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Brachial Plexus: Angela Klein’s Brachial Plexus: Angela Klein’s Painful ArmPainful Arm

Ernest F. Talarico, Jr., Ph.D.Associate Director of Medical EducationAssociate Professor of Anatomy & Cell BiologyAssociate Faculty, Radiologic SciencesCourse Director, Human Gross Anatomy & EmbryologyIndiana University School of Medicine – Northwest (Gary, Indiana)

Human Gross Anatomy

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Patient HistoryPatient History18-year-old female, college 18-year-old female, college studentstudent

Right handedRight handed

CC of right shoulder and arm pain CC of right shoulder and arm pain x3 monthsx3 months

Pain extends down through the 4Pain extends down through the 4thth and 5and 5thth digits of her hand; periodic digits of her hand; periodic numbness and tingling in the numbness and tingling in the same distributionsame distribution

Pain is slowly getting worse; Pain is slowly getting worse; intermittent and exacerbated with intermittent and exacerbated with handwritinghandwriting

Some right arm weaknessSome right arm weakness

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Patient InterviewPatient InterviewPast medical historyPast medical history

– The patient has The patient has neurofibromatosisneurofibromatosis. She has had . She has had multiple multiple neurofibromasneurofibromas removed removed since 1998, including one from her since 1998, including one from her nose in 1998 and one from her left nose in 1998 and one from her left medial thigh in 2000.medial thigh in 2000.

AllergiesAllergies

– No known allergies No known allergies – No known toxic environmental or No known toxic environmental or

occupational exposuresoccupational exposures

MedsMeds

– Medications: birth control pills Medications: birth control pills

Social historySocial history

– Freshman college student; pre-Freshman college student; pre-med med

– Single, no childrenSingle, no children– No travel outside of Indiana in the No travel outside of Indiana in the

last 3 yearslast 3 years– Non-smoker; does not drink Non-smoker; does not drink

alcoholalcohol

Family historyFamily history

– Significant for neurofibromatosis. Significant for neurofibromatosis. Mother, brother, grandmother and Mother, brother, grandmother and great-grandmother have great-grandmother have neurofibromatosis type 1neurofibromatosis type 1. .

– Brother has twice had surgery for Brother has twice had surgery for removal of removal of acoustic neuromasacoustic neuromas. .

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NeurofibromatosisNeurofibromatosis is an inherited disorder characterized is an inherited disorder characterized by the development of multiple tumors (schwannomas by the development of multiple tumors (schwannomas and neurofibromas) of the spinal or cranial nerves, and neurofibromas) of the spinal or cranial nerves, tumors of the skin and cutaneous pigmentation. tumors of the skin and cutaneous pigmentation. Lesions in the nerves and skin usually appear after Lesions in the nerves and skin usually appear after puberty and grow slowly or rapidly after this time; puberty and grow slowly or rapidly after this time; typically, the dermal lesions are of little importance in the typically, the dermal lesions are of little importance in the production of signs and symptoms and they are seldom production of signs and symptoms and they are seldom painful.painful.

Occasionally, schwannomas and neurofibromas form on Occasionally, schwannomas and neurofibromas form on spinal roots and some can grow to considerable size.spinal roots and some can grow to considerable size.

Intraspinal tumors usually arise from the dorsal root and Intraspinal tumors usually arise from the dorsal root and radicular pain is often the first symptom. radicular pain is often the first symptom.

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Physical ExaminationPhysical Examination

Physical examination revealed Physical examination revealed an alert, well-developed an alert, well-developed anxious right-handed white anxious right-handed white female in mild distress who female in mild distress who was nevertheless extremely was nevertheless extremely pleasant and cooperative.pleasant and cooperative.

Heart rate – 80Heart rate – 80

BP - 120/80, both armsBP - 120/80, both arms

Cardiac – regularCardiac – regular

Chest - clear to auscultationChest - clear to auscultation

Skin Skin – multiple cafe-au-lait spots on multiple cafe-au-lait spots on

back, chest, and abdomenback, chest, and abdomen

– multiple small (2-3 mm) multiple small (2-3 mm) dermal dermal neurofibromasneurofibromas on right on right forearm, left breast, and left forearm, left breast, and left ankle; one 1.5 cm soft tumor ankle; one 1.5 cm soft tumor on left torso just below tenth on left torso just below tenth rib.rib.

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Neurological ExaminationNeurological ExaminationMotor systems:Motor systems:

– Left upper extremity, trunk, and Left upper extremity, trunk, and both lower extremities normal with both lower extremities normal with respect to strength, tone, muscle respect to strength, tone, muscle bulk and lack of adventitious bulk and lack of adventitious movements. movements.

– Right upper extremity: There was Right upper extremity: There was evidence of weakness in the right evidence of weakness in the right biceps, triceps, brachioradialisbiceps, triceps, brachioradialis, , wrist extensors, finger extensorswrist extensors, finger extensors, , and abductors and extensors on and abductors and extensors on the thumb.the thumb. The biceps, The biceps, brachioradialis and triceps brachioradialis and triceps reflexes were diminished on the reflexes were diminished on the right compared to the left. right compared to the left.

