Comprehensive Electromyography

 

Description:

Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by nerves and muscles. Interpreting EMG is a mandatory skill for neurologists and rehabilitation specialists. This textbook provides the reader with a detailed discussion of the concepts and principles underlying electrodiagnostic medicine. It is written for an audience without pre-existing knowledge in this discipline, including beginner technicians and physicians in training. It is an ideal review for seasoned practitioners and those preparing for board examinations. It begins with a review of the foundational sciences and works through the field in twenty chapters, including a large number of case studies demonstrating correct application and interpretation. Appendices of information frequently required in the EMG laboratory, such as Nerve Conduction Study techniques and their age-related normal values, anatomic regions assessed by each NCS and needle EMG studies, safety issues, and other important topics, are also included.

 

Table of Contents:

 

Section 1 Introductory Chapters

Chapter 1 Basic Electricity, Electrical Concepts, and Circuits

Introduction

Electricity

History

Charge

Current

Voltage

Resistance

Ohm’s Law

Types of Circuits and Current

Direct Current

Series DC Circuits

Parallel DC Circuits

Capacitors

Alternating Current

The Quantification of AC Signal

Household Electricity

Transformers

Electromagnetic Radiation

References

Recommended Reading

Chapter 2 Instrumentation

Introduction

Capacitance

Impedance

Filters

Filter Arrangements

Analog-to-Digital Converters and Digital-to-Analog Converters

Stimulators

Amplifiers

Monopolar Amplifiers

Differential Amplifiers

The Common Mode Rejection Ratio

References

Suggested Reading

Chapter 3 Anatomy and Physiology of Neurons

Basic Cellular Anatomy

The Cell Membrane

Neuronal Anatomy and Physiology

Motor Neurons

Sensory Neurons

Myelin

Nerve Fiber Classification

Ion Channels

Action Potential Generation and Propagation

Transmembrane Potentials, Nernst Equilibrium Potentials, and Selective Permeability

