Transcript Brachial plexopathy

Non-Traumatic Brachial
Plexopathy
All that radiates…..
Disclosure
I have NO RELEVANT financial
disclosures.
Goals of lecture
• Review common brachial plexopathies
• Discuss key history and physical examination
issues which differentiate plexus from
radiculopathy
• Discuss positives and pitfalls of major
diagnostic studies
Brachial Plexopathy
• Brachial Plexus Neuropathy (Neuralgic
amyotrophy ) (Parsonage-Turner)
• True neurogenic thoracic outlet syndrome
• Diabetic cervical radiculoplexus neuropathy
• Malignancy
– Primary tumor
– Malignant invasion
– Radiation
Brachial plexopathy
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Traumatic plexopathy
Perioperative plexopathy
Stinger/burner
Hematoma/ false aneurysm
Perioperative
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Stretch neck/ shoulder
Medial sternotomy
Regional anesthesia
Local shoulder surgery
Brachial plexus neuropathy
Neuralgic Amyotrophy: Parsonage and
Turner Syndrome
• History
– Sudden onset of severe pain, often nocturnal,
followed by weakness
– Pain presents in cervical spine or shoulder blade
and upper arm
– Pain often diminishes or resolves after weakness
develops
– Often preceded by infection, trauma, vaccination,
surgical intervention, stress
Neuralgic Amyotrophy: Parsonage and
Turner Syndrome
• Physical examination
– Patchy findings which are not dermatomal; may
be a combination of radiculopathy, brachial
plexopathy and peripheral nerve abnormalities
– Presentation (in order of frequency)
• Upper and/or middle plexus
– Frequently with long thoracic nerve involvement
• Pan plexus > middle plexus/ posterior cord
• Lower plexus
• Anterior interosseus nerve predominant
• Van Alfen, 2006
NA: Diagnostic studies
• EMG: patchy findings of root/ plexus/ nerve
• Confounding factors include comorbidites or asymptomatic
electrical findings
• MRI brachial plexus and shoulder
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Most common abnormalities supra/infraspinatus
Acute: increase in T2 signal (muscular edema)
Subacute: T2 changes persist, atrophy may develop
Subacute to chronic: increased T1 signal due to fat
infiltration
• (Scalf, 2007)
Diagnostic studies
• Cervical MRI: watch for “TBU” (true but
unrelated)
– Major “abnormality” in 19% of asymptomatic
patients
• 14% of patients < 40
• 28% of patients > 40
• Milder disc narrowing or degeneration in 60% of
patients > 40
(Boden, 1990)
Neuralgic Amyotrophy: Differential
diagnosis
• Cervical radiculopathy
• Brachial Plexopathy
• Peripheral nerve
True Neurologic TOS
• Most common cause:
cervical rib/band
– Elongated transverse
process of C7, band
arises from this C7 to
upper first rib
– Other etiologies include
anterior scalene injury
– T1 stretched >C8
• Levin, 1998
True Neurologic TOS
• History
– Gradual onset of wasting and weakness of hand
– Paresthesias of ulnar forearm and small finger
– May have achiness in forearm
• Physical
– Thenar weakness/ atrophy> than hypothenar
muscles
– Flexor forearm muscles weak
– Sensory loss varies, may not split ring finger
True Neurologic TOS: Differential
diagnosis
• Cervical radiculopathy (C8 or T1)
– T1 results in more thenar weakness/ dermatomal
findings (more T1 in APB)
– C8 results in more hypothenar weakness/dermatomal
findings
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Peripheral nerve
Spinal cord injury
Other brachial plexopathies
Syrinx
Motor neuron disease
True Neurologic TOS: Studies
• MRI/ Xray of cervical spine
• MRI brachial plexus
• Electrodiagnostic studies
– Most sensitive findings: mabc snap often absent, ulnar snap low
amplitude, median cmap low amplitude
• mabc and median cmap share T1 innervation
• Few small fibs in thenar > hypothenar musculature
• *Vs median sternotomy plexopathy in which ulnar snap and
ulnar cmap have lower amplitudes and and median cmap
/mabc is less affected
– Fibs in hypothenar>thenar musculature
• Levin 1998
Diabetic cervical radiculoplexus
neuropathy (Massie, 2012)
• Median age: 62 years old(32-83)
• Pain initial symptom followed by subacute
progression of weakness and numbness
• Weakness is most common presenting complaint
• Involves motor, sensory and autonomic fibres
• Upper, middle and lower plexus equally involved
• Greater than 50% of patients had at least one
other body region affected (contralateral
extremity, lumbosacral, thoracic)
Diabetic cervical radiculoplexus
neuropathy
• May precede or present simultaneously with
lower extremity symptoms
• Often improves over 2-9 months
• May recur
Diabetic cervical radiculoplexus
neuropathy: studies
• Electrodiagnosis
– Axonal neuropathy, paraspinal denervation
• Snaps/cmaps decreased, ncv normal
• Fibs, polys and large amplitude potentials in distribution of
clinical complaints
– Abnormal sensory and autonomic testing frequent
• MRI reveals brachial plexus abnormality
• Plexus>peripheral nerve increased T2 signal
• Nerve hypertrophy>contrast enhancement
• Muscle increased T2(edema) subacutely
increased T1 (fat) chronically
Diabetic cervical radiculoplexus
neuropathy: studies
