Abstracts

To investigate the effects of lamotrigine on cerebral blood flow, we performed ^99mTc-ethylcysteinate dimer single photon emission computed tomography (SPECT) before and after medication in patients with drug naive idiopathic generalized epilepsy. Brain SPECT was performed before drug treatment started and then repeated after lamotrigine medication for 4 - 5 months in 30 patients with generalized epilepsy (M/F=14/16, 19.3 [plusmn] 3.4 years). Seizure types were generalized tonic clonic seizure in 23 patients, and myoclonic seizures with rare generalized tonic clonic seizure in 7. The mean lamotrigine dose used was 214.1 [plusmn] 29.1 mg /day. For SPM analysis, all SPECT images were spatially normalized to the standard SPECT template and then smoothed using a 12-mm full width at half-maximum Gaussian kernel. The paired [italic]t[/italic]-test was used to compare pre- and post-lamotrigine SPECT images. SPM analysis of pre- and post-lamotrigine brain SPECT images showed decreased rCBF in bilateral dorsomedial nuclei of thalami, bilateral uncus, right amygdala, left subcallosal gyrus, right superior and inferior frontal gyri, right precentral gyrus, bilateral superior and inferior temporal gyri, and brainstem (pons, medulla) after lamotrigine medication at a false discovery rate corrected [italic]p[/italic][lt]0.05. No brain region showed increased rCBF after lamotrigine administration. Our study demonstrates for the first time the effect of lamotrigine on cerebral blood flow in drug naive idiopathic generalized epilepsy patients. In summary, lamotrigine medication was found to reduce rCBF in cortico-thalamo-limbic areas, the orbitofrontal cortex, and brainstem.[figure1] (Supported by a grant (no. HMP-03-PJ1-PG3-21300-0033) of the Good Health R[amp]D Project, Ministry of Health [amp] Welfare, Republic of Korea.)