Sensory systems:Sensory systems:

– DecreasedDecreased sensation to all sensation to all modalities along the modalities along the medial medial aspect of the right armaspect of the right arm. Slight . Slight decrease in pinprick sensation on decrease in pinprick sensation on left side of body below C8 left side of body below C8 dermatomedermatome. Light touch, . Light touch, conscious proprioception, and conscious proprioception, and vibration intact bilaterally.vibration intact bilaterally.

positive for Babinski sign on the right

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Spinal Nerves (31 pairs)Spinal Nerves (31 pairs)

all are mixed nerves all are mixed nerves (sensory and motor)(sensory and motor)

4 fiber components4 fiber components

– SensorySensoryGSA: GSA: general general somatic somatic afferentafferentGVA: GVA: general general visceral visceral afferentafferent

– MotorMotorGSE: GSE: skeletalskeletalGVE: GVE: visceralvisceral

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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

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The Brachial PlexusInnervates all muscles of superior extremity

Sensory & motor nerves

Anterior division fibers supply flexors

Posterior division fibers supply extensors

Roots Trunks Divisions Cords BranchesRobert 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 NervesDorsal Scapular (C5)Dorsal Scapular (C5)

– Rhomboideus major and minorRhomboideus major and minor– Levator scapulaeLevator scapulae

Suprascapular (C5-6)Suprascapular (C5-6)

– SupraspinatusSupraspinatus– InfraspinatusInfraspinatus– Shoulder jointShoulder joint

Subclavian (C5-6)Subclavian (C5-6)

– SubclaviusSubclavius

Lateral Pectoral (C5-C7)Lateral Pectoral (C5-C7)

– Pectoralis Pectoralis majormajor and minor and minor

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Upper Subscapular (C5-Upper Subscapular (C5-6)6)

– SubcapularisSubcapularis

Thoracodorsal (C6-8)Thoracodorsal (C6-8)

– Latissimus dorsiLatissimus dorsi

Lower Subscapular (C5-Lower Subscapular (C5-6)6)

– Teres majorTeres major

Long Thoracic (C5-7)Long Thoracic (C5-7)

– Seratus anteriorSeratus anterior

Medial Pectoral (C8-T1)Medial Pectoral (C8-T1)

– Pectoralis Pectoralis minor minor and and majormajor

Medial Brachial CutaneousMedial Brachial Cutaneous

Medial Antebrachial Medial Antebrachial CutaneousCutaneous

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Localization of Lesion: Anne KleinLocalization of Lesion: Anne Klein

DermatomesDermatomes SensorySensory MotorMotor OtherOther Predicted Predicted Primary Lesion Primary Lesion

rt. shoulderrt. shoulderC5C5

medial rt. armmedial rt. armall modalitiesall modalities

rt. biceps brachiirt. biceps brachiimusculocutaneous n. musculocutaneous n.

C5 < C6C5 < C6

positive for positive for Babinski sign on Babinski sign on

the rightthe rightdescending descending pyramidalpyramidal

tractstracts

rt. shoulderrt. shoulderC6C6

lt. side of body lt. side of body below C8 below C8

dermatomedermatome

rt. triceps brachiirt. triceps brachiiradial n. C6 < C7, C8radial n. C6 < C7, C8

rt. 4rt. 4thth and 5 and 5thth digitsdigitsC6C6

rt. brachioradialisrt. brachioradialisradial n. C5 < C6 > C7radial n. C5 < C6 > C7

rt. finger extensorsrt. finger extensorsradial n. C6, C7, C8radial n. C6, C7, C8

rt. wrist extensorsrt. wrist extensorsradial n. C7, C8radial n. C7, C8

rt. thumb abductors rt. thumb abductors and extensorsand extensors

radial n. C7, C8radial n. C7, C8

C6C6

C7C7

C8C8

rt.rt.

C8C8

C8C8

lt.lt.

C6C6

C7C7

C8C8

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Review of the patient's MRI demonstrated a large paraspinous mass (a Review of the patient's MRI demonstrated a large paraspinous mass (a dumbbell neurofibroma of cervical spine) with invasion of the neural foramina of 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 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 compression of the cervical cord (C6-7) to the left. There was also evidence of tumor invasion of the C7 vertebral body.tumor invasion of the C7 vertebral body.

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PlanPlan

Neurosurgery was consulted. Neurosurgery was consulted.

A C6-7 laminectomy and C6-7 A C6-7 laminectomy and C6-7 facetectomy with tumor resection was facetectomy with tumor resection was scheduled for the following week. scheduled for the following week.

Oncology consultation.Oncology consultation.

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Patient OutcomePatient Outcome

The pathology report came back as benign neurofibroma; The pathology report came back as benign neurofibroma; they did not feel that it was malignant at this time. However, they did not feel that it was malignant at this time. However, at least one neurologist expressed some concern at this at least one neurologist expressed some concern at this interpretation in light of the pronounced tumor invasion of the interpretation in light of the pronounced tumor invasion of the C7 vertebral body. C7 vertebral body.

Postoperatively, the patient did quite well. Motor strength on Postoperatively, the patient did quite well. Motor strength on the right was only slightly less than that on the left, in spite of 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 the fact that the C6 nerve was sacrificed. The patient's arm pain was improved.pain was improved.

At time of discharge, the patient was afebrile and vital signs At time of discharge, the patient was afebrile and vital signs were stable. She had some mild weakness in her right were stable. She had some mild weakness in her right triceps, her pain was better, and she was ambulating without triceps, her pain was better, and she was ambulating without problem. She was released to the care of her family.problem. She was released to the care of her family.