Compression Neuropathy Flashcards
Definition of compression neuropathy?
process why a nerve becomes entrapped and it passes through a narrowing (tunnel, passage, etc). Can happen anywhere along length of a nerve
Biomechanical causes of CN
space occupying lesions, degenerative causes, post-trauma, mechanical/movement, spondylolisthesis
ex of space occupying lesions
herniated discs, cysts
ex of degenerative cause of CN
foraminal stenosis
ex of post-trauma cause of CN
fracture, hematoma, compression from equipment
ex of mechanical/movement cause of CN
muscle spasm, pinching from external or positional forces
Systemic causes of CN
pregnancy, hypothyroidism, diabetes
Anatomy of a nerve from inside out
axons covered by myelin sheath covered by endoneurium > grouped together in fascicles and covered by perineurium > groups of fascicles and the vessels and CT are surrounded by epineurium
microscopic pathological changes (of the nerve) that can be seen in CN
microvascular compressions (leading to ischemia), thickening of epineurium, thinning of myeline sheath, microtubular closure, axonal degeneration
What category of nerve injury is Neuropraxia? and what is it?
Neuropraxia = 1st degree injury.
involves focal damage of myelin fibers around the axon, but the CT sheath remains intact
Recovery: limited course from days to weeks (lease severe)
What category of nerve injury is axonotmesis and what is it?
Axonotmesis = 2nd degree injury.
There is some disruption/injury to the AXON itself, MYELIN SHEATH remains INTACT.
Recover: REGENERATION is possible, but PROLONGED (takes months) without a complete recovery
What category of nerve injury is neurotmesis?
Neurotmesis: can be a 3rd or 4th or 5th degree nerve injury
What would a 3rd degree nerve injury look like?
Neurotmesis
-disruption of the axon AND the endoneurium
Recovery: No axonal regeneration because there is INTRANEURAL FIBROSIS
What would a 4th degree nerve injury look like?
Neurotmesis
-disruption of the AXON and ENDONEURIUM and PERINERIUM (aka nerve fasciculi). There will be a large area of INTRANEURAL SCARRING at site of injury = prevents axon from advancing distal to the level of injury.
Recovery: if be NO IMPROVEMENT in function…need SURGERY to restore
What would a 5th degree nerve injury look like?
Neurotmesis
-disruption of the AXON and ENDONEURIUM and PERINEURIUM and EPINEURIUM. There will be substantial perineural HEMORRHAGE and SCARING.
Recovery: surgery is required
Name of the system that classifies nerve injury
Sunderland Classification (1st degree - 5th degree)
What can you use to identify where/what nerve is pinched?
used dermatomes/sensation, motor, and reflex nerve roots to narrow it down
If you impinge nerve root C5 where will you see changes (motor, sensation, reflex)?
Motor: deltoid, biceps
Sense: lateral arm
Reflex: biceps
If you impinge nerve root C6 where will you see changes (motor, sensation, reflex)?
M: wrist extension, elbow flex
S: radial forearm, thrum and index finger
R: brachioradialis
If you impinge nerve root C7 where will you see changes (motor, sensation, reflex)?
M: wrist flex, elbow extension, finger extension
S: middle finger
R: triceps
If you impinge nerve root C8 where will you see changes (motor, sensation)?
M: finger flexion
S: ulnar forearm, pinky finger
If you impinge nerve root T1 where will you see changes (motor, sensation)?