Depolarization and Repolarization

The Absolute Refractory Period and the Relative Refractory Period

Action Potential Generation

Local Responses

The Advantage of Myelin

Action Potential Propagation Speed

Connective Tissue Elements of Nerve Trunks

References

Chapter 4 Anatomy and Physiology of the Neuromuscular Junction

Introduction

Presynaptic Region

Synaptic Space

Postsynaptic Region

Postsynaptic Membrane Depolarizations

References

Chapter 5 Anatomy and Physiology of Muscle

The Organization of Muscle Tissue

Motor Units

Muscle Innervation Ratios

Structural Organization of Muscle

Excitation–Contraction Coupling

Action Potential Propagation

The Sarcoplasmic Reticulum

The Sarcomere

Neural Control of Muscle

Introduction

The Final Common Path

Types of Lower Motor Neurons

The CNS Influence

Muscle Spindle Anatomy

Muscle Spindle Physiology

Muscle Lengthening

Muscle Shortening

Motor Unit and Muscle Fiber Types

Motor Unit and Muscle Fiber Physiology, Biochemistry, and Metabolism

Motor Unit Force Generation

Motor Unit Size and Distribution

References

Section 2 Nerve Conduction Studies

Chapter 6 Electrodes and Nerve Conduction Study Basics

History

Introduction

Electrodes

History

Surface Recording Electrodes

Proper Placement of the Recording Electrodes

Bipolar versus Referential Recordings

The Surface Stimulating Electrodes

The Basic Technique

Important Basic Concepts

Volume Conduction

Orthodromic versus Antidromic

The Stimulating Electrodes and Their Proper Placement

References

Chapter 7 Motor Nerve Conduction Studies

Introduction

Recording Technique

Belly-Tendon Method

Biphasic Morphology

The Influence of E2 Placement

The E2 Electrode Is Not Inactive

Improper E2 Placement Affects Amplitude

Positive Dip

Using a Needle Electrode for E2

Nerve Stimulation

Physiologic Temporal Dispersion

Standard and Nonstandard Motor NCS

What We Measure and What It Means

Amplitude

Negative AUC

Distal Latency

The Contributors to the Distal Latency Time

Conduction Velocity

Negative Phase Duration

References

Chapter 8 Sensory Nerve Conduction Studies

Introduction

Technique

Measurements

Amplitude

Orthodromic versus Antidromic Techniques

Latency

The Time Periods Composing the SNAP Onset Latency

Fixed Landmarks versus Fixed Distances

Peak Latencies versus Onset Latencies

Converting Latency Values into Conduction Velocity Values

Conduction Velocity

Advantages and Disadvantages of Sensory NCS

Other Important Sensory NCS Issues

Effects of Filtering

Ideal Interelectrode Distance

Mixed Nerve Conduction Studies

References

Chapter 9 The NCS Manifestations of Various Pathologies

Introduction

Effects of Focal Demyelination on Action Potentials

Effects of Focal Axon Loss on Action Potentials

The Motor NCS Manifestations of Pathology and Pathophysiology

Introduction

The Pathology of Focal Demyelination

The Pathophysiology of Focal Demyelination

Focal Demyelinating Conduction Slowing

Uniform Demyelinating Conduction Slowing

Nonuniform Demyelinating Conduction Slowing

Focal Demyelinating Conduction Block

Axon Loss Pathology and Conduction Failure Pathophysiology

Conduction Failure

The Major Advantages and Disadvantages of the Motor NCS

The Sensory NCS Manifestations of Pathology and Pathophysiology

The Major Advantages and Disadvantages of the Sensory NCS

The Timing of NCS Manifestations

References

Chapter 10 The Utility of NCS for Lesion Localization and Characterization

Introduction

The Effect of Focal Demyelination and Axon Disruption on the NCS

Determining the PNS Elements Assessed by the Various Sensory and Motor NCS

Motor NCS

Sensory NCS

References

Chapter 11 Late Responses and Blink Reflexes

Introduction

H Reflexes

Introduction

Technique

Technical Errors

Amplitude and Latency Measurements

Utility of H Wave Testing

F Waves

Introduction

Physiology and Technique

Utility

A Waves

Blink Reflexes

References

Chapter 12 Repetitive Nerve Stimulation Studies and Their Pathological Manifestations

Introduction

Repetitive Nerve Stimulation Studies

Introduction

Low-Frequency RNSS

Introduction

Technique

Postexercise Facilitation and Postexercise Exhaustion

Pseudofacilitation

Criteria for Abnormal RNSS

Specificity of an Abnormal Study

Technical Errors

High-Frequency RNSS

High-Frequency RNSS Technique

References

Section 3 The Needle EMG Examination

Chapter 13 The Needle EMG Examination

History

Introduction

Motor Unit Anatomy and Physiology

The Motor Unit Action Potential

Introduction

Duration

Motor Unit Recruitment (Force Generation)

The Measurements We Make and Their Meanings

Insertional Phase

Resting Phase

Endplate Activity

Miniature Endplate Potentials

Endplate Spikes

Activation Phase

MUAP Amplitude (Peak-to-Peak)

MUAP Duration

The Number of Phases and Turns Composing the MUAP

MUAP Stability

Final Comment

Needle Recording Electrode Types

Concentric Needle Electrodes

Monopolar Needle Electrodes

References

Chapter 14 The Needle EMG Manifestations of Pathology

Introduction

The Arborization Point

Reinnervation

Chapter Organization

Insertional Phase

Decreased Insertional Activity

‘‘Increased’’ Insertional Activity

Resting Phase

Fibrillation Potentials, Positive Sharp Waves, and Insertional Positive Sharp Waves

