Authors :
Presenting Author: Camryn Davis, BS – University of Nebraska Medical Center
Stephen Gliske, PhD – University of Nebraska Medical Center
William Stacey, MD, PhD – University of Michigan
Rationale:
Many patients that undergo resective surgery for drug resistant epilepsy are still unable to achieve seizure freedom. HFOs from intracranial EEG (iEEG) are a promising biomarker for helping guide resective surgery. González Otárula et al. found that the rate of “first source” (initiating) HFOs had higher specificity than counting the rate of all HFOs. Our objective was to replicate their findings using longer recording durations per patient. Methods:
Patients were selected from the University of Michigan iEEG Database who met the following inclusion criteria as of January, 2025: having an SOZ available in the database as well as achieving Engel 1 following resective surgery. HFOs occurring within 0.001 second of each other across all channels were defined as a cluster. We compared the asymmetry of HFO rates relative to the SOZ for both a) all HFOs and b) initiating HFOs. Statistical significance was assessed by the paired Wilcoxon signed rank test.
Results:
Twelve subjects matched our inclusion criteria (mean age 29 ± 13 yrs , 5:7 M:F) with a median of 161.6 ±43.3 hours of iEEG per electrode channel. An average of 53,386 ±40,104 HFOs were analyzed per patient and of those events each patient had on average 30,745 ± 22,717 clusters. The HFO rate asymmetry for all HFOs was not found to be statically significant (p = 0.052), although the p-value was near the threshold of 0.05. We note the study of González Otárula et al. included 15 subjects, 1 hour per subject, and had a final p-value of 0.04.
Conclusions:
In conclusion, we were unable to confirm the findings of González Otárula et al. in this initial pilot study. Data acquisition is ongoing, and followup work will revisit this analysis with a larger patient cohort.Funding: N/A