Speakers Tony Chiodo, MD Tony Chiodo, MD Timothy Dillingham, MD
Timothy Dillingham, MD W. David Arnold, MD W. David Arnold, MD
Shawn Jorgensen, MD Shawn Jorgensen, MD
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Blind spots
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Electrodiagnostic impression: Normal study
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Electrodiagnostic impression: No generalized peripheral
neuropathy
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Patient #1 29 year old female with one week of numbness,
prickly sensation and pain in the feet, progressing to the calves,
later in the hands, lips, mouth. 29 year old female with one week
of numbness, prickly sensation and pain in the feet, progressing to
the calves, later in the hands, lips, mouth. Four days ago began
having difficulty going up stairs, getting out of chairs, getting
her legs in her pants, getting her arms overhead Four days ago
began having difficulty going up stairs, getting out of chairs,
getting her legs in her pants, getting her arms overhead Balancing
is worsening Balancing is worsening No oculobulbar, bowel or
bladder symptoms No oculobulbar, bowel or bladder symptoms 2 weeks
prior saw PCP, diagnosed with a URI, given a tetanus and influenza
vaccine 2 weeks prior saw PCP, diagnosed with a URI, given a
tetanus and influenza vaccine
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Patient #1 Physical examination Physical examination CN normal
Motor 4/5 elbow extension, DIP flexion, ankle dorsiflexion, toe
extension, 5-/5 hip flexion Functionally could not get out of chair
without using her arms Sensory Pinprick, vibration normal Romberg
positive MSR 1+ brachioradialis, others areflexic
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Patient #1 Electrodiagnostics Electrodiagnostics Motor normal
except Left median to APB: decreased amplitude prox + distally
Right fibular: 25% amplitude loss proximal to distal, decreased CV
Left tibial: prolonged DML, decreased CV Sensory normal except
Right sural, bilateral medial dorsal cutaneous prolonged PL Late
responses F-waves decreased amplitude ulnar bilaterally, o/w normal
H-reflex absent bilaterally NEE Left upper, lower, paraspinals
normal
Guillain-Barre Syndrome Acute, autoimmune neuropathy Acute,
autoimmune neuropathy Clinically presents with acutely progressive
sensory dysfunction and weakness, usually in an ascending pattern,
progressing for less that four weeks Clinically presents with
acutely progressive sensory dysfunction and weakness, usually in an
ascending pattern, progressing for less that four weeks Exam should
demonstrate sensory loss (particularly large fiber), weakness of
both proximal and distal muscles, and hyporeflexia Exam should
demonstrate sensory loss (particularly large fiber), weakness of
both proximal and distal muscles, and hyporeflexia
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Guillain-Barre Syndrome EMG findings in GBS EMG findings in GBS
Sensorimotor Non length-dependent Acquired demyelination Abnormal
temporal dispersion Conduction block
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Guillain-Barre Syndrome EMG findings in early GBS EMG findings
in early GBS Demyelination (Albers 1985) Week 1 - 50% meet full
demyelinating criteria Week 5 87% meet criteria Late Responses week
1 (Gordon 2001) 97% abnormal H reflexes (88% day 4) 87% abnormal F
waves
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Guillain-Barre Syndrome Non length-dependence Non
length-dependence Abnormal upper limb/normal lower limb Sural
sparing 50% of patients by week 1 (Gordon 2001)
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EMG BLIND SPOTS!! Guillain-Barre syndrome Guillain-Barre
syndrome Early normal/minimally abnormal EDX Look for late
responses Normal sural Look for abnormal upper limb
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Patient #1 revised impression Electrodiagnostic Impression:
Electrodiagnostic Impression: Abnormal study. Mild generalized
peripheral neuropathy; cannot exclude early AIDP Abnormal study.
Mild generalized peripheral neuropathy; cannot exclude early AIDP
Clinical Impression: Clinical Impression: Monitor closely for
worsening neurological symptoms and repeat NCS in one week if
symptoms dont improve or worsen. Consider consultation with a
neuromuscular specialist. Monitor closely for worsening
neurological symptoms and repeat NCS in one week if symptoms dont
improve or worsen. Consider consultation with a neuromuscular
specialist.
