Chapter 7 - Electrophysiologic Assessment

Question 1

conduction velocity identifies wht type of nerve insults?

Answer 1

Segmental nerve insults

Question 2

Electrodiagnostic findings in carpal tunnel syndrome

Answer 2

Mild - prolongation in sensory latencies
Moderate - motor latency delays
Severe - axonal loss with denervation on EMG

Question 3

EMG and NCS results in neuropraxia (type 1 nerve injury)

Answer 3

NCS with partial/complete conduction block proximally, intact conduction distally
EMG with normal morphology, possibly decreased recruitment

Question 4

EMG changes in guyon’s compression

Answer 4

• intrinsics of the hand are denervated (first dorsal interosseous, abductor digiti minimi)
• FDP ring and small are normal

Question 5

Fibrillations and sharp waves on emg indicate what process

Answer 5

denervation - these are indicators of spontaneous activity which results from membrane destabilization

Question 6

Sunderland type 1 nerve injury is called ________ and results from ________ of a peripheral nerve

Answer 6

neuropraxia, stretching

Question 7

What is disrupted in sunderland type one nerve injury?

Answer 7

Neuropraxia - vascular supply disrupted resulting in focal/segmental demylenation