Electromyography and Neuromuscular Disorders: Clinical-Electrophysiologic-Ultrasound Correlations

Electromyography and Neuromuscular Disorders: Clinical-Electrophysiologic-Ultrasound Correlations......Page 2
Copyright......Page 3
Foreword......Page 4
Preface to the Fourth Edition......Page 5
Preface to the Third Edition......Page 7
Preface to the Second Edition......Page 8
Preface to the First Edition......Page 10
Dedication......Page 11
Acknowledgments......Page 12
1 - Approach to Nerve Conduction Studies, Electromyography, and Neuromuscular Ultrasound......Page 13
LOCALIZATION OF THE DISORDER IS THE MAJOR AIM OF THE ELECTRODIAGNOSTIC STUDY......Page 14
Assessing the Degree of Axonal Loss Versus Demyelination has Implications for Severity and Prognosis......Page 15
Neuromuscular Junction Localization......Page 16
CARDINAL RULES OF NERVE CONDUCTION STUDIES AND ELECTROMYOGRAPHY......Page 17
NEUROMUSCULAR ULTRASOUND......Page 19
Motor Neuron Disease......Page 20
CARDINAL RULES OF NEUROMUSCULAR ULTRASOUND......Page 21
ANATOMY......Page 23
PHYSIOLOGY......Page 26
CLASSIFICATION......Page 31
RECORDING......Page 32
MOTOR CONDUCTION STUDIES......Page 35
Duration......Page 36
Conduction Velocity......Page 37
Peak Latency......Page 38
Conduction Velocity......Page 39
Lesions Proximal to the Dorsal Root ­Ganglion Result in Normal Sensory Nerve Action Potentials......Page 40
Proximal Stimulation: Normal Temporal Dispersion and Phase Cancellation......Page 42
Use Supramaximal Stimulation......Page 44
Axonal Loss......Page 45
Demyelination......Page 47
Conduction Block......Page 48
Myopathy......Page 50
Neuromuscular Junction Disorders......Page 51
4 - Late Responses......Page 53
F RESPONSE......Page 54
F Response Procedure......Page 55
The F Estimate......Page 56
H REFLEX......Page 58
AXON REFLEX......Page 61
BLINK REFLEX PROCEDURE......Page 64
PATTERNS OF ABNORMALITIES......Page 66
NORMAL NEUROMUSCULAR JUNCTION PHYSIOLOGY......Page 69
Modeling Slow Repetitive Nerve Stimulation......Page 70
REPETITIVE NERVE STIMULATION IN THE ELECTROMYOGRAPHY LABORATORY......Page 72
Exercise Testing in the Electromyography Laboratory......Page 73
Temperature Must Be Controlled......Page 74
Nerve Selection......Page 75
Decrement and Increment Calculation......Page 76
Repetitive Nerve Stimulation Protocol......Page 77
Routine Ulnar Conduction Study: Pseudo–Conduction Block Between the Wrist and Below-­Elbow Sites......Page 79
Ulnar Conduction Study: Proximal Martin-­Gruber Anastomosis and Pseudo–Conduction Block Between the Below-­Elbow and Above-­Elbo.........Page 80
Ulnar Conduction Study Recording the First Dorsal Interosseous: Pseudo-­Conduction Block Between the Wrist and Below-­Elbow Site.........Page 81
Routine Median Motor Study: Increased Compound Muscle Action Potential Amplitude Proximally......Page 83
Martin-­Gruber Anastomosis and Carpal Tunnel Syndrome: Positive Proximal Deflection (“Dip”) and Factitiously Fast Conduction Vel.........Page 84
ACCESSORY PERONEAL NERVE......Page 85
Miscellaneous Anatomic Variations......Page 86
Temperature......Page 90
Age......Page 92
Electrode Impedance and Noise......Page 93
Filters......Page 95
Stimulus Artifact......Page 96
Cathode Position: Reversing Stimulator Polarity......Page 98
Supramaximal Stimulation......Page 99
Co-­Stimulation of Adjacent Nerves......Page 100
Electrode Placement for Motor Studies......Page 102
Antidromic Versus Orthodromic Recording......Page 103
Distance Between Recording Electrodes and Nerve......Page 105
Limb Position and Distance Measurements......Page 106
Limb Position and Waveform Morphology......Page 107
Latency Measurements: Sweep Speed and Sensitivity......Page 109
