Partial Seizures and Consciousness: Insights from Rodent Models

Temporal lobe epilepsy (TLE) is a devastating disease in which patients suffer from seizures that often begin in the brain's limbic center. Seizures in TLE can be either simple-partial seizures, in which consciousness is preserved, or complex-partial seizures, in which consciousness is lost. It is perplexing that complex-partial seizures cause loss of consciousness even though the seizure remains confined to temporal lobe areas not associated with consciousness. What causes loss of consciousness during partial seizures? To investigate changes in brain activity during partial seizures, and how they might cause a loss of consciousness, we studied temporal-lobe seizures in rats. Our work suggests that even when a seizure is limited to the temporal lobe, it can lead to brain changes that resemble sleep or coma. However, we were able to prevent these changes with surgery or drugs. These findings may lead to better treatment of TLE, and can help us learn more about consciousness.