M: finger abduction
S: medial arm
Most common cause of cervical nerve root compression?
usually a secondary manifestation of cervical disc disease (bulging disc or disc herniation)
What type of damage will you see in bulging disc
disc is compressed evenly without significant damage to the cartilage rings
What type of damage will you see in herniated disc
Protrusion: only a few cartilage rings are torn and there is no leakage of central material
Extrusion: cartilage rings have torn in a small area and the nucleus pulposus is able to flow out of the disc space
most common direction of disc rupture and complication
posterior-lateral –> compresses nerve root as it exists intervertebral foramen = radiculopathy
general treatment progression for CN:
first try conservative measures (splinting/NSAIDS/injections?OMM/PT for 3-6mon*)»_space; if non-operative management fails consider surgical release
*exception is cubital tunnel syndrome
How does the treatment of cubital tunnel syndrome differ from the rest of the CN treatments?
surgical release is considered/justified in almost all cases (except the most mild) to prevent nerve damage
What nerves are at risk for UE CN?
radial N
median N
ulnar N
musculocutaneous and axillary Ns
What does the radial nerve do (motor, sensation)?
M: triceps, anconeus, wrist extensors
S: most of dorsum of the hand (via posterior interosseous N)
What are the 3 sites for radial nerve entrapment?
1) high on the humerus
2) Radial tunnel
3) at the wrist
High on the humerus radial n entrapment: cause/symptoms
cause: usually 2ndary to humerus fx or compression near spiral groove.
Pt will have WRIST DROP, WEAK ELBOW FLEX, +/- diminished tricep reflex, paresthesia.
Function should return in 4-5mon
Radial tunnel radial n entrapment: causes/symptoms
causes: repetitive rotatory movements (rowing, discus, tennis), heavy manual labor
Pt will have pain and tenderness 5cm distal to lateral epicondyle with wrist drop or pain + restricted to supination
radial nerve entrapment at the wrist: causes/symptoms
causes: the superficial/sensory branch is pinched during pronation
pt will have sensation changes over posterolateral hand (back of hand near thumb, digit 1 and digit 2)
What are the 3 other names for “handcuff neuropathy”? and what are the symptoms?
compression of superficial radial n
cheiralgia paresthetica
wartenberg’s syndrome
symptoms: numbness/tingling/burning/pain in SRN distribution (back of hand)
What are the 4 sites of median nerve entrapment?
- ligament of struthers (somewhere near the elbow)
- bw the superficial and deep heads of the pronator teres m = pronator syndrome
- distal to the pronator teres deep = AIS
- under the flexor retinaculum = carpal tunnel
What is the most common compression syndrome?
Carpal tunnel syndrome (median n entrap)
What are the functions of the median N (motor).
forearm flex and pronation, wrist flex and radial deviation, thumb abduction and opposition, index/middle finger abduction and flexion
What three syndromes did we discuss that are due to median N entrapment?
Pronator syndrome
Anterior Osseous Syndrome
Carpal Tunnel Syndrome
Pronator syndrome: cause,S&S, dx tests
MEDIAN N
cause: repetitive pronating motions = piano, fiddlers, baseball, dentists, lifting weights
S&S: achy pain in mid/prox forearm that is worse with repeated lifting. +/- sensory changes in radial 3.5 fingers
Dx: pt will have pain with resisted forearm pronation
Anterior Interosseous Syndrome (AIS): causes, S&S, dx tests, treatments
MEDIAN N
causes: trauma (cast pressure), bulky tendon of pronator teres m, soft tissue masses, fibrous bands
S&S: NO SENSORY SYMPTOMS (bc deep motor branch of median N) = flexor weakness
dx tests: “OK” sign can’t make round “O”, the fingers pinch flat
Tx: splint elbow in 90deg of flex for 12wks max
Carpal Tunnel Syn: causes, S&S, dx test
MEDIAN N
causes: repetitive motion jobs with wrist flexion common, pregnancy
S&S: nighttime numbness of lateral 3.5fingers, tingling, wrist pain, you drop shit, thenar atrophy
Dx: EMG is gold-standard (but it hurts?). Phalen’s test. Tinel’s test. 2-pt discrimination (can’t tell if closer than 5mm).
Treatment methods for Carpal Tunnel?
