Animal models of nonconvulsive status epilepticus.

Nonconvulsive status epilepticus includes three clinical situations: complex partial status epilepticus; absence status epilepticus: and obtundation in the presence of electrographic status epilepticus. Animal models that provide information helpful to clinical management exist for both complex partial and absence status epilepticus. In models of complex partial status epilepticus (pilocarpine, kainic acid, and various protocols using electrical stimulation), neuronal damage in discrete neuronal populations follows an episode of status epilepticus. Hippocampal populations are particularly susceptible to neuropathologic sequelae. Although it is difficult in some cases to distinguish whether the inducing agent or the status epilepticus causes neuropathology, the similar patterns of damage caused by different inducing stimuli provide converging lines of evidence suggesting that the neuropathologic consequences stem at least in part from status epilepticus. In models of absence status epilepticus (genetic mutants, pentylenetetrazole), there is relatively scarce neuropathology that can be attributed directly to status epilepticus. Together these data from animal models suggest that neuropathologic consequences from complex partial status epilepticus may be more severe than those from absence status epilepticus. If these findings translate to patients, then nonconvulsive status epilepticus of the complex partial type should be managed more aggressively than nonconvulsive status epilepticus of the absence type.