1. (D): Averaging in evoked potential testing increases the signal-to-noise ratio. An amplification of 100,000 is needed to improve the signal-to-noise ratio. (Chiappa 1997, p. 288)

2. (A): Low-frequency filter of 30 Hz is appropriate to record SSEP. This frequency cutoff will filter movement artifact encountered during the recordings. (Chiappa 1997, p. 288)

3. (C): A high-frequency filter of 3,000 Hz is most appropriate for recording SSEP. (Chiappa 1997, p. 288)

4. (D): Sweep duration of 100 ms is needed to record SSEP. Also, the dwell time should be set at 0.2 ms. (Chiappa 1997, p. 288)

5. (C): The N9 of the somatosensory evoked potential originates in the brachial plexus. Cauda equina potential corresponds to N21. N11/13 complex corresponds to cervicomedullary junction. Cubital fosse potentials are not used in SSEP in clinical practice. (Chiappa 1997, p. 288)

6. (A): The N9 of the somatosensory evoked potential originates in the brachial plexus. Cauda equina potential corresponds to N21. N11/13 complex corresponds to cervicomedullary junction. Cubital fosse potentials are not used in SSEP in clinical practice. (Chiappa 1997, pp. 289-290)

7. (C): The N9 of the somatosensory evoked potential originates in the brachial plexus. Cauda equina potential corresponds to N21. N11/13 complex corresponds to cervicomedullary junction. Cubital fosse potentials are not used in SSEP in clinical practice. N20 corresponds to thalamic action potential. (Chiappa 1997, pp. 289-290)

8. (B): Stimulation of posterior tibial nerve at ankle produces higher amplitude of lumbar and scalp potentials than stimulation of common peroneal nerve. This amplitude difference is possibly due to rich innervation of the sole of the foot. (Chiappa 1997, p. 294)

9. (D): SSEP only tests the integrity of myelinated large fibers sensory system, that is, dorsal column. At times, SSEP may be completely normal if the lesion involves the anterior two third of the spinal cord and spares dorsal column. (Chiappa 1997, p. 319)

10. (B): Muscle artifact is the most common problem encountered. It is very crucial that patient relaxes during the testing. If the problem persists, a short acting hypnotic can be given to improve signal-to-noise ratio. (Chiappa 1997, p. 303)

11. (A): SSEP stimulus intensity should be enough to produce a muscle twitch. Inadequate stimulation of the tibial nerve sometimes results in delayed responses. (Chiappa 1997, p. 303)

12. (D): If stimulus intensity is increased, the responses’ latency will become normal. SSEP stimulus intensity should be enough to produce a muscle twitch. Inadequate stimulation of the tibial nerve sometimes results in delayed responses. (Chiappa 1997, p. 306)

13. (C): SSEP bilateral stimulation is not used in clinical practice because of normal responses from good side will mask the abnormality on the bad side. The only possible use for bilateral stimulation in SSEP testing may be for obtaining a larger amplitude response when using the lower limb SSEP to monitor spinal cord functioning during surgery. (Chiappa 1997, p. 306)

14. (C): Bilateral absence of cortical responses (N20) on median somatosensory evoked potential is associated with a poor outcome in comatose patients. The studies suggest that if a comatose patient is missing cortical responses bilaterally, then that patient’s outcome will be a persistent vegetative state at best. (Chiappa 1997, p. 389)