9 - Basic Statistics for Electrodiagnostic Studies......Page 111
BAYES’ THEOREM AND THE PREDICTIVE VALUE OF A POSITIVE TEST......Page 114
LIKELIHOOD RATIOS......Page 116
MULTIPLE TESTS AND THE INCREASING RISK OF FALSE POSITIVES......Page 117
Key Points......Page 119
Distal Distance......Page 120
Key Points......Page 121
Key Points......Page 122
Distal Distance......Page 123
Key Points......Page 124
Key Points......Page 125
Stimulation Site......Page 126
Key Points......Page 127
Distal Distance......Page 129
Recording Sites......Page 130
Recording Site......Page 131
Stimulation Site......Page 132
Key Points......Page 133
Upper Extremity......Page 134
Craniobulbar......Page 135
Key Points......Page 136
Recording Site......Page 137
Key Points......Page 138
Key Points......Page 140
Stimulation Site......Page 141
Key Points......Page 142
Recording Site......Page 143
Key Points......Page 144
Nerve Conduction Studies of the Lower Extremity: Normal Adult Values......Page 145
EQUIPMENT......Page 146
TYPICAL NEEDLE EMG EXAMINATION (BOX 12.1)......Page 148
Cross-­Section Anatomy Key Points......Page 150
Cross-­Section Anatomy Key Points......Page 153
Cross-­Section Anatomy Key Points......Page 157
Cross-­Section Anatomy Key Points......Page 160
Cross-­Section Anatomy Key Points......Page 163
Cross-­Section Anatomy Key Points......Page 166
Cross-­Section Anatomy Key Points......Page 169
Cross-­Section Anatomy Key Points......Page 173
Cross-­Section Anatomy Key Points......Page 176
Cross-­Section Anatomy Key Points......Page 179
Cross-­Section Anatomy Key Points......Page 182
Cross-­Section Anatomy Key Points......Page 185
Cross-­Section Anatomy Key Points......Page 188
Cross-­Section Anatomy Key Points......Page 191
Cross-­Section Anatomy Key Points......Page 195
Cross-­Section Anatomy Key Points......Page 199
Cross-­Section Anatomy Key Points......Page 202
Cross-­Section Anatomy Key Points......Page 206
Cross-­Section Anatomy Key Points......Page 209
Cross-­Section Anatomy Key Points......Page 212
Cross-­Section Anatomy Key Points......Page 215
Cross-­Section Anatomy Key Points......Page 218
Cross-­Section Anatomy Key Points......Page 221
Cross-­Section Anatomy Key Points......Page 225
Cross-­Section Anatomy Key Points......Page 230
Cross-­Section Anatomy Key Points......Page 234
Cross-­Section Anatomy Key Points......Page 238
Morphology......Page 241
INSERTIONAL ACTIVITY......Page 244
SPONTANEOUS ACTIVITY: ABNORMAL MUSCLE FIBER POTENTIALS......Page 245
Positive Sharp Waves......Page 246
Complex Repetitive Discharges......Page 248
Fasciculation Potentials......Page 250
Doublets, Triplets, and Multiplets......Page 251
Myokymic Discharges......Page 252
Neuromyotonic Discharges......Page 253
Rest Tremor......Page 254
PHYSIOLOGY......Page 257
MORPHOLOGY......Page 258
Duration......Page 259
Amplitude......Page 260
STABILITY......Page 261
FIRING PATTERN (ACTIVATION, RECRUITMENT, INTERFERENCE PATTERN)......Page 262
Chronic Axonal Loss......Page 267
Acute......Page 268
Central Nervous System Disorders......Page 269
Axonal Loss Lesions......Page 272
Demyelinating Lesions......Page 273
IMPORTANT NEUROPATHIC PATTERNS......Page 274
Axonal Loss: Acute......Page 275
Demyelination (Slowing and Conduction Block): Single Proximal Lesion......Page 276
Demyelination (Slowing and Conduction Block): Single Distal Lesion......Page 277
MYOPATHIC LESIONS......Page 278
NEUROMUSCULAR JUNCTION LESIONS......Page 279
Upper Motor Neuron Lesion......Page 280
Mononeuropathy: Localizing......Page 281
Chronic Demyelinating Polyneuropathy With Secondary Axonal Changes: Uniform Slowing......Page 282
Radiculopathy......Page 283
Neuromuscular Junction: Postsynaptic Disorders......Page 284
