Abstracts

Impact of Count and Distribution of Seeg Electrodes

Abstract number : 3.563
Submission category : 9. Surgery / 9B. Pediatrics
Year : 2024
Submission ID : 1656
Source : www.aesnet.org
Presentation date : 12/9/2024 12:00:00 AM
Published date :

Authors :
Presenting Author: Sarah Rockwood, BS – Stanford University School of Medicine

Samantha Steeman, BS – Stanford University School of Medicine
Julie Uchitel, PhD – Stanford University School of Medicine
Alexander Ren, BS – Stanford University School of Medicine
Alexander Berg, BS – Stanford
Ariana Rodrigues, BS – Stanford
Prathyusha Teeyagura, BS – Stanford University School of Medicine
Ann Hyslop Segeren, MD – Stanford University School of Medicine
H. Westley Phillips, MD – Stanford University School of Medicine

Rationale:

Stereo-EEG(sEEG) is a minimally invasive intracranial procedure that identifies epileptogenic foci, informing the type and approach for subsequent surgery. The number and location of electrodes currently depends on numerous variables and thus varies between surgeries, but it is unclear whether these vary with age and etiology and if there is an impact on the subsequent procedure type and outcome.



Methods:

Pediatric epilepsy patients undergoing sEEG at Lucille Packard Children’s Hospital at Stanford from February 2014 – December 2023 were analyzed. Patient demographics, seizure history, procedure and progress notes and outcomes were analyzed and input into a REDCap database for retrospective analysis. Count and placement of electrodes were found in the sEEG procedure note and review of post-implantation imaging. Data was exported and analyzed in R.



Results:

We identified 110 patients undergoing 133 sEEGs. The average age at implantation across all patients was 10.3 [9.3-11.3], with 62% occurring in males (68).  A total of 2390 electrodes were placed across all sEEGs, with the majority (42%) in the frontal lobe (Table 2). On average, 18.0 [16.8 – 19.2] electrodes were placed in each sEEG. There was no significant correlation between age at implantation and total electrodes (r2 = -0.07), nor any significant correlations when stratified by brain region (frontal: r2 = -0.18, temporal: r2 = 0.06). Notably, almost one-third of the cohort (n=31, 28.8%) had tuberous sclerosis (TS) (Table 1). On average, TS patients had 19.3 [17.6-21.1] electrodes placed and underwent implantation at a significantly younger age of 6.4 [5.2-7.8].  Patients with a vascular events had the most electrodes placed per surgery (21.8 [17.9-25.7]), while patients with tumors and traumatic brain injury had the fewest (14.3 [8.7-19.9] and 12.5 [8.5-16.5]), respectively). Patients with an unknown etiology, comprised primarily of MRI negative patients, had 17.3 [15.1-19.5] electrodes placed. Out of 133 sEEGs, 86.5% were followed by a subsequent surgery (115) shown in Table 2. A higher number of electrodes was more likely to followed by laser ablation (20.5 [18.5-22.5])), while there was no difference in the number of electrodes preceding lesionectomies or lobectomies (16.7 [14.4-19.0]) and 16.6 [13.8-19.5], respectively).

 

Out of the 115 surgeries, 55.7% were followed by >90% reduction in seizure burden (64) and 27.8% by a < 50% reduction (32). There was not a statically significant difference between the total number of electrodes placed and the surgery outcome, although seizure freedom was associated with the least electrodes (17.3 [15.2-19.4]) and poor outcome (< 50% reduction) was associated with the most (18.6 [15.9-21.6]).



Conclusions:

We demonstrate that sEEG is a useful tool for informing surgical decision making for drug resistant epilepsy. We found that the total number of electrodes implanted are not significantly correlated with age at implantation, etiology, type of surgery performed, or outcome. However, future studies are required to optimize future sEEG implantations. 



Funding: No funding to report.

Surgery