1. Shawn Jorgensen, MD Jeff Strakowski, MD Jeff Strommen, MD

2. Introduction Discuss role of US vs EMG in focal peripheral neuropathies (FPN) Discuss role of US vs EMG in focal peripheral neuropathies (FPN) Examine literature to determine roles in specific FPN Examine literature to determine roles in specific FPN CTS CTS Ulnar neuropathy at the elbow Ulnar neuropathy at the elbow Fibular neuropathies Fibular neuropathies Less common Less common

3. GoalsGoals Attendees should, after this course: Attendees should, after this course: Have an evidence-based approach to ordering EDX, US, or both in specific FPN Have an evidence-based approach to ordering EDX, US, or both in specific FPN

4. GoalsGoals Attendees should, after this course: Attendees should, after this course: Have an evidence-based approach to ordering EDX, US, or both in specific FPN Have an evidence-based approach to ordering EDX, US, or both in specific FPN Ideally, be able to answer these three questions for any FPN Ideally, be able to answer these three questions for any FPN 1. Which test should be the primary test 1. Which test should be the primary test 2. Under what circumstances the primary test would change 2. Under what circumstances the primary test would change 3. Under what circumstances the secondary test should be added 3. Under what circumstances the secondary test should be added

5. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX is clearly superior to MRI and satisfactory for all FPN EDX is clearly superior to MRI and satisfactory for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? MRI only when EDX impossible MRI only when EDX impossible 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? Very few – MRI when EDX non-diagnostic Very few – MRI when EDX non-diagnostic US experimental US experimental

6. Why discuss US? US is valid and reliable (Cartwright 2013) US is valid and reliable (Cartwright 2013)

7. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX is clearly superior to MRI and satisfactory for all FPN EDX is clearly superior to MRI and satisfactory for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? MRI only when EDX impossible MRI only when EDX impossible 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? Very few Very few MRI when EDX non-diagnostic MRI when EDX non-diagnostic US experimental US experimental US valid and reliable

8. Why discuss US? MRI is in the past MRI is in the past US is superior to MRI and is changing the role of imaging in FPN US is superior to MRI and is changing the role of imaging in FPN Greater sensitivity (93% vs. 67%), equal specificity, better at multifocal lesions than MRI (Zaidman 2013) Greater sensitivity (93% vs. 67%), equal specificity, better at multifocal lesions than MRI (Zaidman 2013)

9. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX is clearly superior to MRI and satisfactory for all FPN EDX is clearly superior to MRI and satisfactory for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? MRI only when EDX impossible MRI only when EDX impossible 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? Very few Very few MRI when EDX non-diagnostic MRI when EDX non-diagnostic US valid and reliable US valid and reliable ??? - US when EDX non-diagnostic US only when EDX impossible EDX is clearly superior to US and satisfactory for all FPN

11. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX is clearly superior to US and satisfactory for all FPN EDX is clearly superior to US and satisfactory for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? US only when EDX impossible US only when EDX impossible 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? Very few Very few ??? - US when EDX non-diagnostic ??? - US when EDX non-diagnostic US valid and reliable US valid and reliable EDX is clearly superior to US but not perfect for all FPN

12. Why discuss US? US may be offered for diagnosis of CTS (Cartwright 2012 – AANEM position statement) US may be offered for diagnosis of CTS (Cartwright 2012 – AANEM position statement)

13. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX is clearly superior to US but not perfect for all FPN EDX is clearly superior to US but not perfect for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? US only when EDX impossible US only when EDX impossible 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? Very few Very few ??? - US when EDX non-diagnostic ??? - US when EDX non-diagnostic US valid and reliable US valid and reliable EDX may be superior to US but not perfect for all FPN ??? ??? - US possibly in all patients? ??? - Many or all

14. Why discuss US? US adds value to the diagnosis of CTS (Cartwright 2013 – AANEM position statement) US adds value to the diagnosis of CTS (Cartwright 2013 – AANEM position statement)

15. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX may be superior to US but not perfect for all FPN EDX may be superior to US but not perfect for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? ??? ??? 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? ??? - Many or all ??? - Many or all ??? - US possibly in all patients ??? - US possibly in all patients Specific indications Specific indications ??? - US when EDX is non-diagnostic ??? - US when EDX is non-diagnostic ??? - Failed intervention ??? - Failed intervention ??? - Unilateral CTS ??? - Unilateral CTS ??? - In the setting of trauma ??? - In the setting of trauma ??? – US possibly in all patients – bifid MN / PMA can alter tx

17. Why discuss US? 1. Which test should be the primary test for all FPN? 1. Which test should be the primary test for all FPN? EDX may be superior to US but not perfect for all FPN EDX may be superior to US but not perfect for all FPN 2. Under what circumstances would the primary test change? 2. Under what circumstances would the primary test change? ??? ??? 3. Under what circumstances should the secondary test be added? 3. Under what circumstances should the secondary test be added? ??? - Many or all ??? - Many or all ??? - US possibly in all patients – bifid MN / PMA can alter tx ??? - US possibly in all patients – bifid MN / PMA can alter tx Specific indications Specific indications ??? - US when EDX is non-diagnostic ??? - US when EDX is non-diagnostic ??? - Failed intervention ??? - Failed intervention ??? - Unilateral CTS ??? - Unilateral CTS ??? - In the setting of trauma ??? - In the setting of trauma ???

