 Repeatability of the Intensity Dependence of Cortical Auditory Evoked Potentials in the Assessment of Cortical Information Processing; ; et al in Cephalalgia : An International Journal of Headache (1999), 19(10), 873-9 Data on repeatability and optimal settings are needed when studying the influence of drugs on the intensity dependence of auditory evoked cortical potentials (IDAP). IDAP was recorded at intervals of 1, 2 ... [more ▼] Data on repeatability and optimal settings are needed when studying the influence of drugs on the intensity dependence of auditory evoked cortical potentials (IDAP). IDAP was recorded at intervals of 1, 2, and 24 h at two centers in 22 healthy volunteers. Settings were modified to compare fixed versus randomly varied stimulus repetition rate, as well as 30 Hz and 100 Hz low pass filters. Repeatability was assessed for different intervals and different settings. Group means did not differ between centers, the 2-h or 24-h retest, or when using different settings. We observed an order effect for the 1 h retest. Fixed repetition rate and the 30 Hz filter improved repeatability with still high intraindividual variability. IDAP group means can be compared between centers for retest intervals of 2 h and 24 h and different settings. Variability is too large to compare individuals. [less ▲] Detailed reference viewed: 9 (0 ULg)Auditory evoked potentials in the assessment of central nervous system effects of antimigraine drugs.; ; et al in Cephalalgia : An International Journal of Headache (1999), 19(10), 880-5 Because the "intensity dependence" of cortical auditory evoked potentials (IDAP) is under serotonergic control, it can be used to assess central antimigraine effects of 5HT1B/1D agonists. We measured IDAP ... [more ▼] Because the "intensity dependence" of cortical auditory evoked potentials (IDAP) is under serotonergic control, it can be used to assess central antimigraine effects of 5HT1B/1D agonists. We measured IDAP before and 2 h after naratriptan (5 mg, n = 19) and zolmitriptan (5 mg, n = 19) in healthy volunteers. IDAP was expressed as the amplitude-stimulus intensity function ("ASF slope"). Naratriptan tended to increase ASF slope (mean difference 0.23 +/- 0.62 microV/10 dB, p = 0.06) while zolmitriptan (0.08 +/- 0.95 microV/10 dB, p = 0.35) did not. We assessed the suitability of IDAP for measuring central antimigraine drug effects using repeatability data (see companion paper). We calculated the trade-off between the size of the expected drug effects (ASF slope difference) and the necessary sample size. Because of poor repeatability 36 to 80 subjects are required to detect ASF slope changes in the 0.25-0.5 microV/10 dB range. These data can be used to design trials using IDAP. [less ▲] Detailed reference viewed: 15 (0 ULg) |
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