• CSF protein elevated
• Pathology: ischemic injury secondary to
microvasculitis
Diabetic cervical radiculoplexus
neuropathy: Differential Diagnosis
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Radiculopathy
Neuralgic amyotrophy
Peripheral nerve
CIDP
Myelopathy
Brachial plexus and Malignancy
• Malignancy (78%)
– Primary tumor
– Malignant invasion
• Radiation (22%)
• Kori, 1981
Brachial plexus and tumors
• Primary tumors (rarely malignant)
– Primarily benign: peripheral nerve sheath tumors
– Neurofibroma: Upper trunk, lateral cord
• Present with pain, supraclavicular mass
• Occasionally mild neurologic deficit
– Schwannoma
• Often arise in spinal nerves
• Rare neurologic deficit
– Intraneural perineurioma (rare)
• Slow progressive neurologic deficit
Brachial Plexopathy: malignant
invasion
• Breast and lung (70%), followed by lymphoma
• Multiple others metastasize to upper lung before
spreading to plexus (sarcoma, larynx, melanoma,
bladder, etc)
• (Kori et al, 1981)
• Initial pain in shoulder to medial forearm/ulnar 2
fingers, can be severe in metastatic disease
• Followed by weakness, sensory deficit in C7,8 and
T1 distribution and medial cord distribution
Brachial plexopathy: Malignant
invasion
• Primary tumors from head and neck may
invade superior plexus
• Metastasis to lymph nodes may result in patch
involvement of plexus, but frequently involve
lower trunk due to proximity of lateral axillary
lymph nodes
• Significant number of patients have epidural
extension of disease
• (Jaeckle, 2010)
Pancoast syndrome
• Superior pulmonary sulcus tumor
– Tumor at apex of lung invades lower trunk/ medial
cord
– Pain along medial arm
– Horner’s syndrome (2/3 of patients)
• Paravertebral tumor near T1, involves the sympathetic
trunk or ganglia
Brachial Plexopathy post radiation
treatment
• Most commonly delayed after radiation; risk is for
the patient’s entire lifetime (3months – 26 years)
• Risk factors include radiation dose (>6000 rads),
treatment technique and concomitant use of
chemotherapy
• Rare complication of a radiation-induced nerve
sheath tumor of the brachial plexus (can be
delayed for many years)
• Radiation-induced arteritis can result in ischemia
in arm and hand
• (Kori et al, 1981)(Stewart, 2010)(Jaeckle, 2010)
Brachial plexopathy post radiation
• Most patients have sensory and motor abnormalities
• Edema in arm possible, but also seen with metastasis
• Presents with pain less commonly(18%) but can be
severe and can develop later (65%) (Kori, 1981)
• Distribution is most commonly in upper trunk and less
common “pan plexus”
• Horner’s syndrome less common than in direct
metastatic spread
– 14% with radiation vs 56% with metastasis (Kori, 1981)
• Can be progressive
Studies
• Radiation plexopathy:
– Emg reveals fasciculations, myokymia, axonal
damage
– MRI/ CT scan chest and brachial plexus may need
to repeated in 4-6 weeks if mass not seen
– MRI cervical and thoracic spine if epidural spread
a consideration
– PET scan
Case 1
• 53 year old female
• 1-2 years of numbness in right arm
• 6 weeks ago patient wakes up with severe
pain in the right upper extremity
– Like a blood pressure cuff in upper arm radiating
to the shoulder blade, no change in numbness
Case 1
• 3 days later patient receives cervical epidural.
• 3 days later patient notes weakness in right
hand
• 1 week later patient has pronator teres
injection and pain improves although no
change in weakness or numbness
Case 1
• At time of evaluation (6 weeks after onset of
symptoms), no pain in cervical spine or upper
extremity
• Arm is stiff from elbow to hand
• No change in numbness in right hand
Physical examination
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Cervical and shoulder mobility full
4/5 shoulder abductors, external rotators
4/5 abductor pollicis brevis
0/5 flexor digitorum profundus (median
distribution) flexor pollicis longus
• DTR biceps 1/ 4 bilaterally
• Sensation decreased over distal volar thumb
Studies
• Cervical MRI: small noncompressive central
disc herniation at C56
• Ultrasound : pronator teres entrapment and
median nerve entrapment at wrist
EMG/NCV 6 weeks post flare
• EMG
– Median FDP and FPL spontaneous activity
– FDP repetitive fire
– FPL no voluntary potentials
– APB normal, as is rest of screen
• NCV
– Decreased amplitude right LAC
– Right Median mixed motor sensory prolonged
Actual treatment
• 1 month later:
– Median nerve decompression at wrist
– Median and anterior interosseus neurolysis
– 5 months later “good” recovery of FDP, FPL
• What do you think now?
Original case
• Disputed
– Surgeon says pronator syndrome/anterior
interrosseus syndrome
• Median nerve released at the pronator teres and carpal
tunnel and patient ultimately improved
– I say Neuralgic Amyotrophy
• Patient would have improved with or without surgery
Acute, proximal pain
Patchy exam
LAC involvement in addition to anterior interosseus
Conclusions
• History and physical is critical
• MRI/EDX may help to confirm diagnosis or be
a trap
• Diagnosis can not be made in isolation of the
history and physical