18. Ultrasound for nerves 101 Excellent anatomic detail Excellent anatomic detail Can measure Can measure size size shape shape doppler flow doppler flow echogenicity echogenicity mobility mobility Cross sectional area (CSA) is the only measurement with statistical utility currently Cross sectional area (CSA) is the only measurement with statistical utility currently

19. 1. Which test should be 1 st line for most circumstances? 1. Which test should be 1 st line for most circumstances? Systematic evidence-based medicine criteria for a useful diagnostic test (Frybeck 1991) Systematic evidence-based medicine criteria for a useful diagnostic test (Frybeck 1991) 1. Valid and reliable 1. Valid and reliable 2. Accurate 2. Accurate 3. Changes the diagnosis 3. Changes the diagnosis 4. Changes the treatment plan 4. Changes the treatment plan 5. Improves patient outcomes 5. Improves patient outcomes 6. Good cost-benefit profile 6. Good cost-benefit profile Carpal Tunnel Syndrome: EMG vs. US

20. What do we want a test for focal peripheral neuropathies to do? What do we want a test for focal peripheral neuropathies to do? 1. Diagnose/exclude CTS 1. Diagnose/exclude CTS 2. Rule out the other likely diagnoses 2. Rule out the other likely diagnoses 3. Assess severity 3. Assess severity 4. Establish timing of injury 4. Establish timing of injury 5. Determine etiology 5. Determine etiology 6. Determine prognosis 6. Determine prognosis 7. Guide treatment 7. Guide treatment Carpal Tunnel Syndrome: EMG vs. US

21. 1. Diagnose/exclude CTS - reliably 1. Diagnose/exclude CTS - reliably Electrodiagnostics Electrodiagnostics Test-retest reliabilityGOOD Test-retest reliabilityGOOD CSI – Spearman rho 0.95 (Lew 2000) CSI – Spearman rho 0.95 (Lew 2000) Inter-rater reliabilityPOOR Inter-rater reliabilityPOOR Large enough to limit clinical trials (Dyck 2013) Large enough to limit clinical trials (Dyck 2013) Reference values BEST Reference values BEST Standardization of practiceAVERAGE Standardization of practiceAVERAGE Identify dynamic pathologyWORST Identify dynamic pathologyWORST Use side-to-side comparisonBEST Use side-to-side comparisonBEST Quality assurance Quality assurance Operators – ABEMBEST Operators – ABEMBEST Laboratories – AANEMGOOD Laboratories – AANEMGOOD Carpal Tunnel Syndrome: EMG vs. US

22. 1. Diagnose/exclude CTS - reliably 1. Diagnose/exclude CTS - reliably Ultrasound Ultrasound Test-retest reliabilityBEST Test-retest reliabilityBEST Coefficient >=0.98 (Cartwright 2013) Coefficient >=0.98 (Cartwright 2013) Inter-rater reliabilityBEST Inter-rater reliabilityBEST P<0.001 still; <0.05 most dynamic (Cartwright 2013) P<0.001 still; <0.05 most dynamic (Cartwright 2013) Reference dataBEST Reference dataBEST Standardization of practiceAVERAGE Standardization of practiceAVERAGE Identify dynamic pathologyBEST Identify dynamic pathologyBEST Use side-to-side comparisonsBEST Use side-to-side comparisonsBEST Quality assurance Quality assurance Operators – ARDMSAVERAGE Operators – ARDMSAVERAGE Labs – AIUMBEST Labs – AIUMBEST Carpal Tunnel Syndrome: EMG vs. US

23. 1. Diagnose/exclude CTS - accurately 1. Diagnose/exclude CTS - accurately What is good? What is good? Mammogram for breast cancer Mammogram for breast cancer Sensitivity 68% Sensitivity 68% Specificity 75% (Mushlin 1998) Specificity 75% (Mushlin 1998) CT for appendicitis CT for appendicitis Sensitivity 83% Sensitivity 83% Specificity 93% (Doria 2006) Specificity 93% (Doria 2006) Carpal Tunnel Syndrome: EMG vs. US

24. 1. Diagnose/exclude CTS - accurately 1. Diagnose/exclude CTS - accurately ElectrodiagnosticsBEST ElectrodiagnosticsBEST Sensitivity – 85-90% (Werner 2011) Sensitivity – 85-90% (Werner 2011) Specificity – 95% (Robinson 1998) Specificity – 95% (Robinson 1998) Carpal Tunnel Syndrome: EMG vs. US

25. 1. Diagnose/exclude CTS - accurately 1. Diagnose/exclude CTS - accurately Ultrasound - cross sectional area (CSA)GOOD Ultrasound - cross sectional area (CSA)GOOD Sensitivity: 65-97% (Cartwright 2012) Sensitivity: 65-97% (Cartwright 2012) Specificity: 72-97% (Cartwright 2012) Specificity: 72-97% (Cartwright 2012) Carpal Tunnel Syndrome: EMG vs. US

26. 1. Diagnose/exclude CTS – post CT release 1. Diagnose/exclude CTS – post CT release ElectrodiagnosticsAVERAGE ElectrodiagnosticsAVERAGE Have a description of natural progression of NCS after CT release Have a description of natural progression of NCS after CT release NCS usually remain abnormal, but do normalize compared to pre-operatively (Werner 2011), but can take as long as 42 weeks to improve (El Hajj 2010) NCS usually remain abnormal, but do normalize compared to pre-operatively (Werner 2011), but can take as long as 42 weeks to improve (El Hajj 2010) Carpal Tunnel Syndrome: EMG vs. US

27. Reasonable approach to EDX post CT release Reasonable approach to EDX post CT release Probably need to wait up to 42 weeks Probably need to wait up to 42 weeks EDX normal – no CTS EDX normal – no CTS EDX abnormal EDX abnormal Worse than pre-op EDX – probably CTS Worse than pre-op EDX – probably CTS Same as pre-op EDX – probably CTS Same as pre-op EDX – probably CTS Better than pre-op EDX Better than pre-op EDX No post-op baseline EDX - ?? No post-op baseline EDX - ?? Better than post-op baseline EDX – no CTS Better than post-op baseline EDX – no CTS Same as post-op baseline EDX - ?? Same as post-op baseline EDX - ?? Worse than post-op baseline EDX - probably CTS Worse than post-op baseline EDX - probably CTS Carpal Tunnel Syndrome: EMG vs. US

