New-onset status epilepticus and cluster seizures in the elderly

Abstract

We evaluated the frequency, therapeutic response and predictors of status epilepticus (SE) and cluster seizures among elderly people. Patients over 60years old with epilepsy (n=201; age, 68.0±7.5years) were prospectively recruited. Among them, 64 patients (32%) who presented with new-onset cluster attacks and/or SE formed the study group. All underwent evaluation with electroencephalography (EEG) and CT scans. The mean duration of SE and cluster seizures at admission was 14.9±53.7hours. Cluster seizures were observed in 53 (26.4%) and SE in 34 (17%) elderly patients with seizures (n=201). The types of SE were: generalized convulsive (23 patients), epilepsia partialis continua (eight patients), non-convulsive (two patients) and myoclonic (one patient). The types of epilepsy syndrome included were: acute symptomatic (37 patients; 57.8%), cryptogenic (15 patients; 23.4%) and remote symptomatic (12 patients; 18.8%). Interictal EEG was abnormal in 79.7% of patients with critical presentation compared to 53.3% of patients without critical presentation. Epileptiform activity was observed in 46.9% of patients with SE and/or cluster seizures compared to 27.0% without SE and/or cluster seizures (p=0.001). The neuroimaging differences between the two groups were the absence of white-matter changes on CT scan in those with, compared to those without, SE and/or cluster seizures (28.1% compared to 41.6%, p=0.06). The risk factors for SE and/or cluster seizures were: acute symptomatic seizures, simple partial seizures, a higher number of seizures, lower Glasgow coma scale (GCS) score and an absence of white-matter changes on CT scan. After multivariate analysis, lower GCS score (p=0.01; odds ratio [OR]=0.82) and a higher number of seizures (p=0.03; OR=1.03) significantly predicted the occurrence of SE and/or cluster seizures. Seizures were controlled with two antiepileptic drugs in 70.6%. To conclude, SE and/or cluster seizures are common (32%) among elderly patients with epilepsy. Early and aggressive treatment is effective in the majority.