Abstract Details

Title Gamma and beta Band Activity Pre and Post Botulinum Treatment Detected by Magnetoencephalography

Topic Movement Disorders

Presentation(s) P07 - (-)

Poster/Presentation
Number 196

Objective

Background BACKGROUND: A decreased cortical and spinal inhibition has been implicated in the pathophysiology of dystonia. Cortical beta and gamma band fluctuations may reflect GABAergic inhibition. Gamma band fluctuations in MEG have been shown to be positively correlated with GABA concentration. Bursts of beta activity are associated with a strengthening of sensory feedback in static motor control and are shown to be reduced when there are changes in movement.

Design/Methods DESIGN/METHODS: In seven torticollis patients, whole head MEG was recorded in both a resting-state condition and during stimulation of the right and left forefinger before and after treatment with botulinum toxin. Coherence was calculated in the beta and gamma frequency bands. Discriminant analysis was used to determine if beta and gamma locations were altered after treatment.

Results RESULTS: After treatment with botulinum toxin, torticollis patients demonstrated decreased beta band coherence in bilateral fusiform gyri and increased beta coherence in the right superior frontal and left precentral gyri. (Discriminant analysis identified group difference with p < 0.01 in 149/4168 locations). In the gamma band, coherence was decreased in the right middle temporal and inferior temporal gyri and increased in the left middle frontal, pre and post central gyri. (Discriminant analysis identified group difference with p < 0.01 in 86/4168 locations).

Conclusions CONCLUSIONS: Increased gamma activity in the pre and post central gyrus after botulinum toxin reflects restoration of cortical inhibition, resulting in improvement of torticollis. This may reflect a direct increase in GABA concentration in this region. Beta band coherence changes may reflect strengthening of the sensory feedback in the motor system. In the future, MEG can be used to evaluate treatment response and selection of patients who may optimally benefit.

Authors/Disclosures
Naganand Sripathi, MD (Henry Ford Hospital) PRESENTER	Dr. Sripathi has nothing to disclose.
Kavita M. Grover, MD, FAAN	Dr. Grover has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Janssen. Dr. Grover has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB. Dr. Grover has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Amgen. Dr. Grover has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Kyverna. Dr. Grover has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Argenx. Dr. Grover has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Catalyst.
David A. Stamler, MD (Alterity Therapeutics)	Dr. Stamler has received personal compensation for serving as an employee of Alterity Therapeutics. Dr. Stamler has stock in Alterity Therapeutics.
	No disclosure on file
	No disclosure on file
Susan M. Bowyer, PhD (Henry Ford Hospital)	Dr. Bowyer has nothing to disclose.

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