Introduction

The Visual Characteristics of Fibrillation Potentials

Amplitude

Morphology and Duration

The Auditory Characteristics and Firing Frequency of Fibrillation Potentials

Quantification

Time to Appearance

Specificity and Utility

Insertional Positive Sharp Waves

Fasciculation Potentials and Cramp Potentials

Sites of Origin

Clinical Features

Electrodiagnostic Features

Grading

Myotonic Potentials

EDX Features

Neuromyotonia

Grouped Repetitive Discharges (GRDs) and Myokymia

Complex Repetitive Discharges

Activation Phase

MUAP Morphology

MUAP Duration

MUAP Amplitude

Phases and Turns

The Effect of Reinnervation on MUAP Morphology

Reinnervation via Collateral Sprouting

Reinnervation via Proximodistal Axon Advancement

The Effect of Motor Unit Disintegration Disorders on MUAP Morphology

MUAP Recruitment

Neurogenic Recruitment

Grading Neurogenic Recruitment

Upper Motor Neuron Recruitment

Decreased Spatial And Temporal Recruitment

Early Recruitment

Myopathies

Non-Myopathic Motor Unit Disintegration Disorders

MUAP Stability

Needle EMG and Motor NCS Interrelationships

Proximally Located Demyelinating Conduction Block

Motor Axon Loss Following Reinnervation via Collateral Sprouting

Nonpathological Causes of Low Motor Responses

Summary of the Needle EMG Manifestations of Various Pathophysiologies

References

Chapter 15 Single-Fiber EMG and Macro EMG

Introduction

Single-Fiber EMG

Single-Fiber Needle Electrodes

Technique and Measurements Made

Criteria for Assessment

Utility

Jitter Using a Concentric Needle Electrode

Macro EMG

Macro EMG Needle Electrodes

References

Section 4 Other Pertinent EDX Information

Chapter 16 Assessment and Initial Management of Peripheral Nerve Injuries

Introduction

Demographics

Nerve Injury Type

The Importance of Proper Initial Management

Clinical, Electrodiagnostic, Pathophysiologic, and Temporal Relationships

Correlations between Electrodiagnostic Features and Clinical Features

Correlations between Lesion Acuteness and the Underlying Pathophysiology

Assessing Lesion Severity

Clinical Grading

Electrodiagnostic Grading

Timing of the Study

The Value of Motor Responses in the Assessment of Lesion Severity

The Value of Sensory Responses in the Assessment of Lesion Severity

The Value of Needle EMG Studies in the Assessment of Lesion Severity

Mechanisms of Reinnervation

Collateral Sprouting

Proximodistal Axon Regeneration

Sensory Receptor Reinnervation

Determining the Potential for Reinnervation

Nerve Injury Classification

The Seddon Classification System

Neurapraxia

Axonotmesis

Neurotmesis

The Sunderland Classification System

Sunderland Grade 1

Sunderland Grade 2

Sunderland Grades 3–5

Sunderland Grade 3

Sunderland Grade 4

Sunderland Grade 5

‘‘Sunderland Grade 6’’

Connective Tissue and Electrodiagnostic Assessment Issues

Other Important Considerations

Surgical Intervention

Approach to Axon Loss (Grades 2–5)

Major Surgical Interventions

Types of Nerve Injuries

Stretch Injuries

Compression Injuries

Acute Compression

Chronic Compression

Transection Injuries

Other Types of Nerve Injury

Ischemic Injury

Compartment Syndrome

References

Chapter 17 The Electrodiagnostic Manifestations of Disorders at Various Levels of the Neuraxis

Upper Motor Neuron Disorders

Intraspinal Canal Disorders

Background Anatomy

Anterior Horn Cell Disorders

Acute Poliomyelitis

Post-Poliomyelitis Syndrome

Amyotrophic Lateral Sclerosis

Spinal Muscular Atrophy, Type 3

Kennedy Disease

Radiculopathies

Plexopathies

The Cervical Plexus

The Brachial Plexus

The Lumbosacral Plexus

Peripheral Neuropathies

Focal Neuropathies (Mononeuropathies)

