Presentation of Supratentorial Dysembryoplastic Neuroepithelial Tumors in Children

Symptoms

• Seizures: In the original series of Daumas-Duport et al. (11), all patients with DNETs were suffering from partial epilepsy of long duration that was refractory to medical treatment. The association with focal epilepsy was confirmed by most other series. However, the diagnosis of a DNET is more often made after only one or a few seizures, probably because of the more widespread use of MR imaging after a single paroxysmal event.
• Seizure types are function of tumor location: From a clinical point of view, different types of epilepsy can be found in patients with a DNET: simple partial seizures, complex partial seizures, absence seizures, and generalized tonic-clonic seizures. To a large extent, this is explained by the anatomic location of the tumor, situated in many cases in the temporal lobe.

Patterns of evolution

• History of long-standing epilepsy: Most children with DNET reported in the literature have long-standing chronic epilepsy that was treated with several antiepileptic drugs. No clear pattern can be distilled from these series. As stated in the previous paragraph, in recent years the diagnosis is more and more often made early, after the first few seizures. In these children, it is hoped that early treatment will prevent the evolution towards chronic epilepsy.

Time for evolution

• Slow: The speed of evolution is slow. In general, no neurological symptoms develop apart from the seizure disorder.

Evaluation at Presentation

• See EVALUATION

Intervention

Stabilization

Children with DNET as a rule do not present critically ill and have been followed by their pediatric neurologist for some time. The exception will be the child presenting with intractable status epilepticus due to the DNET.

• Status epilepticus: Children presenting in status epilepticus require maximal antiepileptic treatment, including intensive care, continuous EEG monitoring, sedation, and possibly barbiturate coma.

Preparation for definitive intervention, nonemergent

• Preparation for surgery: Typically, by the time of admission most investigations of the child’s seizures will have been performed in an ambulatory setting.  An MRI scan will be needed for neuronavigation guidance. Depending on the navigation system used and the registration procedure (fiducials, surface matching, electromagnetic), fiducials may need to be attached to the patient’s forehead and scalp.

Admission Orders

• Anticonvulsant medications: Care must be taken to continue or change the antiepileptic drugs in consultation with the epileptologist. If the child has refractory epilepsy, serum levels of any anti-epileptic drugs will be determined and discussed with the child’s neurologist or epileptologist.