Changes of seizures activity during rapid withdrawal of lamotrigine

Quantitatively evaluating the rapid withdrawal effects of lamotrigine (LTG) and carbamazepine (CBZ) on seizure activity during pre-surgical evaluation in patients with pharmacoresistant complex partial epilepsy. The duration and frequency of seizure activities and electrographic seizure onset of 41 patients totally withdrawing from CBZ monotherapy (n ¼ 20), LTG monotherapy (n ¼ 10) and CBZ + LTG combined therapy (n ¼ 11) were intensively studied by therapeutic intensive seizure analysis (TISA) method. Study phases ran from the baseline phase to the antiepileptic drug (AED) withdrawal phase until the AED free phase, 3 days for each phase. Seizure duration and frequency obviously increased during the withdrawal process in each group (P 0.05). There was no change of ictal EEG localization during all withdrawal protocols. All patients experienced more severe seizures during the withdrawal processes. An earlier aggravation of the clonic signs than the tonic signs was observed in each group. Difference between the withdrawal effects of LTG and CBZ monotherapy and LTG + CBZ polytherapy was mainly in the frequency change of ictal signs. The withdrawal process did not influence the ictal EEG localization. This study justified the withdrawal in pre-surgical localization, rationalized precautions for possible accompanying risks, and also aroused attentions in clinical anticonvulsant trials and substitutions involving withdrawal process.