Focal Slowing on EEG Correlates with White Matter Disease Burden in Late Onset Epilepsy
Abstract number :
2.136
Submission category :
4. Clinical Epilepsy / 4B. Clinical Diagnosis
Year :
2023
Submission ID :
681
Source :
www.aesnet.org
Presentation date :
12/3/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: H. Nicolas Lemus E., MD – University of Alabama at Birmingham
Gad Marshall, MD – BWH; Rani Sarkis, MD – BWH; Page Pennell, MD – UPMC
Rationale: Focal slowing on electroencephalogram (EEG) is a common finding on EEG in older adults. However, the underpinnings of this abnormality and its clinical relevance remain unclear. The goal of the current study was to compare the white matter hyperintensity volume (WMV) and hippocampal volumes (HV) of subjects with late-onset unexplained epilepsy (LOUE) with or without focal slowing on EEG.
Methods: Subjects were prospectively recruited from Brigham and Women’s Hospital and affiliated hospitals. Inclusion criteria is: new-onset seizures, ≥60 y/o, onset < 5 years, absence of cortical lesions on MRI and provoking factors. A 24-hour EEG was obtained and reviewed by two epileptologists (HNL, RAS) and a consensus was reached regarding the presence or absence of focal slowing on EEG. Additionally, HV was quantified using Freesurfer, and WMV quantification was performed using the lesion segmentation tool of the statistical parametric mapping (SPM) software.
Results: We enrolled 47 subjects with late-onset seizures. Mean (±SD) age was 69.4 ± 5.8 years and 49% were female. Ambulatory EEG findings included generalized slowing (n=5) and focal slowing (n=33). All focal slowing was temporal: bitemporal in 17, left in 12, and right in 4. The log WMV in subjects with focal slowing was greater compared to those without 7.2±0.3 cm3 vs. 5.7±0.4 cm3 (p=0.0025). Log WMV remained a significant predictor of focal slowing on EEG when controlling for age and sex (p=0.0054). There was no significant difference in HV between those with 6977 ±781 mm3 and without focal slowing 8942 ±1001 mm3 (p=0.9).
Conclusions: Focal slowing on EEG, in adults with late-onset unexplained epilepsy, correlates with white matter hyperintensity volume on MRI, not hippocampal volume. These findings re-emphasize the importance of obtaining an MRI in late-onset epilepsy especially in those with focal slowing on EEG. Future studies need to explore whether these findings also have cognitive implications.
Funding: American Epilepsy Society Junior Investigator Award, NIH K23NS119798 (RAS)
Clinical Epilepsy