Acquired Axon Loss Polyneuropathies

Acquired Demyelinating Polyneuropathies

Acute Inflammatory Demyelinating Polyradiculoneuropathy

Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Mixed Polyneuropathies

Hereditary Polyneuropathies

Other Comments

Neuromuscular Junction Disorders

Myasthenia Gravis

Background

Routine NCS

Repetitive Nerve Stimulation Studies

Needle EMG Study

Lambert-Eaton Myasthenic Syndrome

Background

Routine NCS

Repetitive Nerve Stimulation Studies

Needle EMG Study

Myopathic Disorders

References

Chapter 18 Common Pitfalls and Their Resolution

Introduction

Physiological Pitfalls

Studying Cool Limbs

The Effects of Reduced Temperature on the EDX Study

Nerve Conduction Studies

Repetitive Nerve Stimulation Studies

Needle EMG

Age-Related Issues

Nerve Conduction Studies

Needle EMG

Body Habitus–Related issues

Weight

Gender-Related Issues

Anomalous Innervations

Martin-Gruber Anastomosis

Introductory Comments

MGA to the Hypothenar Eminence

MGA to the First Dorsal Interosseous Muscle

MGA to the Adductor Pollicis Muscle

MGA with Concomitant Carpal Tunnel Syndrome

MGA with a Concomitant Ulnar Neuropathy

Atypically Proximal MGA

Situations in Which MGA Is Unrecognizable

Ulnar-to-Median Anastomosis in the Forearm

Riche–Cannieu Anastomosis

Identifying an RCA

Other Hand Muscle Innervation Patterns

Berretini Anastomosis

Accessory Deep Peroneal Nerve

Identifying an Accessory Deep Peroneal Nerve

Technical Pitfalls

Issues Related to Recording

Electrode Impedance and Impedance Mismatch

The Presence of a Positive Dip

Issues Related to Stimulation

Stimulus (Shock) Artifact

Types of Stimulators

Stimulus Artifact Reduction

Rotation of the Anode about the Cathode

Final Options

The Future

Submaximal Stimulation

Excessive Stimulation

Stimulus Lead

Stimulus Spread

Machine Maximum Stimulation

60 Hz Power Artifact

Averaging

Measurement Errors

Stimulator Reversal

Submaximal Stimulation

Filtering Issues

Nerve Conduction Studies

Needle EMG

Conceptual Pitfalls

Not Using the Technique Used to Collect the Normal Control Values

Changing the Sensitivity to Better Identify the Onset Latency

Sweep Speed and Sensitivity

Time Constraints

Missing Relative Abnormalities

Identifying Demyelination Based on the Latency of a Very Low Amplitude Response

Clinical Bias

Low Amplitude Peroneal-EDB Motor Responses among Normal Individuals

Measurement Errors

Miscellaneous Pitfalls

Impedance between the Signal Source and the Surface Recording Electrode

References

Chapter 19 Safety Issues in the EDX Laboratory

Electrical Injury

Indwelling Medical Devices

Bleeding

Transmission of Infection

Iatrogenic Pneumothorax and Pneumoperitoneum

Prevention

Calcinosis Cutis

References

Chapter 20 Nontechnical Issues, Pain Lessening Techniques, the Encounter, and the Report

Introduction

Nontechnical Issues

EDX Testing as an ‘‘Extension of the Neurological Examination’’

Dependent Versus Independent EDX Study Philosophies – Case Study

The Timing of the EDX Examination

The Utility of Electrodiagnostic Testing

The Limitations of Electrodiagnostic Testing

Electrodiagnostic Study Variation among Different EMG Laboratories

The EDX Study Components Performed and Their Order of Performance

Supervision

The Encounter

Activities Occurring before the Encounter

Reviewing the Consult

Scheduling the Consult

Explaining the EDX Study to the Patient (Verbal Informed Consent)

