Epileptic variant in the spectrum of Alzheimer's disease - practical implications.

Alzheimer's disease (AD) is known to be associated with an increased risk of epilepsy, which is not exclusively related to the late stage of the disease - when a major cognitive impairment is observed, previously known as the dementia stage - but also to its prodromal stage (mild cognitive impairment). Moreover, published case reports and cohorts have shown that epilepsy may occur even earlier, at the preclinical stage of AD: Epileptic seizures may therefore be the sole objective manifestation of the disease. Such a situation is called the epileptic variant of AD (evAD). EvAD is one of the etiologies of late-onset epilepsy, which means that it carries a risk of later progression to dementia and that it can only be diagnosed by assessing amyloid and tau biomarkers. However, evAD is a window of therapeutic opportunity that is probably optimal for preventing, through antiseizure medication treatment, the accelerated cognitive decline associated with AD-related brain hyperexcitability (manifested by seizures or interictal epileptiform activities).