Myopathy With Denervating Features......Page 285
Pure Motor Loss on Nerve Conduction Studies......Page 286
Localizing a Mononeuropathy by Needle EMG: Issues and Limitations......Page 287
NEUROMUSCULAR ULTRASOUND HISTORY......Page 290
BASIC PHYSICS OF ULTRASOUND......Page 291
OPTIMIZING THE IMAGE......Page 294
Tendon......Page 298
Arteries and Veins......Page 299
Skin and Subcutaneous Tissue......Page 300
Cartilage......Page 301
Anisotropy......Page 302
Posterior Acoustic Enhancement......Page 303
Reverberation Artifact......Page 304
ULTRASOUND LIMITATIONS......Page 305
18 - Neuromuscular Ultrasound of Mononeuropathies......Page 307
APPEARANCE OF NORMAL NERVE......Page 308
Measurements......Page 309
Ganglion Cysts......Page 314
Bone Fragments and Callus......Page 315
Tenosynovitis and Synovial Hypertrophy......Page 317
Tumor......Page 318
Hematomas and Blood Vessel Abnormalities......Page 321
Patterns of Muscle Denervation......Page 323
DEMYELINATING POLYNEUROPATHIES......Page 325
Charcot-­Marie-­Tooth Polyneuropathy......Page 326
Chronic Acquired Demyelinating Polyneuropathies......Page 327
Acute-­Onset Chronic Inflammatory Demyelinating Polyneuropathy......Page 328
DIABETIC POLYNEUROPATHY......Page 329
MOTOR NEURON DISEASE......Page 330
MYOPATHY......Page 331
ANATOMY......Page 335
CLINICAL......Page 337
DIFFERENTIAL DIAGNOSIS......Page 339
Nerve Conduction Studies......Page 340
Median-­Versus-­Ulnar Palm-­to-­Wrist Mixed Nerve Studies......Page 341
Median Second Lumbrical-­Versus-­Ulnar Interossei Distal Motor Latencies......Page 342
Wrist-­to-­Palm Versus Palm-­to-­Digit Sensory Conduction Velocity (Segmental Sensory Conduction Studies Across the Wrist)......Page 343
Inching Across the Wrist and Palmar Stimulation......Page 344
Electromyographic Approach......Page 347
Special Situation: EDX Studies After Carpal Tunnel Release......Page 348
ULTRASOUND CORRELATIONS......Page 349
Nonlocalizing Median Neuropathy......Page 353
Persistent Symptoms or Recurrent Symptoms After Carpal Tunnel Release Surgery......Page 354
COMMON ANOMALIES......Page 355
Ganglion Cyst......Page 356
Neuroma in Continuity......Page 357
Tumors......Page 358
Thickened Epineurium and Intraneural Scar......Page 359
DETAILED ANATOMY AT THE ANTECUBITAL FOSSA......Page 370
Ligament of Struthers Entrapment......Page 371
ANTERIOR INTEROSSEOUS NERVE SYNDROME......Page 372
Nerve Conduction Studies......Page 373
Proximal Median Nerve......Page 374
Anterior Interosseous Nerve......Page 378
ANATOMY......Page 384
CLINICAL......Page 385
DIFFERENTIAL DIAGNOSIS......Page 386
Differential Slowing: Flexed Versus Extended Elbow Conduction Techniques......Page 388
Short Segment Incremental Studies (“Inching”)......Page 391
Mixed and Sensory Nerve Conductions......Page 392
Dorsal Ulnar Cutaneous Sensory Study......Page 393
Nerve Conduction Study Pitfalls......Page 395
ULTRASOUND CORRELATIONS......Page 397
CLINICAL......Page 414
DIFFERENTIAL DIAGNOSIS......Page 416
Ulnar Motor Studies Recording the First Dorsal Interosseous......Page 417
Short Segment Incremental Studies......Page 418
Comparison of the Various Electrophysiologic Tests in Ulnar Neuropathy at the Wrist......Page 419
Electromyographic Approach......Page 420
ULTRASOUND CORRELATIONS......Page 422
ANATOMY......Page 429
Deep Branch......Page 431
Posterior Interosseous Neuropathy......Page 432
DIFFERENTIAL DIAGNOSIS......Page 433
ELECTROPHYSIOLOGIC EVALUATION......Page 434
Nerve Conduction Studies......Page 435
Anatomic Considerations of Some Radial-­Innervated Muscles on Needle EMG......Page 437
ULTRASOUND CORRELATIONS......Page 438
ANATOMY......Page 453
