Abstracts

Rationale:
Bilateral tonic-clonic seizure (TCS) can occur in patients suffering from focal or generalized epilepsy. This type of seizure may be followed by prolonged postictal state and agitation that have an even larger impact on quality of life than the ictus itself.  We reviewed video recordings for postictal manifestations, including agitation, after tonic-clonic seizures in patients with various epilepsy localizations to identify differences and predictive factors.
Method:
After receiving approval from the institutional review board at Vanderbilt University Medical Center we retrospectively searched the electronic medical records for patients with generalized or focal epilepsy who had at least one tonic-clonic seizure recorded in the epilepsy monitoring unit between January 2010 and December 2019. We planned to study 15 patients in each of 4 groups: idiopathic generalized epilepsy (IGE), left temporal lobe epilepsy (LTLE), right temporal lobe epilepsy (RTLE), and frontal lobe epilepsy (FLE). Patients were included if 1) they were >18 y, 2) they had Engel I-II outcome at 1 year after epilepsy surgery or had a putative epileptogenic lesion on MRI (focal epilepsy), 3) the diagnosis was confirmed by video-EEG and clinical history (IGE), 4) they had reliable ictal and postictal video and EEG data . The video and EEG for each selected seizure was analyzed from clinical or EEG onset until the patient started to follow commands postictally. One board-certified clinical neurophysiologist (AD) reviewed all the electroclinical data and entered them in an online database.  A second reviewer (SZ) who was blinded to the clinical data also reviewed the video for postictal agitation; differences were resolved by reanalysis in conjunction with input from a third reviewer (BAK).
Results:
We reviewed 60 TCS in 15 patients with IGE and 45 patients with focal epilepsy (Table). Among the latter, 41 had undergone epilepsy surgery with Engel I-II outcome at 1-year follow-up and 4 had a clearly identifiable epileptogenic lesion in the frontal lobe.  Time to responsiveness varied from 2.3 to >30 minutes, with a mean of 11 minutes.  Time to recovery was < 11 min in 13 IGE vs only 6 LTLE patients (p< 0.05), with intermediate values for the remaining groups.  There was no difference between groups in occurrence or duration of postictal generalized EEG suppression (PGES).  Postictal agitation was noted in 15 patients (marked in 1 and mild in 14). There was a trend for more postictal agitation in LTLE than IGE and RTLE with intermediate values for FLE.  There was no relationship between postictal agitation and total seizure duration or duration of bilateral tonic-clonic phase.  Postictal agitation was not less likely with O2 administration and suctioning, which were performed in most patients.
Conclusion:
Patients with IGE tended to recover faster after a TCS than patients with LTLE. Postictal agitation was mostly mild. It tended to occur most frequently in LTLE and least frequently in IGE and RTLE. 
Funding:
:none