This document outlines the protocol for performing a electromyography (EMG) study to evaluate neuromuscular disorders. It details which motor and sensory nerves to test, the muscles to sample, and techniques to use for specific conditions like carpal tunnel syndrome, radial neuropathies, and lumbar radiculopathies. Key aspects include testing a variety of muscles innervated by different nerves and segments, using different stimulation sites, and comparing results to the contralateral side. The goal is to identify patterns of denervation and reinnervation across multiple body regions to diagnose conditions like amyotrophic lateral sclerosis.
Anomalous Innervations in (EMG/NCS) by MurtazaMurtaza Syed
Anomalous Innervation.
These are the sort of normal variants which can be found in any normal subject or can concomitantly be found or superimposed in pathological cases. Identifying these anomalies helps out interpreting and making correct diagnosis and to avoid any misinterpretation.
Anomalous Innervations in (EMG/NCS) by MurtazaMurtaza Syed
Anomalous Innervation.
These are the sort of normal variants which can be found in any normal subject or can concomitantly be found or superimposed in pathological cases. Identifying these anomalies helps out interpreting and making correct diagnosis and to avoid any misinterpretation.
anatomy of median nerve,course in arm and struthers ligament, branches in the forearm, carpal tunnel and course in hand, high and low median nerve injuries, principles of surgical management, pronator teres syndrome, anterior interosseous nerve syndrome, open and endoscopic carpal tunnel release
4th year medical student's seminar presentation under supervision of orthopedic lecturer. Reference is from Dr. Sameh Doss Textbook of upper and lower limb, and also other multiple websites.
Entrapment Neuropathies in Upper Limb.pptxNeurologyKota
This presentation is about the entrapment syndrome of upper limb giving an insight regarding diagnosis clinically as well as electrophysiologically and
its management.
anatomy of median nerve,course in arm and struthers ligament, branches in the forearm, carpal tunnel and course in hand, high and low median nerve injuries, principles of surgical management, pronator teres syndrome, anterior interosseous nerve syndrome, open and endoscopic carpal tunnel release
4th year medical student's seminar presentation under supervision of orthopedic lecturer. Reference is from Dr. Sameh Doss Textbook of upper and lower limb, and also other multiple websites.
Entrapment Neuropathies in Upper Limb.pptxNeurologyKota
This presentation is about the entrapment syndrome of upper limb giving an insight regarding diagnosis clinically as well as electrophysiologically and
its management.
Injuries to the nerves of the upper limb can result from trauma, compression, lacerations, or certain medical conditions. Nerve injuries may lead to various symptoms, including pain, weakness, numbness, or loss of function in specific areas of the upper limb. Nerve injuries may range from mild to severe, and appropriate medical evaluation and treatment are essential. Physical therapy, splinting, medications, or in some cases, surgical intervention may be recommended based on the type and severity of the nerve injury. Early intervention is crucial for optimal recovery.
The somatosensory system is the part of the sensory system concerned with the conscious perception of touch, pressure, pain, temperature, position, movement, and vibration, which arise from the muscles, joints, skin, and fascia.
The somatosensory system is a 3-neuron system that relays sensations detected in the periphery and conveys them via pathways through the spinal cord, brainstem, and thalamic relay nuclei to the sensory cortex in the parietal lobe
Impulses are carried from receptors via sensory afferents to the dorsal root ganglia, where the cell bodies of the first-order neurons are located.
Here the fibers split into 2 functional groups: a lateral group (or anterolateral system) and a medial group (or dorsal column-medial lemniscal system).
The lateral group carries mainly unmyelinated fibers that subserve pain and temperature sensations, whereas the medial group carries mainly myelinated fibers that convey proprioceptive impulses
Their axons then travel through the spinal cord either in an ipsilateral or a contralateral fashion. Note that second-order neuron cell bodies are located in different anatomical areas depending on the sensation they carry.
Broadly, the spinal cord contains the second-order neurons for the fibers carrying pain, touch, and temperature sensations.