Activities Occurring Immediately before the Encounter

Activities Occurring during the Encounter

The Nerve Conduction Studies

Which Nerve Conduction Studies to Perform First

Which Limbs to Study

Needle EMG Studies

Brief Discussion

Which Muscles to Study First

Tips to Lessen the Discomfort Associated with the Needle EMG Study

Activities Occurring after the Encounter

The EDX Report

Format of Report

References

Section 5 Case Studies in Electrodiagnostic Medicine

Case 1 through Case 50

Introduction

Lesion Localization

Identifying Nonorganic Lesions

The Format of the Electrodiagnostic Cases

Initial Studies

Grading MUAP Recruitment

Grading MUAP Morphology

The Range of Needle EMG Findings

Abbreviations

Sensory NCS

Motor NCS

Needle EMG

The Electrodiagnostic Exercises

References

Section 6 Appendices

Appendix 1: Plexus Anatomy

The Brachial Plexus

The Lumbosacral Plexus

Appendix 2: Nerve Anatomy

The Median Nerve

The Ulnar Nerve

The Radial Nerve

The Obturator Nerve

The Femoral Nerve

The Sciatic Nerve Proper

The Tibial Nerve

The Peroneal Nerve

Appendix 3: Myotome Tables for the Upper and Lower Extremities

Appendix 4: The SNAP, CMAP, and Needle EMG Domains of the Brachial Plexus Elements^

Reference

Appendix 5: The Sensory and Motor NCS Techniques Used in Our EMG Laboratories

The Median Sensory NCS, Recording Second Digit

The Median Sensory NCS, Recording Third Digit

The Median Sensory NCS, Recording First Digit

The Ulnar Sensory NCS, Recording Fifth Digit

The Lateral Antebrachial Cutaneous Sensory NCS

The Medial Antebrachial Cutaneous Sensory NCS

Dorsal Ulnar Cutaneous Sensory NCS

Superficial Radial Sensory NCS

Median Palmar Mixed NCS

Ulnar Palmar Mixed NCS

Median Motor NCS, Recording Abductor Pollicis Brevis (Thenar Eminence)

Median Motor NCS, Recording Second Lumbrical

Ulnar Motor NCS, Recording Abductor Digiti Minimi (Hypothenar Eminence)

Ulnar Motor NCS, Recording First Dorsal Interosseous

Radial Motor NCS, Recording Extensor Digitorum Communis

Radial Motor NCS, Recording Extensor Indicis

Musculocutaneous Motor NCS, Recording Biceps

Axillary Motor NCS, Recording Deltoid

Suprascapular Motor NCS, Recording Infraspinatus

Sural Sensory NCS

Superficial Peroneal Sensory NCS

Saphenous Sensory NCS

Medial and Lateral Plantar Mixed NCS

Peroneal Motor NCS, Recording Extensor Digitorum Brevis

Peroneal Motor NCS, Recording Tibialis Anterior

Tibial Motor NCS, Recording Abductor Hallucis

Tibial Motor NCS, Recording Abductor Digiti Quinti

Femoral Motor NCS, Recording Rectus Femoris

Appendix 6: The Age-Related, Normal Control Values Used in Our EMG Laboratories

Appendix 7: Our Screening Sensory and Motor NCS and Needle EMG Muscles

Upper Extremity

Lower Extremity

Appendix 8: The Advantages and Disadvantages of the Individual EDX Studies

Sensory NCS

Motor NCS (and RNSS)

Needle EMG

Appendix 9: Needle EMG Findings with Lesions at Various Levels of the Neuraxis

Anterior Horn Cell

Nerve Root

Polyneuropathy, Length-Dependent, Axonal

Polyneuropathy, Acquired, Generalized Demyelinating

POLYNEUROPATHY, HEREDITARY DEMYELINATING (actually dysmyelination)

Presynaptic NMJ (e.g., LEMS)

Postsynaptic NMJ (e.g., MG)

Myopathy

Index

 

An aparitie	10 May 2018
Autor	Mark A. Ferrante
Dimensiuni	188 x 246 x 25 mm
Editura	Cambridge University Press
Format	Paperback
ISBN	9781107562035
Limba	Engleza
Nr pag	538