1. 27/11/2018

2. 27/11/2018

3. By S. Khosrawi MD Physiatrist
Introduction to
Electrodiagnostic
Medicine
By S. Khosrawi MD
Physiatrist
27/11/2018

4. History
In the late 1700’s scientists realized that bodily tissue could generate an electrical signal.
Not too long after this (1791), Galvani discovered that the muscles used electricity.
Muscular electrodes were developed in as early as 1841.
In the 1930’s EMG began to be used for clinical purposes.
27/11/2018

5. neuromuscular examination
EDX consultation evaluates nerve and muscle function and is a direct extension of the clinical history
and
neuromuscular examination
27/11/2018

6. EDX studies are a supplement to, not a replacement for,
a careful history
and physical examination
by the referring physician
and by the EDX physician
as part of the EDX consultation
27/11/2018

7. EDX consultation provides helpful information to evaluate the integrity and function of
motor, sensory and autonomic neurons, nerve roots, brachial and lumbar plexi, peripheral nerves, neuromuscular junction, and muscles
And sometimes CNS
27/11/2018

8. lower motor neuron lesions ,
Main purposes:
Is there any
lower motor neuron lesions ,
or not ?
If yes , Where ?
27/11/2018

9. numbness, paresthesia dysautonomia
fatigability
weakness
atrophy
pain
27/11/2018

10. Instrumentation
27/11/2018

11. Neuropathic Process NCS Axonal Demyelinating Latency NCV Amplitude
27/11/2018

12. Radiculopathy or
Plexopathy
H-reflex
Late responces
F-wave
27/11/2018

13. EMG
27/11/2018

14. 27/11/2018

15. 27/11/2018

16. 27/11/2018

17. Nerve trauma
27/11/2018

18. NCV in nerve trauma
27/11/2018

19. Axon loss(Wallerian degeneration)
EDx abnormalities appear:
Distal CMAP: days
Distal SNAP: days
Fibrillation and PSWs: days
27/11/2018

20. Regeneration In complete transection
"nascent" potentials within 2 months
Within 4-6 months the motor units become of longer duration, of higher amplitude, and are less polyphasic.
At about 8-12 months they reach normal size for the muscle being examined.
27/11/2018

21. Reinnervation In partial nerve injury
reinnervation is accomplished by collateral sprouting ,begins in the first two months after nerve injury and results in a prolongation in the duration of the reinnervating motor unit duration and an increase in the number of its phases
27/11/2018

22. 27/11/2018

23. Root Lesion Normal S-NCV
Low motor amplitudes and slowed conduction velocity if the axonal loss is severe
The H-reflex and F-wave may be delayed or absent in the areas of involvement
27/11/2018

24. Plexus Lesions Impaired motor & sensory NCS Erb's point stimulation
H-reflex and F-wave studies can be helpful in plexus dysfunction in that responses may be delayed, diminished, or absent
27/11/2018

25. Routine Upper Extremity(NCV)
Median sensory and motor studies with F-waves
Ulnar sensory and motor studies with F-waves
Radial sensory study
27/11/2018

26. Routine Lower Extremity)NCV)
A sural sensory study
A superficial peroneal sensory study
A peroneal motor study with F-waves
A posterior tibial motor study with F-waves
H- refelx studies in peripheral neuropathies and suspected lumbosacral root lesions
27/11/2018

27. Generalized Neuropathic Process )NCV)
A routine upper extremity
A routine lower extremity
H-reflex studies
27/11/2018

28. Routine Upper Extremity (EMG)
The first dorsal interosseous (an ulnar C8, T1 muscle)
The flexor pollicis longus (an anterior interosseous C7,8 muscle)
The flexor carpi radialis (a median C7 muscle)
The brachioradialis (a radial C5,6 muscle)
The triceps (a radial C7,8 muscle)
The deltoid (an axillary C5,6 muscle).
paraspinal
27/11/2018

29. Routine Lower Extremity (EMG)
The extensor digitorum brevis or extensor hallucis longus (peroneal L5-S1 muscles)
The flexor digitorum longus (a posterior tibial L5-S1,2 muscle)
The tibialis anterior (a peroneal L4,5 muscle)
The medial gastrocnemius (a posterior tibial S1,2 muscle)
The vastus lateralis (a femoral L3,4 muscle)
The gluteus medius (a superior gluteal L4,5 and S1 muscle)
paraspinal
27/11/2018

30. Peripheral Neuropathy (EMG)
A routine upper extremity examination with an extra distal muscle included, the abductor digiti minimi
A routine lower extremity examination with the abductor hallucis included
27/11/2018

31. Anterior Horn Cell (EMG)
A routine upper extremity
A routine lower extremity
A third upper or lower extremity depending on the areas of clinical involvement
The tongue
27/11/2018

32. Inconclusive diagnosis Rapidly evolving disease Course of the disease
Clinical situations where appropriate medical management requires repeat testing
Second diagnosis
Inconclusive diagnosis
Rapidly evolving disease
Course of the disease
Unexpected course
Change in course
Recovery from injury
27/11/2018

33. Acceptable tests per 12-month period:
Clinical situations where appropriate medical management requires repeat testing
Second diagnosis
Inconclusive diagnosis
Rapidly evolving disease
Course of the disease
Unexpected course
Change in course
Recovery from injury
Acceptable tests per 12-month period:
Two for CTS,radiculopathy,PNP,myopathy,& NMJ disorders
Three for motor neuronopathy , plexopathy & trauma
But repeat EDX testing is NOT necessary in 80% of all cases
27/11/2018

34. THE END
27/11/2018