Insights into the tetanus toxin model of early-onset epilepsy from long-term video monitoring during anticonvulsant therapy

Video monitoring studies were undertaken to determine if the anticonvulsant , carbamazepine (CBZ), could prevent seizures in infant rats that had been intrahippocampally injected with tetanus toxin (TNTX). in control rats, sei zure frequency peaked 5-6 days after injection and rapidly declined by post injection day 9. Twice-daily CBZ treatments dramatically suppressed behavio ral seizures for 7 days. However, despite increasing the dosage of CBZ, rat s experienced more behavioral seizures during the second week after TNTX in jection. Paradoxically, tetanus-toxin-injected control rats had very few se izures at this time. Results not only suggest that this TNTX model may be u seful in screening drugs for treating intractable focal epilepsy of infancy but also provide some insight into the processes that may contribute to th e rapid decline in behavioral seizure frequency that occurs during the acut e phase of epileptogenesis in this model. (C) 1999 Published by Elsevier Sc ience B.V. All rights reserved.