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Epilepsy surgery in pediatric epileptic encephalopathy: when interictal EEG counts the most

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Abstract

Purpose

Traditionally, seizure onset localization in ictal electro-encephalography (EEG) is the main factor guiding resective epilepsy surgery. The situation is often different in infantile epileptic encephalopathy. We demonstrate the importance of the underrated interictal (rather than ictal) surface EEG in informing decision-making in epilepsy surgery for children with epileptic encephalopathy caused by subtle focal cortical dysplasia (FCD).

Methods

We present a small case series of three children who had an epileptic encephalopathy with either epileptic spasms or tonic seizures. All three were thought initially to have normal neuroimaging.

Results

Ictal EEG localizing features were seen in none and lateralizing features were seen only clinically in one of the three. However, the interictal EEG showed persistent and consistent focal irregular slowing in all, particularly after medically resolving the diffuse encephalopathy. Subtle FCDs were uncovered in all. Surgery was performed in all with excellent outcome.

Conclusion

In infantile epileptic encephalopathy caused by subtle FCD, the often underrated interictal surface EEG (particularly persistent foal irregular slowing) informs the most; not only to the target area for surgical resection but also to its extent. This may negate the need for unnecessary and sometimes non-informative invasive monitoring in these cases. A matter of “zooming out” to define the extent of a resectable abnormality rather than “zooming in” to define a seemingly localized epileptic focus that may change with time.

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References

  1. Arya R, Mangano FT, Horn PS, Holland KD, Rose DF, Glauser TA (2013) Adverse events related to extraoperative invasive EEG monitoring with subdural grid electrodes: a systematic review and meta-analysis. Epilepsia 54(5):828–839

    Article  PubMed  Google Scholar 

  2. Wyllie E, Lachhwani DK, Gupta A, Chirla A, Cosmo G, Worley S, et al. (2007) Successful surgery for epilepsy due to early brain lesions despite generalized EEG findings. Neurology 69(4):389–397

    Article  CAS  PubMed  Google Scholar 

  3. Krsek P, Maton B, Jayakar P, Dean P, Korman B, Rey G, et al. (2009) Incomplete resection of focal cortical dysplasia is the main predictor of poor postsurgical outcome. Neurology 72(3):217–223

    Article  CAS  PubMed  Google Scholar 

  4. Noh BH, Berg AT, Nordli DR (2013) Concordance of MRI lesions and EEG focal slowing in children with nonsyndromic epilepsy. Epilepsia 54(3):455–460

    Article  CAS  PubMed  Google Scholar 

  5. Palmini A, Gambardella A, Andermann F, Dubeau F, da Costa JC, Olivier A, et al. (1995) Intrinsic epileptogenicity of human dysplastic cortex as suggested by corticography and surgical results. Ann Neurol 37(4):476–487

    Article  CAS  PubMed  Google Scholar 

  6. Mathern GW (2009) Challenges in the surgical treatment of epilepsy patients with cortical dysplasia. Epilepsia 50(s9):45–50

    Article  PubMed  Google Scholar 

  7. Widdess-Walsh P, Jeha L, Nair D, Kotagal P, Bingaman W, Najm I (2007) Subdural electrode analysis in focal cortical dysplasia predictors of surgical outcome. Neurology 69(7):660–667

    Article  CAS  PubMed  Google Scholar 

  8. Wyllie E (1995) Developmental aspects of seizure semiology: problems in identifying localized onset seizures in infants and children. Epilepsia 36(12):1170–1172

    Article  CAS  PubMed  Google Scholar 

  9. Lado FA, Moshé SL (2002) Role of subcortical structures in the pathogenesis of infantile spasms: what are possible subcortical mediators? Int Rev Neurobiol 49:115–140

    Article  CAS  PubMed  Google Scholar 

  10. Siniatchkin M, van Baalen A, Jacobs J, Moeller F, Moehring J, Boor R, et al. (2007) Different neuronal networks are associated with spikes and slow activity in hypsarrhythmia. Epilepsia 48(12):2312–2321

    PubMed  Google Scholar 

  11. Asano E, Juhász C, Shah A, Muzik O, Chugani DC, Shah J, et al. (2005) Origin and propagation of epileptic spasms delineated on electrocorticography. Epilepsia 46(7):1086–1097

    Article  PubMed  PubMed Central  Google Scholar 

  12. Parisi P, Bombardieri R, Curatolo P (2007) Current role of vigabatrin in infantile spasms. Eur J Paediatr Neurol 11(6):331–336

    Article  PubMed  Google Scholar 

  13. Chassoux F, Rodrigo S, Semah F, Beuvon F, Landre E, Devaux B, et al. (2010) FDG-PET improves surgical outcome in negative MRI Taylor-type focal cortical dysplasias. Neurology 75(24):2168–2175

    Article  CAS  PubMed  Google Scholar 

  14. Erbayat Altay E, Fessler AJ, Gallagher M, Attarian HP, Dehdashti F, Vahle VJ, et al. (2005) Correlation of severity of FDG-PET hypometabolism and interictal regional delta slowing in temporal lobe epilepsy. Epilepsia 46(4):573–576

    Article  PubMed  Google Scholar 

  15. Kim DW, Lee SK, Chu K, Park KI, Lee SY, Lee CH, et al. (2009) Predictors of surgical outcome and pathologic considerations in focal cortical dysplasia. Neurology 72(3):211–216

    Article  CAS  PubMed  Google Scholar 

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Correspondence to Amre Shahwan.

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Shahwan, A., O’Halloran, P.J., Madigan, C. et al. Epilepsy surgery in pediatric epileptic encephalopathy: when interictal EEG counts the most. Childs Nerv Syst 32, 1293–1298 (2016). https://doi.org/10.1007/s00381-016-3104-4

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  • DOI: https://doi.org/10.1007/s00381-016-3104-4

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