28. 1. Diagnose-exclude CTS – post CT release 1. Diagnose-exclude CTS – post CT release UltrasoundPOOR UltrasoundPOOR Recommended by authorities (Strakowski 2014, Bianchi 2007), but data lacking Recommended by authorities (Strakowski 2014, Bianchi 2007), but data lacking Persistent “notch sign” that has moved distal – sign of incomplete release (Strakowski 2014, Bianchi 2007) Persistent “notch sign” that has moved distal – sign of incomplete release (Strakowski 2014, Bianchi 2007) No indication of frequency, correlation with symptoms No indication of frequency, correlation with symptoms Hypoechoic mass encasing the median nerve – scarring (Bianchi 2007) Hypoechoic mass encasing the median nerve – scarring (Bianchi 2007) No indication of frequency, correlation with symptoms No indication of frequency, correlation with symptoms Carpal Tunnel Syndrome: EMG vs. US

29. 1. Diagnose-exclude CTS – post CT release 1. Diagnose-exclude CTS – post CT release UltrasoundPOOR UltrasoundPOOR Do not have a description of normal progression post CT release Do not have a description of normal progression post CT release All CSA decrease post CT release, 75% stay abnormal (Smidt 2008, Mondelli 2008) All CSA decrease post CT release, 75% stay abnormal (Smidt 2008, Mondelli 2008) CSA increases at pisiform, hamate level, decreases at distal radiocarpal joint (Lee 2005) CSA increases at pisiform, hamate level, decreases at distal radiocarpal joint (Lee 2005) Carpal Tunnel Syndrome: EMG vs. US

30. 1. Diagnose/exclude CTS – post CT release 1. Diagnose/exclude CTS – post CT release UltrasoundPOOR UltrasoundPOOR Does the CSA post op determine prognosis? Does the CSA post op determine prognosis? Smaller CSA post op = better outcome 4 months post CTR (Vogelin 2010) Smaller CSA post op = better outcome 4 months post CTR (Vogelin 2010) CSA doesn’t predict outcome 6 months post CTR (Smidt 2008) CSA doesn’t predict outcome 6 months post CTR (Smidt 2008) Carpal Tunnel Syndrome: EMG vs. US

31. 1. Diagnose/exclude CTS - polyneuropathy 1. Diagnose/exclude CTS - polyneuropathy ElectrodiagnosticsGOOD ElectrodiagnosticsGOOD General conduction slowing of all nerves in polyneuropathy General conduction slowing of all nerves in polyneuropathy Have parameters for that correlate with symptoms of CTS versus normals in setting of polyneuropathy Have parameters for that correlate with symptoms of CTS versus normals in setting of polyneuropathy Latency difference between median SNAP D3, ulnar SNAP D5 Latency difference between median SNAP D3, ulnar SNAP D5 Mild diabetics without sx of CTS: ULN 1.0 (Albers 1996) Mild diabetics without sx of CTS: ULN 1.0 (Albers 1996) Non-diabetics without sx of CTS: 0.5 (Buschbacher 2005) Non-diabetics without sx of CTS: 0.5 (Buschbacher 2005) Carpal Tunnel Syndrome: EMG vs. US

32. 1. Diagnose/exclude CTS - polyneuropathy 1. Diagnose/exclude CTS - polyneuropathy UltrasoundGOOD UltrasoundGOOD Know general pattern of US in setting of polyneuropathy (Hobson-Webb 2013) Know general pattern of US in setting of polyneuropathy (Hobson-Webb 2013) Diabetics – no increase in size Diabetics – no increase in size AIDP, CIDP, CMT, MMN, vasculitis – increase in size, some focally AIDP, CIDP, CMT, MMN, vasculitis – increase in size, some focally Know general pattern for CTS in setting of polyneuropathy Know general pattern for CTS in setting of polyneuropathy Nerve enlargement at sites of entrapment in diabetics without symptoms of CTS Nerve enlargement at sites of entrapment in diabetics without symptoms of CTS CSA 13.5+/- 2.8 (Watanabe 2009) CSA 13.5+/- 2.8 (Watanabe 2009) Carpal Tunnel Syndrome: EMG vs. US

33. 1. Diagnose/exclude CTS – EMG-negative 1. Diagnose/exclude CTS – EMG-negative Ultrasound GOOD Ultrasound GOOD Normal EDX Normal EDX With sx of CTS – 30.5% had a CSA>10.5mm 2 With sx of CTS – 30.5% had a CSA>10.5mm 2 Controls without sx of CTS – 3.3% had a CSA>10.5mm 2 (Koyuncuoglu 2005) Controls without sx of CTS – 3.3% had a CSA>10.5mm 2 (Koyuncuoglu 2005) Carpal Tunnel Syndrome: EMG vs. US

35. 2. Rule out other likely diagnoses - neurological 2. Rule out other likely diagnoses - neurological ElectrodiagnosticsBEST ElectrodiagnosticsBEST Series of failed carpal tunnel release – ultimate diagnosis (Witt 2000) Series of failed carpal tunnel release – ultimate diagnosis (Witt 2000) Polyneuropathy (2/12) Polyneuropathy (2/12) Cervical radiculopathy (1/12) Cervical radiculopathy (1/12) Motor neuron disease (4/12) Motor neuron disease (4/12) Spondylotic myelopathy (1/12) Spondylotic myelopathy (1/12) Syringomyelia (1/12) Syringomyelia (1/12) Multiple sclerosis (2/12) Multiple sclerosis (2/12) TEST OF CHOICE Carpal Tunnel Syndrome: EMG vs. US

36. 2. Rule out other likely diagnoses - neurological 2. Rule out other likely diagnoses - neurological UltrasoundPOOR UltrasoundPOOR Cervical radiculopathy Cervical radiculopathy Brachial plexopathy Brachial plexopathy Ulnar neuropathy Ulnar neuropathy Proximal median neuropathy Proximal median neuropathy Polyneuropathy Polyneuropathy Carpal Tunnel Syndrome: EMG vs. US

