Sleeping-waking rhythm and frequency of seizures in epilepsy without psychoses and with chronic psychoses.

Sleeping-waking is a basic biological rhythm. A study of sleep in epilepsy established that changes in the EEG vary with different sleep phases. Activation of epileptic electroencephalographic phenomena was observed more frequently during NREM (non-rapid eye movement) phases; the REM, or paradoxical, sleep phase seemed to inhibit such phenomena. On this basis some authors are attempting far-reaching conclusions concerning a connection between separate sleep phases and the development of epileptic seizures. To a certain degree, a similar interpretation is focusing on the problem of the relationship of seizures and their frequency to the sleeping-waking rhythm. In this connection, it must be noted that in themselves EEG changes and epilepsy, a disease in which convulsive episodes play a substantial role, are not identical. Horyd and Baransia-Teruszak found no reliable correlation between EEG changes and type of seizure. There was a correlation between frequency of seizures and the electroencephalographic picture in only 30% of the cases. The authors believe that in the remaining 70% the connection between EEG shifts and clinical manifestations of epilepsy is more complex. On the other hand, as N. N. Bemin et al. indicated, based on hypotheses developed by N. P. Bekhtereva on "flexible" and "rigid" connection, sleep is one of the processes that is regulated by flexible connections and for this reason the sequence and duration of sleep phases is exceptionally variable and depends on most various external and internal factors.