woraphon aramrussameekul, md

1. Woraphon Aramrussameekul, MD

2. ??????????????????????? ??????????????????????????????????????????? ???????????????????????????????????

3. Basic Physiology of Nerve Tissue Resting membrane potential Action Potential

14. Relative C/I Bleeding tendency: Aspirin, anticoagulant Skin infection of dermatitis Region of vital organs

17. COMPONENTS AND SHAPE OF THE SNAP Latency (msec) ; - Initial Latency ( conduction time) - Peak Latency Amplitude (uv) Nerve conduction velocity (m/sec) NCV.= DISTANCE / LATENCY

18. SNAP DIFFERENTIATION BETWEEN ORTHODROMIC AND ANTIDROMIC STIMULATION Orthodromic Response Antidromic Response SNAP AMPLITUDE smaller bigger SNAP SHAPE unipolar bipolar CONDUCTION TIME same same ( LATENCY ) NCV. same same

20. 1. Prolonged distal latency ; low temperature generalized/ focal/ multifocal demyelination 2. Slow conduction velocity ; diffuse demyelination loss of large myelinated fibers focal / multifocal demyelination severe axonal stenosis 3. Decrease amplitude ; temporal dispersion conduction block loss of axonal nerve fibers severe axonal stenosis

21. MOTOR NERVE CONDUCTION STUDY

24. STIMULATION - Supramaximal intensity PICK UP ; Active electrode – motor point of muscle Reference electrode - silence area RECORD ; Compound muscle action potential ( CMAP / ‘ M ’ WAVE RESPONSE )

25. COMPONENTS AND SHAPE OF THE CMAP Latency (msec) Amplitude (mv) Conduction time (msec) Nerve conduction velocity(m/sec) NCV.= D2-D1/L2-L1

29. ??????????????????????????????????????????

32. H REFLEX Stim.Tibial N.at popliteal fossa Submaximal intensity Record act.potential at medial gastrocnemius m. Monosynaptic Reflex Stim.Ia afferent in m. spindle Dorsal horn cell in spinal cord Synapse with ant. horn c. (S1) Deporalization ???? Act.Potential

35. Stim. motor fiber with supramaximal intensity ventral root ,anterior horn cell motor fibers,action potential PROLONGED F WAVE CONDUCTION DEFECT IN CENTRAL / PROXIMAL PATHWAY F WAVE

37. Late response H-reflex & F-wave Study proximal region Repetitive stimulation Myasthenia gravis Myasthenic syndrome of Lambert Eton

40. Needle electromyography: Interpretation includes analysis of oscilloscope tracings & characteristic sounds produced by electrical potentials 1. Insertional activity 2. Spontaneous activity 3. Motor unit action potential( MUAP) 4. Motor unit recruitment pattern

41. Abnormal findings in EMG Axonal involvement? Neuropathy or Myopathy?

42. EMG IN NORMAL SUBJECT 1. Muscle at rest ?????????????????? - Insertional activity - End-plate noise ; nerve potentials miniature end plate potential 2. At minimal contraction - Single motor unit action potential 3. At maximal contraction - Complete interference pattern

43. EMG IN NORMAL SUBJECT

44. ??????????????????????????????????????

45. Spontaneous potential of single muscle fiber sound Rain on tin roof Regular rhythm , amplitude 50 - 300uv , duration 0.5 - 2 msec. Diphasic / triphasic with initial phase positive ??????????? membrane irritability FIBRILLATION POTENTIAL

47. POSITIVE SHARP WAVE POTENTIAL Spontaneous potential ?????????? sharp positive deflection ??????? long duration negative phase of low amplitude Sound Dull thud ?????? ??? ??????????????? ??????????? membrane irritability ????????? fibrillation

49. EDx in orthopedics Nerve injury Nerve entrapment Nerve root compression or radiculopathy BPI Etc.

51. * The electrodiagnosis (EDX) is most helpful to patients with problems of weakness, paresthesia,pain or fatique. * These can usually be diagnosed with respect to anatomical localization, severity, and nature of dysfunction. * Electrodiagnosis can support or confirm clinical diagnosis and have an important role in prognosis and guiding management of a variety of neuromuscular conditions.

52. CONCLUSION EDX : adjunct investigation to the Hx, P.E. & other Investigations to provide the definite diagnosis EDX : LMN lesion

54. Summary Root : 3 Dorsal scapular C5, nerve to subclavius, Long thoracic n.C5-7 Trunk : 1 Suprascapular n. C5-6 Division Cord : 3 5 5 Branch

55. Root : Dorsal scapular N. C5

56. Cord Lateral cord : 3 Lateral pectoral n. Musculocutaneous n. Median n. Medial cord : 5 Medial pectoral n. Medial cutaneous n. of arm Medial cutaneous n. of forearm Ulnar n. Median n. Posterior cord : 5 Radial n. Axillary n. : Deltoid Teres minor Thoracodorsal n. : Latissimus dorsi Upper subscapularis n. Lower subscapularis n.

57.

58. Thigh muscles

59. Leg muscles