Incidence and predictors of seizures in patients with Alzheimer's disease.
OBJECTIVE
To determine cumulative incidence and predictors of new-onset seizures in mild Alzheimer's disease (AD) with a cohort followed prospectively. Limited information is available on the incidence of seizures, and no reports exist of seizure predictors in AD patients.


METHODS
Mild AD patients were prospectively followed at 6-month intervals to estimate incidence of unprovoked seizures, compare age-specific risk of unprovoked seizures with population norms, and identify characteristics at baseline (demographics, duration and severity of AD, physical and diagnostic test findings, and comorbid medical and psychiatric conditions) influencing unprovoked seizure risk. Review of study charts and medical records supplemented coded end-point data.


RESULTS
The cumulative incidence of unprovoked seizures at 7 years was nearly 8%. In all age groups, risk was increased compared with a standard population, with an 87-fold increase in the youngest group (age 50-59 years) and more than a threefold increase in the oldest group (age 85+ years). In multivariate modeling, independent predictors of unprovoked seizures were younger age [relative risk (RR), 0.89 per year increase in age; 95% confidence interval (CI), 0.82-0.97], African-American ethnic background (RR, 7.35; 95% CI, 1.42-37.98), more-severe dementia (RR, 4.15; 95% CI, 1.06-16.27), and focal epileptiform findings on electroencephalogram (EEG) (RR, 73.36; 95% CI, 1.75-3075.25).


CONCLUSIONS
Seizure incidence is increased in people starting with mild-to-moderate AD. Younger individuals, African Americans, and those with more-severe disease or focal epileptiform findings on EEG were more likely to have unprovoked seizures.
Amatniek
Joan C
JC
Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Hauser
W Allen
WA
DelCastillo-Castaneda
Carrie
C
Jacobs
Diane M
DM
Marder
Karen
K
Bell
Karen
K
Albert
Marilyn
M
Brandt
Joseph
J
Stern
Yaakov
Y