Memory loss and memory reorganization patterns in temporal lobe epilepsy patients undergoing anterior temporal lobe resection, as demonstrated by pre-versus post-operative functional MRI.

This study was aimed to longitudinally assess memory function and whole-brain memory circuit reorganization in patients with temporal lobe epilepsy (TLE) by comparing activation potentials before versus after anterior temporal lobe (ATL) resection. Nineteen patients with medically-intractable TLE (10 left TLE, 9 right TLE) and 15 healthy controls were enrolled. Group analyses were conducted pre- and post-ATL of a novelty complex scene-encoding paradigm comparing areas of blood oxygen-level-dependent (BOLD) signal activations on functional magnetic resonance imaging (fMRI). None of the pre-operative patient characteristics we studied predicted the extent of pre- to post-operative memory loss. On fMRI, extra-temporal activations were detected pre-operatively in both LTLE and RTLE, particularly in the frontal lobe. Greater activations also were noted in the contralateral hippocampus and parahippocampus in both groups. Performing within-subject comparisons, post-op relative to pre-op, pronounced ipsilateral activations were identified in the left parahippocampal gyrus in LTLE, versus the right middle temporal gyrus in RTLE patients. Memory function was impaired pre-operatively but declined after ATL resection in both RTLE and LTLE patients. Post-operative fMRI results indicate possible functional adaptations to ATL loss, primarily occurring within the left parahippocampal gyrus versus right middle temporal gyrus in LTLE versus RTLE patients, respectively.

Electroencephalographic and Electrocardiographic Effect of Intravenous Lacosamide in Refractory Focal Epilepsy.

PURPOSE: Lacosamide selectively enhances slow inactivation of voltage-gated sodium channels to achieve seizure reduction. We studied the effect of intravenous lacosamide given as one of three single doses on EEG and electrocardiogram, as well as its tolerability in patients with drug-resistant epilepsy. METHODS: This Canadian, investigator-initiated, multicenter, double-blind study recruited patients with refractory focal epilepsy admitted to a seizure monitoring unit. Participants received a loading dose of 100, 200, or 400 mg lacosamide over 30 minutes during continuous monitoring by video-EEG and 12-lead electrocardiogram. The number of interictal spikes, frequency and quantity of background EEG rhythms, corrected QT interval (QTc), PR interval, heart rate (HR), blood pressure, and respiration rate during 60 minutes before the administration were compared with 60 minutes after the infusion. We documented any adverse event during and after the infusion. RESULTS: Seventy-one patients completed the study. There was a significant decrease in interictal spikes (P = 0.039) and decreased frequency of the alpha rhythm (P = 0.003). No significant difference in beta, theta, and delta frequency or amount was noted. There were significant increases in PR interval (153.4-155.8 ms, P = 0.031) and HR (73.4-75.5 bpm, P = 0.022), but QTc, blood pressure, and respiration rate were not affected. Twelve patients (16.9%) experienced transient and mild adverse events, mainly dizziness and leg tingling. More adverse events occurred with 400 mg lacosamide than with the lower doses (P = 0.048). CONCLUSIONS: Intravenous lacosamide is effective in decreasing interictal spikes. Despite a small effect on EEG and electrocardiogram rhythms, it is well tolerated with no serious adverse events.