Abstract
Objective
To establish if advanced workup including long-term EEG (LT-EEG) and brain MRI provides an additional yield for the diagnosis of new onset epilepsy (NOE) in patients presenting with a first seizure event (FSE).
Methods
In this population-based study, all adult (≥16 years) patients presenting with FSE in the emergency department (ED) between 1.3.2010 and 1.3.2017 were assessed. Patients with obvious non-epileptic or acute symptomatic seizures were excluded. Routine EEG, LT-EEG, brain CT and brain MRI were performed as part of the initial workup. These exams’ sensitivity and specificity were calculated on the basis of the final diagnosis after 2 years, along with the added value of advanced workup (MRI and LT-EEG) over routine work-up (routine EEG and CT).
Results
Of the 1010 patients presenting with FSE in the ED, a definite diagnosis of NOE was obtained for 501 patients (49.6%). Sensitivity of LT-EEG was higher than those of routine EEG (54.39 vs 25.5%, p<0.001). Similarly, sensitivity of MRI was higher than that of CT (67.98 vs 54.72%; p=0.009). Brain MRI showed epileptogenic lesions in an additional 32% compared to brain CT. If only MRI and LT-EEG were considered, 5 would have been incorrectly diagnosed as non-epileptic (5/100; 5%) compared to patients with routine EEG and MRI (25/100; 25%; p=0.0001). In patients with all four exams, advanced workup provided an overall additional yield of 50% compared to routine workup.
Significance
Our results demonstrate the remarkable added value of the advanced workup launched already in the ED for the diagnosis of NOE vs non-epileptic causes of seizure mimickers. Our findings suggest the benefit of first-seizure tracks or even units with overnight EEG, similar to stroke units, activated upon admission in the ED.
SEP