ELECTRODIAGNOSTICS

John Gambin, M.D.

NMJ

Fiber Types Involved Pathology Temporal Course

Sensory

Motor

Mixed

Axonal

Demyelinating

Acquired Inherited

Hyperacute

Acute

Subacute

Chronic

Severity

Goals of the EDX Study

Muscle Nerve

Localization

Neuronopathy

Radiculopathy

Plexopathy

Mononeuropathy

Multiple Mononeuropathies

Polyneuropathy

CNS

Proximal

Distal

Generalized

Cranio-bulbar

Presynaptic

Postsynaptic

Localization

Myopathic NMJNeuropathic

Elements of the Peripheral Nervous System

Neurons of the Peripheral Nervous System

Sensory Nerve

Motor Nerve

Post Synaptic Membrane

Muscle Contraction

Motor Unit

MUAP

Nerve Conduction or EMG ?Indications for Nerve Conduction

Peripheral entrapment Suspicion of polyneuropathy Suspicion of Myasthenia Gravis Nerve Trauma

Indications for EMG Suspicion of disorder Brachial plexus injury Lumbosacral plexus pathology Muscle disorder

Nerve Root

Patterns of Nerve Conductions Stimulation

Types of Nerve Damage

Nerve Recovery PatternsMuscle Demyelinating

Other- Mixed Injury

Measurement Parameters

(DML)

(PML)

Conduction Velocity = Distance (Proximal - Distal)Time (PML –DML)

Entrapment Sites

Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Right Med/Uln/Rad Nerve

Patient: Patient A Test Date: 02/02/10Age: 49

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 2.9 3.3 14.8 16.0 80 80ACF 6.1 6.6 13.6 15.7 190 195 60.0 59.1

Motor Nerve StudyUlnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 2.6 2.7 19.5 17.1 80 80B.Elbow 5.4 5.5 18.5 16.2 175 175 62.5 63.3A.Elbow 7.2 7.0 17.4 15.4 110 115 63.5 75.0

Sensory Nerve StudyMed/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec Site L R L R L R L RMedMidPM 1.8 2.0 84.3 70.7 80 80 43.6 40.0UlnMidPlm 1.9 1.7 43.7 52.0 80 80 42.9 46.2MedSenAnt 3.1 3.1 111. 69.0 140 140 45.7 45.2UlnSenAnti 3.4 3.1 48.0 73.0 140 140 41.2 45.2

Summary/Interpretation:Normal nerve conduction studies of the upper extremities.

Left Median Nerve

Left Med/Uln/Rad Nerve

Normal Study – Upper Extremities

Patient: Patient C Test Date: 10/01/09Age: 87

Motor Nerve StudyLeft Median NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim SiteWrist 8.2 2.8 80ACF 11.7 2.9 185 52.9Mid Palm 1.7 4.7 40

Motor Nerve StudyLeft Ulnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim SiteWrist 4.2 9.7 80B.Elbow 7.6 8.6 195 56.8A.Elbow 9.2 8.7 85 54.3

Sensory Nerve StudyLeft Med/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec SiteMedMidPM 3.8 19.0 80 21.2UlnMidPlm 2.5 30.0 80 32.0MedSenAnt 5.6 15.3 140 25.1UlnSenAnti 4.4 18.0 140 31.8

Summary/Interpretation:Nerve conduction studies of the left upper extremity demonstrate a severe left carpal tunnel syndrome.

Left Median Nerve

Left Ulnar Nerve

Left Med/Uln/Rad Nerve

Severe Carpal Tunnel Syndrome

Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Left Med/Uln/Rad Nerve Right Med/Uln/Rad Nerve

Patient: Patient D Test Date: 11/04/09Age: 24

History/Comments:Pain and numbness in both upper extremities, right greater than left.

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 3.3 3.9 16.4 15.0 80 80ACF 6.7 6.9 16.3 15.0 195 190 61.6 61.3

Motor Nerve StudyUlnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 2.8 2.8 17.2 15.1 80 80B.Elbow 5.4 5.7 16.5 14.7 175 185 67.3 63.1A.Elbow 7.4 7.6 15.8 14.0 125 125 62.5 67.0

Sensory Nerve StudyMed/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec Site L R L R L R L RMedMidPM 1.9 2.2 144. 140. 80 80 42.1 36.4UlnMidPlm 1.8 1.5 67.5 51.7 80 80 43.6 53.3MedSenAnt 3.3 3.6 76.7 70.0 140 140 42.9 38.5UlnSenAnti 3.2 3.3 68.3 48.3 140 140 43.8 42.0

Summary/Interpretation:Nerve conduction study of both upper extremities shows minimal slowing across the right carpal tunnel.

