[Epilepsy and sleep: with special reference to nonconvulsive status epilepticus with continuous diffuse spike-waves...

There are numerous important problems concerning relationship between epilepsy and sleep. To clarify the clinical significance and pathophysiology of the nonconvulsive status epilepticus with continuous diffuse spike-waves during slow-wave sleep (CSWS) in EEG, this study was carried out on seven cases each of epilepsies with electrical status epilepticus during slow sleep (ESES) and with peculiar type of nonconvulsive status epilepticus in childhood (PNSE) and four cases of atypical benign partial epilepsy (ABPE). Mental deterioration was most frequently observed in ESES, less in PNSE but none in ABPE. In both ESES and PNSE, mentally deteriorated cases showed suppression of CSWS at significantly later ages than those without deterioration. And spike-wave indices during slow-wave sleep, which were the highest in ESES and lower in PNSE and ABPE, also had a strong relation to mental deterioration. In these three disorders, both clinical seizures and CSWS were suppressed at or before 16 years of age, although they were intractable before adolescence. This finding indicated age dependent evolutions of the three disorders. Coherence and phase analysis of CSWS was undertaken to differentiate primary and secondary bilateral synchrony in seven cases of these three disorders, which have both features of generalized and partial epilepsies. This analysis disclosed secondary bilateral synchrony as the nature of CSWS in six cases. And this analysis method was considered to provide a clue to their pathophysiology. Thus, in these disorders, importance of early diagnosis by EEG including deep sleep and early treatment was recognized.