Peripheral Nerve Lesions Flashcards
Double Crush Syndrome
Existence of two separate lesions along the same nerve that. Creat more severe symptoms than if only one lesion existed
Mononeuropathy
An isolated nerve lesion; associated conditions include trauma and entrapment
Neuroma
Abnormal growth of nerve cells; associated conditions included vasculitis, AIDS, and amyloidosis
Peripheral neuropathy
Impairment or dysfunction of the peripheral nerves; associated conditions include diabetic peripheral neuropathy, trauma, alcoholism
Polyneuropathy
Diffuse nerve dysfunction that is symmetrical and typically sencodnar to pathology and not trauma; associated conditions include Guillain-Barré syndrome, peripheral neuropathy use of neurotoxin drugs and HIV
Wallerian degenration
Degeneration that occurs distally specifically to the myelin sheath and axon
What are the classification of acture Nerve injures?
- Neurapraxia
- Axonotmetsis
- Neurotmesis
Describe Neurapraxia
- Mildest form of injury
- Conduction block usually due to Myeline dysfunction
- Axonal continuity preserved
- Axons, epineurium, perineurium and endoneurium intact
- Nerve conduction is preserved proximal and distal to the lesion
- Nerve fibers are not damaged, no evidence of nerve degeneration is noted
- Sxs include pain, minimal muscle atrophy, numbness or greater loss of motor and sensory function, dismissed proprioception
- Recovery is rapid and complete and will occur within 4-6 weeks
- Pressure injuries are most common
Describe Axonotmesis
- More severe grade of injury to a peripheral nerve
- Reversible injury to damaged fibers since they maintain an anatomical relationship to each other
- Damage occurs to the axons with preservation of the endoneurium (neural connective tissue sheath), epineurium, Schwann cells, and supporting structures
- Distal Wallerian degeneration can occur
- The nerve can regenerate distal to the site of the lesion at a rate of one millimeter per day
- Recovery is spontaneous and varies from spotty to no recovery; surgery may be required for repairs
- Traction, compression and crush injures are the most common
Describe Neurotmesis
- The Mose severe grade of injury to a peripheral nerve
- Axon, myeline, connective tissue components are all damaged or transected
- Irreversible injury; no possibility of regeneration
- Flaccid paralysis and wasting of muscles occur; total loss of sesnation to area supplied by the nerve
- All motto and sensory loss distal to the lesion becomes permanently impaired
- No spontaneous recovery; with surgical reattachment potential regeneration axons may grow at one millimeter per day with Proximal recovery first; sensory recovery occur sooner than motor fibers
- Complete transaction of the nerve trunk
What is the common etiology associated with the axillary nerve lesion?
Fracture of the neck of the humerus; anterior dislocation of the shoulder
What is the common etiology of the Musculocutaneous nerve lesion?
Fracture of the clavicle
What is the common etiology associated with a radial nerve lesion?
Compression of the nerve in the radial tunnel; Fx of the humerus
What is the common etiology associated with median nerve lesion?
Compression in the carpal tunnel, pronator teres entrapment
what is the common etiology associated with an ulnar nerve lesion?
Compression in the cubital tunnel,, entrapment in Guyon’s canal
T or F; In the LE many Nerve injures for women are secondary to labor, deliver or surgical procedures around the pelvis
True
What is the common two logo associated with a femoral nerve lesion?
Total hip arthroplasty (THA), displaced acetabular Fx, anterior dislocation of the femur, hysterectomy, apendectomy
What is the common etiology assocatied with a sciatic lesion?
Blunt force trauma to the buttocks, total hip arthroplasty, accidental injection to the nerve
What is the common etiology associated with an obturator lesion?
Fixation of a femur Fracture, total hip arthroplasty
What is a common etiology associated with a peroneal nerve lesion?
Femur, tibia or fibula Fx, positoning during surgical procedures
What is a common etiology associated with a tibial nerve lesion?
Tarsal tunnel entrapment, popliteal fossa compression
What is a common etiology associated with Sural nerve lesion?
Rx of the calcaneus or lateral malleolus
Characteristics of an anterior horn cell pathology?
- Sensory component intact
- Motor weakness and atrophy
- Fasciculation
- Decreased DTR
Example: ALS (amyotrophic lateral sclerosis); poliomyelitis
Characteristics of a muscle pathology?
- Sensory component intact
- Motor weakness; fasciculations are rare
- Normal or decreased DTRs
Example: muscular dystrophy
Characteristics of a Peripheral Nerve (Mononeuropathy) pathology?
- Sensory loss along the nerve route
- Motor weakness and atrophy in a peripheral distribution; may have fasciculations
Example: trauma
Characteristics of a peripheral polyneuropathy pathology?
- Sensory Impairments; “stocking glove” distribution
- Motor weakness and atrophy; weaker distally than proximally; may have fasciculations
- Decreased DTRs
Example: Diabetic peripheral polyneuropathy
Characteristics of Spinal Roots and Nerves Pathologies?
- Sensory component will have corresponding dermatomes deficits
- Motor weakness in an innervated pattern; may have fasciculations
- Decreased DTRs
Example: Herniated disk