37. 2. Rule out other likely diagnoses - MSK 2. Rule out other likely diagnoses - MSK ElectrodiagnosticsWORST ElectrodiagnosticsWORST Carpal Tunnel Syndrome: EMG vs. US

38. 2. Rule out other likely diagnoses - MSK 2. Rule out other likely diagnoses - MSK UltrasoundBEST UltrasoundBEST Tenosynovitis Tenosynovitis Trigger finger Trigger finger Synovitis Synovitis Ganglion cysts Ganglion cysts Carpal Tunnel Syndrome: EMG vs. US TEST OF CHOICE / ALTERNATE

39. 3. Establish timing of injury 3. Establish timing of injury ElectrodiagnosticsBEST ElectrodiagnosticsBEST Needle EMG Needle EMG Size of fibrillation potentials Size of fibrillation potentials Size of motor unit action potentials (MUAP) Size of motor unit action potentials (MUAP) Carpal Tunnel Syndrome: EMG vs. US

40. 3. Establish timing of injury 3. Establish timing of injury UltrasoundWORST UltrasoundWORST Carpal Tunnel Syndrome: EMG vs. US

41. 4. Assess severity 4. Assess severity Electrodiagnostics Electrodiagnostics Electrophysiologic rating scales Electrophysiologic rating scales Steven scale Steven scale Canterbury scale Canterbury scale Combined sensory index (CSI) Combined sensory index (CSI) Carpal Tunnel Syndrome: EMG vs. US

42. Canterbury Scale (Bland 2000) Canterbury Scale (Bland 2000) 0 – NORMAL 0 – NORMAL no neurophysiological abnormality no neurophysiological abnormality 1 – VERY MILD 1 – VERY MILD detected only in two sensitive tests (inching, palm/wrist median/ulnar comparison, ringdiff) detected only in two sensitive tests (inching, palm/wrist median/ulnar comparison, ringdiff) 2 – MILD 2 – MILD index finger CV <50m/s, motor latency <4.5ms index finger CV <50m/s, motor latency <4.5ms 3 – MODERATELY SEVERE 3 – MODERATELY SEVERE motor latency 4.5-6.5ms with preserved SNAP D2 motor latency 4.5-6.5ms with preserved SNAP D2 4 –SEVERE 4 –SEVERE motor latency 4.5-6.5ms with absent SNAP D2 motor latency 4.5-6.5ms with absent SNAP D2 5 – VERY SEVERE 5 – VERY SEVERE motor latency >6.5ms motor latency >6.5ms 6 – EXTREMELY SEVERE 6 – EXTREMELY SEVERE motor amplitude <0.2mV motor amplitude <0.2mV Carpal Tunnel Syndrome: EMG vs. US

43. 4. Assess severity 4. Assess severity Electrodiagnostics – correlation with clinical symptoms Electrodiagnostics – correlation with clinical symptoms No - several studies No - several studies Yes - Bland 2000 Yes - Bland 2000 Carpal Tunnel Syndrome: EMG vs. US

44. 4. Assess severity 4. Assess severity Electrodiagnostics – correlates with surgical outcome Electrodiagnostics – correlates with surgical outcome No – several studies No – several studies Yes – Canterbury scale (Bland 2001) Yes – Canterbury scale (Bland 2001) 0 – no CTS – 51% success 0 – no CTS – 51% success 1 – very mild – 65% success 1 – very mild – 65% success 2 – mild – 76% success 2 – mild – 76% success 3 – moderately severe – 77% success 3 – moderately severe – 77% success 4 – severe – 74% success 4 – severe – 74% success 5 – very severe – 66% success 5 – very severe – 66% success 6 – extremely severe – 47% success 6 – extremely severe – 47% success Carpal Tunnel Syndrome: EMG vs. US

45. 4. Assess severity 4. Assess severity Electrodiagnostics – correlates with surgical outcome Electrodiagnostics – correlates with surgical outcome Yes - Combined sensory index (Malladi 2010) Yes - Combined sensory index (Malladi 2010) Normal (<1.0) – 50% complete resolution of sx Normal (<1.0) – 50% complete resolution of sx 1.0-2.4 – 50% complete resolutions of sx 1.0-2.4 – 50% complete resolutions of sx 2.5-4.6 – 71% complete resolutions of sx 2.5-4.6 – 71% complete resolutions of sx >4.6 - 54% complete resolution of sx >4.6 - 54% complete resolution of sx Absent – 37% complete resolution of sx Absent – 37% complete resolution of sx Carpal Tunnel Syndrome: EMG vs. US

46. 4. Assess severity 4. Assess severity Ultrasound – correlation with EDX severity Ultrasound – correlation with EDX severity No correlation (Bland reference, Mhoon 2012, Mohammadi 2010, Kaymak 2008) No correlation (Bland reference, Mhoon 2012, Mohammadi 2010, Kaymak 2008) Correlation (Karadag 2010, ?Lee 2005, Bayrak 2007, Padua 2008, Ziswiler 2005) Correlation (Karadag 2010, ?Lee 2005, Bayrak 2007, Padua 2008, Ziswiler 2005) Carpal Tunnel Syndrome: EMG vs. US

47. 4. Assess severity 4. Assess severity ElectrodiagnosticsGOOD ElectrodiagnosticsGOOD Carpal Tunnel Syndrome: EMG vs. US

48. 4. Assess severity 4. Assess severity Ultrasound POOR Ultrasound POOR Carpal Tunnel Syndrome: EMG vs. US

49. 4. Assess severity 4. Assess severity Ultrasound POOR Ultrasound POOR Carpal Tunnel Syndrome: EMG vs. US

50. 5. Determines etiology 5. Determines etiology ElectrodiagnosticsWORST ElectrodiagnosticsWORST Carpal Tunnel Syndrome: EMG vs. US

