Seizures in patients with Alzheimer's disease or vascular dementia: a population-based nested case-control analysis

Epilepsia. 2013 Apr;54(4):700-7. doi: 10.1111/epi.12045. Epub 2012 Dec 6.

Abstract

Purpose: Patients with Alzheimer's disease (AD) have an increased risk of developing seizures or epilepsy. Little is known about the role of risk factors and about the risk of developing seizures/epilepsy in patients with vascular dementia (VD). The aim of this study was to assess incidence rates (IRs) of seizures/epilepsy in patients with AD, VD, or without dementia, and to identify potential risk factors of seizures or epilepsy.

Methods: We conducted a follow-up study with a nested case-control analysis using the United Kingdom-based General Practice Research Database (GPRD). We identified patients aged ≥65 years with an incident diagnosis of AD or VD between 1998 and 2008 and a matched comparison group of dementia-free patients. Conditional logistic regression was used to estimate the odds ratio (OR) with a 95% confidence interval (CI) of developing seizures/epilepsy in patients with AD or VD, stratified by age at onset and duration of dementia as well as by use of antidementia drugs.

Key findings: Among 7,086 cases with AD, 4,438 with VD, and 11,524 matched dementia-free patients, we identified 180 cases with an incident diagnosis of seizures/epilepsy. The IRs of epilepsy/seizures for patients with AD or VD were 5.6/1,000 person-years (py) (95% CI 4.6-6.9) and 7.5/1,000 py (95% CI 5.7-9.7), respectively, and 0.8/1,000 py (95% CI 0.6-1.1) in the dementia-free group. In the nested case-control analysis, patients with longer standing (≥3 years) AD had a slightly higher risk of developing seizures or epilepsy than those with a shorter disease duration, whereas in patients with VD the contrary was observed.

Significance: Seizures or epilepsy were substantially more common in patients with AD and VD than in dementia-free patients. The role of disease duration as a risk factor for seizures/epilepsy seems to differ between AD and VD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / complications*
  • Alzheimer Disease / epidemiology*
  • Body Mass Index
  • Case-Control Studies
  • Comorbidity
  • Data Interpretation, Statistical
  • Databases, Factual
  • Dementia, Vascular / complications*
  • Dementia, Vascular / epidemiology*
  • Epilepsy / epidemiology
  • Epilepsy / etiology
  • Female
  • Follow-Up Studies
  • General Practice / statistics & numerical data
  • Humans
  • Logistic Models
  • Male
  • Odds Ratio
  • Population
  • Risk
  • Risk Factors
  • Seizures / complications*
  • Seizures / epidemiology*
  • Sex Factors
  • Smoking / epidemiology
  • United Kingdom / epidemiology