Negative Myoclonic Status Due to Antiepileptic Drug Tapering: Report of Three Cases

摘要: Summary: Purpose: Epileptic negative myoclonus (ENM) has been increasingly recognized in different epilepsies, but the reasons for its appearance and prognosis remain uncertain. We report 3 patients who developed de novo, almost continuous ENM, triggered by antiepileptic drug (AED) tapering, that resolved with treatment. Methods: Three aged 16, 19, 65 years a 13to 36-year history of partial epilepsy were receiving therapeutic dosage carbamazepine or phenobarbital plus either clobazam (CLB) valproate (VPA). None had previously ENM. Forty-eight to 72 h after CLB VPA withdrawal, habitual seizures recurred. The patient also began repetitive postural lapses one more limbs interfered eating writing. At this time, each underwent polygraphy simultaneous surface electromyography (EMG) deltoid, biceps, triceps muscles wrist extensor flexor bilaterally. Results: In all patients, EEGs demonstrated epileptiform discharges whose spatial distribution was similar observed before ENM appearance. Polygraphic recordings showed loss EMG activity limbs, 100400 ms duration, which occurred conjunction spike-waves. One milligram clonazepam intravenously always terminated status, not recurred ensuing 9-36 months. Conclusions: may emerge as new type seizure due tapering AED therapy. This effect is possibly related great activation consequent interference cortical activity. Key Words: Antiepileptic drugs-Electroencephalography-Negative myoclonusPartial epilepsy-Status epilepticus.