51. 5. Determines etiology 5. Determines etiology UltrasoundBEST UltrasoundBEST In patients with CTS In patients with CTS Ganglion – 25% in unilateral CTS, 7% bilateral by US (Nakamichi 1993, Buchberger 1991) Ganglion – 25% in unilateral CTS, 7% bilateral by US (Nakamichi 1993, Buchberger 1991) Tenosynovitis – 10% in CTS by US, confirmed in surgery (Buchberger 1991) Tenosynovitis – 10% in CTS by US, confirmed in surgery (Buchberger 1991) Fatty tissue on the floor of CT – 7% in CTS by US, confirmed in surgery (Buchberger 1991) Fatty tissue on the floor of CT – 7% in CTS by US, confirmed in surgery (Buchberger 1991) Intrusive FDS – 7% in CTS by US (Buchberger 1991) Intrusive FDS – 7% in CTS by US (Buchberger 1991) Instrusive lumbricals – 22% (Touborg-Jensen 1970) Instrusive lumbricals – 22% (Touborg-Jensen 1970) Fracture Fracture Dislocation Dislocation Carpal Tunnel Syndrome: EMG vs. US

52. 5. Determines etiology 5. Determines etiology UltrasoundBEST UltrasoundBEST Determining causation Determining causation Test can potentially detect abnormality Test can potentially detect abnormality Increased incidence in CT than in normals (association) Increased incidence in CT than in normals (association) ? Treating  improving symptoms or other disease marker (causation) ? Treating  improving symptoms or other disease marker (causation) Carpal Tunnel Syndrome: EMG vs. US

53. 6. Determines prognosis 6. Determines prognosis Electrodiagnostic Electrodiagnostic Carpal Tunnel Syndrome: EMG vs. US

54. 6. Determines prognosis 6. Determines prognosis US US Carpal Tunnel Syndrome: EMG vs. US

55. 7. Change treatment 7. Change treatment A. By severity (and presumed natural history) A. By severity (and presumed natural history) B. By etiology (and treatments specific to that cause) B. By etiology (and treatments specific to that cause) Carpal Tunnel Syndrome: EMG vs. US

56. 7. Change treatment 7. Change treatment Electrodiagnostics GOOD Electrodiagnostics GOOD A. By severity (and presumed natural history) A. By severity (and presumed natural history) This does not tell you whether a patient should have surgery or not! This does not tell you whether a patient should have surgery or not! Mild - probably shouldn’t Mild - probably shouldn’t Doesn’t compare outcomes with or without surgery, just surgery with different severities Doesn’t compare outcomes with or without surgery, just surgery with different severities B. By etiology (and treatments specific to that cause) B. By etiology (and treatments specific to that cause) none none Carpal Tunnel Syndrome: EMG vs. US

58. 7. Change treatment 7. Change treatment Ultrasound Ultrasound A. By severity (and presumed natural history) A. By severity (and presumed natural history) None None B. By etiology (and treatments specific to that cause) B. By etiology (and treatments specific to that cause) ?? ?? Carpal Tunnel Syndrome: EMG vs. US

61. 7. Change treatment 7. Change treatment Ultrasound – etiologies that may change txAVERAGE Ultrasound – etiologies that may change txAVERAGE Any surgery – relative contraindications Any surgery – relative contraindications Tenosynovitis 6% – injection probably favorable (Beekman 2003) Tenosynovitis 6% – injection probably favorable (Beekman 2003) Thrombosed persistent median artery – treated with thrombolysis? (Fumiere 2002, Bianchi book 465) Thrombosed persistent median artery – treated with thrombolysis? (Fumiere 2002, Bianchi book 465) Endoscopic surgery – relative contraindications Endoscopic surgery – relative contraindications Space occupying lesion (Bianchi book 467) Space occupying lesion (Bianchi book 467) Ganglion cyst – 25% unilateral (Nakamichi 1993) Ganglion cyst – 25% unilateral (Nakamichi 1993) Persistent median artery 9% (Padua 2011) Persistent median artery 9% (Padua 2011) Bifid median nerve 9% (Padua 2011) Bifid median nerve 9% (Padua 2011) May have separate compartments requiring separate treatments (Ianicelli 2000, Szabo 1994, Amadio 1987) May have separate compartments requiring separate treatments (Ianicelli 2000, Szabo 1994, Amadio 1987) Carpal Tunnel Syndrome: EMG vs. US

62. Negatives of testing Negatives of testing Electrodiagnostics Electrodiagnostics Tolerability WORST Tolerability WORST SafetyBEST SafetyBEST Price AVERAGE Price AVERAGE 95908+95861 = ~$200 95908+95861 = ~$200 SpeedAVERAGE SpeedAVERAGE ~30 minutes ~30 minutes Readily available Readily available Equipment GOOD Equipment GOOD Competent operators GOOD Competent operators GOOD Carpal Tunnel Syndrome: EMG vs. US

63. Negatives of testing Negatives of testing Ultrasound Ultrasound TolerabilityBEST TolerabilityBEST SafetyBEST SafetyBEST Price GOOD Price GOOD 76881 = $114 76881 = $114 SpeedBEST SpeedBEST Full anterior wrist, forearm comparison = ~12 minutes Full anterior wrist, forearm comparison = ~12 minutes Readily available Readily available Equipment GOOD Equipment GOOD Competent operators WORST Competent operators WORST Carpal Tunnel Syndrome: EMG vs. US

64. USEDX GOODSensitivity BEST AVERAGESpecificityBEST BESTReliabilityBEST POORpost CTRAVERAGE GOODPolyneuropathy GOOD POOR (MSK) Rule out mimickers BEST (PN) POORTimingBEST POORSeverityGOOD BESTEtiologyWORST POORPrognosticateGOOD AVERAGEDirect treatmentGOOD

