Mononeuropathies, Plexopathies, Radiculopathies

Question 1

What is a mononeuropathy

Answer 1

Diseasesof single nerves in the peripheral nervous system.

Question 2

Name three common histopathologies that are recognized in the peripheral nerve

Answer 2

Segmental demyelination
Wallerian Degeneration
Axonal Degeneration

Question 3

Describe Segmental Degen

Answer 3

Degeneration of MYELIN,
Axon is SPARED
Disappearance of the myelin sheath over segments of variable length with preserve segments in between. Lonf segments of the axon are exposed to the interstitial environment
eg. carpal tunnel

Question 4

Describe Wallerian Degen

Answer 4

“Dying Forward”
Eg. pressure palsies
Axon and myelin affected distal to the site of disruption

Question 5

Describe axonal degeneration

Answer 5

Eg. “dying back”
Axonaffected from distal site to proximal.
eg. polyneuropathy

Question 6

What are the gaps between axon myelin sheaths called, and what do they have in high concentration there?

Answer 6

NOde of Ranvier,

High SODIUM CONC

Question 7

What are some SYMPTOMS OF PERIPHERAL NERVE DISEASE?

Answer 7

Impaired motor function
Decreased Tendon reflex
Sensory loss
Paraesthesia- sensation
Sensory ataxia
Trophic change
Cramp and spasms

Question 8

What are the two reasons myelin sheaths may breakdown?

Answer 8

A primary process effecting shwann cells or of the myelin sheath
A secondary proces due to disease affecting it’s axon

Question 9

How do you diagnose a motor neuropathy?

Answer 9

Relies on finding MOTOR, REFLEX and SENSORY changes in the territory of a single nerve

Question 10

What is a plexopathy?

Answer 10

Motor, reflex and sensory changes referable to an entire plexus- eg. lumbosacral

Question 11

What pathology occurs with the brachial plexus?

Answer 11

Develops without a cause and manifests as a sensorimotor change within one or more cords of the plexus
Identifiable causes include: tumour, compression, delayed effects of radiotherapy, idiopathic

Question 12

Plexopathy: panbrachial plexopathy:

Answer 12

Entire arm is paralysed
Hangs uselessly at the side
Sensory loss complete below a line extending from the shoulder diagonally downwards
Common cause is trauma

Question 13

plexopathy: upper brachial plexus paralysis

Answer 13

Injury to the distal fifth and sixth cervical roots

- Harm hangs internally rotated and extended at the elbow

Question 14

Plexopathy: Lower brachial plexus paralysis:

Answer 14

sensory loss limited to the ulnar border of the han and inner forearm

Question 15

Lateral cord plexopathy

Answer 15

Wakness of flexion and pronation of forearm

Question 16

Medial cord plexopathy

Answer 16

Weakness to muscles supplied by the medial root of the ulnar nerve and median nerve = combinded median and ulnar nerve palsy

Question 17

Posterior cord plexopathy

Answer 17

Sensory loss to outer surface of upper arm

Weak deltoid, elbow extensor, wrist and fingers

Question 18

Brachial mononeuropathy: Medial neuropathy

Answer 18

Cant pronate forearm, flex hand, inhibits flexing finger,

Question 19

Brachial mononeuropathy: Carpal Tunnel Syndrome

Answer 19

commonest- sensory symptoms, pain radiating to forearm

Question 20

Brachial Mononeuropathy: Ulnar nerve entrapment

Answer 20

same

Question 21

Brachial mononeuropathy: Radial nerve entrapment

Answer 21

Saturday night palsy- sleep on arm funny- weakness of brachioradialis

Question 22

Plexopathy: Lumbar plexus

Answer 22

Weakness, sensory loss and reflex changes:

weak hip flexion, sensory loss to anterior thigh, decreased knee jerk

Question 23

what is a radiculopathy

Answer 23

disorder of nerve roots
injury- bathed in CSF- infection, inflammation or neoplasm, osteophites
or
osteoarthritis- radicular pain, 90% in the lumbar region due to posterolateral discherniation