DSA Compression Neuropathies Flashcards
What is neuropathy?
functional or pathological changes in peripheral nervous system
What is compression neuropathy?
process where a NERVE becomes entrapped as it passes thru a narrow tunnel or passage
Bio-mechanical causes of compression neuropathy
space occupying lesions
degenerative causes
post-trauma
mechanical (muscle spasm or pinching)
Systemic causes of compression neuropathy
pregnancy
hypothyroidism
diabetes
What pathological changes affect nerves?
microvascular compression (ischemia) thickened epineurium myelin thinning distortion microtubule closure axonal degneration
What is the first degree category of nerve injuries?
Neuropraxia (focal damage of myelin fibers around axon w/ CT sheath intact)
What is second degree category of nerve injuries?
Axonotmesis (some disruption/injury to axon itself w/ myelin sheath intact)
What is the 3rd-5th degree category of nerve injuries?
Nerotmesis (requires surgical intervention to fix 5th degree disruption of axon thru epineurium)
C5 nerve root
motor to deltoid, biceps
sensation to lateral arm
biceps reflex
C6 nerve root
wrist extension, elbow flexion
sensation to radial forearm, thumb & index finger
brachioradialis reflex
C7 nerve root
wrist flexion, elbow extension, finger extension
sensation to middle finger
triceps reflex
C8 nerve root
finger flexion
sensation to ulnar forearm & small finger
T1 nerve root
finger abduction
sensation to medial arm
When does cervical nerve root compression occur?
usually caused secondary to cervical disc dz
How does cervical nerve root compression occur?
What does it cause?
disc ruptures posterior-laterally causing compression of nerve root as it exits the intervertebral foramen
causes radiculopathy (pain caused by compression of spinal nerve that radiates in distribution of defined nerve root)
What is the Spurling test?
+ is pain elicited by extending & rotating neck TOWARD symptomatic side
DX cervical radiculopathy (herniated disc)
What is the Adson test?
+ is obliteration of radial pulse on affected side when have pt elevate chin & rotate head toward affect side while inhale
DX thoracic outlet syndrome
What is the Hoffmann test?
+ is quick flexion of thumb & index finger when grabbing middle finger (dorsal side)
DX cervical myelopathy (cervical spinal stenosis)
What are the general tx options for cervical neuropathy?
conservative measures (change activity, use anti-inflammatory, splinting, PT & OMM for 3-6months)
surgical release if non-operative management fails
*will most likely need operative decompression for cubital tunnel syndrome
Radial nerve
motor to triceps brachii, anconeus & wrist extensors
sensation to majority of dorsum of hand (via posterior interosseous n)
What are the 3 sites for radial nerve entrapment?
high on humerus (secondary to fracture)
radial tunnel (repetitive rotatory movements)
@ the wrist (superficial branch w/ pronation)
What is cheiralgia paresthetica/handcuff neuropathy?
numbness, tingling, burning, or pain in SRN distribution
caused by compression, edema, surgical injury
What are the 4 sites for median nerve entrapment?
ligament of struthers
pronator syndrome
anterior osseous syndrome
carpal tunnel syndrome
What is pronator syndrome?
occurs as median nerve passes btwn superficial & deep heads of pronator teres muscle
usually w/ repetitive pronating motions, achy pain in mid & proximal forearm that worsens w/ repeated lifting
How do you DX pronator syndrome?
pain w/ resisted forearm pronation
may have sensory abnormality in radial three & 1/2 digits
What is anterior interosseous syndrome?
deep motor branch of median N distal to pronator teres
due to trauma & cast pressure, bulky tendinous origin of ulnar head of pronator teres, soft tissue masses, fibrous bands
How do you DX ant interosseous syndrome?
no sensory sxs
DX w/ OK sign (pt is unable to hold & resist tip to tip of thumb to index piinch)
What is carpal tunnel syndrome?
MOST COMMON COMPRESSION SYNDROME
compression of median N as passes w/ flexor tendons under flexor retinaculum
How do you DX carpal tunnel syndrome?
night numbness of lateral 3 1/2 digits, tingling, wrist drop
common in repetitive motion jobs
DX w/ gold-standard EMG
What special tests are done to assess for carpal tunnel syndrome?
Phalen’s sign (flex hands to 90) & Tinel’s sign (tap over flexor retinaculum)
What nerve is affected in carpal tunnel syndrome?
Median Nerve
What are the 2 sites of ulnar nerve entrapment?
