Week 14: VEMP

Question 1

stimulus characteristics for VEMP

Answer 1

• frequency= 500 Hz
• level= 95 dB nHL and above
• gating= 2 cycle rise, 1 cycle plateau, 2 cycle fall, blackman-weighted tone burst
• rate= 3 per second

Question 2

electrode montage for VEMP

Answer 2

• electrode locations= noninverting inputs, left and right SCM 1/3 distance from mastoid to clavicle; inverting on the dorsum of the hand, ground at mid forehead (Fz)
• impedance should be less than <10000
• you need 2 channels (one for the left SCM and 2 for the right SCM)

Question 3

bandpass filter, epoch, number of samples, number of averages, and artifact rejection for VEMP

Answer 3

• amplification= at least 5000
• filter bandpass=10-1500 Hz
• epoch= 50 ms
• number of accepted samples=100 (approximately) per completed average, with acquisition paused after 50 samples to allow the pt to rest
• number of completed averages= 2 minimum to check for repeatability
• artifact rejection is disables

Question 4

pt position for VEMPs

Answer 4

*pt supine, head turned away from the test side, head elevated from that position during testing

Question 5

what responses do you see in a VEMP recording

Answer 5

• p13

* n23

Question 6

what is the mean latency of the p13 VEMP response

Answer 6

16.9ms and the limit is 20.47ms

Question 7

what is the mean latency of the n23 VEMP response

Answer 7

25.24ms and the limit is 29.31ms

Question 8

what is the amplitude between the p13 and n23 amplitude

Answer 8

180.71 microvolts with a standard deviation of 120.42 microvolts

Question 9

what are the side asymetry values of the VEMP response means and limits

Answer 9

• p13 mean latency asymmetry 0.09 with limit of 3.39
• n23 mean latency asymmetry -0.16 with a limit of 3.54
• side asymmetry of the p13-n23 amplitude -0.02 with a limit of 0.47

Question 10

what frequency range gives the best VEMP responses

Answer 10

200-400… up to 800Hz so we test 500Hz?

Question 11

what is another option for stimuli of vemps?

Answer 11

skull tap