One of the most important achievement of contemporary epileptology has been a 
concept of epileptic syndromes. According to the Commission on Classification 
and Terminology of the International League Against Epilepsy there are many 
epileptic syndromes which differ from each other not only by prognosis but also 
by reaction to pharmacotherapy. Nevertheless the differentation between the some 
of epileptic syndromes may be difficult in spite of quite precise clinical and 
electrophysiological criteria. Good example of this problem may be the course of 
disease of the boy who is now eleven years old. His refractory epilepsy which 
started 7 years ago shares symptoms and signs of both epilepsy with 
myoclonic-astatic seizures (Doose Syndrome) and Lennox-Gastaut Syndrome. 
Felbamate therapy was consider to be the turning-point in both therapeutic and 
diagnostic meaning.