Clonazepam-induced tonic seizure
Iwakawa, Y.; Niwa, T.; Suzuki, H.
No To Hattatsu 18(5): 347-353
1986
ISSN/ISBN: 0029-0831 PMID: 3756018 Document Number: 277709
The clonazepam (CZP)-induced tonic seizure was reported in a girl with psychomotor seizures (PM). She had been uneventful until the age of 1 year when febrile tonic-clonic seizures began. At 5 years, she had the first attack of unconsciousness with behavioral automatism. During loss of consciousness, the EEG showed high voltage and irregular 4 .apprx. 7 Hz slow bursts in the centro-parieto-occipital region. From 12 years, in addition to phenobarbital, sodium valproate, carbamazepin and phenytoin, CZP was administered daily. At 15 years, she experienced tonic seizures; with myoclonia of eyelids, eyes-rolling from side to side, hypertonia of the limbs, increased salivary secretion and irregular respiration in the drowsy state. The seizures, lasting 1 to 3 minutes, ceased suddenly with a sigh. The ictal EEG revealed a diffuse fast activity of 10 .apprx. 20 Hz and 100 .apprx. 200 .mu.v, ending without electrical suppression. CZP was gradually discontinued and the tonic seizures disappeared within 1 weeks. Four serial polysomnographical (PSG) recordings were performed. During the period under the CPZ therapy, both tonic (% stage REM and % slow wave sleep) and phasic (gross movements, twitch movements and REMs) events of sleep components were severely suppressed. At 1 week and 2 months after withdrawal of CZP, both parameters returned to normal except the abnormality of gross movements and twitch movements. Our previous PSG studies indicated that the prognosis of epileptic seizures in PM and age-dependent epileptic encephalopathy related to the neural mechanism regulating sheep parameters. It was suggested that the neural mechanism controlling sleep parameters are etiologically important in CZP-induced tonic seizures.