Lecture 14 +15 - Neuroanatomy

Immobilization
Stretch
Compression
Laceration
Repetitive Stress

induces cell biological changes in axons and axon terminas, myelin degeneration, deposition of collagen in endoneurium, 6 weeks deposition of collagen and alteration in large diameter myelinated fibers

6-8% strain for short duration are tolerable no injury to nerve, increasing tensile load in nerve results in structural separtion in core-sheath interface and then axons and finally cells
lengthening creates compression in diameter and disruption of vascular flow blocking conduction and resulting in inflammatory effects

20-30 mm Hg has been shown to reduce nerve blood flow and result in injury
50 mm Hg sustained for 2 minutes has been shown to result in 30% axon demyelination

vibration causes loss in sensory and motor performance, dennervation and reinnervation.
repetitive motion chronic inflammation, hydrostatic compressive stress and increased stiffness

pain, tingling, numbness that radiates from neck into shoulder, arm, hand, fingers
Neck pain, periscapular pain, elbow pain, wrist and hand pain
+ Spurlings

Dermatome - lateral upper arm
Myotome - shoulder abduction, elbow flexion
Reflex - Biceps

lateral forearm to the thumb and 2nd digit
wrist extension, elbow flexion
brachioradialis

anterior and posterior 3rd digit and hand
wrist flexion and elbow extension
triceps

ulnar side 4-5th digits and proximal wrist
finger flexion and thumb pinch
finger flexors

women
late teens-40s
obesity, hypermobility, postural abnormalities
repetitive use of hands
young athletic males

numbness, tingling, dead arm
pain at rest/night
weakness/clumsiness
caused by compression of brachial plexus

compression of subclavian vein
sweling in arm/hand/fingers
bluish skin
fatigue in limb
tingling/numbness/ burning
progressive in nature, increases with activity

rarest - subclavian artery
cold, pale, discolored
weak/absent pulse
pain
tingling/numbness/ burning
progressive in nature: increases with activity

can present as both vascular and nerve
no specific pattern
change in pain with use of arm

trauma - fracture of 1st rib or clavicle
congenital - 1st rib anomalies, cervical rib (extra rib from 7th vertebra), elongated C7 transverse process

trauma - scalene (anterior/middle)
congenital/acquired - abnormal cervical ligaments/ bands which tighten the space

fracture of upper extemity consider anatomy near or around nerve
surgical interventions
joint dislocations or instability
chronic tendon disorders

direct blow
traction - lateral flexion of the cervical spine with the arm over head
compression against the chest wall
heav effort above shoulder height
repetitive strain

Erb's point direct impact
Compression in the suprascapular notch
Spenoglenoid notch
forceful scapula depression with cervical sidebending
RTC Tear

anterior shoulder dislocation
surgical procedures for capsular repair
aggressive manipulatio of adhesive capsulitis

entrapment in coracobrachialis
heavy weight lifting with flexion, elbow flexion, and forearm pronation
mid-shaft humeral fracture

serratus anterior
no sensory

supraspinatus, infraspinatus
small area on shoulder above spine of scapula

deltoid, teres minor
lateral upper arm over deltoid

biceps, coracobrachialis, brachialis
lateral forearm anterior/posterior to wrist

Pronator teres
flexor carpi radialis
Palmaris longus

FDS, FPL, FDP (2+3), pronator quadratus
no sensory

Thenar muscles: APB, FPB, OP,
first and 2nd lumbricals
finger flexors?
palmar surface of thumb through middle half of 4, posterior tip of DIPs

FCU, FDP 4+5, ECU
dorsal and palmar 4th and 5th digits of hand to wrist crease

interossei
4th and 5th digits
ADpollicis
1 head of FPB
lumbricals 3, 4
Abd Digiti minimi
ODM
FDM
PB

triceps, supinator, brachioradialis, ECRL
dorsal surface of hand, thumb-3rd

abductor pollicis longus
extensor pollicis longus
extensor digitorum
supinator
ECU
extensor pollicis brevis + longus
extensor digitorum
extensor digiti minimi
abductor pollicis longus
extensor indicis
ECRL and ECRB
no sensory

brachialis - mostly musculocutaneous though
brachioradialis

repetitive tasks using pronation/supination of forearm, medial instability, fractures distal humerus and proximal ulna

sustained compression in axilla, fracture of mid shaft of humerus, posteriolateral rotary instability, chronic lateral epicondylitis, surgical debridement LET, radial head instability, sustained prolonged BP cuff inflation

valgus instability, chronic medial epicondylitis, direct or indirect trauma to medial elbow, throwing (traction injuries), positions that increase stretch

