The patient meets none of the following criteria (mark if absent):
Active seizures (Patients with a history of seizures, who have been seizure-free on an antiepileptic regimen for six months or more would be eligible).
Rett's Syndrome or Childhood Disintegrative Disorder
Active treatment with an acetylcholinesterase inhibitor
Prior or current treatment with memantine
Current treatment with lamotrigine
Genetic, metabolic or degenerative disorder (excepting Fragile X).
