Y P O C T O N O D E Mar Cortes, MD S Non-invasive Brain - - PowerPoint PPT Presentation

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Feb 03, 2024 171 likes •334 views

Y P O C T O N O D E Mar Cortes, MD S Non-invasive Brain Stimulation & Human Motor Control Laboratory Burke Medical Research Institute A Instructor of Neurology, Cornell University New York, NY E mac2083@med.cornell.edu L P Y

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Mar Cortes, MD Non-invasive Brain Stimulation & Human Motor Control Laboratory Burke Medical Research Institute Instructor of Neurology, Cornell University New York, NY mac2083@med.cornell.edu

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How can we induce plastic changes at the brain level? Paired Associative Stimulation (PAS)

Or when the peripheral stimulation meets the MEP

How can we induce plastic changes at the spinal level? Spinal Associative Stimulation (SAS)

Or when the central stimulation meets the H-reflex

Investigating Hebbian principles of neural plasticity in humans "Cells that fire together, wire together"

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How do we measure cortical excitability? The MEP

EMG Instrument Magnetic Stimulator

TMS

STIMULUS

MEP

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PAS protocol:

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The increase of cortical excitability (MEP amplitude)

was dependent on the synchronous timing between the afferent and the magnetic stimulation

Plasticity induced by PAS 1. evolved rapidly (within

30 min), 2. was persistent (minimum duration 30-60 min) yet reversible, and 3. was topographically specific – properties signature of associative long- term potentiation (LTP).

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How do we measure spinal excitability? The H-REFLEX

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SAS protocol:

90 paired stimuli PNS TMS 20ms 0.1 Hz 900 10 40 30 20 50 890 sec

PRE POST INTERVENTION (15 min) H-Reflex RC H-Reflex RC

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Peripheral stimulation of somatosensory afferents conditioned by low frequency TMS, increases spinal excitability

Cortes et al, Clin Neurophys, 2011

Electrical Stimulator Magnetic

Stimulator

Ia afferents fibers Efferent motor fibers Dorsal root (sensory) Ventral root (motor)

SAS protocol:

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SAS experimental set up

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