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Patient #2 67 year old patient with slowly progressive
ambulatory decline 67 year old patient with slowly progressive
ambulatory decline Thinks it has been going on for 3 years Thinks
it has been going on for 3 years Feels weakness is in his legs and
has some in arms as well Feels weakness is in his legs and has some
in arms as well When asked, notes numbness in feet and hands When
asked, notes numbness in feet and hands No oculobulbar or sphincter
complaints No oculobulbar or sphincter complaints PMH: DM2, mild
CHF PMH: DM2, mild CHF
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Patient #2 Physical examination Physical examination Cranial
nerves - normal Motor normal excepts 3+/5 right, 4/5 left arm
abduction 4/5 finger abduction 2/5 hip flexion 4/5 knee extension
4/5 right, 3-/5 left ankle dorsiflexion MSR Trace in uppers, 0 in
lowers Sensation Absent vibration at ankles Pinprick normal
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Patient #2 Electrodiagnostics Electrodiagnostics Motor NCS
Diffusely diminished conduction velocities Dramatic temporal
dispersion across the forearm on right ulnar motor Lower limb
studies unobtainable Sensory NCS Lowers unobtainable Ulnar sensory
low amplitude Needle EMG Abnormal spontaneous activity, large
amplitude MUAP in distal LE muscles
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Patient #2 Electrodiagnostic Impression: Electrodiagnostic
Impression: Abnormal study. Generalized sensorimotor neuropathy
with axonal and demyelinating features. Abnormal study. Generalized
sensorimotor neuropathy with axonal and demyelinating
features.
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CIDP Chronic inflammatory demyelinating polyradiculoneuropathy
Chronic inflammatory demyelinating polyradiculoneuropathy MS of the
PNS (Amato 2009) MS of the PNS (Amato 2009) Autoimmune
demyelinating often relapsing/remitting course, other progressive
More common than you think! More common than you think! Of those
with cryptogenic neuropathy referred for intensive referral center
investigation, about 1/5 have CIDP (and are treatable) (Dyck
1981)
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CIDP Clinical features Clinical features Progresses for 8 weeks
or more Weakness classically proximal and distal, symmetrical
Hyporeflexia Sensory complaints Lab features Lab features EDX
diffuse sensorimotor acquired demyelination (similar to AIDP) CSF
cytoalbuminic dissociation
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CIDP Atypical forms Atypical forms Not all meet even basic
clinical features Asymmetrical or pure sensory in 50% cases
(Breiner 2014)
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CIDP Criteria (AAN) Criteria (AAN) Clinical Motor and or
sensory loss in >1 limb Hyporeflexic Over 2 months
Electrodiagnostic 3 out of 4 CB/TD in >=1 nerve CV decreased in
>=2 nerves DL prolonged in >=2 nerves FW prolonged in >=2
nerves
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CIDP Criteria Criteria At least 15! No consensus Sensitivities
range from 11-91% (Breiner 2014) False negatives treatable patients
missed Specificity range from 63-100% (Breiner 2014) False
positives non-treatable patients exposed to unnecessary risks,
MAJOR costs Of those with treatable disease (by expert consensus),
about 1/3 never met ANY criteria (Bromberg 1991)
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Patient #2 Diagnostics Diagnostics CSF analysis Protein 97,
otherwise normal Treatment Treatment Moderate improvement with IVIg
Strength improved to >=4/5 proximal muscles Reflexes 2+ uppers,
patella Able to ambulate with walker and minimal assistance
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BLIND SPOTS!! CIDP CIDP Not meeting criteria Consider those
with basic clinical features Asymmetrical, no proximal and distal
weakness Consider asymmetrical, pure sensory forms
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Patient #2 revised impression Electrodiagnostic Impression:
Electrodiagnostic Impression: Abnormal study. Generalized
peripheral neuropathy with features of acquired demyelination;
suspicious for but not meeting research criteria for chronic
inflammatory demyelinating polyneuropathy (CIDP) Abnormal study.
Generalized peripheral neuropathy with features of acquired
demyelination; suspicious for but not meeting research criteria for
chronic inflammatory demyelinating polyneuropathy (CIDP) Clinical
Impression: Clinical Impression: This patient may have a
non-classic form of CIDP. Consultation with a neuromuscular
specialist and lumbar puncture could be considered. This patient
may have a non-classic form of CIDP. Consultation with a
neuromuscular specialist and lumbar puncture could be
considered.
