EDT Evoked Potentials 3

Question 1

What filter bandpass setting is typically recommended for somatosensory evoked potential (SSEP) recordings?

Accepted Answer

30–3000 Hz

Answer

A bandpass of 30–3000 Hz is standard for SSEPs because it captures the brief, high-frequency transients of somatosensory responses while reducing low-frequency drift.

Question 2

In the 10-20 electrode placement system, where is the Oz electrode positioned for VEP recordings?

Accepted Answer

Occipital midline, 10% of the nasion-inion distance above the inion

Answer

Oz is the midline occipital electrode in the 10-20 system and is the primary recording site for VEPs because it overlies the primary visual cortex.

Question 3

Which type of artifact most frequently contaminates evoked potential recordings and is the most common technical challenge?

Accepted Answer

Muscle (EMG) artifact from patient tension or movement

Answer

Muscle artifact from patient tension or involuntary movement has a broad frequency spectrum overlapping with evoked potentials, making it the predominant source of technical interference.

Question 4

What is the recommended minimum number of averages for reliable cortical SSEP recording, with replication required?

Accepted Answer

200–500 averages

Answer

A minimum of 200–500 averages is needed to achieve adequate signal-to-noise ratio for cortical SSEPs, and replication of the waveform confirms reproducibility.

Question 5

The P37 component in lower extremity tibial nerve SSEPs is generated by which anatomical structure?

Accepted Answer

Paracentral lobule of the contralateral primary somatosensory cortex

Answer

P37 is the cortical response to tibial nerve stimulation generated in the paracentral lobule, which is the medial cortical representation for lower extremity sensation.

(EDT) Electrodiagnostic Technician Certification Practice Test

(EDT) Electrodiagnostic Technician Certification Practice Test

EDT Evoked Potentials 3