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Cortical Plasticity: What you need to know when teaching surgeons new tricks

Cortical Plasticity: What you need to know when teaching surgeons new tricks. DJ Anastakis, MD, MEd, FRCSC, FACS, FICS Associate Professor Divisions of Plastic and Orthopedic Surgery Department of Surgery, University of Toronto. Overview. Definition. How and why. Methods of study.

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Cortical Plasticity: What you need to know when teaching surgeons new tricks

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  1. Cortical Plasticity: What you need to know when teaching surgeons new tricks DJ Anastakis, MD, MEd, FRCSC, FACS, FICS Associate Professor Divisions of Plastic and Orthopedic Surgery Department of Surgery, University of Toronto

  2. Overview • Definition • How and why • Methods of study • Current theory • Surgical skills training

  3. Cortical Plasticity • plastic (Gk: plastikos) • “to be molded” • brain’s ability to change, adapt, learn

  4. Cortical Plasticity capacity of the human cortex for functional remodelling by reorganization of synaptic connections in response to intrinsic or extrinsic influences

  5. Cortical Plasticity • change in school of thought •  awareness and evidence of importance of cortical plasticity in adult human brain • spinal cord injury • cortical injury • upper extremity injury

  6. Methods of Study • Transcranial Magnetic Stimulation (TMS) • Electro-enchephalography • Magnetoencephalography (MEG) • Functional MRI (fMRI) • Positron Emission Tomography (PET)

  7. Comparison of Experimental Techniques

  8. Control - finger flexion fMRI • scan while subject alternately performs a task and rests • changes in signal intensity associated with task performance displayed on anatomic image

  9. While performing a motor task:  neuronal activity (M1)  blood flow (45%)  O2 extraction (16%)  [oxyhem]/[deoxyhem]  MRI signal fMRI MRI signal is blood-oxygen dependent

  10. 8-shaped coil EMG Transcranial Magnetic Stimulation • wire coil placed on scalp - large current passes through wire coil • magnetic field stimulates underlying motor cortex • effects measured as changes on EMG • access many indices of cortical organization and function

  11. Transcranial Magnetic Stimulation • magnetic stimulation of motor cortex • results reflect: • motor cortex mapping • cortical excitability • motor threshold • intracortical inhibition

  12. Motor System Reorganization fMRI • high spatial resolution for assessment of motor and sensory representations TMS • measure degree of motor cortex excitability two complementary methods measuring different aspects of cortical plasticity

  13. Challenges in Human Studies • MRI constraints • no head movement • no metal • simple movements Simple motor skill model

  14. Reconstructive Surgery Restoration of Movement • Free functioning muscle transfers • Toe transfers • Nerve repair • Tendon transfers

  15. Upper Extremity Reconstructive Surgery Functional Outcomes • Patient Age • Occupation • Etiology • Operative Technique • Nerve Regeneration • Muscle/Tendon Factors • Rehabilitation Central Nervous System Cortical Plasticity

  16. Motor Skills Learning A motor skill is a motor skill • dance • new thumb • play hockey • small bowel anastomosis

  17. Cortical Plasticity & Motor Skills Learning • activation changes • thresholds changes • patterns variations in different subjects learning a new motor skill

  18. In Search of a Simple Motor Skill • 26-year-old RHD miner • amputation R index finger and thumb • left great toe transfer Manduch M, Bezuhly M, Anastakis DJ, Crawley AP, Mikulis DJ: Serial fMRI assessment of the primary motor cortex following thumb reconstruction. Neurology 2002: 59(8): pp 1278-1281.

  19. Methods fMRI • scans conducted at various time-points • simple motor task (thumb flexion)

  20. contralateral Sensory Motor Cortex (cSM1) IPJ flexion

  21. contralateral Sensory Motor Cortex (cSM1) Modulators of Motor Plasticity (1) Practice (2) Sensory input

  22. Pre-op 5 weeks 114 weeks

  23. Conclusions • temporal pattern of activation may represent a “signature” of good functional recovery or motor learning Modulators of Motor Plasticity (1) Practice (2) Sensory input Manduch M, Bezuhly M, Anastakis DJ, Crawley AP, Mikulis DJ: Serial fMRI assessment of the primary motor cortex following thumb reconstruction. Neurology 2002

  24. Cortical Plasticity Following Thumb Reconstruction A Murji, DJ Anastakis, D Mikulis, R Chen, K Davis, M Chang Funded by the American Association for Hand Surgery

