Compression Neuropathy Flashcards
What are biomechanical causes of neuropathy?
- -space-occupying lesions (cysts, herniated discs)
- -degenerative changes (foraminal stenosis)
- -post-trauma (compartment syndrome, fracture/cast)
- -mechanical (muscle spasm, pinching d/t positioning)
What are systemic causes of neuropathy?
- pregnancy
- hypothyroidism
- diabetes
What is the outer covering of a nerve?
-epineurium: contains the fascicles, blood vessels and connective tissue within
What is a fascicle?
- covered by perineurium, contains groups of axons
- groups of fascicles together form a nerve, which is covered by epineurium
What layers cover an axon?
- directly covered with myelin, which is then covered by the endoneurium
- groups of axons together form a fascicle, which is covered by perineurium
What are the five degrees of nerve injury?
1st: neuropraxia (focal damage of myelin)
2nd: axonotmesis (some injury to axon itself)
3rd: neurotmesis (axon and endoneurium)
4th: neurotmesis (axon, endoneurium, and perineurium)
5th: neurotmesis (axon, endo-, peri-, and epineurium)
What motor, sensation, and reflex is associated with C5?
motor: deltoid and biceps
sensation: lateral arm
reflex: biceps
What motor, sensation, and reflex are associated with C6?
motor: wrist extension, elbow flexion
sensation: radial forearm, thumb and index finger
reflex: brachioradialis
What motor, sensation, and reflex are associated with C7?
motor: wrist flexion, elbow extension, finger extension
sensation: middle finger
reflex: triceps
What motor and sensation are associated with C8?
motor: finger flexion
sensation: ulnar forearm, little finger
What motor and sensation are associated with T1?
motor: finger abduction
sensation: medial arm
What is the usual cause of cervical nerve root compression?
- cervical disc disease
- -bulging disc (no significant damage to cartilage rings)
- -herniation (some tearing of cartilage rings)
What is protrusion in regards to a disc herniation?
- only a few cartilage rings are torn
- no leakage of central material
What is extrusion in regards to a disc herniation?
- cartilage rings have been torn in a small area
- nucleus pulposus is able to flow out of the disc space
In what direction does the disc usually rupture?
posterolateral, because the longitudinal ligament is located centrally
(longitudinal ligament becomes the tectorial membrane)
What is radiculopathy?
-pain caused by compression of the spinal nerve that radiates in the distribution of the defined nerve root
List some tests for cervical nerve roots?
-Spurling, Adson, and Hoffman
What is a Spurling Test?
-extend and rotate neck toward symptomatic side
+ if radicular pain is exacerbated
= cervical radiculopathy (e.g. herniated disc)
What is the Adson Test?
-elevate chin and rotate head toward affected side while inhaling deeply
+ if radial pulse on affected side is obliterated
= thoracic outlet syndrome
What is the Hoffman Test?
-firmly grasp middle finger and quickly snap or flip the dorsal surface of distal phalanx ventrally
+ if thumb and index finger quickly flex
= cervical myelopathy (e.g. cervical spine stenosis)
How does the treatment of cubital tunnel syndrome differ from the general treatment of other cervical nerve root compression?
-cubital tunnel syndrome warrants operative decompression in most all cases (except super mild) in order to prevent nerve damage
–normally 3-6mos of PT, OMM, pain mgmt, splints, etc.
What motor function does the radial nerve supply?
- triceps brachii
- anconeus
- wrist extensors
What area of sensation does the radial nerve supply?
-majority of the dorsum of the hand (via posterior interosseous N.)
What are the three sites for radial nerve entrapment?
- high on the humerus
- radial tunnel
- at the wrist
What are the characteristics of a radial nerve entrapment that happens high on the humerus?
- usually secondary to a humerus fracture
- Tx: fxn usually returns within 4-5mos
Symptoms: wrist drop, pain, numbness, weak elbow flexion (brachioradialis), triceps reflex diminished
What are the characteristics of a radial nerve entrapment at the radial tunnel?
- due to repetitive rotatory mvmts (rowing, discus, racquet sports), or heavy manual labor
- pain/tenderness 5cm distal to lateral epicondyle, wrist drop or pain w/ resisted supination
What are the characteristics of a radial nerve entrapment at the wrist (aka Cheiralgia Paresthetica, aka Wartenberg’s Syndrome, aka Handcuff Neuropathy)?
- a superficial sensory branch is pinched b/w brachioradialis and extensor carpi radialis ligament during forearm pronation
- sensation changes over the posterolateral hand
What three syndromes are caused my median nerve entrapment?
