Based on investigations done so far, children with NS appear to suffer from multiple clinical and electrographic seizure types, including generalized tonic-clonic, partial complex, atypical absence, and atonic seizures. Seizures are classified as partial generalized, and unclassified based on the clinical features and associated electroencephalographic findings (Appendix Y). There are many causes for seizures, including infectious, metabolic, drugs, genetic, nutritional, endocrinal, and trauma. In some cases, an etiology is not known, and the seizures are referred to as idiopathic or cryptogenic. Currently, because an etiology for NS has not been identified, the children suffer from multiple different seizure types, and many children demonstrate cognitive impairment, NS could be considered a form of cryptogenic epileptic encephalopathy. This is important because such epilepsies can be very difficult to control with standard AEDs, and in some cases, may be exacerbated with certain AEDs (e.g., carbamazepine) (18, 19, 20, 21, 22). Thus, a formal assessment of the effects of AEDs on children with NS is important.