SEARCH

SEARCH BY CITATION

The treatment of childhood onset epilepsy can be complex and may require more than antiepileptic drugs (AEDs). From 10 to 40% of children may continue to suffer from intractable seizures despite adequate trials of AEDs.1,2 In children with temporal lobe epilepsy, outcomes following surgical resection are generally excellent, with the vast majority (74–88.5%) achieving seizure freedom.3–5 Although outcomes following extratemporal resections in children have not been as robustly explored, they are generally thought to be less successful.

D’Argenzio et al.6 provide evidence that surgical workups are worthwhile to pursue in children with medically intractable extratemporal epilepsy. After analyzing data from 80 children who underwent extratemporal resections, they discovered 50% achieved complete seizure freedom. When entered into a proportional hazard model, non-specific lesion pathology emerged as the only factor associated with a higher risk of post-operative seizure recurrence.

The study by D’Argenzio et al. is one of the largest to demonstrate the potential beneficial effects of extratemporal resections in children. It adds to the growing body of literature suggesting that such resections, although not as successful as amygdalohippocampectomies, are often the best option for children whose seizures have not responded to at least two AEDs. Unlike the third AED, which has a success rate no higher than 5% to 10%, surgical resection may offer up to half of those children the promise of seizure freedom. Although the process needed to reach surgery may be costly, requiring advanced imaging, prolonged video-electroencephalographic monitoring, and even intracranial monitoring, the rewards are vast. Such intervention may reduce the risk of subsequent intellectual and behavioral decline, injury from seizures and/or status epilepticus, and sudden unexpected death in epilepsy (SUDEP). Control of extratemporal seizures with surgery also has the potential to incur social benefits, allowing children to once again safely and actively participate in their homes, schools, and communities. Ask any adolescent with medically intractable epilepsy whether he or she would like a 5% to 10% chance or 50% chance of one day being able to get a learner’s permit to drive; the answer likely won’t come as a surprise.

The study by D’Argenzio et al. was not without limitations. A sizable minority (38%) of their cohort had <2 years of post-operative follow-up. Two years is generally considered the criterion standard in epilepsy surgery research. Therefore, it is possible extending the follow-up for those children may have resulted in decreased numbers remaining seizure-free. Conversely, the authors’ primary focus on only those children achieving complete seizure freedom (Engel classification Ia) downplays the number of additional children who benefited meaningfully from extratemporal resections. Three percent had only auras following surgery (Engel classification Ib), 3% had some seizures following surgery but were ultimately seizure-free for more than 2 years (Engel classification Ic), and 10% had only rare or nocturnal seizures following surgery (Engel classification II). Therefore, the true percentage of children with good outcomes was likely to be closer to 64%.

Despite those limitations, the findings of D’Argenzio et al. deserve notice. They support the importance of presurgical workup in all children with medically intractable focal onset epilepsy and hint at ways postsurgical outcomes may be improved in the future. Given that non-specific lesion pathology was associated with worse outcome, reseachers should focus on ways to improve existing imaging technologies (such as magnetic resonance imaging). With higher resolution scanners, it may be possible to identify subtle lesions that previously escaped detection and are amenable to resection with a higher rate of cure. In addition, the role of imaging modalities that have become more widespread since 1997 (such as magnetoencephalography and ictal single-photon emission computed tomography) in identifying appropriate extratemporal surgical candidates needs to be further explored. Hopefully, with such research, it may be possible to one day offer the same rate of postoperative seizure freedom to children with extratemporal epilepsy as their temporal lobe counterparts.

References

  1. Top of page
  2. References
  • 1
    Berg AT, Shinnar S, Levy SR, Testa FM, Smith-Rapaport S, Beckerman B. Early development of intractable epilepsy in children: a prospective study. Neurology 2001; 56: 144552.
  • 2
    Dlugos DJ, Sammel MD, Strom BL, Farrar JT. Response to first drug trial predicts outcome in childhood temporal lobe epilepsy. Neurology 2001; 57: 225964.
  • 3
    Mittal S, Montes JL, Farmer JP, et al. Long-term outcome after surgical treatment of temporal lobe epilepsy in children. J Neurosurg 2005; 103(Suppl. 5): 40112.
  • 4
    Terra-Bustamante VC, Inuzuca LM, Fernandes RM, et al. Temporal lobe epilepsy surgery in children and adolescents: clinical characteristics and post-surgical outcome. Seizure 2005; 14: 27481.
  • 5
    Benifla M, Otsubo H, Ochi A, et al. Temporal lobe surgery for intractable epilepsy in children: an analysis of outcomes in 126 children. Neurosurgery 2006; 59: 120313.
  • 6
    D’Argenzio L, Chiara Colonnelli M, Harrison S, et al. Seizure outcome after extra-temporal epilepsy surgery in childhood. Dev Med Child Neurol DOI: 10.1111/j.1469-8749.2012.04381.x. (Published online).