Simultaneous kindling of the bilateral hippocampi: An advanced model for epilepsy research

Purpose: To examine whether simultaneous kindling of bilateral hippocampi [ bilateral kindling (BK)] could accelerate the achievement of seizures by th e breakdown of kindling antagonism or decelerate the achievement of seizure s by its enhancement. Methods: The hippocampi of 17 adult rabbits were simultaneously kindled bil aterally according to Goddard's method. Results: All animals developed stage 5 convulsions after a mean of 28 stimu lations. Six animals showed spontaneous seizure discharges. Afterdischarge duration increased abruptly during the early period of kindling, but therea fter it gradually progressed. Chronological analyses of interictal discharg es (IIDs) demonstrated that simple as weil as complex types of IIDs increas ed their frequencies during BK. Conclusions: Compared with unilaterally kindled animals, the BK procedure s ignificantly increased the percentage of animals that successfully kindled (100% vs. 59%; p < 0.01), whereas it significantly decelerated the kindling progression (28 days vs. 19 days; p < 0.02). We conclude that the BK proce dure represents potentiation of both excitatory and inhibitory mechanisms. Although the reason why such an antagonistic relationship between them brea ks down is still unknown, the BK provides an advanced animal model to study the pathogenic mechanisms of kindling and to screen anticonvulsants.