EDT EDT Clinical Correlations & Pathology

Question 1

Which EDX pattern is most consistent with a diagnosis of Guillain-Barré syndrome (acute inflammatory demyelinating polyneuropathy)?

Accepted Answer

Diffuse demyelination with prolonged distal latencies, slow conduction velocities, and absent F-waves

Answer

AIDP/GBS shows widespread demyelination including absent F-waves, prolonged distal latencies, slow conduction velocities, and conduction block.

Question 2

In diabetic polyneuropathy, the typical EDX pattern is:

Accepted Answer

Length-dependent axonal sensorimotor polyneuropathy with earliest changes in distal lower extremity sensory nerves

Answer

Diabetic polyneuropathy is a length-dependent axonal process affecting the longest nerves first, so sural and peroneal responses are affected earliest.

Question 3

EDX findings in radial nerve palsy due to 'Saturday night palsy' (compression at the spiral groove) typically show:

Accepted Answer

Conduction block or axonal loss across the spiral groove sparing radial muscles proximal to the groove

Answer

Spiral groove compression spares proximal radial muscles (triceps, brachioradialis partially) while affecting wrist and finger extensors, with conduction block localized across the groove.

Question 4

In a patient with peroneal nerve palsy at the fibular head, needle EMG of which muscle would help differentiate it from L5 radiculopathy?

Accepted Answer

Short head of the biceps femoris

Answer

The short head of the biceps femoris is innervated by the peroneal division of the sciatic nerve above the fibular head; denervation there indicates a more proximal sciatic or L5 lesion, not isolated fibular head palsy.

Question 5

Which EDX finding best differentiates cervical radiculopathy from brachial plexopathy?

Accepted Answer

Abnormal needle EMG in paraspinal muscles at the affected spinal level

Answer

Paraspinal muscle denervation at the affected level is seen only in radiculopathy because the posterior primary ramus arises proximal to the plexus.

(EDT) Electrodiagnostic Technician Certification Practice Test

(EDT) Electrodiagnostic Technician Certification Practice Test

EDT EDT Clinical Correlations & Pathology