Parra Jaime, Lopes da Silva Fernando H, Stroink Hans, Kalitzin Stiliyan
Dutch Epilepsy Clinics Foundation, SEIN, Meer en Bosch, Heemstede, The Netherlands.
Brain. 2007 Jun;130(Pt 6):1679-89. doi: 10.1093/brain/awm103.
Considering that the role of colour in photosensitive epilepsy (PSE) remains unclear, we designed a study to determine the potential of different colours, colour combinations and white light to trigger photoparoxysmal responses (PPRs) under stringent controlled conditions. After assessing their photosensitivity to stroboscopic white light and black and white patterns, we studied 43 consecutive PSE patients (mean age 19 years, 34 women), using a specially designed colour stimulator. Stimuli included: pulse trains between 10 and 30 Hz of white light and of all primary colours, and also isoluminant alternating time-sequences of colours. Illuminance was kept constant at 100 lux. A progressive stepwise increase of the modulation-depth (MD) of the stimuli was used to determine PPRs threshold. Whereas all the 43 patients were found to be sensitive during the stroboscopic and pattern protocol, only 25 showed PPRs (Waltz's score >2) at least in one session when studied with the colour stimulator. Coloured stimuli elicited PPRs in all these patients, whereas white light did so only in 17 patients. Of the primary colours, red elicited more PPRs (54 in 22 patients) and at a lower MD (max Z-score 0.93 at 10 Hz). Of the alternating sequences, the red-blue was the most provocative stimulus, especially below 30 Hz (100% of patients, max Z-score: 1.65 at 15 Hz). Blue-green was the least provocative stimulus, since it elicited only seven PPRs in seven (28%) patients (max Z-score 0.44 at 10 Hz). Sensitivity to alternating colours was not correlated to sensitivity to individual colours. We conclude that colour sensitivity follows two different mechanisms: one, dependent on colour modulation, plays a role at lower frequencies (<30 Hz). Another, dependent on single-colour light intensity modulation correlates to white light sensitivity and is activated at higher frequencies. Our results suggest that the prescription of spectacles with coloured lenses, tailored to the patient, can be an effective preventative measure against visually induced seizures.
鉴于颜色在光敏性癫痫（PSE）中的作用仍不明确，我们设计了一项研究，以确定在严格控制的条件下，不同颜色、颜色组合和白光引发光阵发性反应（PPR）的可能性。在评估了他们对频闪白光以及黑白图案的光敏性之后，我们使用专门设计的颜色刺激器对43例连续的PSE患者（平均年龄19岁，34名女性）进行了研究。刺激包括：10至30Hz的白光和所有原色的脉冲序列，以及等亮度交替颜色时间序列。照度保持恒定在100勒克斯。通过逐步增加刺激的调制深度（MD）来确定PPR阈值。虽然在频闪和图案测试中发现所有43例患者均敏感，但在用颜色刺激器研究时，只有25例至少在一个测试环节中出现了PPR（Waltz评分>2）。彩色刺激在所有这些患者中均引发了PPR，而白光仅在17例患者中引发了PPR。在原色中，红色引发的PPR更多（22例患者中有54次），且MD更低（10Hz时最大Z值为0.93）。在交替序列中，红蓝序列是最具刺激性的刺激，尤其是在30Hz以下（100%的患者，15Hz时最大Z值：1.65）。蓝绿序列是刺激性最小的刺激，因为它仅在7例（28%）患者中引发了7次PPR（10Hz时最大Z值0.44）。对交替颜色的敏感性与对单一颜色的敏感性无关。我们得出结论，颜色敏感性遵循两种不同机制：一种依赖于颜色调制，在较低频率（<30Hz）下起作用。另一种依赖于单色光强度调制，与白光敏感性相关，并在较高频率下被激活。我们的结果表明，为患者量身定制的有色镜片眼镜处方可能是预防视觉诱发癫痫发作的有效措施。