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Patient #3 47 year old with 2 months of cramping, numbness and
tingling on the anterolateral ankle and dorsal foot 47 year old
with 2 months of cramping, numbness and tingling on the
anterolateral ankle and dorsal foot Has had numbness in the right
hand for years Has had numbness in the right hand for years Balance
is fine Balance is fine No orthostatic hypotension, constipation,
nausea No orthostatic hypotension, constipation, nausea Strength is
normal Strength is normal Blurry vision, otherwise no oculobulbar
complaints or trouble controlling her bowel or bladder Blurry
vision, otherwise no oculobulbar complaints or trouble controlling
her bowel or bladder
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Patient #3 Physical examination Physical examination Cranial
nerves normal Motor exam normal Sensory exam Decreased pinprick
sensation in the distal foot, otherwise normal Normal vibration,
light touch, temperature sensation Reflexes - normal Coordination -
normal
Slide 31
Patient #3 Electrodiagnostics Electrodiagnostics CMAP normal
median, ulnar, fibular SNAP normal sural, medial dorsal cutaneous,
median, ulnar, radial NEE normal UE/LE
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Pictures of EDX
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Patient #3 Electrodiagnostic impression: Electrodiagnostic
impression: Normal study. No generalized peripheral neuropathy or
lumbosacral radiculopathy. Normal study. No generalized peripheral
neuropathy or lumbosacral radiculopathy.
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Subtle neuropathies EDX techniques to increase sensitivity EDX
techniques to increase sensitivity Medial plantar Mild diabetics
50% with prolonged sural latency, 70% prolonged/absent medial
plantar (Reeves 1984)
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Small fiber neuropathy Sensory fibers for pain, temperature,
autonomic fibers Sensory fibers for pain, temperature, autonomic
fibers Clinical presentation with pain, burning Clinical
presentation with pain, burning Usually no numbness, tingling,
weakness Usually no numbness, tingling, weakness Physical
examination Physical examination Loss of pinprick and temperature
sensation with normal light touch, proprioception and vibration
Normal strength Normal MSR
Slide 36
Small fiber neuropathy Studies Studies Electrodiagnostics
normal!!! Skin biopsy Measurement of intraepidermal nerve fiber
density Decreased in 77% of patients at the distal calf with
clinical suspicion of small fiber neuropathy (Holland 1998)
Autonomic testing Different tests, yields
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EMG BLIND SPOTS!! Subtle neuropathies Subtle neuropathies
Consider tests with increased sensitivity (medial plantar) Small
fiber neuropathy Small fiber neuropathy Remember standard EDX only
tests large fibers
Slide 38
Patient #3 revised impression Electrodiagnostic Impression:
Electrodiagnostic Impression: Normal study. No generalized
peripheral neuropathy affecting large fibers. Normal study. No
generalized peripheral neuropathy affecting large fibers. Clinical
Impression: Clinical Impression: A neuropathy primarily affecting
small fibers cannot be excluded with standard electrodiagnostic
studies. Specialized testing (skin biopsy, autonomic testing) could
be considered to further assess this possibility. A neuropathy
primarily affecting small fibers cannot be excluded with standard
electrodiagnostic studies. Specialized testing (skin biopsy,
autonomic testing) could be considered to further assess this
possibility.
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EMG BLIND SPOTS!! summary GBS GBS Be aware of low yield in
early testing use H-reflex Be aware of non length-dependent
findings (sural sparing) CIDP CIDP Be aware of low sensitivity of
research criteria Be aware of relatively high frequency of atypical
presentations Possible subtle neuropathies Possible subtle
neuropathies Consider testing with increased sensitivity (i.e.
medial plantar) Remember small fiber neuropathies have negative
EDX!
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Thank you!!
Slide 42
Asbury AK, Cornblath DR. Assessment of current diagnostic
criteria for Guillain-Barre syndrome. Ann Neurol
1990;27(suppl):S21-S24. Albers JW, Donofrio PD, McGonagle TK.
Sequential electrodiagnostic abnormalities in acute inflammatory
demyelinating polyradiculoneuropathy. Muscle Nerve 1985;8:528-539.
Gordon PH, Wilbourne AJ. Early electrodiagnostic findings in
Guillain-Barre syndrome. Arch Neurol 2001;58:913-917. Amato AA,
Russell JA. Neuromuscular disorders. New York: McGraw Hill Medical;
2008. Dyck PJ, Oviatt KF, Lambert EH. Intensive evaluation of
referred unclassified neuropathies yields improved diagnosis. Ann
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TH. Comparison of sensitivity and specificity among 15 criteria for
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for primary demyelination in chronic polyneuropathy. Muscle Nerve
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dysfunction in patients with diabetes mellitus. Am J Med
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