EDT EDT Nerve Conduction Studies Interpretation

Question 1

What does a prolonged distal latency in a motor nerve conduction study primarily indicate?

Accepted Answer

Slowed conduction at the distal segment, suggesting demyelination

Answer

Axonal loss at the motor neuron

Answer

Increased amplitude of the CMAP

Answer

Normal variation in conduction velocity

Question 2

In a sensory nerve conduction study, which parameter is most sensitive for detecting early axonal loss?

Accepted Answer

Amplitude of the SNAP

Answer

Conduction velocity

Answer

Distal latency

Answer

F-wave latency

Question 3

A compound muscle action potential (CMAP) with normal distal latency but reduced amplitude most likely indicates:

Accepted Answer

Axonal motor neuropathy

Answer

Demyelinating neuropathy

Answer

Neuromuscular junction disorder

Answer

Central nervous system lesion

Question 4

Which NCS finding is characteristic of carpal tunnel syndrome?

Accepted Answer

Prolonged median sensory peak latency across the wrist

Answer

Reduced median motor CMAP amplitude

Answer

Absent ulnar sensory response

Answer

Slowed peroneal motor conduction velocity

Question 5

Temporal dispersion in a motor nerve conduction study refers to:

Accepted Answer

Broadening and reduction of CMAP with proximal stimulation

Answer

Increased CMAP amplitude with repetitive stimulation

Answer

Absent F-waves bilaterally

Answer

Increased conduction velocity across a segment

Question 6

In ulnar neuropathy at the elbow, the most diagnostic NCS finding is:

Accepted Answer

Focal slowing of ulnar motor conduction velocity across the elbow segment

Answer

Absent ulnar sensory response at the wrist

Answer

Prolonged median distal motor latency

Answer

Reduced radial sensory amplitude