CNIM TEST QUESTIONS AND ANSWERS

An increase in stimulation intensity causes a linear increase of which of the following SSEP components? 1. N20 2. N45 3. P31 4. P37 - Answer- 3. P31 Epidural electrodes are made of platinum because 1. It is the most durable metal 2. It is the lowest impedance metal 3. The chance of allergic reaction is eliminated 4. Other metals may become toxic when currents are applied - Answer- 4. Other metals may become toxic when currents are applied During a median nerve preoperative study, a patient has discomfort at the wrist. Stimulation electrodes are 10 mm gold disk, stimulus intensity is 20 mA, and stimulus duration is 100 usec. Which of the following would most likely reduce the patients discomfort while maintaining adequate stimulation? 1. Increase stimulus duration 2. Use larger stimulating electrode 3. Use smaller stimulating electrode 4. Decrease stimulus intensity below motor threshold - Answer- 2. Use larger stimulating electrode Which of the following would enhance wave I of the BAEP? 1. Increase the rate 2. Increase the intensity 3. Decrease the analysis time 4. Decrease the number of repetitions - Answer- 2. Increase the intensity In BAEPs, wave I can most easily be differentiated from cochlear microphonics based upon 1. Amplitude 2. Morphology 3. Click polarity 4. Absence in contralateral recording - Answer- 3. Click polarity What is the interstimulus interval of a 50 Hz click stimulus? 1. 0.02 msec 2. 0.20 msec 3. 0.50 msec 4. 20.00 msec - Answer- 4. 20.00 msec Contralateral masking should be used during BAEPs to 1. H