Peroneal Neuropathy at the Fibular Neck......Page 455
ETIOLOGY......Page 456
Nerve Conduction Studies......Page 457
Electromyographic Approach......Page 458
ULTRASOUND CORRELATIONS......Page 460
CLINICAL......Page 471
DIFFERENTIAL DIAGNOSIS......Page 472
Nerve Conduction Studies......Page 473
ULTRASOUND CORRELATIONS......Page 474
CLINICAL......Page 480
Nerve Conduction Studies......Page 481
Electromyographic Approach......Page 482
ULTRASOUND CORRELATIONS......Page 483
Trigeminal Nerve......Page 490
Facial Neuropathy......Page 492
Trigeminal Neuropathy......Page 493
Nerve Conduction Studies......Page 494
Nerve Conduction Studies and Blink Reflex......Page 495
Electromyographic Approach......Page 496
CLINICAL......Page 502
Key Question No. 2: Which Fiber Types Are Involved (Motor, Large Sensory, Small Sensory, Autonomic)?......Page 503
Key Question No. 5: Is There a Family History of Polyneuropathy?......Page 505
Special Situations in Axonal Polyneuropathy: The Use of the Sural/Radial Amplitude Ratio in Mild Polyneuropathy......Page 507
Diabetes......Page 508
DEMYELINATING POLYNEUROPATHY......Page 509
Guillain-­Barré Syndrome (GBS)......Page 510
Electrophysiology......Page 511
Charcot-­Marie-­Tooth Neuropathy......Page 512
Electrophysiology......Page 513
Prognosis......Page 514
Electrophysiology......Page 515
Nerve Conduction Studies......Page 516
Electromyographic Approach......Page 517
ULTRASOUND CORRELATIONS......Page 518
Classic Amyotrophic Lateral Sclerosis......Page 537
Primary Lateral Sclerosis......Page 538
Cervical/Lumbar Stenosis......Page 539
Inclusion Body Myositis......Page 540
Mimics of Primary Lateral Sclerosis......Page 541
Nerve Conduction Studies......Page 542
Electromyographic Approach......Page 545
ULTRASOUND CORRELATIONS......Page 546
31 - Atypical and Inherited Motor ­Neuron Disorders......Page 552
Paralytic Poliomyelitis and Postpolio Syndrome......Page 553
Retrovirus-­Associated Motor Neuron Disorders......Page 554
X-­Linked Bulbospinal Muscular Atrophy (Kennedy Disease)......Page 555
Adult-­Onset Hexosaminidase A Deficiency (Late-­Onset Tay-­Sachs Disease)......Page 556
Monomelic Amyotrophy......Page 557
Delayed Radiation-­Induced Motor Neuron Syndrome......Page 559
Nerve Conduction Studies......Page 560
Electromyographic Approach......Page 561
ETIOLOGY......Page 569
Nerve Conduction Studies......Page 570
Superficial Peroneal SNAP and L5 Radiculopathy: The Rare Exception......Page 573
Electromyographic Approach......Page 574
TIME COURSE IN RADICULOPATHY......Page 576
ABERRANT REINNERVATION AND THE “BREATHING ARM”......Page 577
It May Be Difficult to Localize a Radiculopathy to a Single Root Level......Page 578
If the Sensory Nerve Root Is Predominantly Affected, the Electromyographic Study Will Be Normal......Page 579
Abnormal Paraspinal Muscles Are Useful in Identifying a Radiculopathy but Not the Segmental Level of the Lesion......Page 581
There May Be Few or No Electromyographic Abnormalities in Spinal Stenosis......Page 582
Fibrillation Potentials in the Paraspinal Muscles Do Not Necessarily Imply Radiculopathy......Page 583
ANATOMY......Page 589
CLINICAL......Page 590
Lateral Cord Plexopathy......Page 591
Neuralgic Amyotrophy......Page 592
Postoperative Brachial Plexopathy......Page 593
Thoracic Outlet Syndrome......Page 594
Nerve Conduction Studies......Page 595
Electromyographic Approach......Page 598
Neurogenic Thoracic Outlet Syndrome......Page 599
Neuralgic Amyotrophy......Page 600
Brachial Plexopathy......Page 602
Neuralgic Amyotrophy......Page 607
Clinical......Page 618
Clinical......Page 621
Electrodiagnosis......Page 622
Electrodiagnosis......Page 623
Electrodiagnosis......Page 624
Clinical......Page 625