65. USEDX BESTTolerabilityWORST BESTSafetyBEST GOODExpense AVERAGE BESTSpeedAVERAGE POORAvailabilityGOOD

66. US as a screening tool US as a screening tool US should be used as a screen US should be used as a screen Screening test profile Screening test profile Tolerable Tolerable Safe Safe Quick Quick Cheap Cheap Can confirm borderline values with a gold standard tests Can confirm borderline values with a gold standard tests Carpal Tunnel Syndrome: EMG vs. US

67. US as a screening test US as a screening test TolerabilityBEST TolerabilityBEST SafetyBEST SafetyBEST Time (12 minutes)BEST Time (12 minutes)BEST Price ($114)GOOD Price ($114)GOOD Sensitivity (65-97%)GOOD Sensitivity (65-97%)GOOD Specificity (72-97%)AVERAGE Specificity (72-97%)AVERAGE SeverityWORST SeverityWORST EtiologyBEST EtiologyBEST Rule out mimickersPOOR Rule out mimickersPOOR PrognosisPOOR PrognosisPOOR Direct TreatmentGOOD Direct TreatmentGOOD Carpal Tunnel Syndrome: EMG vs. US

68. Ringdiff <= 0.04 TolerabilityGOOD TolerabilityGOOD SafetyBEST SafetyBEST Time (1 minute)BEST Time (1 minute)BEST Price ($91)BEST Price ($91)BEST Sensitivity (74%)AVERAGE Sensitivity (74%)AVERAGE Specificity (92%) BEST Specificity (92%) BEST SeverityGOOD SeverityGOOD EtiologyWORST EtiologyWORST Rule out mimickersAVERAGE Rule out mimickersAVERAGE PrognosisGOOD PrognosisGOOD Direct treatmentGOOD Direct treatmentGOOD Carpal Tunnel Syndrome: EMG vs. US

69. CSI <=0.09 CSI <=0.09 TolerabilityGOOD TolerabilityGOOD SafetyBEST SafetyBEST Time (2 minutes)BEST Time (2 minutes)BEST Price ($136)BEST Price ($136)BEST Sensitivity (83.1%)GOOD Sensitivity (83.1%)GOOD Specificity (95.4%) BEST Specificity (95.4%) BEST EtiologyWORST EtiologyWORST SeverityGOOD SeverityGOOD Rule out mimickersAVERAGE Rule out mimickersAVERAGE PrognosisGOOD PrognosisGOOD Direct treatmentGOOD Direct treatmentGOOD Carpal Tunnel Syndrome: EMG vs. US

70. USCSI BESTTolerability GOOD BESTSafety BEST BEST (12m)Time BEST (2m) GOOD ($114)Price GOOD ($136) GOOD(65-97%)Sensitivity GOOD (83%) AVERAGE (72-97%)Specificity BEST (95%) POORSeverity GOOD BESTEtiology WORST POOR (MSK) R/O Mimickers GOOD (PN) POORPrognosis GOOD GOODDirect treatment GOOD

71. Conclusions: Conclusions: 1. Which test should be first line for CTS 1. Which test should be first line for CTS EDX because of it’s mildly superior sensitivity and significantly superior specificity; ability to rule out likely mimickers, assess severity and thereby prognosticate and direct treatment (surgery) EDX because of it’s mildly superior sensitivity and significantly superior specificity; ability to rule out likely mimickers, assess severity and thereby prognosticate and direct treatment (surgery) Carpal Tunnel Syndrome: EMG vs. US

72. Conclusions: Conclusions: 2. Are there circumstances in which the primary test should change (US be first line) 2. Are there circumstances in which the primary test should change (US be first line) EDX unsafe or intolerable EDX unsafe or intolerable If symptoms are localized hand or wrist pain without numbness or tingling (unproven) If symptoms are localized hand or wrist pain without numbness or tingling (unproven) Carpal Tunnel Syndrome: EMG vs. US

73. Conclusions: Conclusions: 3. Are there circumstances in which both tests should be performed? 3. Are there circumstances in which both tests should be performed? Suspected false-negative EDX (proven yield) Suspected false-negative EDX (proven yield) Sudden onset CTS (unproven yeild for thrombosed PMA) Sudden onset CTS (unproven yeild for thrombosed PMA) Unilateral CTS (proven yield for occult ganglia) Unilateral CTS (proven yield for occult ganglia) After fracture (proven yield, change dx, tx) After fracture (proven yield, change dx, tx) After trauma (proven yield, change dx, tx) After trauma (proven yield, change dx, tx) In patients undergoing dialysis (unproven) In patients undergoing dialysis (unproven) Rheumatoid arthritis (unproven) Rheumatoid arthritis (unproven) Considering endoscopic CT release (proven yield) Considering endoscopic CT release (proven yield) Failed treatment (unproven) Failed treatment (unproven) Carpal Tunnel Syndrome: EMG vs. US

75. What do we want a test for focal peripheral neuropathies to do? What do we want a test for focal peripheral neuropathies to do? 1. Diagnose/exclude UNE 1. Diagnose/exclude UNE 2. Rule out the other likely diagnoses 2. Rule out the other likely diagnoses 3. Assess severity 3. Assess severity 4. Establish timing of injury 4. Establish timing of injury 5. Determine etiology 5. Determine etiology 6. Determine prognosis 6. Determine prognosis 7. Guide treatment 7. Guide treatment Ulnar Neuropathy at the Elbow: EMG vs. US