- Pronator Syndrome
- Anterior Osseous Syndrome
- Carpal Tunnel Syndrome
What are the motor functions of the median nerve?
- forearm flexion and pronation
- wrist flexion and radial deviation
- thumb abduction and opposition
- index and middle finger abduction and flexion
What are the causes of pronator syndrome?
- occurs as median n. passes b/w superficial and deep heads of the pronator teres m.
- repetitive pronating motion: pianists, fiddlers, baseball players, dentists, weight trainers
What are the symptoms of pronator syndrome?
- achy pain in the mid/proximal forearm, aggravated by repeated lifting
- may have sensory abnormality in the radial three and a half digits
How is pronator syndrome diagnosed?
-pain w/ resisted forearm pronation
What is the cause of Anterior Interosseous Syndrome?
- entrapment of the anterior interosseous n. (a deep motor branch of the median nerve) just distal to the pronator teres m.; it innervates flexors
- trauma, casts, soft tissue masses, fibrous bands
Are there sensory symptoms associated with Anterior Interosseous Syndrome?
No
How do you test for Anterior Interosseous Syndrome?
-have pt. make the “ok” sign
+ if the pt. is unable to hold and resist pinching pressure of the tip of the thumb against the tip of the index finger, due to weak flexion ability
What is the treatment for Anterior Interosseous Syndrome?
- elbow can be splinted in 90 degrees of flexion for up to 12 weeks
- other general treatments
What is the most common compression syndrome?
carpal tunnel syndrome
-median nerve compression as it passes under the flexor retinaculum with other flexor tendons
What are the symptoms of carpal tunnel syndrome?
-nighttime numbness of lateral three and a half digits, tingling, wrist pain, dropping things, thenar atrophy
What can be causes of carpal tunnel syndrome?
- common in repetitive motion jobs
- common in pregnancy
How is carpal tunnel syndrome diagnosed?
- the gold standard is an EMG
- other tests: Phalen’s and Tinel’s
How is a two-point discrimination test used to diagnose carpal tunnel syndrome?
+ if the pt. is unable to distinguish between two points on a caliper if they’re closer than 5mm
How do you treat carpal tunnel syndrome?
- NSAIDS, MFR, ST, lymphatics if pregnant
- rest from repetitive motion, and self stretch
- splint wrist with 30 degrees of hand extension
- -usually at night
If conservative treatment options fail in carpal tunnel syndrome, what are other treatments that can be used?
- steroid injections
- surgical release
What is a common site of ulnar nerve entrapment?
cubital tunnel
What is the nerve function of the ulnar nerve?
-innervates skin and muscles of the ulnar side of the forearm and hand (flexors)
What does the deep branch of the ulnar nerve in the hand do?
-motor innervation for interosseous muscles and adductor pollicis
What does the superficial branch of the ulnar nerve in the hand do?
-sensory innervation to ring and pinky finger
What is the most common nerve compression seen in the elbow?
Cubital Tunnel Syndrome
What structures for the source of compression in the cubital tunnel?
- medal epicondyle
- medial trochlea
- olecranon
- ulnar collateral ligament
What are common causes of cubital tunnel syndrome?
- baseball pitchers
- prolonged elbow flexion (eg. during sleep)
- external compression against a hard surface
- thickened cubital tunnel retinaculum
What are the symptoms of cubital tunnel syndrome?
- parasthesia to the 4th and 5th digits
- medial elbow pain radiating to the hand
- can’t turn a key in a door
How do you test for cubital tunnel syndrome?
+ Tinel’s sign at elbow
-or if you get a reproduction of the symptoms with elbow flexion and wrist extension
What is the treatment for cubital tunnel syndrome?
- padded elbow sleeve to limit terminal elbow flexion and provide cushioning
- other general treatments
What is Froment’s Sign?
- an indication of ulnar nerve entrapment in cubital tunnel syndrome
- pt. has to flex the thumb in order to pinch paper b/w 1st and send digits d/t weak 1st dorsal interosseous m.
What is thoracic outlet syndrome?
-compression of the brachial plexus and/or the subclavian vessels
What are the sites of compression in thoracic outlet syndrome?
- scalene triangle
- costoclavicular passage
-at the pectoralis minor attachment at the coracoid process
What are the symptoms of thoracic outlet syndrome?
-weakness, paresthesia of medial arm, forearm, and hand exacerbated by overhead activities
What lower extremity nerves are at risk for compression?