Left Median NerveVery Minimal or Mild Carpal Tunnel Syndrome

Left Median Nerve Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Left Med/Uln/Rad Nerve Right Med/Uln/Rad Nerve

Patient: Patient E Test Date: 10/06/09Age: 82

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 5.8 5.3 11.0 12.9 80 80ACF 9.8 9.6 10.4 12.4 205 215 51.3 50.4

Motor Nerve StudyUlnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 3.8 4.1 14.5 12.9 80 80B.Elbow 7.8 8.0 14.8 11.7 210 200 52.1 50.8A.Elbow 10.3 10.0 13.6 13.1 105 110 43.2 55.9

Sensory Nerve StudyMed/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec Site L R L R L R L RMedMidPM 3.7 2.9 20.7 160. 80 80 21.6 27.6UlnMidPlm 2.4 2.0 8.9 19.0 80 80 33.8 40.0MedSenAnt 6.2 4.8 7.6 7.3 140 140 22.6 29.2UlnSenAnti 4.8 4.3 6.7 14.0 140 140 29.0 32.6

Summary/Interpretation:Nerve conduction studies of both upper extremities show changes of a bilateral carpal tunnel syndrome, moderately severe, left worse than right, superimposed on a modest generalized polyneuropathy.

Carpal Tunnel Syndrome With

Underlying Mild Neuropathy

Patient: Patient F Age: 87

History/Comments:Numbness and tingling in both hands, right greater than left.

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 4.8 5.5 9.8 9.2 80 80ACF 9.5 10.0 9.3 9.1 245 225 54.0 48.6

Motor Nerve StudyUlnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 3.0 3.3 14.6 17.7 80 80B.Elbow 7.0 8.0 14.1 17.3 220 235 55.5 50.0A.Elbow 9.6 10.4 13.5 16.1 130 125 50.6 52.1

Sensory Nerve StudyMed/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec Site L R L R L R L RMedMidPM 3.0 3.6 30.3 13.7 80 80 27.0 22.2UlnMidPlm 2.2 2.2 26.0 79.3 80 80 36.4 38.7MedSenAnt 4.5 5.8 27.7 8.0 140 140 31.3 24.3UlnSenAnti 3.6 3.6 28.3 17.3 140 140 39.3 38.9

Summary/Interpretation:Nerve conduction study of both upper extremities reveals bilateral carpal tunnel syndromes, severe on the right and moderate on the left.

Left Median Nerve Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Left Med/Uln/Rad Nerve Right Med/Uln/Rad Nerve

Carpal Tunnel Syndrome

Severe on the right / Moderate on the left

Ulnar Nerve

The most common place for nerve entrapment is in the elbow.

Ulnar Neuropathy

Cubital Tunnel

Tardy Ulnar Palsy

Left Median Nerve Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Left Med/Uln/Rad Nerve Right Med/Uln/Rad Nerve

Patient: Patient G Test Date: 01/05/10Age: 57

History/Comments:Possible ulnar neuropathy.

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 3.4 3.8 10.8 9.4 80 80ACF 7.1 7.3 10.3 9.3 220 200 59.5 56.1

Motor Nerve StudyUlnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L R L RWrist 3.7 3.4 16.3 16.5 80 80B.Elbow 6.3 6.5 16.2 16.6 185 180 63.8 60.7A.Elbow 8.5 8.1 12.4 16.8 80 110 36.9 71.7

Sensory Nerve StudyMed/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec Site L R L R L R L RMedMidPM 2.2 2.4 79.7 72.0 80 80 36.9 32.9UlnMidPlm 2.1 1.9 30.7 25.7 80 80 42.9 38.7MedSenAnt 3.4 3.8 124.2 38.7 140 140 41.6 36.8UlnSenAnti 3.8 3.5 22.5 34.7 140 140 37.5 37.2

Summary/Interpretation:Nerve conduction study of both upper extremities shows an ulnar neuropathy with significant drop in the velocity across the elbow.

Ulnar Neuropathy

Patient: Patient I Test Date:11/24/09Age: 57

Motor Nerve StudyMedian NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R

L R L R

Wrist 4.4 3.8 12.7 12.080 80

ACF 8.3 7.7 12.7 12.3215 235 59.7 62.4

Motor Nerve StudyUlnar NerveRec Site: ADMLat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R

L R LR

Wrist 4.0 3.7 10.4 16.780 80

B.Elbow 7.7 7.0 9.4 15.5230 220 61.6

66.0A.Elbow 11.5 9.1 1.8 14.7

100 140 26.568.9

Sensory Nerve StudyLeft Med/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV)

Dist (mm) C.V. (m/s)Rec SiteMedMidPM 2.4 125.7

80 33.8UlnMidPlm 2.2 21.6

80 36.4MedSenAnt 3.7 28.3

140 38.2UlnSenAnti 3.9 44.7

140 35.9

Summary/Interpretation:Nerve conduction studies of the upper extremities show:1. Severe ulnar neuropathy at the left elbow, (amplitude and velocity drop).2. Mild left carpal tunnel syndrome.