76. 1. Diagnose/exclude UNE - reliably 1. Diagnose/exclude UNE - reliably Electrodiagnostics Electrodiagnostics Test-retest reliabilityGOOD Test-retest reliabilityGOOD CSI – Spearman rho 0.95 (Lew 2000) CSI – Spearman rho 0.95 (Lew 2000) Inter-rater reliabilityPOOR Inter-rater reliabilityPOOR Large enough to limit clinical trials (Dyck 2013) Large enough to limit clinical trials (Dyck 2013) Reference values BEST Reference values BEST Standardization of practiceAVERAGE Standardization of practiceAVERAGE Identify dynamic pathologyWORST Identify dynamic pathologyWORST Use side-to-side comparisonBEST Use side-to-side comparisonBEST Quality assurance Quality assurance Operators – ABEMBEST Operators – ABEMBEST Laboratories – AANEMGOOD Laboratories – AANEMGOOD Ulnar Neuropathy at the Elbow: EMG vs. US

77. 1. Diagnose/exclude UNE - reliably 1. Diagnose/exclude UNE - reliably Ultrasound Ultrasound Test-retest reliabilityBEST Test-retest reliabilityBEST Coefficient >=0.98 (Cartwright 2013) Coefficient >=0.98 (Cartwright 2013) Inter-rater reliabilityBEST Inter-rater reliabilityBEST P<0.001 still; <0.05 most dynamic (Cartwright 2013) P<0.001 still; <0.05 most dynamic (Cartwright 2013) Reference dataBEST Reference dataBEST Standardization of practiceAVERAGE Standardization of practiceAVERAGE Identify dynamic pathologyBEST Identify dynamic pathologyBEST Use side-to-side comparisonsBEST Use side-to-side comparisonsBEST Quality assurance Quality assurance Operators – ARDMSAVERAGE Operators – ARDMSAVERAGE Labs – AIUMBEST Labs – AIUMBEST Ulnar Neuropathy at the Elbow: EMG vs. US

78. 1. Diagnose/exclude UNE - accurately 1. Diagnose/exclude UNE - accurately ElectrodiagnosticsAVERAGE ElectrodiagnosticsAVERAGE Sensitivity – 37-86% (AANEM 1997) Sensitivity – 37-86% (AANEM 1997) Specificity – 95% (AANEM 1997) Specificity – 95% (AANEM 1997) Ulnar Neuropathy at the Elbow: EMG vs. US

79. 1. Diagnose/exclude UNE - accurately 1. Diagnose/exclude UNE - accurately Ultrasound - cross sectional area (CSA)POOR Ultrasound - cross sectional area (CSA)POOR Sensitivity: 46-81% (Beekman 2001) Sensitivity: 46-81% (Beekman 2001) Specificity: 43-97% (Beekman 2001) Specificity: 43-97% (Beekman 2001) Ulnar Neuropathy at the Elbow: EMG vs. US

80. 1. Diagnose/exclude UNE – post surgical 1. Diagnose/exclude UNE – post surgical EDX AVERAGE EDX AVERAGE Significant improvement of NCV for all patients, regardless of success of surgery (Mondelli 2004) Significant improvement of NCV for all patients, regardless of success of surgery (Mondelli 2004) Ulnar Neuropathy at the Elbow: EMG vs. US

81. 1. Diagnose/exclude UNE – post surgical 1. Diagnose/exclude UNE – post surgical USAVERAGE USAVERAGE CSA decreases significantly post-operatively; not with surgical treatment (Beekman 2004) CSA decreases significantly post-operatively; not with surgical treatment (Beekman 2004) Ulnar Neuropathy at the Elbow: EMG vs. US

82. 2. Rule out other likely diagnoses 2. Rule out other likely diagnoses ElectrodiagnosticsBEST ElectrodiagnosticsBEST C8 radiculopathy C8 radiculopathy Lower trunk / medial cord plexopathy Lower trunk / medial cord plexopathy Ulnar neuropathy at the wrist Ulnar neuropathy at the wrist Medial epicondylalgia Medial epicondylalgia Carpal tunnel syndrome Carpal tunnel syndrome Generalized peripheral neuropathy Generalized peripheral neuropathy ALS ALS Cervical myelopathy Cervical myelopathy Ulnar Neuropathy at the Elbow: EMG vs. US

83. 2. Rule out other likely diagnoses 2. Rule out other likely diagnoses UltrasoundPOOR UltrasoundPOOR C8 radiculopathy C8 radiculopathy Lower trunk / medial cord plexopathy Lower trunk / medial cord plexopathy Ulnar neuropathy at the wrist Ulnar neuropathy at the wrist Medial epicondylalgia Medial epicondylalgia Carpal tunnel syndrome Carpal tunnel syndrome Generalized peripheral neuropathy Generalized peripheral neuropathy ALS ALS Cervical myelopathy Cervical myelopathy Ulnar Neuropathy at the Elbow: EMG vs. US

84. 3. Assess severity 3. Assess severity ElectrodiagnosticsGOOD ElectrodiagnosticsGOOD Ulnar Neuropathy at the Elbow: EMG vs. US

85. 3. Assess severity 3. Assess severity Ultrasound – correlation with EDX GOOD Ultrasound – correlation with EDX GOOD CSA correlates with EDX grading of severity in multiple studies (Beekman 2011) CSA correlates with EDX grading of severity in multiple studies (Beekman 2011) Ulnar Neuropathy at the Elbow: EMG vs. US

86. 4. Assess timing of injury 4. Assess timing of injury ElectrodiagnosticsBEST ElectrodiagnosticsBEST Size of fibrillation potentials Size of fibrillation potentials Size of MUAP Size of MUAP Ulnar Neuropathy at the Elbow: EMG vs. US

87. 4. Assess timing of injury 4. Assess timing of injury UltrasoundWORST UltrasoundWORST Ulnar Neuropathy at the Elbow: EMG vs. US

88. 5. Determine etiology 5. Determine etiology ElectrodiagnosticsPOOR ElectrodiagnosticsPOOR Short segmental incremental studies (inching) – location and thus site of likely entrapment Short segmental incremental studies (inching) – location and thus site of likely entrapment Ulnar Neuropathy at the Elbow: EMG vs. US