- common fibular n. (L4-S2)
- deep fibular n. (L4-S2)
- posterior tibial n. (L4-S2)
- lateral femoral cutaneous n. (L2-L3)
What is the motor function of nerve roots L1-L2?
-hip flexion
What are the sensation functions of nerve roots L1-L2?
- inguinal crease (L1)
- anterior thigh (L2)
What are the motor functions of nerve roots L2-L3?
-knee extension
What are the sensation functions of nerve roots L2-L3?
- anterior thigh (L2)
- anterior thigh just above the knee (L3)
What is the motor function of the nerve root L4?
-ankle dorsiflexion
What is the sensory function of the nerve root L4?
-medial leg and foot
What is the reflex associated with nerve root L4?
patellar reflex
extension reflex
What is the motor function of the nerve root L5?
-extensor hallucis longus
What is the sensory function of the nerve root L5?
- lateral leg
- dorsum of foot
What is the motor function of the nerve root S1?
-ankle plantarflexion
What is the sensory function of the nerve root S1?
- lateral foot
- plantar foot
What reflex is associated with the nerve root S1?
-ankle jerk (achilles)
What is Meralgia Paresthetica?
-compression of the lateral femoral cutaneous n. underneath the inguinal ligament at the inguinal canal
What are possible etiologies of meralgia paresthetica?
- -very intense athletics
- -obesity
- -tight girdle or belt, or tight clothing
- -seat belt misplacement or post-accident
- -anatomic anomaly (eg. runs through sartorius)
What are the symptoms of meralgia paresthetica?
-numbness or burning pain on anterolateral thigh
-hyperesthesia to the point of not using pockets
-trophic skin changes (later on)
+ Tinel’s Sign 1cm medial and inferior to ASIS
What does the common fibular nerve divide into?
- deep branch that innervates the anterior compartment (tibialis anterior, extensor digitorum longus and brevis)
- superficial branch that innervates the lateral compartment (fibularis longus and brevis)
Where does the compression of the common fibular nerve happen?
-as the nerve winds around the fibular neck and enters the fibular tunnel
What are possible etiologies of common fibular nerve compression?
- leg hooked over a rail (bedridden, comatose)
- time spent in a squatting position
- ankle sprains or trauma to fibular head
- lithotomy position during childbirth
- idiopathic
What are the symptoms of common fibular nerve compression?
- pain along proximal third of lateral leg
- FOOT DROP w/ a slapping gait
-exacerbation of symptoms during plantarflexion and inversion of foot
What is the treatment for compression of the common fibular nerve?
- posterior fibular head HVLA or muscle energy
- muscle energy on gastroc/soleus or biceps femoris
What is Anterior Tarsal Tunnel Syndrome?
- compression of the deep fibular nerve (L4-S2)
- -at the inferior extensor retinaculum
What are the symptoms of Anterior Tarsal Tunnel Syndrome?
- pain over dorsomedial aspect of foot
- pain worse at rest
- weakness of extensor digitorum brevis
What are common causes of Anterior Tarsal Tunnel Syndrome?
- trauma (recurrent ankle sprains, i.e. soccer players)
- talonavicular dysfunction
- prolonged plantarflexion
- compression from shoes
What is the treatment for Anterior Tarsal Tunnel Syndrome?
- remove compressive forces
- myofascial release of extensor retinaculum
- traction tug of talonavicular joint
- hiss whip for navicular, cuneiforms, 1st-2nd metatarsal
What is Tarsal Tunnel Syndrome?
-compression of the posterior tibial n. in the tarsal tunnel behind the medial malleolus w/ the overlying flexor retinaculum
What is the function of the posterior tibial nerve?
- motor to plantar muscles of the foot
- sensation to plantar aspect of the foot and toes
What is the etiology of Tarsal Tunnel Syndrome?
- idiopathic in 50% of cases
- cysts, lipomas, tenosynovitis
- trauma to medial malleolus, distal tibia, or calcaneus
- congenital
- autoimmune, diabetes
What are the symptoms of Tarsal Tunnel Syndrome?
- pain on plantar surface of the foot
- -vague burning, tingling, numbness
- gait is seldom affected
What are treatments for Tarsal Tunnel Syndrome?
- MFR, HVLA
- Physical therapy
- Rest and NSAIDS
- acupuncture
What does the “ok sign” test for?
medial nerve entrapment
What does the Froment’s Sign test for?
ulnar nerve entrapment
What does Hoffman’s Sign test for?
CNS problems
What causes the majority of Sciatica?
-weak SI ligaments
