[Confluence of dementia and epilepsy pathologies].

Epilepsy in patients with Alzheimer's disease (AD) is not a mere complication of another common disease, but a result of synaptic dysfunction due to accumulation of toxic amyloid β (Aβ). An epileptic attack triggers formation of a new neuronal circuit to lower the threshold of the next attack, which is a result of inherent neuronal plasticity. In patients with AD, this plasticity is impaired such that a "seizures beget seizures" situation does not occur. Thus, patients with epilepsy in AD often respond well to medication.