To the Editors:
Sarkis et al. (2012) reported worsening of seizures in 18.5% of their surgical patients and attributed the worsening to extratemporal resections, incomplete resections, and multiple recorded ictal patterns. An additional explanation may be that surgery could not prevent a worsening pattern of epilepsy in the natural history of epilepsy that would have occurred without surgery. A worsening pattern of epilepsy—with uncontrolled seizures after initial remission—has been reported in 14% of patients with new-onset epilepsy during long-term observations in a nonsurgical series of childhood-onset epilepsy (Sillanpää & Schmidt, 2006). In addition, Geerts et al. (2012) recently noted that antiepileptic drug treatment had only a small effect on patterns of intractability in childhood-onset epilepsy. Given that the study by Sarkis et al. (2012) did not report how many of their patients had a stable pattern of drug-resistant epilepsy and how many had a history of worsening epilepsy prior to surgery, further work is needed to assess the effect of surgery, if any, on these patterns of the natural history of medically treated epilepsy.