Y P O C T O N Plasticity Inducing Protocols O D E S A E - PowerPoint PPT Presentation

Y P O C T O N Plasticity Inducing Protocols O D E S A E L P

Y P Plasticity: TMS Operational O Definition C T O Plasticity: “The brain’s ability to constantly N change, grow and reorganize over the O course of a lifetime.” D E Any change in the outcome measure that S outlasts the TMS application can be A thought of as a plastic response of the E brain. L P

Y P Noninvasive Protocols that Lead to O Plastic Changes C T O • TDCS N • Conventional rTMS protocols (inter-pulse O interval) D • Patterned rTMS protocols (inter-pulse and E inter-train interval) S A • Paired Associative Stimulation Protocols E • Combinations L P

Y P O tDCS C T • Anodal = generally facilitatory O • Cathodal= generally inhibitory N O D E S A E L P

Y P O rTMS protocols C T O N O D E S A E L P

Y P O Effects of Conventional rTMS C T O N O D E S A E L P Maeda et al., 2000

Y P Theta Burst Stimulation O C – Theta Burst stimulation T • 3 Pulses of TMS at 50 Hz with a 200 ms Intertrain Interval O (total of 200 trains) N – Continuous Theta Burst Stimulation (40 sec) O D – Intermittent Theta Burst Stimulation (190 sec) E • 2 seconds (10 trains) repeated every 10 seconds S A E L P Huang et al., 2005

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Y P O Why Theta Burst Stimulation? C • Rat Hippocampal cells fire T in bursts of theta frequency O during learning. N • Human EEG Theta O frequency increases during learning. D • Time course of MEP E change is similar to LTP S and LTD in slice A preparations E • Modulated by GABA and L Glutamate, like LTP and P LTD.

Y P O Theta Burst Stimulation C T • Effect of TBS O N O im=5 sec D train repeated E every 15 sec for 110 S sec A E L P Huang et al., 2005

Y P Computational Model of effects of O TBS C T O N O D E S A E L Huang et al., P 2011

Y P O TBS in Aging C T O N O D E S A E L P

Y P TBS in clinical populations O A B C 1.60 1.40 iTBS cTBS 1.50 1.30 [ proportion of baseline] [ proportion of baseline] T 1.40 Red= individuals with 1.20 MEP amplitude MEP amplitude 1.30 autism O 1.10 1.20 Blue= healthy 1.10 1.00 Baseline 1.00 N Baseline 0.90 controls 0.90 0.80 0.80 ASD 0.70 O Controls 0.70 cTBS 0.60 0.60 15 30 45 60 75 90 105 120 5 10 20 30 40 50 60 75 90 105 120 D Time after TBS [ min] Time after TBS [ min] C E 1.30 S cTBS Green= individuals 1.20 [ proportion of baseline] with schizophrenia A MEP amplitude 1.10 Blue= healthy E Baseline 1.00 controls L 0.90 P 0.80 0.70 5 10 20 30 40 50 60 75 90 105 120 Time after TBS [ min]

Y P O C T O N O D E S A E L CON=control RUN=running P EEO=enriched environment (only) EER=enriched environment +running (Mustroph et al, 2012; Kobilo et al, 2011)

Y P O Running enhances LTP C T • Training O dose=4.7km±0.41 N • Over 10 days O • Neurogenesis D • Morris water maze E S A E L P (van Praag et al, 2009)

Y P O TBS and exercise C T Pre-exercise Post-exercise O N O D E S A E L Responses “pushed out” the 95% P confidence interval

Y P Paired Associative Stimulation: O Sensory-Motor Plasticity C T O N O D E 90 pairs S ISI 25 ms A 90 pairs E ISI 10 ms L P Stefan et al., 2000

Y P O What you should know… C • Effects are influenced in both duration and direction T by: O – Intensity of Stimulation N – Duration of Stimulation – Location of Stimulation O – Sensitivity of outcome measure D – Time of Day (Sale et al., 2007) – Attention (Stephan et al., 2004) E – Hormones (Smith et al., 1999) S – Brain State A • Inter and intra-individual differences: E – 1 Hz can be facilitatory in some individuals L – Only approximately 50% of individuals respond to PAS P – TBS has high intraindividual reliability, PAS does not.

Y P Example of Brainstate affecting O rTMS effect C T Lang et al ,2004 O N O D E S A E • 1mA 10mins tDCS L • rTMS at 5Hz 100stim train at AMT – decreases SICI, but not lasting change in P excitability as tested by single pulse TMS • Result= after effects of tDCS can generate opposite effects of rTMS or conversely can alter the after effects of tDCS

Y P O Step-by-Step Procedure C T • 1. Find hot-spot O • 2. Find active motor threshold N • 3. Baseline single-pulse measures O • 4. TBS (cTBS or iTBS) D • 5. Post-TBS assessments (single-pulse E S TMS) A – T5 E – T10 L P – T20 – T30

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