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