ORTHO I LECTURE 17: PERIPHERAL NERVE INJURY (EXAM III)

S/sx of ____ ____ ____:

- pain

- stabbing

- burning

- tingling

- muscle weakness

- muscle atrophy

Peripheral nerve injuries

_____ types of pain (MSK):

- nociceptive

- peripheral neuropathic

- central sensitization

Primary

____ ____ pain arises from impairment of or a lesion within peripheral neural tissue

Peripheral neuropathic

Peripheral neuropathic pain is referred in a ____ or _____ distribution

Dermatonal or cutaneous

____ ____ pain is associated with a history of injury, pathology or mechanical compromise

Peripheral neuropathic

With peripheral neuropathic pain there is pain or symptom provocation with _____/_____ tests that compress neural tissue

Mechanical/movement

____ ____:

- neuropraxia

- axonotmesis

- neurotmesis

Nerve injuries

_____:

- least severe

- involves focal damage of myelin fibers around axon (axon & CT sheath remain intact)

- limited course (minutes to days to weeks)

- recovery usually uncomplicated

- etiology includes mild blunt blows, prolonged mild compression or stretch

Neuropraxis

_____:

- more severe

- involves injury to axon

- recovers occurs through regeneration of the axon

- regeneration is possible but prolonged (months)

- direct correlation between recovery and the distance from the nerve to its innervated tissue (uncomplicated recovery rates from 1.5mm/day to 3mm/day)

Axonotmesis

_____:

- involves complete disruption of the axon, including injury to CT sheaths

- little likelihood of normal regrowth or clinical recovery

Neurotmesis

____ ____:

- "stinger" or "burner"

Brachial plexus

Brachial plexus in an acute setting must be differentiated from a _____ injury:

- point tenderness of cervical vertebrae

- pain with neck movement

- bilateral sx

- UE & LE sx

C-spine

____ ____ sx:

- acute onset of paresthesia in upper arm

- circumferential pattern vs. dermatonal pattern

- lasts seconds to minutes

- motor symptoms may present initial or develop later

Brachial plexus

____ ____ exam findings:

- if motor symptoms, UE muscle group exhibiting weakness correlated with part of brachial plexus injured

- should reassess after 24 hours and every few days for 2 weeks

Brachial plexus

____ ____ ____:

- CN XI

- innervated trap & SCM

Spinal accessory nerve

____ ____ ____ injury from:

- blow to the shoulder

- radial neck dissection

- carotid endarterectomy

- cervical node biopsy

Spinal accessory nerve

____ ____ ____ sx:

- generalized shoulder & neck pain

- medial scapular pain

- no sensory changes

Spinal accessory nerve

____ ____ ____ exam findings:

- asymmetry in shoulders (affected side sags)

- unable to shrug shoulder

- unable to ABDarm above horizontal

- atrophy of trap with chronic injury

Spinal accessory nerve

____ ___ ____ confirmatory test:

- ADD of the scapula & PT resists medial border of inferior angle

Spinal accessory nerve

____ ___ ____ injury from:

- blow to the shoulder or lateral chest wall

- chronic repetitive traction on nerve (throwing, swimming, tennis)

- compression between clavicle & 1st rib

Long thoracic nerve (C5-7)

____ ____ ____ is motor to the Serratus anterior

Long thoracic nerve (C5-7)

____ ____ ____ sx:

- diffuse shoulder or neck pain that worsens with overhead activity

- no sensory changes

Long thoracic nerve (C5-7)

____ ____ ____ exam findings:

- scapular winging

- inability to fully elevate arm overhead

- shoulder flexion & ABD are weak & limited in AROM

Long thoracic nerve (C5-7)

____ ____ ___ confirmatory test:

- patient unable to fully flex & extend arm

Long thoracic nerve (C5-7)

_____ _____ is motor to the supraspinatus & infraspinatus

Suprascapular nerve (C5-6)

____ ____ sensory to the shoulder capsule, GH & AC joints

Suprascapular nerve (C5-6)

_____ _____ injury from:

- repetitive overhead activity

- cyst formation at suprascapular notch

- direct blow to the shoulder

Suprascapular nerve (C5-6)

____ ____ sx:

- dull ache posterior & lateral shoulder

- muscle atrophy and weakness of supraspinatus & infraspinatus

- increase scapulae elevation during arm elevation (impingement like sx)

Suprascapular nerve (C5-6)

____ ____ exam findings:

- weak ER

- weak elevation of humerus

- increases scapular elevation during humeral elevation

- atrophy of supraspinatus & infraspinatus

Suprascapular nerve (C5-6)

____ ____ is motor to deltoid & teres minor

Axillary nerve (C5-6)

_____ ____ areas of vulnerability:

- quadrilateral space

- surgical neck

Axillary nerve (C5-6)

____ ____ injury from:

- shoulder dislocation

- humeral neck fx

- upward pressure (improper crutch use)

- repetitive overhead activities (pitching, swimming)

Axillary nerve (C5-6)

____ ___ sx:

- arm fatigue with overhead activity/throwing

- paresthesia of lateral upper arm

Axillary nerve (C5-6)

_____ ____ exam findings:

- weak ABD

- weak ER

- atrophy of deltoid & teres minor

- loss of sensation in lateral deltoid region

Axillary nerve (C5-6)

____ ____ confirmatory test:

- patient asked to ABD arm to 90 degrees and bring it back into horizontal extension (very difficult)

Axillary nerve (C5-6)