Cubital Tunnel (elbow) Guyon's canal
What does the ulnar nerve supply?
motor to skin & muscles of ulnar side of forearm & hand flexors
deep branch (to interosseous muscles & adductor pollicis)
superficial branch (sensory innervation to ring & pinky finger)
What is cubital tunnel syndrome?
most common compression seen in elbow
common in baseball pitchers, prolonged elbow flexion, external compression against hard surface, thickened cubital tunnel retinaculum
What are sx/dx of ulnar nerve entrapment?
sxs of paresthesia to 4th & 5th digits, medial elbow pain radiating to hand w/ decreased intrinsic muscle strength (can’t turn key in door)
+ Tinel’s sign at elbow
sxs reproduced w/ elbow flexion & wrist extension
What is Froment’s sign and what is it used for?
pt must flex thumb in order to pinch paper btwn 1st & 2nd digits
dx of cubital tunnel syndrome
What is thoracic outlet syndrome?
compression of brachial plexus or subclavian vessels
What are the sites of compression for TOS?
scalene triangle
costoclavicular passage
@ pectoralis minor attachment @ coracoid process
What are the sxs of TOS?
weakness, paresthesia of medial arm & forearm & arm which exacerbated by overhead activities
What tests are used for dx of TOS?
EAST test/Roos test
Wrigth’s HyperABduction Test
Adson’s test
Military/Costoclavicular maneuver
L1, L2 nerve root
motor for hip flexion
sensation to inguinal crease (L1) & ant thigh (L2)
L2, L3 nerve root
motor for knee extension
sensation to ant thigh (L2), ant thigh above knee (L3)
L4 nerve root
motor for ankle dorsiflexion
sensation to medial leg & foot
patellar reflex
L5 nerve root
motor for extensor hallicus longus
sensation to lateral leg, dorsum of foot
S1 nerve root
motor for ankle plantarflexion
sensation to lateral foot & plantar foot
Achilles reflex
What is meralgia paresthetica?
compression of lateral femoral cutaneous nerve (L2, L3) under inguinal ligament @ inguinal canal
due to obesity, tight clothing, intense athletics
sxs include numbness or pain on anterolateral thigh, hyperesthesia (don’t put things in pockets)
What test is + in meralgia paresthetica?
+ TInel’s sign 1cm medial & inferiot to ASIS
What is common fibular nerve compression?
compression as nerve winds around fibular neck & enters fibular tunnel that affects L4-S2 dermatomes
occurs if leg hooked over rail, squatting, ankle sprain or trauma to fibular head
What are sxs & tx of common fibular nerve compression?
FOOT drop w/ slapping gait, worsens w/ plantarflexion & inversion of foot
tx w/ posterior fibular head HVLA or MET
What is anterior tarsal tunnel syndrome?
compression of deep fibular nerve @ inferior extensor retinaculum (thickened fascia affects dorsum of foot)
seen w/ prolonged plantar flexion & trauma (soccer player)
What are sxs of anterior tarsal tunnel syndrome?
pain over dorsomedial aspect of foot, worse @ rest
weakness of extensor digitorum brevis
What is tarsal tunnel syndrome?
compression of posterior tibial nerve in tarsal tunnel behind medial malleolus w/ overlying flexor retinaculum
often idiopathic, seen w/ space occupying lesion, trauma, autoimmune or lifestyle
What are sxs of tarsal tunnel syndrome?
pain on plantar surface of foot, vague burning & tingling, does NOT usually affect gait
What is spinal disc disease?
initial herniation that is extremely painful acutely
disc slowly shrivels away so resolves in 2-6 weeks
usually affects middle aged to elderly pts
What is the outcome of spinal disc dz?
weak back ligaments w/ radiating pain down legs
pt may change biomechanics & accelerate osteoarthritis & stress on other joints
What is sciatica?
pain emerging from lower back felt along distribution of sciatic nerve in LE
a SYMPTOM (not a cause)
What are the sxs/manifestations of sciatica?
pt may experience pain on walking but long periods of sitting also worsen pain
pain when get up from seated position
What is an important complication or outcome of sciatica?
tight hamstrings leads to posterior pelvic tilt & flattening of lumbar curve
increased laxity of ACL & increased tension on PCL
How do you tx pt w/ sciatica sxs?
must release adductors first (b/c tight adductor magnus will cause limitation of full hamstring lengthening)
must treat hamstring trigger points
tx posterior pelvic tilt
