EDT EDT Special Populations & Considerations

Question 1

When performing nerve conduction studies in neonates and infants, conduction velocities are expected to be:

Accepted Answer

Approximately half of adult values, reaching adult levels by age 3–5 years

Answer

Myelination is incomplete at birth; neonatal conduction velocities are approximately 50% of adult values and reach adult levels by age 3–5 years as myelination completes.

Question 2

In elderly patients, age-related changes in NCS include:

Accepted Answer

Reduced SNAP amplitudes, slightly slowed conduction velocities, and prolonged distal latencies

Answer

Normal aging causes gradual axonal loss and mild myelin changes, resulting in decreased SNAP amplitudes, mildly reduced conduction velocities, and slightly prolonged latencies.

Question 3

Which safety precaution is essential before performing nerve conduction studies in a patient with an implanted cardiac pacemaker?

Accepted Answer

Consult with cardiology and avoid stimulation over the chest or neck; keep currents distal and away from the pacemaker leads

Answer

NCS can be performed safely in pacemaker patients if stimulation is kept in the extremities, away from the pacemaker generator and leads, and with prior cardiology consultation if uncertain.

Question 4

In patients with lymphedema following mastectomy, EDX of the ipsilateral upper extremity requires caution because:

Accepted Answer

There is risk of introducing infection or worsening lymphedema with needle insertion; surface techniques are preferred

Answer

Needle EMG in a lymphedematous extremity post-mastectomy carries infection risk; the referring clinician should be consulted and non-invasive techniques prioritized where possible.

Question 5

EDX studies in pediatric patients may require sedation because:

Accepted Answer

Movement and poor cooperation can produce artifact and make needle EMG technically unreliable

Answer

Children may not cooperate with voluntary relaxation or contraction needed for EMG; movement artifact and lack of cooperation can significantly compromise study quality.

(EDT) Electrodiagnostic Technician Certification Practice Test

(EDT) Electrodiagnostic Technician Certification Practice Test

EDT EDT Special Populations & Considerations