Add pollicis brevis
Flex DM
Abd DM
OP DM

FPB
OP
Abd PB

Carpal Tunnel Syndrome

8

women
common with pregnancy because of fluid retentiono
changes in estrogen with higher BMI + repetitive movement of limb

aging
synovial fluid is thicker, bigger joint = less space for the nerve

individuals with vibration exposure through work or recreation

female
BMI >30
Diabetes
Reduced physical activity
OA
Pregnancy
Estrogen replacement therapy
Genetics
CV disease
Hypothyroidism

forceful exertion wrist and hand
repetitive use
vibration
wrist position

tingling, numbness, burning or pain in at least 2 of the digits (thumb index and long)
excluded if symptoms in the palm and dorsum of hand
small finger symptoms, wrist pain, or radiation proximal to the wrist allowed

Vitals
AROM of cervical spine
Sensory Integrity in entire UE: distal thumb, 3rd and 5th digit; monofilament middle finger and tip of thumb 3.22; two point discrimination testing less than 4-5 mm
Motor assessment wrist/hand, all lumbricals (median vs ulnar)
Reflexes in UE
Mobility Wrist/elbow/forearm
joint play intercarpal bones/CMC of thumb
Specific Tissue tests: carpal compression, phalens, reverse phalens, tinnels, wrist ratio

wrist ratio
phalen
carpal compression
tinel's sign median
monofilament testing

age >45
shaking hands provide relief
wrist ratio greater than 0.67
dimished light touch in median nerve distribution
CTQ-SSS >1.9

AP/ML
>.7 at risk for carpal tunnel

ulnar nerve - paper in fingers
forearm
intrinsic is weak, extrinsic wants to take over, bend the knuckles

pronator syndrome
anterior interosseous syndrome

cubital tunnel syndrome

high radial
radial sensory
posterior interosseous syndrome

median nerve compressed by pronator teres
everything distal is affected - FDS, palmaris longus, FCR
pain and weakness through the 1st and 3 fingers similar to CTS, numbness at proximal wrist distal thumb
pain in the forearm

impaired sensory and motor in the 1st and 3 digits of the hand
impaired sensation in base of wrist
proximal muscle weakness
-carpal tunnel maneuvers for provocation
+ pronator compression test
Break tests:
pronator teres
biceps aponeurosis
FDP
reflexes intact

motor only
pronator quadratus
FDP 2,3
FPL
Pain in forearm, clumsiness of fingers
loss of grip of thumb and 1st finger
no atropgt of thenar eminence
no numbness or tingling only motor loss

impaired motor only of the FDP of lateral hand
FPL and pronator quadratus
+Anterior Interosseous Sign
+Pronator Compression Sign
no loss of sensation
reflexes in tact

ulnar nerve proximal most irritated
FCU, FDP 4+5, hand things
if compressed at wrist, then FDP and FCU are fine
if elbow, weak and sensory motor loss hand

elbow, humerus, sensory branch more distal

deep digital muscles, thumb abd and ext
wrist extensors
below elbow ECRB
above elbow ECRL and brachioradialis

pain in posterior lateral arm and dorsal hand
significant loss of motor function in all wrist and finger/thumb extensors, brachioradialis, supinator
sensory loss in the dorsal arm and hand
motor loss in all muscles innervated by radial nerve, elbow, wrist and hand

pain along the radial distribution of the lateral forearm and dorsal wrist and thumb
loss of sensation along the dorsal lateral arm ad hand

pain in the lateral elbow and forearm
loss of MCP extension, thumb IP extension and abduction
motor loss only: ECRB, supinator, ECU, EDM, EI, ED, APL, EPL, EPB

medial elbow pain
snapping or popping with elbow motion
numbness and tingling in 4th and 5th digits
clumsiness of hand, loss of coordination of fingers

sensory loss of ulnar boarder ofhand, 4th and 5th digit
weakness of FDP 4th and 5th, FCU
ADM, FDM, ODM, DI, VI, 4th and 5th lumbricals, Add Pol, FPB

P/A rule out cervical spine
sensory assessment of involved UE
motor assessment of intrinsic vs extrinsic
UE reflex testing
Range of motion elbow/forearm/wrist
Selective tissue testing: anterior interosseous sign, pronator compression test, ulnar nerve compression test

p/a rule out cervical spine
sensory assessment of involved UE
Motor assessment of muscles innervated by peripheral nerves
UE reflex testing
Range of motino of shoulder girdle
muscle length pectoralis minor/scales
Selective tissue testing: upper limb tension testing and thoracic outlet tests

Adson's Vascular
Allen's (Wrights) pec minor test
Costoclavicular test