NCV

Question 1

demyelination

Answer 1

causes slow conduction across the lesion with relative sparing in amplitude of the compound muscle action

Question 2

degeneration

Answer 2

absent or reduced muscle responses

Question 3

purpose of NCV

Answer 3

evaluate diseases of peripheral nerves

• demyelinating diseases
• axonal degeneration
• location of injury
• type of injury (neurapraxia, axonotomesis, neurotemesis)

Question 4

motor NCV calculation

Answer 4

=(distance between stimulating cathodes in mm) / (latency 2 - latency 1 in ms)

Question 5

methods

Answer 5

Motor

Sensory

• Orthodromic
• Antidromic

Question 6

sensory- orthrodromic

Answer 6

stimulation electrodes are ring electrodes placed around the fingers in the nerve distribution.

• cathode placed proximally
• anode distally

Pick up electrodes are placed proximally along the course of the nerve

• cathode placed distally
• anode proximally

Question 7

sensory- antidromic

Answer 7

stimulating electrode is placed along the course of the nerve

• cathode distally
• anode proximally

Pick up electrodes-ring electrodes placed over the fingers

• cathode prox
• anode distal

ground over bony prominence

Question 8

SCV calculation

Answer 8

=(distance between stimulation and recording site) / latency

Question 9

latency

Answer 9

=measure of time delay