NSAIDS… steroid injections/surgery if everything else doesn’t work
OMT: MFR, ST, lymphatics (if preggers)
xray (if think fx), MRI (if soft tissue injury)
stop repetitive motions, splint wrist at 30deg extension @night
Two locations for ulnar nerve entrapment?
- cubital tunnel = cubital tunnel syndrome
2. guyon’s canal
Ulnar nerve: motor, sensory
motor: muscles of ulnar side of forearm and hand (flexors). deep branch in hand = interosseous and adductor pollicis
sense: ring finger? and pinky
What is the name of the syndrome we talked about in class that deals with ulnar n entrapment?
Cubital Tunnel Syndrome = most common compression in the elbow
What structures form the cubital tunnel (and are therefore the cause of the compression)
medial epicondyle, medial trochlea, olecranon, ulnar collateral L
What activities can cause Cubital Tunnel syndrome?
baseball pitchers, prolonged elbow flexion during sleep, external compression against something hard, thickened cubital tunnel retinaculum.
Cubital Tunnel syndrome: S&S, dx tests, tx?
S&S: paresthesia to 4th and 5th digits, medial elbow pain that radiates to the hand with decreased intrinsic muscle strength = can’t turn key in a door
dx tests: (+) Tinel’s test at elbow, Froment’s sign (pinch paper)
symptom reproduction with elbow flex and wrist ext
tx: general and padded elbow sleeve to limit terminal elbow flexion + cushions
What things are compressed in thoracic outlet syndrome?
brachial plexus and/or subclavian vessels
What are the 3 sites of compression in thoracic outlet syn (TOS)?
- scalene triangle (bw the anterior and middle scalenes)
- costoclavicular passage (under the clavicle)
- pec minor attachment at coracoid process
What are the symptoms of TOS?
weakness, paresthesia of medial arm, forearm, and hand that is made worse with overhead activities
If you suspect TOS take these steps for diagnosis…
- c-spine xray if yes = cool. if unclear/negative > EMG if diagnosis = cool if inconclusive > arteriography or venography
What are the special tests and results that would indicate TOS?
- Military/costoclavicular maneuver = hold pt arms in extension and abduction, they retract scapula/ext spine. (+) with symptom reproduction/dec pulse
- East/Roos test = open close hands above head. (+) with symptom reproduction
- Wright’s hyperabduction test =
Adson’s test = monitor radial pulses as they look away. (+) decrease in pulse on side contralat to the direction they’re looking
A (+) Wright’s hyperabduction test indicates what?
thoracic outlet syndrome due to Pectoralis Minor m
What LE nerves are at risk of compression and what are their nerve roots?
Common Fibular N (peroneal n) = L4-S2
Deep fibular n = L4-S2
posterior Tibial N = L4-S2
lateral fermoral cutaneous n = L2, L3
L1 and L2: motor, sense?
motor: hip flex
sense: inguinal crease (L1) and anterior thigh (L2)
L2 and L3: motor, sense?
motor: knee extension
sense: anterior thigh (L2) and ant thigh just above knee (L3)
L4: motor, sense, reflex?
motor: ankle dorsiflexion
sense: knee, medial leg and foot
reflex: patellar
L5: motor, sense?
motor: extensor hallucis longus
sense: lateral leg, dorsum of the foot
L6: motor, sense, reflex?
motor: ankle plantarflexion
sense: lateral foot and plantar aspect of foot
reflex: achilles
What nerve is compressed in meralgia paresthetica?
Lateral femoral cutaneous N
What causes meralgia paresthetica?
lat fem cut n compression in inguinal canal
from… v hard sports, fat, tight belt, seatbelt, anatomic abnormality = runs through sratorius m
What are the symptoms of meralgia paresthetic?
numbness/burning on skin of ANTEROLATERAL THIGH, eventually trophic skin changes, (+) tinne’s sign 1cm inferomedially to ASIS
What do the branches of the common fibular N innervate?
the deep branch of CFN: anterior compartment of leg (tibialis anterior, extensor digitorum longus and brevis, extensor hallicus longus).
the superficial branch of CFN: lateral compartment (fibularis longus and brevis)
What are the nerve roots associated with the common fibular N?
