Abstracts

Rationale: Literature comparing morbidity and mortality outcomes between the three major types of epilepsy surgery (resection, disconnection and modulation) for refractory status epilepticus (RSE) patients is scarce. Previous case series have focused on only one type of surgery or does not directly compare outcomes between the types of surgery. Our aim is to determine if any modality of surgery leads to better outcomes for RSE.

Methods: A retrospective analysis of 12 patients that were admitted and underwent epilepsy surgery for RSE between 2010 and 2021 was done. Sociodemographic data, semiology and etiology for all patients was collected. The patients were deidentified using our institute’s software, and comparison data was extracted from the secure system. Data collected included lag time between diagnosis and surgery, number of anti-seizure medications (ASMs) tried, EEG and imaging data, type of surgery performed, level of post-operative care, number of post-operative days admitted, complications and seizure freedom outcomes (Engel outcomes).

Results: The mean age was 35.6 + 23.5 years (range; 1-87 years), with 4 out of 12 patients being female. Seizure types were primarily generalized tonic-clonic or focal seizures with impaired awareness. Etiologies were variable including syndromic causes, trauma and lesions among others. The mean number of ASMs tried was 2.3 + 1.4. Every patient had EEG and MRI Brain performed with occasional ancillary testing such as grid placement or interictal single-photon emission computerized tomography (SPECT). Out of 12, 6 had resection, 5 disconnections and 2 neuromodulations. Nearly every patient required an ICU admission (11/12) and mean post-operative days admitted was 12 + 11.2. 33% of our resection patients had minor or no complications and 66% had major complications. While 40 % of our disconnection patients had minor complications and 60 % had major complications. 50% of our modulation patients had major complications. Patients that had undergone resections had Class 1 outcomes (3/4) and a Class 3 outcome (1/4). Patients that had undergone disconnections had Class 1 outcomes (3/5), a Class 3 outcome (1/5) and a Class 4 outcome (1/5). Patients that received modulation had a Class 4 outcome and 1 patient death.

Conclusions: Our study reveals that while there is no substantial difference between resection and disconnection, resections tend to have slightly better outcomes and fewer complications for RSE patients. Modulation had much poorer seizure freedom outcomes due to an inability to localize the seizure onset zone. Modulation may only be considered as a temporizing measure for further workup and future surgeries.

Funding: None