Right Median Nerve

Left Ulnar Nerve Right Ulnar Nerve

Left Med/Uln/Rad Nerve

Left Median NerveSevere Ulnar Neuropathy and Mild Carpal Tunnel

Patient: Patient J Test Date: 10/05/09Age: 60

Motor Nerve StudyRight Median NerveRec Site: APB Lat (ms) Amp (mV) Dist (mm)

C.V. (m/s)Stim SiteWrist 3.9 12.7

80ACF 8.2 12.2

210 49.6

Motor Nerve StudyRight Ulnar NerveRec Site: ADM Lat (ms) Amp (mV) Dist (mm)

C.V. (m/s)Stim SiteWrist 5.0 1.4

80B.Elbow 11.0 .967

200 33.3A.Elbow 19.5 1.1

100 11.8

Sensory Nerve StudyRight Med/Uln/Rad NerveStim Site: Wrist Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Rec SiteMedMidPM 2.3 36.7

80 34.8UlnMidPlm NR

MedSenAnt 3.8 43.7140 36.8

UlnSenAnti NR

Summary/Interpretation:Nerve conduction studies of the right upper extremity show changes of a severe neuropathy at the elbow, predominantly axonal.

Right Ulnar Nerve

Right Med/Uln/Rad Nerve

Right Median NerveSevere Ulnar Neuropathy

Peroneal Neuropathy

Neurology December 2005

MRI Detection of Cysts in the Knee Causing Common Peroneal Neuropathy.

Donald J. Iverson, M.D.

Patient: Patient K Test Date:01/29/10Age: 67

Motor Nerve StudyPeroneal NerveRec Site: EDB Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L

R L RAnkle 6.1 5.4 .383 1.1 80

80B.Fibular 16.8 16.1 .408 .617 315

290 29.5 27.2A.Fibular 19.4 19.4 .433 .583 90

110 33.8 33.0

Motor Nerve StudyTibial NerveRec Site: AH Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L

R L RAnkle 5.7 5.9 .100 .117 80

80Pop.Fos. 21.5 20.3 .333 .300 470

420 29.7 29.3

Motor Nerve StudyPeroneal@AT NerveRec Site: Ant Tibialis Lat (ms) Amp (mV) Dist (mm) C.V. (m/s)Stim Site L R L R L

R L RB.Fibular 3.5 3.6 10.1 8.9

A.Fibular 6.2 6.5 10.1 9.7 90110 33.8 37.7

Sensory Nerve StudyPeroneal NerveRec Site: dors.ft Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Stim Site L R L R L

R L RLower leg 4.7 4.1 3.3 2.0 140

140 30.0 33.9NOTES:

Left side: not reliable Right side: not reliable

Sensory Nerve StudySural NerveRec Site: Ankle Lat (ms) Amp (uV) Dist (mm) C.V. (m/s)Stim Site L R L R L

R L Rmid calf 4.5 4.2 4.2 2.7 140

140 31.1 33.1NOTES:

Left side: not reliable Right side: not reliable

Summary/Interpretation:Nerve conduction study of both lower extremities shows severe length dependent mixed axonal greater than demylenating polyneuropathy.

Right Peroneal Nerve

Left Tibial Nerve Right Tibial Nerve

Left Peroneal@AT Right Peroneal@AT

Left Peroneal Nerve

Sensory waveforms not shown.

Severe (Length Dependent) Polyneuropathy

EMG Studies

Johnny Gambin Age 5

MUAP Morphologies

Spontaneous Waveform Generators

Interference Patterns

End Plate Spikes

Fibrillations

Positive Sharp Waves

Fibrillation Potentials + 1

Fibrillations + 4

Myotonic Discharge

Complex Repetitive Discharge

Fasciculation Potentials

Fasciculation with Reinnervated Potentials

Myokymic Discharge

Cramp

Rest Tremor

Normal Activation and Recruitment

Reinnervation - Long Duration & Polyphasic

Moderately Decreased Recruitment

Myopathic Brief Duration

Abnormal Neuromuscular Function

The possible sites of abnormal function of the peripheral nerves and muscle are:

• Motor neuron cell body, sensory neuron cell body, or both

• Root

• Plexus nerve axons, peripheral nerve axons, or both

• Plexus nerve myelin, peripheral nerve myelin, or both

• Neuromuscular junction

• Muscle

Sites of Damage in Nerve and Muscle Site Disorder

Neuron cell body Amyotrophic lateral sclerosis

Root Cervical or lumbar radiculopathy

Axonal neuropathy Toxic neuropathy

Demyelinating neuropathy Guillain-Barre syndrome

Neuromuscular junction Myasthenia Gravis

Muscle Muscular dystrophy

The End

Thank you!

Patterns of Nerve Conductions

Normal

Axonal

Demyelinating

Demyelinating with conduction block

Distal Latency = 3.0 msecConduction Velocity = 59 m/sec

Distal Latency = 4.4 msecConduction Velocity = 51 m/sec

Distal Latency = 12.7 msecConduction Velocity = 12 m/sec

Distal Latency = 12.7 msecConduction Velocity = 12 m/sec

5 mV

5 msec

Amplitude

Duration

Distal Latency

Proximal Latency

Measurement Parameters