AIM OF THE STUDY: The aim of the study was to evaluate the clinical characteristics of patients with previous stroke (either ischemic or hemorrhagic), who developed status epilepticus (SE) mimicking a stroke relapse.
MATERIALS AND METHODS: The research team performed a retrospective cohort study of patients brought to hospital by the emergency service between December 2016 and January 2018 with a stroke code as possible candidates for intravenous thrombolysis and who had already have a previous stroke. Among them, patients admitted for negative symptoms and finally discharged with a diagnosis of SE mimicking stroke were selected and their clinical characteristics collected.
All patients underwent routine blood sample analysis, head computed tomography (CT) scan and, when indicated, CT angiography and CT-perfusion imaging of the head. After admission in the researchers’ stroke unit, an Electroencephalogram (EEG) was performed within 3 hours in patients suspected with SE, then classified according to International League Against Epilepsy (ILAE) classification (2015). Outcome measures were SE duration, antiepileptic drugs (AEDs) administered, mortality at 12 months, Engel scale, and modified Rankin scale (m-RS) at 6 months. A second cohort included those consecutive patients discharged with a true stroke relapse in the same considered time span. Clinical characteristics of these two cohorts were compared using Mann-Whitney test or Student t-test (Confidence Interval (C.I.) 95%, p < 0.05) for continuous variable and Fisher exact test or Pearson-Chi test for dichotomic variables (p < 0.05). Survival rates were calculated, and a Log-Rank test was performed to evaluate differences in survival distribution. Only in the group with SE, m-RS at 6 months and recurrence of SE were also evaluated.
RESULTS: Eleven patients were discharged with a diagnosis of SE mimicking stroke and 65 patients with stroke relapse. Temporal lobe localization was significantly more represented in group with SE (p = 0.036) while there was no difference regarding age, sex, and National Institutes of Health Stroke Scale (NIHSS). The m-RS was significantly higher in patients with hemorrhage relapse, mainly due to the high incidence of amyloid angiopathy in this subgroup. Status epilepticus recurred in 36.4% of patients, presenting with the same clinical features, and most patients (62.5%) achieved a good seizure control at 6 months (Engel scale = 1). A difference in mortality at 12 months (all cause considered) appeared only when distinguishing strokes between ischemic and hemorrhagic (Chi-Square: 10.711, p < 0.005).
DISCUSSION AND CONCLUSION: Status epilepticus is not infrequent in patients with previous stroke and may present with negative neurological symptoms, thus mimicking a stroke recurrence. EEG should be considered as a potential diagnostic tool in the acute stroke setting, at least in patients with previous stroke.