preoperative MRI (RR 1.64, 95% CI 1.32–2.08), and localized frontal resection versus more extensive lobectomy with or without an extrafrontal component (RR 1.71, 95% CI 1.26–2.43). Within lesional FLE cases, gross-total resection led to significantly improved outcome versus subtotal lesionectomy (RR 1.99, 95% CI 1.47–2.84).

Conclusions

These findings suggest that FLE patients with a focal and identifiable lesion are more likely to achieve seizure freedom than those with a more poorly defined epileptic focus. While seizure freedom can be achieved in the surgical treatment of medically refractory FLE, these findings illustrate the compelling need for improved noninvasive and invasive localization techniques in FLE.

Abbreviations used in this paper:ECoG = electrocorticography; EEG = electroencephalography; FLE = frontal lobe epilepsy; RR = relative risk; SMA = supplementary motor area; TLE = temporal lobe epilepsy.

Article Information

Address correspondence to: Dario J. Englot, M.D., Ph.D., Department of Neurological Surgery, University of California, San Francisco, 505 Parnassus Avenue, Box 0112, San Francisco, California 94143-0112. email: englotdj@neurosurg.ucsf.edu.

Please include this information when citing this paper: published online February 3, 2012; DOI: 10.3171/2012.1.JNS111620.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Seizure-freedom rates across all studies by year. Each data point represents 1 study, with rate of seizure freedom (Engel Class I outcome) after FLE surgery plotted against year of publication. A line of best fit is provided. No significant trend is observed (r = 0.26, p = 0.25).

  • View in gallery

    Forest plots of meta-analysis results. Effect size for each study is shown as RR with 95% CI reflecting likelihood of postoperative seizure freedom for: lesional over nonlesional FLE (A), abnormal over normal preoperative MRI (B), partial lobectomy/focal resection over lobectomy or extended resection (C), and gross-total over subtotal resection for lesional cases (D). Each box represents 1 study, with box size proportional to number of patients. Overall effect size and 95% CI represented by X at the bottom of each panel. Data are displayed using logarithmic scale. Number of patients for each study is provided in Table 1.

References

1

Chang EFChristie CSullivan JEGarcia PATihan TGupta N: Seizure control outcomes after resection of dysembryoplastic neuroepithelial tumor in 50 patients. Clinical article. J Neurosurg Pediatr 5:1231302010

2

Chang EFGabriel RAPotts MBGarcia PABarbaro NMLawton MT: Seizure characteristics and control after microsurgical resection of supratentorial cerebral cavernous malformations. Neurosurgery 65:31382009

3

Chang EFPotts MBKeles GELamborn KRChang SMBarbaro NM: Seizure characteristics and control following resection in 332 patients with low-grade gliomas. J Neurosurg 108:2272352008

4

Chang EFWang DDBarkovich AJTihan TAuguste KISullivan JE: Predictors of seizure freedom after surgery for malformations of cortical development. Ann Neurol 70:1511622011

5

du Boisgueheneuc FLevy RVolle ESeassau MDuffau HKinkingnehun S: Functions of the left superior frontal gyrus in humans: a lesion study. Brain 129:331533282006

6

Duffau H: The “frontal syndrome” revisited: lessons from electrostimulation mapping studies. Cortex 48:1201312012

7

Elsharkawy AEAlabbasi AHPannek HSchulz RHoppe MPahs G: Outcome of frontal lobe epilepsy surgery in adults. Epilepsy Res 81:971062008

8

Engel J Jr: Surgical treatment for epilepsy: too little, too late?. JAMA 300:254825502008

9

Engel J JrVan Ness PCRasmussen TBOjemann LMOutcome with respect to epileptic seizures. Engel J Jr: Surgical Treatment of the Epilepsies ed 2New YorkRaven Press1993. 609621

10

Englot DJBerger MSBarbaro NMChang EF: Factors associated with seizure freedom in the surgical resection of glioneuronal tumors. Epilepsia 53:51572012

11

Englot DJBerger MSBarbaro NMChang EF: Predictors of seizure freedom after resection of supratentorial low-grade gliomas. A review. J Neurosurg 115:2402442011

12

Englot DJBlumenfeld H: Consciousness and epilepsy: why are complex-partial seizures complex?. Prog Brain Res 177:1471702009

13

Englot DJHan SJLawton MTChang EF: Predictors of seizure freedom in the surgical treatment of supratentorial cavernous malformations. Clinical article. J Neurosurg 115:116911742011

14

Ferrier CHEngelsman JAlarcón GBinnie CDPolkey CE: Prognostic factors in presurgical assessment of frontal lobe epilepsy. J Neurol Neurosurg Psychiatry 66:3503561999

15

Fish DRSmith SJQuesney LFAndermann FRasmussen T: Surgical treatment of children with medically intractable frontal or temporal lobe epilepsy: results and highlights of 40 years' experience. Epilepsia 34:2442471993

16

Helmstaedter CKockelmann E: Cognitive outcomes in patients with chronic temporal lobe epilepsy. Epilepsia 47:Suppl 296982006