The lateral group of fibers enters the spinal cord, then ascend to terminate on the substantia gelatinosa and the nucleus proprius, where the second-order neurons are housed
Fibers then ascend via the brainstem to the thalamus in the spinothalamic tracts (or STT).
The medulla contains the second-order neurons for fibers carrying touch, position, and vibratory sensations. The fibers are then either conveyed to the thalamus (where the third-order neurons are located)
The medial group also sends its fibers into the posterior spinal cord; however, upon reaching it, most fibers ascend to the dorsal column nuclei in the medulla and synapse there
These tracts synapse on a second-order neuron in the nucleus gracilis and cuneatus, which are located in the medulla.
Their axons then decussate form a bundle known as the medial lemniscus.
Fibers of the posterior columns and medial lemniscus are concerned primarily with position sense and fine discriminative touch
These fibers travel to the midbrain on their way to the thalamus. Once in the thalamus, they synapse on third-order neurons in the ventral posterior lateral (VPL) nucleus.
The third-order neurons then project to the primary somatosensory cortex, which is located in the postcentral gyrus (also known as Brodmann areas 1, 2, and 3) of the parietal lobe
Primary somatosensory cortex subserves general and proprioceptive sensations and serves to integrate sensory information
Somesthetic cortex is organized in a sensory homunculus
Body areas particularly important to the sensory system (for example the face, lips, and hand) are given larger representation than other areas
Sensory receptorsperipheral nerve dorsal
This presentation looks at intraoperative monitoring of auditory evoked potential, somato sensory evoked potential and motor evoked potential, procedure, pitfalls and utility.
This presentation describes the common conditions, anatomy and the ideal ways to do and perform nerve conduction studies in lower limbs. It is nicely depicted with self explanatory pictures.
Radial Nerve is very important topic for first year MBBS Students and as well as for day today clinical practice. This slide gives you full course & relations with clear diagrams as well as applied anatomy with clinical Co-relation.
CONCEPT OF NODOPATHIES AND PARANODOPATHIES.pptxNeurologyKota
emergence of autoimmune neuropathies and role of nodal and paranodal regions in their pathophysiology.
Peripheral neuropathies are traditionally categorized into demyelinating or axonal.
dysfunction at nodal/paranodal region key for better understanding of patients with immune mediated neuropathies.
antibodies targeting node and paranode of myelinated nerves have been increasingly detected in patients with immune mediated neuropathies.
have clinical phenotype similar common inflammatory neuropathies like Guillain Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy
they respond poorly to conventional first line immunotherapies like IVIG
This presentation briefs out the approach of dementia assessment in line with consideration of recent advances. Now the pattern of assessment has evolved towards examining each individual domain rather than lobar assessment.
This presentation contains information about Dementia in Young onset. Also it describes the etiologies, clinical feature of common YOD & their management.
Entrapment Syndromes of Lower Limb.pptxNeurologyKota
This presentation contains information about the various Entrapment syndromes of Lower limb in descending order of topography. It also contains information about etiology, clinical features and management of each of these entrapment syndromes with special emphasis on electrodiagnostic confirmation.
3. Motor study -Ipsilateral to most symptomatic side
1. Median nerve- recording APB stimulating wrist
and anticubital fossa.
2. Ulnar nerve- recording ADM stimulating wrist,
below and above elbow.
3. Ulnar nerve-recording FDI stimulating wrist, below
and above elbow.
4. Peroneal nerve-recording EDB stimulating ankle,
below fibular neck,lateral popliteal fossa
5. Tibial nerve-recording AHB stimulating ankle,
popliteal fossa.
4. Sensory study
1. Median SNAP
2. Ulnar SNAP
3. Radial SNAP
4. Sural SNAP
Late responses
1. F response
2. H reflexes
5. Contralateral motor studies done if
predominatly LMN signs without definite UMN
signs.
Proximal stimulation done if predominatly
LMN signs with normal routine motor study
with abnormal late responses.
6. Amplitude ratio of APB/ADM and FDI/ADM.
APB/ADM <0.6
FDI/ADM <0.9
If both ratio are abnormal, highly suggestive
of ALS.
