Extremity Compression Neuropathy Lecture/Lab/OSCE - Kelsey Flashcards
What is a compression neuropathy?
Nerve becomes entrapped as it passes through a narrow tunnel or passage.
Five pathological changes that occur with neuropathy.
1) Microvascular compression»_space; ischemia
2) Thickened epineurium
3) Myelin thinning distortion
4) Microtubule closure
5) Axonal degeneration
Five etiologies of nerve entrapment.
1) Increased muscle mass by repetitive activity
2) Space occupying lesions (cysts/tumors)
3) Inflammation of surrounding tissues (=nerve anoxia)
4) Post traumatic conditions (hematoma, fx, compression)
5) Systemic - pregnancy, hypothyroid, diabetes
What are the three categories of nerve injury, least to most severe?
1) Neurapraxia
2) Axonotmesis
3) Neurotmesis
What is neurapraxia nerve injury?
- Least severe
- Focal damage to myelin fibers around axon, but CT sheath of axon remains intact
- Limited course
What is axonotmesis nerve injury?
- Injury to axon itself
- Regeneration possible, but months without full recovery
What is neurotmesis nerve injury?
- Complete disruption of axon with little likelihood of recovery.
Tx options for compression neuropathy.
1) Conservative
- modification of activity, antiinflammatories, injections, splinting.
- Multidisciplinary - PT, OMM, pain mgmt
2) Surgery after 3-6 months if nonoperative mgmt fails
What is cervical nerve root compression caused by and what is it?
It is caused secondarily to cervical disc disease (disc bulging or HERNIATION).
When a disc ruptures posterior-laterally, it compresses the nerve root.
What is radiculopathy?
Compression of spinal nerve radiates in the distribution of the defined nerve root.
How do you test for cervical nerve root compression?
Spurlings
Central nerve root sensation, motor, and reflex dermatomes (C4-T1).
C4 - Superior shoulder
C5 - Lateral arm over deltoid. Motor: deltoid and biceps. Reflex: biceps
C6 - Radial forearm and thumb/index finger. Motor: wrist E and elbow F. Reflex: brachioradialis
C7 - middle finger. Motor: wrist F elbow E finger E. Reflex: triceps
C8 - Ulnar forearm and pinky finger. Motor: finger F
T1 - Medial arm. Motor: finger aBDuction
What are the three peripheral nerves at risk?
Radial nerve, median nerve, ulnar nerve
Two main sites of radial nerve entrapment.
- High on the humerus
- Radial tunnel (at elbow level)
What is the normal radial nerve (C5-C8) function?
- motor to WRIST EXTENSORS, triceps, and aconeus
- sensation to dorsum of hand
A person has a humerus fracture and consequential:
- wrist drop
- weakness of elbow F
- diminished triceps rflex
- pain/numbness
What nerve is entrapped? And how do you tx
- Radial nerve entrapment high on humerus secondary to humerus fx or compression of nerve near spiral groove.
- Tx - Function normally returns within 4-5 months
What is the main location of compression of radial nerve?
compression of posterior interosseus branch of the radial nerve as it passes UNDER THE SUPINATOR MUSCLE at the Arcade of Frohse.
Pain and tenderness 5cm distal to lateral epicondyle. This person does repetitive motions (rowing/discus/raquet sports/heavy labor).
- What does this person have?
- How do you dx this?
- Supinator Syndrome, compression as it passes under the supinator muscle.
- To dx, wrist drop or pain with resisted supination.
What are the three sites (syndromes) of median nerve entrapment?
1) Pronator syndrome
2) Anterior interosseus syndrome
3) Carpal tunnel syndrome
Normal 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
Achy pain in the mid/proximal forearm, aggravated by repetitive lifting. Possible sensory abnormality in radial 3.5 digits. This person does repetitive motions - pianists, fiddlers, baseball players, dentists, weight trainers
- What does this person have and what nerve is affected?
- How do you dx this?
- Pronator Syndrome, median nerve entrapment as it passes between superficial/deep heads of pronator teres muscle.
- Dx by pain with resisted forearm pronation
Which median nerve syndrome has no sensory symptoms?
Anterior Interosseus syndrome
What is the etiology of the Anterior Interosseous Syndrome? How do you dx? What is the tx?
- Trauma, bulky TENDINOUS origin of ulnar head or pronator teres.
- Dx is the “ok” sign (weak index’s DIP and thumb’s IP)
- Tx is to splint elbow in 90degrees of flexion for up to 12 weeks.
***What is the most common compression syndrome?
Carpal Tunnel Syndrome
- Compression of nerve as it passes under flexor retinaculus.
