Outcome of Therapies for Dysembryoplastic Neuroepithelial Tumors in Children

Tumor Recurrence

• Rare after complete resection: From the oncological point of view, recurrences and malignant transformation are rare.

Seizure Recurrence

• 60–90% Engel Class I: More important is the discussion about long-term seizure control. In most published series (1, 3, 9, 11, 23, 27, 36, 38), most patients obtained very good results for epilepsy control, with figures of Engel class I of 60–90%.

Predictors of poor outcome

• Duration of seizures: Duration of seizures is especially relevant in earlier series, where most patients were recruited from large conservatively managed epilepsy populations(1,21).

• Incomplete resection of epileptogenic focus: This is more common with extratemporal DNETs, possibly due to the fact that these tumors are resected without the wide margin of additional brain parenchyma, as is case with temporal DNETs  where a temporal lobectomy is frequently also done. It is advisable to also resect adjacent regions of focal cortical dysplasia, since these are epileptogenic, and residual dysplastic parenchyma is highly associated with recurrence of seizures (37).

Cognitive Outcome

• Unclear and in need of study: Most authors do not describe a negative effect on cognitive functioning of the children in their surgical series, while most epilepsy surgery programs have some form of systematic neuropsychological testing. All the same, a recent report by Qaddoumi et al. (30) warns of a possible negative effect on cognitive functions. Definite conclusions cannot be drawn from this relatively small but extensively studied series. However, all children with glioneural tumors should be closely followed for a possible decline in academic functioning.