8. ALS defined electrophysiologically by active
denervation and reinervation in three out of
four body segments(craniobulbar, cervical,
thoracic, lumbosacral)
That cannot be explained by multiple
mononeuropathies or radiculopathies.
Neuropathic changes -muscles innervated
both by different nerves that share same
myotome and by different myotomes.
9. Definite- 3 region with UMN and LMN
features
Probable-2 region with UMN and LMN
features with few UMN features rostral to
LMN
Possible-1 region with UMN and LMN features
or UMN features in 2 regions
10.
11. 1.Sensory potentials-lateral antebrachial
cutaneous, radial, median, ulnar, medial
antebrachial cutaneous
Compare with unaffected side
2.Median nerve- recording APB stimulating
wrist and anticubital fossa.
3.Ulnar nerve- recording ADM stimulating
wrist, below and above elbow.
12. In suspected lower trunk/median cord injury
median and ulnar motor study also
stimulated at axilla and Erbs point
Proximal median conduction study, collision
techniques can be used
Compare with unaffected side
Suspected upper/middle trunk lesion-
stimulating Erbs point recording biceps,
triceps, deltoid, supraspinatus, infraspinatus
13. SNAP Cord Trunk
Lateral antebrachial
cutaneous
Lateral Upper
Radial to thumb Posterior Upper
Median to thumb Lateral Upper
Radial to snuffbox Posterior upper/middle
Median to index finger Lateral Upper/middle
Median to middle
finger
Lateral Middle
Median to ring finger Medial middle/lower
Ulnar to ring finger Medial Lower
Ulnar to little finger Medial Lower
Dorsal ulnar
cutaneous
Medial Lower
Medial antebrachial
cutaneous
Medial Lower
14. Atleast 1 muscle in each peripheral nerve
distribution
All clinically weak or paralysed muscles
should be examined
Proximal muscles including paraspinal
muscles
Upper trunk lesion examine rhomboids
and/or serratus anterior
If finding equivocal or borderline compare
with other side
17. Routine studies
1. Median motor study recording at APB
stimulating at wrist,anticubital fossa
2. Ulnar motor study recording at ADM
stimulating at wrist, below and above elbow
3. Median and ulnar F waves
4. Median sensory recording digit2 or 3
5. Ulnar sensory recording digit 5
6. Radial sensory recording snuffbox
18. Highly suggestive of CTS if
Median study shows prolonged distal motor
and sensory latencies
Prolonged minimum F wave latencies
Median CMAP and SNAP amplitudes may be
reduced
Ulnar motor, sensory and F wave studies are
normal
Radial sensory response is normal.
19. 1. Median vs ulnar palm to wrist mixed nerve
study
Stimulating median nerve in palm on line
connecting median nerve in middle of wrist
to web space between 2 and 3 digit
Ulnar nerve stimulated in palm on line
connecting ulnar nerve to web space
between 4 and 5 digit
Recording electrodes at median and ulnar
nerve
Distance between electrodes=8 cm
20. Antidromic technique
Recording ring electrodes placed over 4th
digit
G1 over metacarpophalengeal joint
G2 over distal interphalengeal joint
Median and ulnar nerves stimulated one at a
time at wrist
Difference in onset or peak latencies noted
21. Active electrode(G1) slightly distal and lateral
to midpoint of third metacarpal
Reference electrode over proximal
interphalengeal joint of 2nd digit
Stimulation at wrist for median and ulnar
nerve
Difference between distal latencies is
compared
22. Begins 4 cm proximal to distal wrist crease,
continues 6cm distal to wrist crease
Segmental stimulation at 1 cm increments
For each 1 cm increment latency usually
increases 0.2 to 0.3ms
Limitation- difficulty in stimulation just distal
to wrist crease
23. G1 over metacarpophalengeal joint of 1st digit
G2 over interphalengeal joint of 1st digit
Stimulation at wrist for median and radial
nerve equidistant from recording electrodes
Difference between latencies noted
24. G1 and G2 placed at proximal and distal
interphalengeal joint of 3rd digit
Median nerve stimulated at wrist
Stimulated at palm at half wrist to digit
distance
Wrist to palm conduction velocity calculated
P to D CV X W to D CV/2P X to D CV -W to D
CV
Reversal seen in CTS
25. 1. Abductor pollisis brevis
2. Atleast 2 C6-C7 innervated muscle
(pronator teres,flexor carpi radialis, triceps
brachi, extensor digitorum communis)
*APB sudy is painful. So best not studied first
26. If APB is abnormal
Atleast 1 proximal median innervated muscle
(flexor carpi radialis, pronator teres, flexor
pollicis longus) to exclude proximal
neuropathy
Atleast 2 non median lower trunk/C8-T1
innervated muscle(FDI, extensor indicis
proprius)
27.