L4-S2
what are some causes of Common fibular nerve compression?
compression as nerve enters fibular tunnel (lat side of knee)
- leg hooked over a rail (bedridden, coma, post-op)
- lots of squatting (picking stawberries)/or lotus position
- ankle sprain/trauma to fibular head
- lithotomy position during childbirth
- idiopathic
Common fibular n compression: S&S, tx?
s&s: pain along proximal 1/3 of lateral leg, FOOT DROP = SLAPS THE FLOOR, symps worse during plantarflex & inversion
Tx: post fibular head HVLA or ME on gastroc/soleus, biceps femoris
What are the reason for anterior tarsal tunnel syndrome?
DEEP FIBULAR N compression in the tarsal tunnel at the inferior extensor retinaculum
- trauma to distal tibia/calcaneus (ankle sprains, soccer)
- talonavicular dysfunction
- prolonger planter flexion
- compression from shoes too tight
How do you treat anterior tarsal tunnel syndrome?
remove compression forces, MFR of extensor retinaculum, traction tug of talonavicular joint, hiss whip navicular, cuneiforms, 1/s metatarsal
what are symptoms of Anterior tarsal tunnel syndrome?
pain over dorsomedial foot that is worse at rest.
extensor digitorum brevis weakness
Tarsal Tunnel Syndrome is caused by
compression of POSTERIOR TIBIAL N in the tarsal tunnel behind the medial malleolus with the overlying flexor retinaculum
what does the posterior tibial nerve innervate: motor, sense?
motor to the planter muscles of the foot
sense: to plantar aspect of foot and toes
What can cause tarsal tunnel syndrome?
idiopathic (50%) space-occupying lesions trauma to medial malleolus, distal tibia, calcaneus ankylosing spondylitis long time standing
Tarsal tunnel syndrome: S&S, Tx?
POSTERIOR TIBIAL N
s&s: pain on planter surface of foot (vague burning/tingling/numbness), rarely effects gait
Tx: NSAIDs, US, PT, acupuncture, rest
OMM tx: MFR, HVLA
(+) OK Sign
median nerve entrapment
(+) froment’s sign
ulnar n entrapment
(+) hoffman’s sign
CNS problem
Stereotypical cause of median nerve entrapment syndromes:
pronator syndrome - weight lifter
anterior interosseous syn - post case pressure
carpal tunnel syn - gymnasts
1 most common compression neuropathy
median nerve compression = carpal tunnel syndrome
3 most common compression neuropathy
common fibular n compression = foot drop
What is the path of internal herniation?
acute = extreme pain and then the disc slowly shrivels away in days to weeks and most resolve tx in 2-6wks. 90% back to normal activity within 1 mon
Spinal disc disease that doesn’t resolve will have what s&s?
weak back ligaments that cause pain to radiate down their legs, and can accelerate osteoarthritis
definition of radiculopathy
term used to describe pinching of the nerve roots as they exit the spinal cord or cross intervertebral disc
definition of myelopathy
compression of the spinal cord itself
definition of neuropathy
result of damage to peripheral nerves, often causes weakness, numbness and pain, usually in hands and feet
What is sciatica?
A SYMPTOM. pain that comes from lower back felt along the back of the leg (not in the dermatomal pattern, but along nerve distribution).
What is the major cause of sciatica?
sacroiliac ligament weakness
What are the symptoms of sciatica?
pain with walking or long periods of sitting, pain when getting up from sitting. hamstrings and quadratus femoris are both tight.
OMM Treatments of sciatica?
treat BOTH the hamstrings and the quadratus femoris ms so you don’t creat unbalanced tension between flexors and extensors that may make the problem worse. Release adductor magnus FIRST.