Electrodiagnosis......Page 626
ULTRASOUND CORRELATIONS......Page 627
Special Considerations: Musculocutaneous, Suprascapular, and Spinal Accessory Nerves......Page 628
Obturator Nerve......Page 634
CLINICAL......Page 635
Retroperitoneal Hemorrhage......Page 636
Postpartum Plexopathy......Page 639
Diabetic Amyotrophy......Page 640
Electrophysiologic Evaluation......Page 641
Nerve Conduction Studies......Page 642
Electromyographic Approach......Page 643
ULTRASOUND CORRELATIONS......Page 644
CLINICAL......Page 653
ETIOLOGY......Page 655
Piriformis Syndrome......Page 656
Nerve Conduction Studies......Page 657
Special Studies on Suspected Piriformis Syndrome......Page 658
Electromyographic Approach......Page 659
ULTRASOUND CORRELATIONS......Page 660
Example: Sciatic Neuropathy Secondary to a Bone Fragment......Page 661
MYASTHENIA GRAVIS......Page 666
Clinical......Page 667
Nerve Conduction Studies......Page 668
Repetitive Nerve Stimulation......Page 669
Single-­Fiber Electromyography......Page 670
Clinical......Page 673
Electrophysiologic Evaluation......Page 674
Clinical......Page 675
CONGENITAL MYASTHENIC SYNDROMES......Page 676
38 - Myopathy......Page 687
CLINICAL......Page 688
Nerve Conduction Studies......Page 689
Spontaneous Activity in Myopathies......Page 690
Motor Unit Action Potential Analysis in Myopathies......Page 691
Polymyositis and Dermatomyositis......Page 693
Inclusion Body Myositis......Page 694
Late-­Onset Acid Maltase Deficiency (Pompe Disease)......Page 695
ULTRASOUND CORRELATIONS......Page 696
39 - Myotonic Muscle Disorders and Periodic Paralysis Syndromes......Page 705
Prolonged Exercise Test......Page 706
Myotonic Dystrophy......Page 708
Clinical......Page 709
Electrophysiologic Evaluation......Page 711
Electrophysiologic Evaluation......Page 712
Electrophysiologic Examination......Page 713
Paramyotonia Congenita......Page 714
Clinical......Page 715
Clinical......Page 716
Electrophysiologic Examination......Page 717
OTHER CONDITIONS ASSOCIATED WITH MYOTONIA AND PERIODIC PARALYSIS......Page 718
DIFFERENTIAL DIAGNOSIS OF NEUROLOGIC WEAKNESS IN THE ICU......Page 725
ELECTRODIAGNOSTIC STUDIES IN THE ICU: TECHNICAL ISSUES......Page 727
Low or Absent Motor Responses With Normal Sensory Responses......Page 729
Decreased Activation......Page 731
NERVE CONDUCTION AND ELECTROMYOGRAPHIC PROTOCOL IN THE INTENSIVE CARE UNIT......Page 732
ULTRASOUND CORRELATIONS......Page 733
MATURATION ISSUES......Page 741
TECHNICAL ISSUES......Page 743
APPROACH TO THE CHILD AS A PATIENT......Page 744
ULTRASOUND CORRELATIONS......Page 746
BASICS OF ELECTRICITY......Page 749
Ohm’s Law......Page 750
Kirchhoff’s Laws......Page 751
Resistors in Parallel......Page 752
Direct Current and Alternating Current......Page 753
Capacitance......Page 754
Inductance......Page 756
WAVEFORMS, FREQUENCY ANALYSIS, AND FILTERING......Page 757
Low-­Frequency (High-­Pass) Filters......Page 758
High-­Frequency (Low-­Pass) Filters......Page 759
PRACTICAL IMPLICATIONS FOR ELECTRODIAGNOSTIC STUDIES......Page 760
ELECTRICAL ISSUES......Page 763
Central Lines and Electrical Wires......Page 765
Implanted Pacemakers and Cardioverter-­Defibrillators......Page 766
PNEUMOTHORAX......Page 767
BLEEDING......Page 768
Coexistent Medical Conditions......Page 769
Needle Electromyography and Patients at Risk of Bleeding......Page 770
INFECTION......Page 771
ULTRASOUND CORRELATIONS......Page 772
SUMMARY......Page 773
Palmar Mixed Nerve Studies......Page 775
Phrenic Motor Studya......Page 776
Motor Studies......Page 777
Late Responsesa......Page 778
Mean Motor Unit Action Potential Duration Based on Age and Muscle Group......Page 779
Pediatric Normalsa......Page 780