Abstract Details

Title EEG ß-power and ß-synchrony in the Sensorimotor Network as a Potential Biomarker for Disease Severity and Progression of Motor Symptoms in ALS

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P1 - Poster Session 1 (12:00 PM-1:00 PM)

Poster/Presentation
Number 1-008

Objective

To investigate resting-state EEG β-band power and β-band functional synchrony in the cortical sensorimotor network as a robust measure of severity and progression of motor symptoms in ALS patients.

Background In ALS, the slope of decline of the ALSFRS-R (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised) is accepted as a primary outcome measure in clinical trials, but is limited by variance (Rooney, J Neurol.Neurosurg.Psychiatry 2017). There is a need for direct quantitative markers of the neurodegenerative process. Quantitative high-density EEG directly measures the synchronous activity of underlying populations of neurons. Altered EEG patterns in ALS correlate with behavioural impairment and MRI measures of motor-system degeneration(Nasseroleslami, Cereb.Cortex 2017; Dukic, Hum.Brain.Mapp. 2019).

Design/Methods Using 6 minutes of 128-channel resting-state EEG, source-reconstructed β-power and β-synchrony (β-band imaginary coherence) in the sensorimotor network (pre- and post-central gyrus bilaterally) were calculated in 18 ALS patients using the automated anatomical labelling atlas (AAL) (Tzourio-Mazoyer, N., NeuroImage, 2002). Clinical examination included: ALSFRS-R (Fine/Gross-Motor functions sub-scores, Bulbar and Respiratory sub-scores), manual muscle testing (deltoid, triceps, biceps, wrist flexors and extensors, fingers flexors and extensors, FDI, APB) and standardised measures of upper motor neuron impairment. Both ALSFRS-R and sub-score Progression Rates were calculated between disease onset and recording time. Lower/Upper Motor Neuron-scores were found for the upper limbs (LMN/UMN-scores). Partial Pearson’s correlation coefficient (controlled for age) was used to test the clinical relevance of the EEG measures.

Results Mean β-power in the sensorimotor network correlated with Fine Motor Functions sub-score (r=-0.522, p=0.026), Fine Motor Functions-Progression Rate (r=0.602, p=0.008), LMN-score (r=-0,572, p=0,013). Mean β-synchrony correlated with the LMN-score (r=-0,503, p=0,033).

Conclusions

Source-reconstructed β-band power and β-synchrony likely reflect cortical hyperexcitability observed in ALS with structural degeneration of motoneurons and cortical inhibitory interneurons, and they have potential to be developed as data-driven quantitative markers of severity and progression in ALS.

A.F., S.D., A.C. contributed equally to this work

Authors/Disclosures
PRESENTER	No disclosure on file
Stefan Dukic (Trinity College Dublin)	No disclosure on file
Amina Coffey (Trinity College Dublin)	No disclosure on file
	No disclosure on file
	No disclosure on file
Ibrahim Laleka	No disclosure on file
	No disclosure on file
Peter Bede, MD, PhD (Academic Unit of Neurology)	Dr. Bede has nothing to disclose.
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Orla Hardiman, MD, DSc, FRCPI, MRIA, FAAN (Trinity Biomedical Sciences Institute)	Dr. Hardiman has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Wave Pharmaceuticals. Dr. Hardiman has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Cytokinetics . Dr. Hardiman has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Dr. Hardiman has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Taylor and Francis. The institution of Dr. Hardiman has received research support from Science Foundation Ireland. The institution of Dr. Hardiman has received research support from HRB.