___ ___ ___ is caused from compression of the median nerve as it passes through the carpal tunnel

Carpal tunnel syndrome

Carpal tunnel syndrome is common between the ____-_____ decades

4th-6th

Carpal tunnel syndrome is more common in _____

Women

____ ____ ___:

- sx worse at night

- muscle weakness can occur

- intermittent pain/paresthesia in median nerve distribution

Carpal tunnel syndrome

____ ___ ____ treatment:

- splint (neutral to 15 degrees extension)

- activity modification

- NSAIDs

- tendon glides

- ergonomic modifications

- carpal and wrist joint mobilization

- median nerve mobilization

Carpal tunnel syndrome

_____ _____ is compression of the median nerve distal to the antecubital fossa

Pronator syndrome (median nerve)

_____ ____ has insidious onset of pain on:

- anterior aspect of the elbow

- radial side of the palm

- dorsal fingertips of 1-3 and half of 4th

- palmar side of 1-3 and half of 4th digit

Pronator syndrome (median nerve)

____ _____ is different from CTS because there is no Tinel sign at the wrist & no nocturnal sx

Pronator syndrome (median nerve)

____ ____:

- paresthesia in median nerve distribution

- minimal motor changes

- reproduced by compressing pronator teres

Pronator syndrome (median nerve)

_____ _____ ____:

- compression of median nerve in mid forearm

- forearm pain

- possible weakness of FPL, pronator quadratus, lateral half of FDP ((+) pinch grip test —> "OK" sign)

- no sensory changes/paresthesia (differentiates from PS & CTS)

Anterior interosseous syndrome (median nerve)

____ ____ ____:

- irritation of the ulnar nerve in the cubital tunnel

- 2nd most common nerve entrapment in UE

- vulnerable to traction, friction, and compression

Cubital tunnel syndrome (ulnar nerve)

___ ___ _____:

- traction injuries common throwers due to valgus stress

- flexion contractures or longstanding valgus deformity could also cause traction injury

Cubital tunnel syndrome (ulnar nerve)

____ _____ may occur as a result of:

- thickening UCL

- adhesions within tunnel

- hypertrophy of surrounding muscles

- joint changes

Cubital tunnel syndrome (ulnar nerve)

____ ____ ____ sx:

- medial elbow pain

- pain radiates to forearm or upper shoulder

- numbness/tingling in ulnar nerve distribution

- clumsiness in hand or loss of coordination of fingers

Cubital tunnel syndrome (ulnar nerve)

____ ____ _____ treatment:

- activity modification

- elbow padding

- modalities

- soft tissue mobilization of flexor muscles

- splinting of elbow to prevent excessive flexion

- nerve glides

- strength progression

- important to identify UCL insufficiency

- failure of conservative management —> surgical intervention (decompression or anterior transposition of the ulnar nerve)

Cubital tunnel syndrome (ulnar nerve)

___ ___ ___ ____:

- compression occurs at level of mid arm (strenuous triceps exercise)

- damage to radial nerve can result from mid shaft humerus or fx (spiral groove)

- loss of wrist extension, finger/thumb extension

- decreased sensation in dorsal web space

- triceps involvement is dependent upon level of compression/pathology

High radial nerve compression

___ ____ injury from:

- compression at axilla

- Saturday night palsy

- improper crutch use

- humeral shaft fx

- supracondylar fx

- sleeping posture

Radial nerve (C6-T1)

____ ____ sx:

- wrist drop

- sensory changes

Radial nerve (C6-T1)

____ ____ exam findings:

- depends on site of injury

- triceps weakness

- brachioradialis weakness

- wrist/finger extensor weakness

- loss of sensation posterior forearm and hand

Radial nerve (C6-T1)

____ ____ ____ ____:

- compression of posterior interosseous nerve as it transverse radial tunnel (motor branch of radial nerve)

- may occur with repetitive pronation/supination (especially resisted supination)

Posterior interosseous nerve syndrome (radial nerve)

___ ___ ___ ___ sx:

- lateral elbow pain; may radiate into distal forearm (aggravated by repetition pronation/supination)

- tenderness 3-4 cm distal to lateral epicondyle

- mimics lateral epicondylitis

- weakness of finger extensors, thumb ABD, and supinator

- no sensory disturbances

Posterior interosseous nerve syndrome (radial nerve)

____ ___ ___ ____ treatment:

- rest/activity modification

- cock-up splint (45 degrees wrist extension)

- gently stretching of wrist extensors with elbow fully extended

Posterior interosseous nerve syndrome (radial nerve)

____ ___ ___:

- compression of deep branch of radial nerve (compression of PIN with pain only)

- dynamic compression syndrome (occurs during elbow extension, forearm pronation, and wrist flexion)

- mimics lateral epicondylitis

Radial tunnel syndrome

____ ____ _____ sx:

- lateral elbow pain; may radiate into proximal forearm (poorly localized over radial aspect of proximal forearm)

- pain on passive stretching of extensor muscles and resisted wrist/finger extension

- tenderness to palpation over radial tunnel

- no motor or sensory changes

Radial tunnel syndrome

____ ___ ____ treatment is similar to PIS

Radial tunnel syndrome

____ ____ ____ ___:

- aka Wartenberg Syndrome

- entrapped in the fascia tween the Brachioradialis & ECRL tendons

- shooting or burning pain along the posterior/lateral forearm, wrist & thumb, associated with wrist flexion & ulnar deviation

Radial sensory nerve entrapment