This book collects the results of clinical experience and research, as well as the opionions of the specialists who have studied in depth several rare and complex syndromes associated with "Continuous Spikes and Waves During Slow Sleep", the Landau-Kleffner syndrome, and related conditions. It also presents a wide-ranging collection of cases presented by the participants in the meeting, and analysed in its various clinical, electrophysiological and psycho-intellectual aspects. The purpose of the book is to provide a thorough updated on specialised knowledge about the syndromes characterised by the presence of CSWS on the EEG, to bring out the many, still unanswered -- questions, and to stimulate further interdisciplinary research to verify the validity of present hypotheses, in order to clarify which preventive and therapeutic methods can best attain the control of such syndromes.