28. 1. Posterior interosseous nerve
2. Radial nerve at spiral grove
3. Radial nerve in axilla
4. Posterior cord of brachial plexus
5. C7 radiculopathy
29. 1. Radial motor study-recording extensor
indicis proprius stimulating forearm, elbow,
below and above spiral grove, bilaterally
2. Ulnar motor study-recording ADM
stimulating wrist below and above groove in
flexed elbow position
3. Median motor study-recording APB
recording wrist, anticubital fossa
30. 4. Median and ulnar F waves
5. Superficial radial sensory study-recording
over extensor tendons of thumb, stimulating
forearm, bilaterally
6. Ulnar sensory study-recording 5th digit
7. Median sensory study-recording 2nd or 3rd
digit
31. 1. Posterior interosseous neuropathy(axonal)-
normal superficial radial sensory SNAP, low
amplitude distal CMAP
2. Posterior interosseous neuropathy
(demyelinating)-normal SNAP, conduction
block between forearm and elbow,normal
CMAP amplitude
3. Radial neuropathy in spiral grove(axonal)-
reduced SNAP, reduced CMAP amplitude
32. 4. Radial neuropathy at spiral grove
(demyelinating)-normal SNAP, conduction
block at spiral groove
5. Radial neuropathy in axilla(axonal)-reduced
SNAP, low amplitude CMAP
6. Radial neuropathy at axilla (demyelinating)-
normal SNAP, normal motor study above
spiral groove
7. Superficial radial sensory neuropathy-
reduced SNAP, normal radial motor study
33. Atleast 2 posterior interosseous innervated
muscles(Extensor indicis proprius, extensor
carpi ulnaris, extensor digitorum communis)
Atleast 1 radial innervated muscle proximal
to bifurcation of main radial nerve distal to
spiral groove(brachioradialis,extensor carpi
radialis)
Atleast 1 radial innervated muscle proximal
to spiral groove(triceps, anconeus)
36. 1. Deep peroneal nerve
2. Common peroneal nerve
3. Sciatic nerve
4. Lumbosacral plexus
5. L5 radiculopathy
37. Routine studies
1. Peroneal motor study- recording extensor
digitorum brevis stimulating ankle, below
fibular head, lateral popliteal fossa
2. No conduction block or focal slowing at
fibular head then recording at Tibialis
anterior stimulating below fibular head,
lateral popliteal fossa
38. 2. Tibial motor study recording abductor
hallucis brevis stimulating medial ankle,
popliteal fossa
3. Superficial peroneal sensory study
stimulating lateral calf recording lateral ankle
4. Sural sensory study stimulating calf
recording posterior ankle
5. Tibial and peroneal F responses
39. Routine study
1. Atleast 2 muscles innervated by deep
peroneal nerve (eg. Tibialis anterior,
extensor hallucis longus)
2. Atleast 1 muscle in superficial peroneal
nerve( peroneus longus, brevis
3. Tibialis posterior and atleast 1 other tibial
innervated muscle(medial gastrocnemius,
soleus, flexor digitorum longus)
4. Short head of biceps femoris
40. If short head of biceps femoris or any tibial
innervated muscle is abnormal then EMG
study of other sciatic muscles, gluteal,
paraspinal muscles performed
42. 1. Electromyography and neuromuscular
disorders: D. Preston, B Shapiro:2013
Elsevier Inc
2. American association of Neuromuscular and
electrodiagnostic medicine;Practice
guidelines 2012