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Brachial Plexus: Angela Klein’s
Painful Arm
Human Gross Anatomy
Ernest F. Talarico, Jr., Ph.D.
Associate Director of Medical Education
Associate Professor of Anatomy & Cell Biology
Associate Faculty, Radiologic Sciences
Course Director, Human Gross Anatomy & Embryology
Indiana University School of Medicine – Northwest (Gary, Indiana)
1
Patient History
18-year-old female, college
student
Right handed
CC of right shoulder and arm pain
x3 months
Pain extends down through the 4th
and 5th digits of her hand; periodic
numbness and tingling in the
same distribution
Pain is slowly getting worse;
intermittent and exacerbated with
handwriting
Some right arm weakness
2
Patient Interview
Past medical history
– The patient has
neurofibromatosis. She has had
multiple neurofibromas removed
since 1998, including one from her
nose in 1998 and one from her left
medial thigh in 2000.
Social history
– Freshman college student; premed
– Single, no children
– No travel outside of Indiana in the
last 3 years
– Non-smoker; does not drink
alcohol
Allergies
– No known allergies
– No known toxic environmental or
occupational exposures
Meds
Family history
– Significant for neurofibromatosis.
Mother, brother, grandmother and
great-grandmother have
neurofibromatosis type 1.
– Brother has twice had surgery for
removal of acoustic neuromas.
– Medications: birth control pills
3
Neurofibromatosis is an inherited disorder characterized
by the development of multiple tumors (schwannomas
and neurofibromas) of the spinal or cranial nerves,
tumors of the skin and cutaneous pigmentation.
Lesions in the nerves and skin usually appear after
puberty and grow slowly or rapidly after this time;
typically, the dermal lesions are of little importance in the
production of signs and symptoms and they are seldom
painful.
Occasionally, schwannomas and neurofibromas form on
spinal roots and some can grow to considerable size.
Intraspinal tumors usually arise from the dorsal root and
radicular pain is often the first symptom.
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Physical Examination
Physical examination revealed
an alert, well-developed
anxious right-handed white
female in mild distress who
was nevertheless extremely
pleasant and cooperative.
Heart rate – 80
Skin
– multiple cafe-au-lait spots on
back, chest, and abdomen
– multiple small (2-3 mm)
dermal neurofibromas on right
forearm, left breast, and left
ankle; one 1.5 cm soft tumor
on left torso just below tenth
rib.
BP - 120/80, both arms
Cardiac – regular
Chest - clear to auscultation
8
Neurological Examination
Motor systems:
– Left upper extremity, trunk, and
both lower extremities normal with
respect to strength, tone, muscle
bulk and lack of adventitious
movements.
– Right upper extremity: There was
evidence of weakness in the right
biceps, triceps, brachioradialis,
wrist extensors, finger extensors,
and abductors and extensors on
the thumb. The biceps,
brachioradialis and triceps
reflexes were diminished on the
right compared to the left.
Sensory systems:
– Decreased sensation to all
modalities along the medial
aspect of the right arm. Slight
decrease in pinprick sensation on
left side of body below C8
dermatome. Light touch,
conscious proprioception, and
vibration intact bilaterally.
positive for
Babinski
sign on the
right
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Spinal Nerves (31 pairs)
all are mixed nerves
(sensory and motor)
4 fiber components
– Sensory
GSA: general somatic
afferent
GVA: general visceral
afferent
– Motor
GSE: skeletal
GVE: visceral
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31 pairs of spinal nerves
Cervical
Thoracic
Lumbar
Sacral
Cocygeal
C1 - C4; C5 - C8
T1 - T12
L1 - L5
S1 - S5
Cy1
Cervical Plexus ventral rami of C1-C4
Brachial Plexus ventral rami of C5-T1
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The Brachial Plexus
Innervates all muscles of
superior extremity
Sensory & motor nerves
Anterior division fibers
supply flexors
Posterior division fibers
supply extensors
Roots Trunks Divisions Cords Branches
Robert Taylor Drinks
Cold Beer
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Brachial Plexus: Major Branches
Musculocutaneous (C5-7)
Median Nerve (C6-T1)
Ulnar Nerve (C8-T1)
Axillary Nerve (C5-6)
Radial Nerve (C7-8)
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Brachial Plexus: Major Branches
Musculocutaneous
(C5-7)
– Biceps Brachii
(C5, C6)
– Coracobrachialis
(C5, C6, C7)
– Brachialis (C5, C6)
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Brachial Plexus: Major Branches
Median Nerve (C6-T1)
–
–
–
–
–
–
–
–
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor digitorum profundus
(lateral)
Flexor digitorum superficialis
Flexor pollicus longus
Pronator quadratus
and hand mm.
