1. Nerve conduction Sompol Tapechum M.D., Ph.D. Department of Physiology Faculty of Medicine Siriraj Hospital

2. Objectives • นักศึกษาสามารถบอกประโยชน์ของการวัด nerve conduction velocity ได้ • นักศึกษาสามารถบอกวิธีการวัด nerve conduction velocity ได้ • นักศึกษาสามารถบอกปัจจัยที่มีผลต่อ nerve conduction velocity ของ axon ได้

3. Nervous system

4. Structure of Nervous system • Central nervous system (CNS) • Brain • Cerebrum • Cerebellum • Brainstem • Spinal cord • Peripheral nervous system (PNS) • Nerves • Cranial nerve 12 pairs • Spinal nerve 31 pairs

5. Spinal nerve and Cranial nerve

6. Nerve structure • Nerve = Bundle of axon • Component of nerve • Motor • Somatic • Autonomic • Sensory • Somatic • Visceral

7. Axon Orthodromic Motor neurons Antidromic Sensory neurons Orthodromic Antidromic

8. Types of axon

9. Type of axon

11. Nerve conduction

12. Sensory conduction study • Antidromic

13. Sensory conduction study • Orthodromic

14. Motor conduction study • Orthodromic

15. Median nerve

16. Motor conduction study:Median nerve

17. Motor neuron Neuromuscular junction

18. Neuromuscular junction

19. D1-D2 NCV = L1-L2 Nerve conduction velocity D2 D1 Latency (s) L1 L2

20. Sensory conduction study:Median nerve

21. Purposes of Nerve conduction study • To diagnose nerve damage or destruction • To follow up nerve regeneration after damage • To evaluate diseases of nerve or muscle

22. Normal nerve conduction velocity • normal conduction velocity • approximately 50 to 60 meters per second. • may vary from one individual to another and from one nerve to another.

23. Carpal tunnel syndrome

24. Nerve injury

25. Axon regeneration 2-4 mm/day

26. Myasthenia gravis