17

Hoh BLChapman PHLoeffler JSCarter BSOgilvy CS: Results of multimodality treatment for 141 patients with brain arteriovenous malformations and seizures: factors associated with seizure incidence and seizure outcomes. Neurosurgery 51:3033112002

18

Hosking PG: Surgery for frontal lobe epilepsy. Seizure 12:1601662003

19

Jeha LENajm IBingaman WDinner DWiddess-Walsh PLüders H: Surgical outcome and prognostic factors of frontal lobe epilepsy surgery. Brain 130:5745842007

20

Jobst BCSiegel AMThadani VMRoberts DWRhodes HCWilliamson PD: Intractable seizures of frontal lobe origin: clinical characteristics, localizing signs, and results of surgery. Epilepsia 41:113911522000

21

Kim CHChung CKLee SK: Longitudinal change in outcome of frontal lobe epilepsy surgery. Neurosurgery 67:122212292010

22

Kloss SPieper TPannek HHolthausen HTuxhorn I: Epilepsy surgery in children with focal cortical dysplasia (FCD): results of long-term seizure outcome. Neuropediatrics 33:21262002

23

Laskowitz DTSperling MRFrench JAO'Connor MJ: The syndrome of frontal lobe epilepsy: characteristics and surgical management. Neurology 45:7807871995

24

Lee JJLee SKLee SYPark KIKim DWLee DS: Frontal lobe epilepsy: clinical characteristics, surgical outcomes and diagnostic modalities. Seizure 17:5145232008

25

Luyken CBlümcke IFimmers RUrbach HElger CEWiestler OD: The spectrum of long-term epilepsy-associated tumors: long-term seizure and tumor outcome and neurosurgical aspects. Epilepsia 44:8228302003

26

Mosewich RKSo ELO'Brien TJCascino GDSharbrough FWMarsh WR: Factors predictive of the outcome of frontal lobe epilepsy surgery. Epilepsia 41:8438492000

27

Rasmussen T: Tailoring of cortical excisions for frontal lobe epilepsy. Can J Neurol Sci 18:4 Suppl6066101991

28

Rosenberg KNossek ELiebling RFried IShapira-Lichter IHendler T: Prediction of neurological deficits and recovery after surgery in the supplementary motor area: a prospective study in 26 patients. Clinical article. J Neurosurg 113:115211632010

29

Rougier ADartigues JFCommenges DClaverie BLoiseau PCohadon F: A longitudinal assessment of seizure outcome and overall benefit from 100 cortectomies for epilepsy. J Neurol Neurosurg Psychiatry 55:7627671992

30

Salanova VQuesney LFRasmussen TAndermann FOlivier A: Reevaluation of surgical failures and the role of reoperation in 39 patients with frontal lobe epilepsy. Epilepsia 35:70801994

31

Schramm JKral TKurthen MBlümcke I: Surgery to treat focal frontal lobe epilepsy in adults. Neurosurgery 51:6446552002

32

Sinclair DBAronyk KSnyder TMcKean JDWheatley MGross D: Extratemporal resection for childhood epilepsy. Pediatr Neurol 30:1771852004

33

Smith JRLee MRKing DWMurro AMPark YDLee GP: Results of lesional vs. nonlesional frontal lobe epilepsy surgery. Stereotact Funct Neurosurg 69:2022091997

34

Spencer SHuh L: Outcomes of epilepsy surgery in adults and children. Lancet Neurol 7:5255372008

35

Swartz BEDelgado-Escueta AVWalsh GORich JRDwan PSDeSalles AA: Surgical outcomes in pure frontal lobe epilepsy and foci that mimic them. Epilepsy Res 29:971081998

36

Talairach JBancaud JBonis ASzikla GTrottier SVignal JP: Surgical therapy for frontal epilepsies. Adv Neurol 57:7077321992

37

Téllez-Zenteno JFDhar RWiebe S: Long-term seizure outcomes following epilepsy surgery: a systematic review and meta-analysis. Brain 128:118811982005

38

Tigaran SCascino GDMcClelland RLSo ELRichard Marsh W: Acute postoperative seizures after frontal lobe cortical resection for intractable partial epilepsy. Epilepsia 44:8318352003

39

Wennberg RQuesney LFLozano AOlivier ARasmussen T: Role of electrocorticography at surgery for lesion-related frontal lobe epilepsy. Can J Neurol Sci 26:33391999

40

Williamson PD: Frontal lobe seizures. Problems of diagnosis and classification. Adv Neurol 57:2893091992

41

Yun CHLee SKLee SYKim KKJeong SWChung CK: Prognostic factors in neocortical epilepsy surgery: multivariate analysis. Epilepsia 47:5745792006

42

Zaatreh MMSpencer DDThompson JLBlumenfeld HNovotny EJMattson RH: Frontal lobe tumoral epilepsy: clinical, neurophysiologic features and predictors of surgical outcome. Epilepsia 43:7277332002

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 69 69 30
Full Text Views 172 172 29
PDF Downloads 112 112 23
EPUB Downloads 0 0 0

PubMed

Google Scholar