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Brachial Plexus: Major Branches
Ulnar Nerve (C8-T1, often C7)
 + 13 hand mm.
– Flexor digitorum profundus (medial)
– Flexor carpi ulnaris
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Brachial Plexus: Major Branches
Axillary Nerve (C5-6)
– Deltoid
– Teres minor
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Brachial Plexus: Major Branches
Radial Nerve (C5-T1)  12 + anconeus
–
–
–
–
–
–
–
–
–
–
–
Brachioradialis
Triceps brachii (C6, C7, C8)
Extensor carpi radialis longus
and brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
Supinator
Abductor pollicus longus
Extensor pollicus longus and brevis
Extensor indicus
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Brachial Plexus: Other Nerves
Dorsal Scapular (C5)
– Rhomboideus major and minor
– Levator scapulae
Suprascapular (C5-6)
– Supraspinatus
– Infraspinatus
– Shoulder joint
Subclavian (C5-6)
– Subclavius
Lateral Pectoral (C5-C7)
– Pectoralis major and minor
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Upper Subscapular (C56)
– Subcapularis
Thoracodorsal (C6-8)
– Latissimus dorsi
Lower Subscapular (C56)
– Teres major
Long Thoracic (C5-7)
– Seratus anterior
Medial Pectoral (C8-T1)
– Pectoralis minor and
major
Medial Brachial Cutaneous
Medial Antebrachial
Cutaneous
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Localization of Lesion: Anne Klein
Dermatomes
Sensory
Motor
rt. shoulder
C5
 medial rt. arm
all modalities
 rt. biceps brachii
musculocutaneous n.
C5 < C6
rt. shoulder
C6
rt. 4th and 5th
digits
C6
 lt. side of body
below C8
dermatome
 rt. triceps brachii
radial n. C6 < C7, C8
 rt. brachioradialis
radial n. C5 < C6 > C7
Other
Predicted
Primary Lesion
positive for
Babinski sign on
the right
rt.
descending
pyramidal
C6
tracts
C7
C8
C8
 rt. finger extensors
radial n. C6, C7, C8
C6
 rt. wrist extensors
radial n. C7, C8
C8
 rt. thumb abductors
and extensors
radial n. C7, C8
lt.
C7
C8
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Review of the patient's MRI demonstrated a large paraspinous mass (a
dumbbell neurofibroma of cervical spine) with invasion of the neural foramina of
C6-7 and C7-T1 and extending out into the brachial plexus. There was some
compression of the cervical cord (C6-7) to the left. There was also evidence of
tumor invasion of the C7 vertebral body.
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Plan
Neurosurgery was consulted.
A C6-7 laminectomy and C6-7
facetectomy with tumor resection was
scheduled for the following week.
Oncology consultation.
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Patient Outcome
The pathology report came back as benign neurofibroma;
they did not feel that it was malignant at this time. However,
at least one neurologist expressed some concern at this
interpretation in light of the pronounced tumor invasion of the
C7 vertebral body.
Postoperatively, the patient did quite well. Motor strength on
the right was only slightly less than that on the left, in spite of
the fact that the C6 nerve was sacrificed. The patient's arm
pain was improved.
At time of discharge, the patient was afebrile and vital signs
were stable. She had some mild weakness in her right
triceps, her pain was better, and she was ambulating without
problem. She was released to the care of her family.
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