1. 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)

2. 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

3. Patient Interview Past medical history Allergies Meds Social 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.
Allergies
No known allergies
No known toxic environmental or occupational exposures
Meds
Medications: birth control pills
Social history
Freshman college student; pre-med
Single, no children
No travel outside of Indiana in the last 3 years
Non-smoker; does not drink alcohol
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.

4. 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.

8. 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
BP - 120/80, both arms
Cardiac – regular
Chest - clear to auscultation
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.

9. 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

10. 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

11. 31 pairs of spinal nerves Cervical C1 - C4; C5 - C8 Thoracic T1 - T12
Lumbar L1 - L5
Sacral S1 - S5
Cocygeal Cy1
Cervical Plexus ventral rami of C1-C4
Brachial Plexus ventral rami of C5-T1

12. 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

15. Brachial Plexus: Major Branches
Musculocutaneous (C5-7)
Median Nerve (C6-T1)
Ulnar Nerve (C8-T1)
Axillary Nerve (C5-6)
Radial Nerve (C7-8)

16. Brachial Plexus: Major Branches
Musculocutaneous (C5-7)
Biceps Brachii (C5, C6)
Coracobrachialis (C5, C6, C7)
Brachialis (C5, C6)

17. 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.

18. Brachial Plexus: Major Branches
Ulnar Nerve (C8-T1, often C7)
 + 13 hand mm.
Flexor digitorum profundus (medial)
Flexor carpi ulnaris

19. Brachial Plexus: Major Branches
Axillary Nerve (C5-6)
Deltoid
Teres minor

20. 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

21. 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

22. Upper Subscapular (C5-6)
Subcapularis
Thoracodorsal (C6-8)
Latissimus dorsi
Lower Subscapular (C5-6)
Teres major
Long Thoracic (C5-7)
Seratus anterior
Medial Pectoral (C8-T1)
Pectoralis minor and major
Medial Brachial Cutaneous
Medial Antebrachial Cutaneous

24. Localization of Lesion: Anne Klein
Dermatomes
Sensory
Motor
Other
Predicted Primary Lesion
rt. shoulder C5
 medial rt. arm
all modalities
 rt. biceps brachii
musculocutaneous n. C5 < C6
positive for Babinski sign on the right
descending pyramidal
tracts C6
 lt. side of body below C8 dermatome
 rt. triceps brachii
radial n. C6 < C7, C8
rt. 4th and 5th digits
 rt. brachioradialis
radial n. C5 < C6 > C7
 rt. finger extensors
radial n. C6, C7, C8
 rt. wrist extensors
radial n. C7, C8
 rt. thumb abductors and extensors
rt.
lt. C6 C7 C8 C8 C6 C7 C8 C8

25. 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.

28. Plan Neurosurgery was consulted.
A C6-7 laminectomy and C6-7 facetectomy with tumor resection was scheduled for the following week.
Oncology consultation.

29. 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.