Authors :
Presenting Author: Jay Pathmanathan, MD, PhD – Beacon Biosignals
Timothy Sheehan, BS – Beacon Biosignals
Rebecca Reh, PhD – Beacon Biosignals
Kim Laberinto, BS – Beacon Biosignals
Katherine McGuckin, BA – Beacon Biosignals
Maya Dorsey, RN – Beacon Biosignals
Matt brzezinski, BS – Beacon Biosignals
Albert Misko, MD – Novartis
J Michael Graglia, BS – Syngap Research Fund
Virginie McNamar, MA – Syngap Research Fund
Jacob Donoghue, MD, PhD – Beacon Biosignals
Rationale:
Advances in EEG technology have led to simplified ambulatory systems capable of being operated by patients. Here we assessed the ability of caregivers to apply the Waveband dry EEG electrode system and collect data from their children with SYNGAP1. Methods:
21 patients with SYNGAP1 haploinsufficiency (11 male, mean age 14.3 years) were recruited through the SynGAP Research Fund to complete up to ten at-home overnight recordings using the Waveband headband. A separate group of healthy controls (10 participants, 6 male, mean age 13.2 years) completed the same protocol. The Waveband headband has four dry EEG electrodes (f7, f8, o1, o2) referenced in a bipolar montage. Recordings were algorithmically assigned sleep stages using a validated and FDA approved algorithm. Spectral power was estimated after excluding noisy or low quality epochs during each sleep stage. A mixed effects model was used to estimate delta power with fixed effects for sleep state, population (SYNGAP1 vs. control), age, and the interaction of age and population. A random effect for each subject was included to account for repeated measurements across nights.Results:
19/21 participants were able to successfully record and upload at least one night of EEG data of any quality and 14/21 uploaded at least one recording with over one hour of usable EEG. 10 of these 14 participants were able to complete at least three overnight recordings with over 4 hours of usable data suggesting that device burden was manageable once SYNGAP1 participants were comfortable with the device. Spectral power was evaluated for all recordings with over 1 hour of usable data. Both frontal `f8-f7` and occipital `o2-o1` absolute delta power were significantly higher in the SYNGAP1 population during NREM sleep (4.9 dB, p=.02 frontal; 4.7 dB, p=.0002 occipital; Figure A). In REM sleep, frontal activity no longer showed a significant difference between groups (1.8 dB, p=.47) while occipital activity continued to show elevations in SYNGAP1 (4.2 dB, p=.0016; Figure B). These differences may be due to lateralized brain activity, as no significant effects were observed in anterior-posterior electrode pairs `f7-o1` or `f8-o2` during either sleep stage (Figure A-B). We examined the relationship between age and delta power, and found the control population demonstrated a declinine in frontal delta power with age (-1.4 dB/year), but not the SYNGAP1 population (0.3 dB/year; Figure C).
Conclusions:
This study is the first to examine ambulatory multinight sleep metrics and participant collected EEG in a SYNGAP1 population. Most participant families were able to acquire valid data with the Waveband system. Spectral activity during sleep revealed abnormalities that distinguish SYNGAP1 patients from neurotypical controls. While elevated occipital delta power has previously been identified in the SYNGAP1 population, we additionally identified hemispheric asymmetries and an increase in frontal power during NREM sleep. SYNGAP1 patients also failed to show a reduction in frontal delta power with age. Further analyses will be performed to evaluate epileptic features of SYNGAP1 on sleep EEG.
Funding: This work was funded by Novartis AG and Beacon Biosignals.