Purpose of review
To illustrate the frequency and trends of the comorbidity of epilepsy and dementia and the effects of antiepileptic drugs (AEDs) on cognitive functions.
Although the mortality and incidence of epilepsy are decreasing overall, they are increasing in the elderly as a result of population growth and increased life expectancy. Alzheimer's disease and other dementias are among the commonest causes of seizures and epilepsy. Epilepsy can be also complicated by cognitive impairment, suggesting a bidirectional association. Although epilepsy with onset in the elderly can be the manifestation of a CNS disease/injury, the cause of cognitive impairment is multifactorial and includes static (genetic background, age at seizure onset, developmental and acquired cerebral lesions) and dynamic factors [recurrent seizures, epileptiform discharges, type and number of AEDs and psychiatric comorbidities]. Most AEDs, with special reference to first-generation drugs, have negative effects on cognitive functions; however, none was found to increase the risk of dementia.
A net increase in the burden of epilepsy, dementia and epilepsy-dementia comorbidity is expected. The growing use of second-generation AEDs might help reducing adverse cognitive effects. However, the fairly high cost of these drugs might delay their widespread use in resource-poor countries.