EDT EDT Special Populations & Considerations 2

Question 1

When performing EDX studies in a patient with suspected acute Guillain-Barré syndrome within the first week of symptom onset, results may be:

Accepted Answer

Initially normal or show only subtle F-wave abnormalities, as demyelination evolves over days to weeks

Answer

Always dramatically abnormal from day one

Answer

Consistent with a pure axonal pattern immediately

Answer

Show marked denervation on needle EMG within 24 hours

Question 2

In a patient with end-stage renal disease on hemodialysis, expected EDX findings include:

Accepted Answer

Length-dependent axonal sensorimotor polyneuropathy (uremic neuropathy)

Answer

Focal entrapment neuropathies only

Answer

Pure demyelinating neuropathy

Answer

Normal EDX in all patients on dialysis

Question 3

In evaluating a patient with chemotherapy-induced peripheral neuropathy (CIPN), EDX typically shows:

Accepted Answer

Length-dependent axonal sensory-predominant polyneuropathy affecting distal SNAP amplitudes earliest

Answer

Proximal demyelinating polyneuropathy

Answer

Normal NCS with myopathic EMG

Answer

Multifocal motor neuropathy

Question 4

For EDX evaluation of a patient with obesity (BMI >40), a key technical adjustment is:

Accepted Answer

Increasing stimulus intensity and potentially needle electrode placement for NCS to achieve supramaximal stimulation through thick tissue

Answer

Decreasing stimulus intensity to prevent discomfort

Answer

Avoiding all sensory nerve studies

Answer

Using only bipolar surface electrodes for EMG

Question 5

EDX evaluation of a patient with bilateral carpal tunnel syndrome superimposed on diabetic polyneuropathy is challenging because:

Accepted Answer

Diabetic neuropathy may reduce baseline sensory amplitudes and slow conduction, making superimposed CTS difficult to isolate without comparison studies

Answer

Carpal tunnel syndrome does not occur with diabetes

Answer

Diabetes accelerates NCS conduction velocities

Answer

Needle EMG is contraindicated in diabetics

Question 6

In a patient with bilateral lower extremity amputations, evaluation of peripheral neuropathy EDX strategy should include:

Accepted Answer

Upper extremity NCS (median, ulnar, radial sensory and motor), sural at the stump if accessible, and EMG of residual limb muscles

Answer

Upper extremity NCS only, which is sufficient to diagnose polyneuropathy

Answer

Only H-reflexes at the knee level

Answer

No EDX is possible in amputees