Evoked Potentials
MGH Evoked Potential Normative Values
Pattern Shift Visual Evoked Potentials
P 100 Latency (msec) Inter-eye difference (msec) P 100 Amplitude (µV) P 100 Amplitude % difference
Mean
102.3 1.3 10.1 85.5%
SD
5.1 2 4.2 10.50%
Mean + 3 SD
117.6 7.3 N/A
Notes
(Smallest/Largest) 53.9% X 100
Brainstem Auditory Evoked Potentials
Latencies (msec) I II III IV V VI Inter-wave latencies (msec) I-III I-V III-IV III-V IV-V V-VI
Mean
1.7 2.8 3.9 5.1 5.7 7.3
SD
0.15 0.17 0.19 0.24 0.25 0.29
Mean + 3 SD
2.2 3.3 4.5 5.8 6.5 8.2
2.1 4 1.2 1.9 0.7 1.5
0.15 0.23 0.16 0.18 0.19 0.25
2.6 4.7 1.7 2.4 1.3 2.3
Median Somatosensory Evoked Potentials Mean
Latencies (msec) EP P/N 13 N 19 P 22 Intervave latencies (msec) EP-P/N 13 EP-N 19 EP-P 22 P/N 13-N 19 Amplitudes (µV) EP P/N 13 N 19 P 22 9.7 13.5 19 22
SD
0.76 0.92 1.02 1.29
Mean + 3 SD
12.0 16.3 22.1 25.9
3.8 9.3 12.3 5.5
0.45 0.53 0.86 0.42
5.2 10.9 14.9 6.8
3 2.3 1 2.2
1.86 0.87 0.56 1.1
8.6 4.9 2.68 5.5
Posterior Tibial Somatosensory Evoked Po Mean
Latencies (msec) LP N/P 37 LP-N/P 37 Left - Right Latency Difference (msec) LP N/P 37 LP-N/P 37 19.9 36.3 16.4
SD
1.8 2.4 1.4
Mean + 3 SD
25.3 43.5 20.6
0.42 0.62 0.67
0.28 0.37 0.42
1.26 1.73 1.93
Modified from Chiappa, KH. Evoked Potentials in Clinical Medicine. Raven Press, 1983
This data is for internal use only. Values are based on normal subjects evaluated at Massachusetts General Hospital. Clinical situations and considerations may vary. These norms have been developed for use by our team at MGH in appropriate circumstances. Changes in our practice may occur without notice. We make no statements or warranties about the appropriateness or accuracy of these values in other clinical settings.
Pattern Shift Visual Evoked Potentials
P 100 Latency (msec) Inter-eye difference (msec) P 100 Amplitude (µV) P 100 Amplitude % difference
Mean
102.3 1.3 10.1 85.5%
SD
5.1 2 4.2 10.50%
Mean + 3 SD
117.6 7.3 N/A
Notes
(Smallest/Largest) 53.9% X 100
Brainstem Auditory Evoked Potentials
Latencies (msec) I II III IV V VI Inter-wave latencies (msec) I-III I-V III-IV III-V IV-V V-VI
Mean
1.7 2.8 3.9 5.1 5.7 7.3
SD
0.15 0.17 0.19 0.24 0.25 0.29
Mean + 3 SD
2.2 3.3 4.5 5.8 6.5 8.2
2.1 4 1.2 1.9 0.7 1.5
0.15 0.23 0.16 0.18 0.19 0.25
2.6 4.7 1.7 2.4 1.3 2.3
Median Somatosensory Evoked Potentials Mean
Latencies (msec) EP P/N 13 N 19 P 22 Intervave latencies (msec) EP-P/N 13 EP-N 19 EP-P 22 P/N 13-N 19 Amplitudes (µV) EP P/N 13 N 19 P 22 9.7 13.5 19 22
SD
0.76 0.92 1.02 1.29
Mean + 3 SD
12.0 16.3 22.1 25.9
3.8 9.3 12.3 5.5
0.45 0.53 0.86 0.42
5.2 10.9 14.9 6.8
3 2.3 1 2.2
1.86 0.87 0.56 1.1
8.6 4.9 2.68 5.5
Posterior Tibial Somatosensory Evoked Po Mean
Latencies (msec) LP N/P 37 LP-N/P 37 Left - Right Latency Difference (msec) LP N/P 37 LP-N/P 37 19.9 36.3 16.4
SD
1.8 2.4 1.4
Mean + 3 SD
25.3 43.5 20.6
0.42 0.62 0.67
0.28 0.37 0.42
1.26 1.73 1.93
Modified from Chiappa, KH. Evoked Potentials in Clinical Medicine. Raven Press, 1983
This data is for internal use only. Values are based on normal subjects evaluated at Massachusetts General Hospital. Clinical situations and considerations may vary. These norms have been developed for use by our team at MGH in appropriate circumstances. Changes in our practice may occur without notice. We make no statements or warranties about the appropriateness or accuracy of these values in other clinical settings.