No. 30 1. Cervical Plexus 1. Cervical Plexus 2. Brachial Plexus 2. Brachial Plexus.
Electrophysiologic evaluation in Brachial Plexus lesion
description
Transcript of Electrophysiologic evaluation in Brachial Plexus lesion
Electrophysiologic evaluation in Brachial
Plexus lesion
José A Garbino - ILSL
José A Garbino - ILSL
1st. International Meeting on Brachial Plexus
Clínica Fausto Viterbo – Cirurgia Plástica FMUNESP
1st. International Meeting on Brachial Plexus
Clínica Fausto Viterbo – Cirurgia Plástica FMUNESP
Botucatu - 2009Botucatu - 2009
Summary
• Routine electroneuromiography– Motor studies– Sensory studies– Electromyography
• Expected results– Lesion localization– Severity– Dennervation and Reinnervation– Prognosis
routine electroneuromyograph
y and its fundamentals
CMAP, Distal Latency, Conduction Velocity (CV m/s = distancy/L2-L1) and F wave (late latencies)
CMAP: Compound Motor Action Potential = sum of MU potentials = estimation of motor axons in one nerve
Nerve conduction – large fibers
1. Motor nerve conduction - parameters
2 MU2 MU
MNC- belly-tendon setting
Active electrode in muscle belly and reference in tendonActive electrode in muscle belly and reference in tendon
How to do it in animal models?How to do it in animal models?
Isolated stimulation with hook electrodes and belly-tendon setting using needlesIsolated stimulation with hook electrodes and belly-tendon setting using needles
Muscle fiber diameter X CMAP amplitude experimental data
G5G5 G6G6
Brambilla, E. J. S. Dupla inervação muscular com neurorrafia término-lateral: estudo em ratos.Tese apresentada à FMB, UNESP, Curso Bases Gerais da Cirurgia, 2009.Brambilla, E. J. S. Dupla inervação muscular com neurorrafia término-lateral: estudo em ratos.Tese apresentada à FMB, UNESP, Curso Bases Gerais da Cirurgia, 2009.
↓↓
↓↓
Myelination, axon fiber diameter X nerve conduction (latency)
Brambilla, E. J. S. Dupla inervação muscular com neurorrafia término-lateral: estudo em ratos.Tese apresentada à FMB, UNESP, Curso Bases Gerais da Cirurgia, 2009.Brambilla, E. J. S. Dupla inervação muscular com neurorrafia término-lateral: estudo em ratos.Tese apresentada à FMB, UNESP, Curso Bases Gerais da Cirurgia, 2009.
G5G5 G6G6
↓↓↓↓
Amplitudes CMAP (M wave) side to side comparison – crucial in prognosis and graduation
<< 50% reduction = 50% reduction = normalnormal
≥ ≥ 50% 50% reductionreduction
Differences Differences > 50%> 50% 50-80%50-80%: SLIGHT : SLIGHT
80-90%80-90%: MODERATE : MODERATE NO RESPONSESNO RESPONSES: complete : complete lesionlesion
> 90%> 90%: PRONOUNCED: PRONOUNCED
2. sensory CV = distancy/ L1 m/s
Action sensory potential (ASP) = sum of sensory fiber potentials = estimated number of sensory axons in one nerve
Sensory conduction normal and abnormal
normal
amplitude ↓ latency ↑velocity ↓
SC: crucial in BP assessment - topography pre and post-ganglionic
lesions
pre-ganglionic
post-ganglionic - myelinic
post-ganglionic - axonal
GarbinoGarbino
pre-ganglionicpre-ganglionicpost-ganglionicpost-ganglionic
←←→→
MBS, male, 60 y, 27 days after
complete axonal losscomplete axonal loss
partial axonal losspartial axonal loss
conduction block - myelinicconduction block - myelinic
complete axonal losscomplete axonal loss
partial axonal losspartial axonal loss
Normal distal CB proximally Normal distal CB proximally
Complete axonal lesion: terminal reinnervation, 1mm/day
Partial axonal lesion: collateral and terminal sprouting
Myelinic lesion: remyelination/ months
Complete axonal lesion: terminal reinnervation, 1mm/day
Partial axonal lesion: collateral and terminal sprouting
Myelinic lesion: remyelination/ months
post – ganglionic lesionspost – ganglionic lesions
3. Needle Electromyography
Motor unit potential: Shape, polyphasia, amplitude and duration will define the reinnervation patterns: collateral and terminal
a) resting musclea) resting muscle
b) voluntary contractionb) voluntary contraction
voluntary contractionvoluntary contraction
Reinnervation patterns: collateral and terminal sprouting
collateralcollateral terminalterminal
GarbinoGarbino
• Muscles mapping • spontaneus activities
distribution in the target limb • Lesion localization: related
to root, clavicle position and cords
• Quantify the amount of spared motor units
• Look for reinnervation signs
Needle Electromiography evaluation
plexusplexus
rootroot
Electrophysiologic evaluation
expected results
Expected results
• NCS: suprascapularis, musculocutaneus, axillary radial superficialis (upper trunk), radial, posterior interosseus (middle trunk), medial cutaneous antebrachialis, median and ulnar nerves (lower trunk)– Determine: pre and post-ganglionic lesions, underline neuropathology, and severity
• Electromyography: in the above nerve territories plus paraspinalis muscles – Determine: root lesions, supra and infra
clavicular or, severity and reinnervation or not