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

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 P Investigating Hebbian principles of neural plasticity in humans O "Cells that fire together, wire together" C T How can we induce plastic changes at the brain level? O N Paired Associative Stimulation (PAS) Or when the peripheral stimulation meets the MEP O D How can we induce plastic changes at the spinal level? E S Spinal Associative Stimulation (SAS) A Or when the central stimulation meets the H-reflex E L P

Y P How do we measure cortical excitability? The MEP O C TMS T O M1 N MEP α Magnetic O Stimulator D E STIMULUS S A E L EMG P Instrument

Y PAS protocol: P O C T O N O D E S A E L P

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Y P O C • The increase of cortical excitability (MEP amplitude) T was dependent on the synchronous timing between O the afferent and the magnetic stimulation N O • Plasticity induced by PAS 1. evolved rapidly (within D 30 min), 2. was persistent (minimum duration 30-60 min) yet reversible, and 3. was topographically E S specific – properties signature of associative long- A term potentiation (LTP ). E L P

Y P How do we measure spinal excitability? The H-REFLEX O C T O N O D E S A E L P

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Y SAS protocol: P O C T O N PRE POST INTERVENTION O (15 min) H-Reflex RC H-Reflex RC D TMS PNS E 20ms 90 0.1 Hz S paired stimuli A E sec 0 10 20 30 40 50 890 900 L P

Y SAS protocol: Peripheral stimulation of somatosensory afferents conditioned by P low frequency TMS, increases spinal excitability O C T O Magnetic Stimulator N O Dorsal root (sensory) D Ia afferents Ventral root fibers E (motor) S Efferent A motor fibers E L P Electrical Stimulator Cortes et al, Clin Neurophys, 2011

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Y SAS experimental set up P O C T O N O D E S A E L P

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