Non convulsive status epilepticus after replacement of valproate with lamotrigine.

Purpose: Lamotrigine (LTG) and valproate (VPA) are widely used in the treatment of generalized epilepsies. Nevertheless seizure aggravation with LTG has been reported in juvenile myoclonic epilepsy and epilepsy with myoclonic absences. The aim of this study was to describe clinical features and EEG findings in patients with non convulsive status epilepticus (NCSE) after replacement of VPA with LTG.

Method: Retrospective analysis of three identified patients in a large university hospital.

Results: We describe three adult patients aged 39, 50 and 75 years, who developed non-convulsive status epilepticus (NCSE) after replacement of VPA with LTG. The episodes of NCSE presented as an acute confusional state with mild myoclonus. Ictal EEG showed generalized spike-wave or polyspike wave activity. The clinical symptoms and the EEG responded promptly to IV benzodiazepines and patients remained well controlled with dose reduction of LTG (in one patient) or discontinuation of LTG (in two patients).

Conclusion: The reported episodes of NCSE in these patients with generalized epilepsy may be either due to a possible paradoxical reaction to LTG or due to a withdrawal effect of VPA.