The purpose of this study is to report the case of a patient with normal
lithium serum levels who developed
non-convulsive status epilepticus (NCSE). A 52-year-old woman with
bipolar disorder type I (DSM-IV) treated with
lithium experienced bradypsychism and episodes of
confusion and spatial disorientation without signs or symptoms of
lithium intoxication.
Lithium serum levels were in the normal range. A brain MR scan was negative; the electroencephalogram (EEG) revealed a background 3-4 Hz delta rhythm and diffuse spike discharges. Prompt EEG and clinical response to intravenous
diazepam therapy was observed. Based on these findings, a diagnosis of NCSE was made and
lithium therapy was withdrawn, resulting in symptom remission and EEG normalization. The treatment was resumed after two months to test the correlation between NCSE and
lithium therapy. Resumption of therapeutic range
lithium induced the same clinical symptoms and EEG patterns; the
therapy was thus definitively discontinued. The present data-signalling the temporal correlation of clinical and EEG changes with
drug administration and withdrawal-suggest that even in the therapeutic range
lithium treatment may trigger NCSE onset in predisposed subjects.