  25. Methods • Subjects • 4 patients • thumb reconstruction with great toe transfer • fMRI and TMS studies obtained pre- and post-operatively for up to two years

  26. consistent  in cortical representation at onset of motor skills learning varying degrees of expansion fMRI

  27. TMS Results •  excitability at onset of motor learning •  cortical excitability as motor skill learned Increased excitability Decreased inhibition Decreased excitability Increased inhibition

  28. Conclusions “Signature” of motor learning: •  cortical activation with initiation of motor skills learning •  cortical excitability and disinhibition at onset of motor skills learning •  cortical activation & excitability as motor skill mastered

  29. Gracilis muscle

  30. Modulators of Motor Plasticity (1) Practice (2) Sensory input (3) Cognitive factors

  31. Expert Current theories of motor plasticity Novice  Learning  Decreased excitability Increased inhibition Increased excitability Decreased inhibition

  32. Expert Current theories of motor plasticity Novice  Learning  Decreased excitability Increased inhibition Increased excitability Decreased inhibition

  33. Training Across the Professions…From Competence to Virtuosity Association for Surgical Education Twentieth Annual Meeting Toronto, Ontario, Canada

  34. Novice new convert inexperienced person beginner Virtuoso person with special knowledge of or taste for works of art or virtu person skilled in the technique of fine art perform skill under any adverse conditions Novice to Virtuoso

  35. Dr. Janet Starkes Professor and Chair – Department of Kinesiology McMaster University

  36. Ms. Carina Bomers Former Ballerina - National Ballet of Canada Coordinator of Tutorials National Ballet School of Canada

  37. Mr. Mike Gartner Former Professional Hockey PlayerNational Hockey League Director- Business Relations National Hockey League Players Association National Hockey League

  38. ASE Panel 2000 - Toronto Virtuoso traits: • Motivated • Practice • Self-evaluation • Visual-spatial abilities • Visualization – The Minds Eye

  39. Modulators of Motor Plasticity (1) Practice (2) Sensory input (3) Cognitive factors (4) VSA (5) Visualization

  40. Practice

  41. Learning  Expert Novice  How much practice? • Basic Skills • suturing • Simple procedures • chest tube insertion • Complex procedure • Whipple

  42. How much practice? A lot Quality

  43. Curriculum Evaluation • Surgical Skills Centre at MSH • evaluation 2 year curriculum • too much didactic teaching • not enough time to practice technical skills • focus on skills and not procedures Anastakis DJ, Wanzel KR, Brown MH, McIlroy J, Hamstra S, Ali J, Hutchison CR, Murnaghan J, Regehr G, Reznick RK: Evaluating the effectiveness of a two-year curriculum in a surgical skills centre. American Journal of Surgery 2003: 185(4): pp 378-385.

  44. Wound Closure and Knot Tying • Year III Medical Student • Technical Skills Session • 9 – 12 AM • One hour didactic lecture • 4 x 30 min rotations (4 stations) • Suturing Station • Knot Tying • Prep and Drape • Gowning

  45. Suturing Station • 10 minute demonstration • 20 minutes to practice • Suturing Station 20 minutes • Knot Tying 20 minutes • Prep and Drape 10 minutes • Gowning 10 minutes 60 minutes 33% of their time practicing

  46. Quality of Technical Teaching • little time for practice • a lot of talking • verbal feedback • no hands on Modulators of Motor Plasticity (1) Practice (2) Sensory input (3) Cognitive factors (4) VSA (5) Visualization

  47. Effect of visual-spatial ability on learning of spatially-complex surgical skills Wanzel KR, Hamstra SJ, Anastakis DJ, Matsumoto ED, Cusimano MD Wanzel KR, Hamstra S, Anastakis DJ, Matsumoto E, Cusimano M: Effect of visual-spatial ability on learning of spatially-complex surgical skills. Lancet 2002: 359(9302): pp 230 - 231.

  48. Purpose • To determine the relation between VSA and performance on a surgical procedure • To determine whether VSA relates to the capacity to learn that procedure

  49. Hypothesis • Performance and ability to learn the Z-plasty would correlate with the ability to mentally manipulate objects in two and three dimensions

  50. Methods 37 junior surgical residents Two parts Part One Visual Spatial Testing Part Two Surgical Skill Testing

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