89. 5. Determine etiology 5. Determine etiology UltrasoundBEST UltrasoundBEST Finding Finding Subluxation Subluxation Healthy controls 20-23% Healthy controls 20-23% UNE 18-33% UNE 18-33% Luxation Luxation Healthy controls 8-27% Healthy controls 8-27% UNE 10% (Beekman 2011) UNE 10% (Beekman 2011) Ulnar Neuropathy at the Elbow: EMG vs. US

90. 5. Determine etiology 5. Determine etiology Ultrasound (Beekman 2011)BEST Ultrasound (Beekman 2011)BEST Other findings Other findings UNE UNE Accessory muscles - anconeus epitrochlearis – 6-21% Accessory muscles - anconeus epitrochlearis – 6-21% Medial elbow ganglia – 1% with UNE Medial elbow ganglia – 1% with UNE Osteophytes – 7% with UNE Osteophytes – 7% with UNE Healthy controls Healthy controls ??? ??? Ulnar Neuropathy at the Elbow: EMG vs. US

91. 6. Determine prognosis 6. Determine prognosis ElectrodiagnosticsGOOD ElectrodiagnosticsGOOD Predicting outcome of surgery (pre-operative) Predicting outcome of surgery (pre-operative) Ulnar SNAP D5 amplitude is a good predictor of improvement (Mondelli 2004) Ulnar SNAP D5 amplitude is a good predictor of improvement (Mondelli 2004) NCV is not, but NCS decreased amplitudes and fibrillation potentials a negative significant predictor of improvement (Adelaar 1984) NCV is not, but NCS decreased amplitudes and fibrillation potentials a negative significant predictor of improvement (Adelaar 1984) Motor conduction block and slowing indicate good prognosis (Beekman 2004) Motor conduction block and slowing indicate good prognosis (Beekman 2004) Ulnar Neuropathy at the Elbow: EMG vs. US

92. 6. Determine prognosis 6. Determine prognosis UltrasoundGOOD UltrasoundGOOD Larger nerves indicate poor prognosis (Beekman 2004) Larger nerves indicate poor prognosis (Beekman 2004) Ulnar Neuropathy at the Elbow: EMG vs. US

93. 7. Guide treatment 7. Guide treatment ElectrodiagnosticsGOOD ElectrodiagnosticsGOOD By severity By severity Establishes severity with meaning; not clear if it changes outcomes Establishes severity with meaning; not clear if it changes outcomes By etiology By etiology none none Ulnar Neuropathy at the Elbow: EMG vs. US

94. 7. Guide treatment 7. Guide treatment UltrasoundGOOD UltrasoundGOOD By severity By severity Correlates with EDX; not clear if this guides tx Correlates with EDX; not clear if this guides tx By etiology By etiology Subluxation Subluxation Not clear if it is pathologic Not clear if it is pathologic Simple decompression is recommended even if patients sublux (Bartels 2005) Simple decompression is recommended even if patients sublux (Bartels 2005) Ulnar Neuropathy at the Elbow: EMG vs. US

95. USEDX POORSensitivityPOOR AVERAGESpecificityBEST BESTReliabilityBEST AVERAGEPost surgeryAVERAGE POOR (MSK) Rule out mimickers BEST (PN) WORSTTimingBEST GOODSeverity GOOD BESTEtiologyPOOR GOODPrognosticate GOOD GOODDirect treatment GOOD

96. Negatives of testing Negatives of testing Electrodiagnostics Electrodiagnostics Tolerability WORST Tolerability WORST SafetyBEST SafetyBEST Price AVERAGE Price AVERAGE 95909+95861 = ~$213 95909+95861 = ~$213 SpeedAVERAGE SpeedAVERAGE ~40 minutes ~40 minutes Readily available Readily available Equipment GOOD Equipment GOOD Competent operators GOOD Competent operators GOOD Ulnar Neuropathy at the Elbow: EMG vs. US

97. Negatives of testing Negatives of testing Ultrasound Ultrasound TolerabilityBEST TolerabilityBEST SafetyBEST SafetyBEST Price GOOD Price GOOD 76881 = $114 76881 = $114 SpeedBEST SpeedBEST Full medial elbow = ~10 minutes Full medial elbow = ~10 minutes Readily available Readily available Equipment GOOD Equipment GOOD Competent operators WORST Competent operators WORST Ulnar Neuropathy at the Elbow: EMG vs. US

98. US EDX BESTTolerability WORST BESTSafety BEST GOOD $114Expense AVERAGE $213 BEST10minSpeed AVERAGE 40min POORAvailability GOOD

99. Conclusions: Conclusions: 1. Which test should be first line for UNE 1. Which test should be first line for UNE EDX because of it’s superior specificity; ability to rule out important and likely mimickers, and possible better ability to assess severity. EDX because of it’s superior specificity; ability to rule out important and likely mimickers, and possible better ability to assess severity. Ulnar Neuropathy at the Elbow: EMG vs. US

100. Conclusions: Conclusions: 2. Are there circumstances in which the primary test should change (US be first line) 2. Are there circumstances in which the primary test should change (US be first line) EDX unsafe or intolerable EDX unsafe or intolerable If symptoms are localized medial elbow pain without numbness or tingling (unproven) If symptoms are localized medial elbow pain without numbness or tingling (unproven) Ulnar Neuropathy at the Elbow: EMG vs. US

101. Conclusions: Conclusions: 3. Are there circumstances in which both tests should be performed? 3. Are there circumstances in which both tests should be performed? Suspected false-negative EDX (unproven) Suspected false-negative EDX (unproven) After fracture (proven yield, change dx, tx) After fracture (proven yield, change dx, tx) After trauma (proven yield, change dx, tx) After trauma (proven yield, change dx, tx) Failed treatment (unproven) Failed treatment (unproven) Severe UNE that is non-localizable (unproven) Severe UNE that is non-localizable (unproven) Ulnar Neuropathy at the Elbow: EMG vs. US