Shibata K, Yamane K, Iwata M, Ohkawa S
Department of Medicine, Tokyo Women's Medical University, School of Medicine, Daini Hospital, 2-1-10 Nishiogu, Arakawa-ku, Tokyo 116-8567, Japan.
Clin Neurophysiol. 2005 Sep;116(9):2220-7. doi: 10.1016/j.clinph.2005.05.015.
To clarify the effects of contrast and spatial frequency in patients with migraine by means of pattern-reversal visual evoked potentials (PVEPs).
PVEPs were obtained from 14 patients who had migraine without aura (MO), 11 patients who had migraine with aura (MA), and 25 age-matched, healthy controls (CO). PVEPs were binocularly recorded with a reversal rate of 1Hz (2 reversal/s) at 3 spatial frequencies (0.5, 1.0 and 4.0 cpd) at high (98%), medium (83%) and low (29%) contrast. N75, P100 and N135 latency and the amplitudes of P50-N75, N75-P100 and P100-N135 were analyzed.
Increased amplitude of PVEPs in patients with migraines were revealed at 3 different spatial frequencies in all components. The MO and the MA showed increased amplitudes mostly in high contrasts (98%). These findings were detected more at a high spatial frequency (4.0 cpd) than at a low spatial frequency (0.5 cpd). Increased amplitude with prolonged latency of N135 were found both in MO and MA at 4.0 cpd.
We conclude that pattern stimuli of high contrasts may be particularly effective in uncovering abnormal cortical reactivity which may be modified in the primary and secondary visual cortex in the interictal state of migraine.
These findings indicate that there is abnormal visual cortex processing in patients with migraine.
通过图形翻转视觉诱发电位（PVEPs）阐明对比度和空间频率对偏头痛患者的影响。
对14例无先兆偏头痛（MO）患者、11例有先兆偏头痛（MA）患者和25例年龄匹配的健康对照者（CO）进行PVEPs检测。在高（98%）、中（83%）和低（29%）对比度下，以1Hz（每秒2次翻转）的翻转率双眼记录3种空间频率（0.5、1.0和4.0周/度）的PVEPs。分析N75、P100和N135潜伏期以及P50 - N75、N75 - P100和P100 - N135的波幅。
偏头痛患者在所有成分的3种不同空间频率下均显示PVEPs波幅增加。MO和MA主要在高对比度（98%）下波幅增加。这些发现更多地在高空间频率（4.0周/度）而非低空间频率（0.5周/度）下检测到。在4.0周/度时，MO和MA均发现N135潜伏期延长且波幅增加。
我们得出结论，高对比度的图形刺激可能在揭示偏头痛发作间期初级和次级视皮层中可能发生改变的异常皮层反应性方面特别有效。
这些发现表明偏头痛患者存在视觉皮层处理异常。
