Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Musculoskeletal > Peripheral nerve injuries > Flashcards

Peripheral nerve injuries Flashcards

1
Q

What diameter do peripheral nerves range from

A

0.2-22 um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What coats the axons

A

Endonurium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What coats the fascicles

A

Perineurium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What coats the nerve itself

A

Epineurium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are Aa function

A

Large motor axons
Muscle stretch
Tension sensory axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are Ab function

A

Touch
Pressure
Vibration
Joint sensory position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Ay function

A

Gamma efferent motor axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are A (delta) function

A

Sharp pain
Very light touch
Temperature sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are B function

A

Sympathetic preganglionic motor axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are C function

A

Dull, aching burning pain

temperature sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can injury to a peripheral nerve occur

A

Compression

trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can compress nerves

A

Nerve entrapment

Compression conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are Classical compression conditions

A

Carpal tunnel syndrome

Sciatica

Morton’s neuroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is compressed in carpal tunnel syndrome

A

median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is compressed in sciatica

A

Spinal root compression by intervertebral disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is compressed in mortons neuroma

A

digital nerve in 2nd or 3rd web space of forefoot are compressed in sole of foot)

17
Q

What nerve damage can trauma cause

A
  • Neurapraxia
  • Axonotmesis
  • neurotmesis
18
Q

What is neupraxia

A
  • Nerve in continuity in neuropraxia.
  • Stretched (8% will damage microcirculation) or bruised
  • You get a Reversible conduction block due to local ischaemia and demyelination
  • For a short area in the nerve you cannot get conduction.
  • Prognosis good (weeks or months)
19
Q

What is axonotmesis

A
  • Endoneurium intact (tube in continuity), but disruption of axons within it;
20
Q

what causes axonotmesis

A
  • Can occur by the nerve being stretched (15% elongation disrupts axons) or severly crushed or direct blow
21
Q

What is pathophysiology of axonotmesis

A
  • Wallerian degeneration follows (distal to sight of injury. The nerve fibre disappears but the endoneurial tube remains. Proximally the nerve shrinks back to the last node of ranvier.
22
Q

what is prognosis of axonotmesis

A
  • Prognosis fair (sensory recovery often better than motor - often not normal but enough to recognise pain, hot & cold, sharp & blunt)
23
Q

What is Neurotmesis

A
  • Complete nerve division and loss of endoneurium (possibly perineurium)
24
Q

What typically causes Neurotmesis

A

Laceration or Avulsion

25
Q

What is prognosis of Neurotmesis

A

Poor prognosis

No recovery unless repaired (by direct suturing or grafting)

26
Q

What are closed nerve injuries

A

Neuropraxis

axonotmesis,

27
Q

What is treatment for closed nerve injuries

A

Surgery indicated after 3 months if it has not recovered
If no recovery is identified
- Clinical
- Electromyography-

28
Q

What is the Axonal growth rate

A

Axonal growth rate (1–3 mm/day)

29
Q

What are open nerve injuries

A

Neurotmesic injuries

30
Q

what is wallerian degeneration

A

Changes (death) of axons distal to the sight of a nerve injury

31
Q

What are motor changes seen in nerve injury

A
  • Paresis (weakness) or paralysis ± wasting
  • Dry skin
    o Loss of tactile adherence since sudomotor nerve fibres not stimulating sweat glands in skin
32
Q

What are sensory changes in a nerve injury

A 
-	Dysaethesiae (disordered sensation) 
o	Anaesthetic (numb), hypo- & hyper-aesthetic, paraesthetic (pins & needles)
33
Q

What happens about 4 days after a peripheral nerve injury

A

Proximal axonal budding occurs after about 4 days

34
Q

What does the Prognosis for recovery depend on:

A
  • whether nerve is
    o “pure” (only sensory or only motor)
    o “mixed” (both sensory and motor within same nerve)
  • how distal the lesion is (proximal worse)
35
Q

Does a pure nerve or mixed nerve have a better prognosis

A

pure nerve tends ro receoer better because in general even if there is miswiring and they grow and miss their own tube but grow down to antoher oenen. They will all grow down to motor end plates of sensory end plates

36
Q

Why do mixed nerves have a worse prognosis

A

mixed nerves have a variable recovery as the senory nerves (some) can gorw back down the motor tubes and the motor axons down the sensry tubes and you will therefore get a much more imcomplete recovery.

37
Q

Why does the nerve recover better if the injury is more distal

A

Distal better recovery due to the 1mm growth a day. If it’s a long distance to grow back down then you get degeneration of the endplates to when the nerve gets to the end plate it doesn’t function as well.

38
Q

What can be used to monitor recovery of a nerve

A

Tinnel’ sign

Electrophysiological Nerve Conduction Studies

Musculoskeletal (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions